Level IV Clinical Treatment - Unit C__formatted_raw__v1

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LEVEL IV · CLINICAL TREATMENT

Unit C

Indications for Orthognathic Surgery ·

Orthodontic Management of Patients with Cleft Lip and Palate · The Best Time for Orthodontic Treatment

Proffit Instruction — generated for offline reference

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Contents

1. Indications for Orthognathic Surgery
2. Orthodontic Management of Patients with Cleft Lip and Palate
3. The Best Time for Orthodontic Treatment

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1. Indications for Orthognathic Surgery Orthognathic Surgical Procedures

Nature of Orthognathic Surgery “Orthognathic” literally means “straight jaws,” and orthognathic surgery is surgery to bring the jaws into a correct relationship.

The first orthognathic procedures, to correct mandibular prognathism by moving the mandible back, were done 100 years ago, but this surgery really developed only in the second half of the 20th century, as new methods allowed the mandible to be moved forward or back, made it possible to reposition the maxilla in all three planes of space and in multiple segments if necessary, and were developed for surgical repositioning of the chin and dentoalveolar segments.

In the 21st century, it is possible to surgically move the jaws and teeth in any direction, but the soft tissues limit the amount of movement and make some directions more favorable than others.

Click on the icons for illustrations (from Bell, Proffit, White, Surgical Correction of Dentofacial Deformities) of the different types of mandibular and chin surgery that are commonly done today.

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{{PAGE_4}} Mandibular deficiency: Skeletal mandibular deficiency, surgical mandibular advancement indicated.

Sagittal split advancement: Sagittal split osteotomy for mandibular advancement, done with intraoral approach—the usual surgical approach.

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{{PAGE_5}} C-osteotomy for advancement: C-osteotomy for mandibular advancement (requires extraoral approach), shown with lower border osteotomy to further augment the chin.

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{{PAGE_6}} Sagittal split setback: Sagittal split osteotomy for mandibular setback.

Nature of Orthognathic Surgery (cont.)

Click on the icons for illustrations of maxillary and combined maxillary-mandibular-chin surgery that is commonly done today (from Bell, Proffit, White, Surgical Correction of Dentofacial Deformities).

The key development in modern orthognathic surgery for the mandible was the sagittal split osteotomy of the ramus, which gives good bone-to-bone contact for mandibular advancement and setback. For the maxilla, it was the development of the LeFort I osteotomy technique, which allows movement of the maxilla in all three planes of space.

Surgery for the maxilla today is used as frequently as surgery to reposition the mandible, and often maxillary and mandibular surgery are done in the same operation. Because the maxilla can be repositioned without concern about maintaining joint function, in some ways orthognathic surgery for the maxilla is more flexible than mandibular surgery. It is quite feasible now to combine maxillary and mandibular surgery when it is needed to obtain acceptable facial proportions.

In current orthognathic surgery, screws and plates for rigid internal fixation have largely replaced the external wires shown in these illustrations.

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{{PAGE_7}} Maxilla up: Vertical maxillary excess, indication to move maxilla up.

LeFort I osteotomy: LeFort I osteotomy to move maxilla up: removal of measured amounts of bone from the lateral walls.

{{PAGE_8}} Maxilla up, mandible rotates: LeFort I osteotomy, maxilla up: vertical repositioning of maxilla allows mandible to rotate upward and forward.

Segmented maxilla: LeFort I osteotomy with segmentation of the maxilla to allow transverse expansion, closure of premolar extraction space.

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{{PAGE_9}} 2-jaw surgery plus chin: LeFort I, sagittal split and lower border osteotomies combined for correction of long face, mandibular deficiency problem.

Sagittal Split for Repositioning the Mandible

The most frequently used orthognathic procedure now is the sagittal split osteotomy, which can be used for mandibular advancement (illustrations from Proffit, White and Sarver, Contemporary Treatment of Dentofacial Deformity) or setback (see screen 1).

The procedure is done completely intraorally, using an incision in the mandibular vestibule (image 1). A cut is made through the medial cortical bone of the ramus above the lingula and extended diagonally across the front of the ramus to the second molar area, then down to the lower border (image 2).

With the cuts completed, an osteotome is used to split the ramus through medullary bone, so that the inferior alveolar neurovascular bundle is with the tooth-bearing segment (image 3). This allows it to be moved forward and rotated as desired (image 4), so that the teeth are brought into the planned occlusion. Backward movement requires removal of a segment of the bone on the facial side of the split, but everything else is similar whether the mandible is advanced or set back.

The teeth are wired together temporarily so that screws can be placed in the ramus for fixation (image 5). Then the interdental wires are removed and the patient is able to function while bone healing occurs. Rigid internal fixation with screws as shown here, rather than wiring the teeth together for 6 weeks after surgery, has the advantages of improving both postsurgical stability and patient comfort, and has almost completely replaced interdental fixation for orthognathic surgery and treatment of jaw fractures.

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{{PAGE_10}} Image 1, sagittal split incision: Intraoral incision for sagittal split ramus osteotomy. Image 2, cuts through cortical bone: Osteotomy through medical cortical bone is extended across the front of the ramus and down to the facial lower border. Image 3, sagittal split: An osteotome is twisted to separate the tooth-bearing segment from the ramus. Image 4, dental segment advanced: After the split, the tooth-bearing segment can be advanced to its planned position.

{{PAGE_11}} Image 5, rigid internal fixation: Screws are placed (in any desired pattern) to hold the segments while healing occurs, which allows jaw function during healing.

LeFort I Osteotomy to Reposition the Maxilla

The most frequently used surgical procedure to reposition the maxilla is the LeFort I osteotomy. The steps in this surgery are illustrated in this set of images.

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*Image 1, LeFort 1 incision: The sinus walls are sectioned above the roots of the teeth and the roof of the mouth.* </td> <td> *Image 2, sectioning the sinus wall: The sinus walls are sectioned above the roots of the teeth and the roof of the mouth.* </td>

*Image 3, freeing the pterygoid plates: The maxilla is separated from the pterygoid plates so that it can be rotated down anteriorly.* </td> <td> *Image 4, maxilla in down-fractured position: With the maxilla in the down-fractured position so that it can be approached from above, the vertical height of the lateral nasal and sinus walls is reduced.* </td>

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{{PAGE_13}} The Envelope of Discrepancy Indications for Orthognathic Surgery Who needs orthognathic surgery? Patients with a severe skeletal problem or a very severe dentoalveolar problem, too severe for correction with orthodontics alone (image 1). How severe does a malocclusion have to be before it is too severe to be corrected by orthodontics alone? Guidelines for this are provided by the “envelope of discrepancy” (image 2). Consider the distance that incisor teeth can be repositioned orthodontically. In the diagram in image 2, the ideal position of the incisal edge of the central incisor is in the center, and the dimensions of the envelope around that position (dotted line) indicate the distance that this tooth can be moved forward, back, up, or down to correct a malocclusion. Note that the envelope for the upper and lower arch is different and that the dimensions vary by direction. The diagram suggests that upper incisors can be retracted 7 mm to correct maxillary dental protrusion but can moved forward only 2 mm in most circumstances. They can be elongated 4 mm but intruded only 2 mm. For the lower incisor, the distances of possible movement are different for retraction (3 mm) and forward movement (5 mm) but are identical for elongation (4 mm) and intrusion (2 mm). Obviously, these numbers are guidelines. Could you move the teeth farther? Probably. Could you get them to stay in a more extreme position? That’s more difficult—probably not. Stability is increasingly unlikely as the envelope is stretched further and further.

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{{PAGE_14}} WHAT ARE THE INDICATIONS FOR ORTHOGNATHIC SURGERY?

SEVERE skeletal problem or VERY SEVERE dentoalveolar problem (too severe for conventional orthodontics)

How severe is too severe?

1 – Dental occlusion / malocclusion

The Envelope Of Discrepancy as a Treatment Planning Tool

Image 1, who needs surgery? Image 2, envelope for tooth movement: Possible distances of a-p and vertical tooth movement.

Envelope of Discrepancy: Tooth Movement

Three important points about tooth movement:

1. Remember, the envelope reflects bodily movement and also takes long-term stability into account. For example, it is possible to intrude an incisor more than 2 mm but difficult to maintain more than that amount of intrusion long-term.

2. If teeth are severely tipped, it may be possible to move the crown more than the envelope implies. For instance, in a patient with Class II, division 2 malocclusion, the crowns of the lingually tipped maxillary central incisors can be brought forward more than the 2-mm limitation.

3. Guidelines, after all, are just that—not rigid rules. For some patients, the distances in the guidelines can be exceeded, and for some, you would be hard pressed to move the teeth that far. When someone shows you a case with tooth movement outside the guidelines, remember: The improbable isn’t impossible, it just doesn’t happen very often.

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{{PAGE_15}} Envelope of Discrepancy: Growth Modification

A second envelope, the envelope of growth modification (yellow), surrounds the tooth movement envelope. It reflects the amount of change in tooth positions that can be achieved by changing the growth of the jaws.

This envelope differs from tooth movement. The drawings show growth modification wrapped around tooth movement for both the upper and lower dental arches, but that’s potentially misleading. There is only one growth modification envelope. It is drawn to show the possible change in jaw relationship. So the approximate limit of growth change to improve a skeletal Class II relationship is about 5 mm. It makes little difference whether that is achieved primarily by restraining growth of the maxilla or stimulating growth of the mandible. Either way, a 5-mm change in the jaw relationship is about the limit of growth modification for Class II patients. Tooth movement, of course, can be added to obtain greater correction of the malocclusion.

Note that the growth modification possibility for skeletal Class III patients (3-mm improvement from differential growth) is smaller than for skeletal Class II patients. It is difficult to restrain excessive mandibular growth, so this 3 mm is primarily from forward growth of the maxilla.

Does that mean more Class II than Class III problems can be treated without surgery? Yes.

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{{PAGE_16}} The growth envelopes are the same for both jaws, so they can’t be added together

Orthodontic tooth movement (red) plus growth (yellow)

Envelope of Discrepancy: Surgery

A third envelope, the envelope of surgical change, wraps around the other two envelopes. Surgical changes in the position of each jaw can be achieved independently.

In some directions, the possible magnitude of surgical correction is much greater than the potential of growth modification plus tooth movement. For example, surgery can set the mandible back a long way if necessary—much further than the maximum correction from orthodontic treatment based on a combination of tooth movement and growth modification.

In other directions, the difference is not so great. Note that surgery to advance the mandible adds only a few millimeters to the maximum of growth modification plus tooth movement.

Vertical changes in the position of one jaw, of course, affect the other jaw as well. Particularly, repositioning the maxilla vertically requires rotation of the mandible to a new position. So the limits of vertical change are the same for the two jaws—but surgery can change vertical positions by a centimeter or more.

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{{PAGE_17}} Image 1, mandible: The surgical envelope for the mandible. Image 2, maxilla: The surgical envelope for the maxilla. Image 3, both: Envelopes of surgical change.

Envelope of Discrepancy: Effect of Age

What’s the indication for orthognathic surgery? Obviously, having a malocclusion too severe to correct with orthodontics alone. That means it’s outside the combined tooth movement and growth modification envelopes. The envelopes suggest, for instance, that if you have more than 5-mm reverse overjet at any age, surgery will be required to correct it satisfactorily. As long as growth modification is possible and the tooth movement would not damage the patient’s facial appearance, correction of overjet as large as 12 mm is within the reach of nonsurgical treatment.

But of course the growth modification envelope disappears as growth is completed. Its maximum dimension still is available at the beginning of the adolescent growth spurt, then this envelope shrinks until it totally disappears in adults.

Does that mean some malocclusions that could have been corrected with orthodontics if treated earlier would require surgery after growth is completed? Yes, it means exactly that. With orthodontic treatment, you can’t reduce overjet as much in a nongrowing patient as you could in one who is

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{{PAGE_18}} What’s the indication for surgery? Being outside the envelope of orthodontic possibility—which changes with age as the growth modification envelope disappears

So the growth modification envelope shown here is correct only until the adolescent growth spurt

Indications for Surgical Treatment: Health

For any type of elective surgery, the patient must be in acceptable health. For orthognathic surgery, that means that any pathologic conditions must be under control—but the patient does not have to be in perfect health.

As an example, orthognathic surgery for a hemophiliac patient is entirely feasible, and in fact may be the best way to correct some severe malocclusions in such patients. The missing clotting factors must be replaced before the surgery. Then the quicker treatment that surgery makes possible may actually reduce the risk versus more prolonged orthodontic treatment.

Smoking is not a good idea from a health point of view for many reasons. One that you may not have thought of is the reduction in capillary blood flow produced by nicotine. This has a direct effect on bone healing. Because smokers do not heal as well after orthognathic surgery, most surgeons will not consider this treatment until smoking has been discontinued for a few months.

Control of periodontal disease is required before orthognathic surgery, as it is for any treatment involving orthodontics. Some tooth movement cannot be avoided when orthognathic surgery is performed.

{{PAGE_19}} Mental as well as physical health must be considered—emotionally disturbed people are not good candidates for any type of elective surgery. It is important for the patient to have realistic expectations of the outcome of treatment and the effect it is likely to have on life adjustment.

Camouflage Limitations

Surgery Indication: Camouflage Impossible

The second major indication for orthognathic surgery is a condition in which a jaw discrepancy is beyond orthodontic camouflage. Camouflage is defined as displacement of the teeth to correct a malocclusion even though the underlying jaw discrepancy is not corrected. The term implies, correctly, that the jaw discrepancy no longer is noticed and is not a problem.

For instance, if protruding maxillary incisors are retracted in a patient whose Class II malocclusion is primarily due to mandibular deficiency, successful camouflage would require that the mandibular deficiency no longer is noticed. The treatment would be unsuccessful if the facial appearance after treatment was unacceptable—no matter how good the dental occlusion was. For an example, see the program To Extract or Not to Extract, part 2, Camouflage.

For a patient with Class III malocclusion and reverse overjet, would successful treatment be possible by tipping the upper incisors tipped facially and retracting the lower incisors? One limit would be how far the teeth could be moved, but there also is a limitation related to facial appearance.

{{PAGE_20}} Retracting the lower incisors tends to make a prominent chin even more prominent, just the reverse of camouflage, so Class III camouflage can be done only for mild Class III problems.

Vertical problems (long face, for example) can rarely be camouflaged. Elongating teeth in a long face patient, even if the occlusion is corrected, is likely to make the patient look worse, not better. For that reason, surgery may be needed in long face patients even if the dental discrepancy is within the envelope of discrepancy. As we have noted in Level III, skeletal anchorage now makes it possible to intrude maxillary posterior teeth, so that the mandible rotates upward and forward in the same way it does when the maxilla is moved superiorly with a LeFort I osteotomy, but the more severe long face / open bite problems still will require surgery.

WHAT ARE THE INDICATIONS FOR ORTHOGNATHIC SURGERY?

• SEVERE skeletal problem or VERY SEVERE dentoalveolar problem (too severe for conventional orthodontics)
• acceptable health
• unacceptable esthetics with orthodontic camouflage

Class III Camouflage Failure

Consider the situation for Linda, who was unhappy with the outcome of two years of orthodontic treatment as an adult. She had worn Class III elastics to tip her maxillary incisors facially and upright her mandibular incisors, and the space of an unerupted maxillary left second premolar was closed (producing an asymmetry in the maxillary midline).

On facial examination (images 1, 2), her maxillary deficiency is apparent. Note the lack of support for her upper lip and for the facial tissues adjacent to the nose and the concave profile.

Her malocclusion was corrected reasonably well (images 3-5), but she was unhappy about both her facial and dental appearance.

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{{PAGE_21}} Is this a camouflage failure? Yes, because she is unhappy with her appearance. Moving the upper incisors forward does nothing to augment the deficient areas adjacent to the nose and can make them even more apparent (in image 1, note the depth of the nasolabial folds). This makes her look older than her 39 years. Moving the lower incisors back does not reduce the prominence of the chin and can make it also more prominent.

The bottom line: If the esthetic outcome isn’t satisfactory, it’s not satisfactory treatment.

{{PAGE_22}} Image 1, full face view: Age 39, camouflage failure after 2 years of orthodontics to correct a skeletal Class III malocclusion. Image 2, profile: Age 39, camouflage failure after 2 years of orthodontics to correct a skeletal Class III malocclusion. Image 3, frontal view: Reasonably normal occlusion nevertheless is a treatment failure. Image 4, right lateral: Reasonably normal occlusion nevertheless is a treatment failure.

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{{PAGE_23}} Class III Camouflage Failure: Presurgical Orthodontics

Linda, a high school teacher, sought further consultation after one of her students had orthognathic surgery. Linda thought the result was much better than the outcome of her own treatment—so she was prepared to be told that jaw surgery might be needed in her case.

The initial cephalometric tracing (image 1) confirmed a skeletal Class III jaw relationship, due primarily to maxillary deficiency. Note that the maxilla is behind a perpendicular line dropped from the bridge of the nose, and the mandible is in front of it—just the reverse of the normal relationship.

To prepare her for orthognathic surgery, as the superimposition tracing from pretreatment to presurgery shows (image 2), it was necessary to create reverse overjet, retracting the maxillary incisors and moving the lower incisors forward. Then, when the maxilla was moved forward surgically, reasonably normal dental occlusion still could be achieved. The effect, of course, was to remove the effects of the original orthodontic treatment.

Another problem with ambitious tooth movement for camouflage of jaw discrepancies is that if it doesn’t succeed, you have to re-create the malocclusion as part of the preparation for surgery—not a happy situation for patient or doctor.

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{{PAGE_24}} Image 1, pre-tx tracing: Cephalometric tracing, after initial orthodontic treatment.

Image 2, progress superimposition: Presurgical orthodontics, with reverse overjet recreated by tipping lower incisors facially and retracting upper incisors.

Class III Camouflage Failure: Surgery

The maxilla was moved forward and rotated slightly to improve the dental midline, which created better support for the facial tissues adjacent to the maxilla. After the retreatment with surgical maxillary advancement, she was pleased with the change in her facial appearance (compare age 39 before treatment to age 41 afterward). Treatment time was 18 months.

Note that the improvement in smile esthetics (image 1) has two components that are obvious in the full face view: The maxillary dental midline is now closer to the midline of her face, and because the paranasal deficiency is improved, the nasolabial folds are not so deep. Examination of the profile photographs (image 2) also reveals the effect of augmenting the paranasal area as well as better support of the upper lip by the incisors. Because the soft tissues are better supported, she looks younger at age 41 than she did at 39.

Interestingly, the dental occlusion after retreatment with maxillary advancement surgery was very similar to the pretreatment occlusion (images 3-5).

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{{PAGE_25}} The difference, of course, was in the facial appearance. Keep in mind that successful treatment for dentofacial problems requires both acceptable occlusion and acceptable esthetics. For Linda, more extensive facial change would have required more extensive orthodontic preparation for the surgery, so that the jaw could be moved further without compromising the occlusion too much. Presurgical orthodontics often must focus on making the occlusion worse temporarily, so that it can be better after the jaw is repositioned.

Class II Camouflage

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{{PAGE_26}} Class II camouflage is built around retracting the maxillary incisors, and almost always requires extraction of maxillary first premolars to provide space for this tooth movement. Typically, in Class II camouflage, the upper incisors are retracted and the lower incisors are moved forward somewhat. If premolar extractions are done in the mandibular arch, it is to allow use of Class II elastics (from lower molars to upper incisors) (image 1) to help with retraction of the upper teeth, so that the lower molars come forward and the lower incisors are not retracted.

Skeletal Class II malocclusion can include a component of excessive maxillary growth—and if that happens, the problem almost always is too much downward growth of the maxilla. Then the mandible rotates downward and backward unless it grows vertically as much as the maxilla, which rarely occurs. The effect is a long face with a deficient chin, and a tendency toward Class II malocclusion with an anterior open bite.

With that skeletal pattern, Class II elastics (lower molars to upper incisors) can accentuate the vertical problem (image 2), because the elastic force tends to elongate the lower molars, which rotates the mandible down and back even more. The elastics also elongate the upper incisors, which may be desirable in a short face patient but usually not in a long face patient.

What does that mean? Camouflage is more difficult when the patient has both vertical and a-p problems.

Class II Camouflage Failure

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{{PAGE_27}} At age 15, Melissa had had nearly 4 years of orthodontic treatment, with extraction of first premolars—and her Class II open bite problem was not totally corrected (images 1-3). The residual malocclusion was a problem, but Melissa’s facial appearance (image 4) also was unsatisfactory. She had to strain to bring her lips together, and in the profile photograph, her mandibular deficiency is apparent. Note the poor throat form (short throat length and submandibular fullness), which often is part of the esthetic problem in mandibular deficiency. The superimposition tracing (image 5) shows the problem: She had almost no mandibular growth during the treatment period, but her maxilla grew downward—so the mandible rotated down and back, and even though the maxillary incisors were retracted and the lower incisors were proclined, the overjet was not corrected and anterior open bite persisted. For a growth pattern like this, Class II elastics make things worse. When Melissa and her parents were told that surgery was needed at this point, they were angry and said, “Just take the braces off.” So this is the unsatisfactory result of prolonged treatment, a camouflage failure.

{{PAGE_28}} Image 1, frontal view: Dental occlusion after nearly 4 years of orthodontic treatment. Image 2, right lateral: Dental occlusion after nearly 4 years of orthodontic treatment. Image 3, left lateral: Dental occlusion after nearly 4 years of orthodontic treatment. Image 4, facial appearance: Melissa, age 15, camouflage failure.

{{PAGE_29}} Image 5, superimposition tracing: Superimposition tracing, downward-backward mandibular rotation.

Class II Camouflage Failure: Surgery

After a couple of months, Melissa and her parents changed their mind and decided to go ahead with surgical treatment to correct the problem. A fixed orthodontic appliance was put back on, for stabilization of the teeth during the surgery and for use in postsurgical orthodontics to bring the teeth into their final position. Then (image 1) she had a LeFort I osteotomy to elevate the posterior maxilla so the mandible could rotate upward and forward, and a lower border osteotomy of the mandible to bring her chin forward (which improves both chin prominence and throat form). The upward-forward rotation of the mandible corrected the malocclusion, closing the open bite and correcting the excess overjet (image 2).

In comparing the facial images before and after the orthognathic surgery (images 3, 4), note the

• decrease in face height,
• improved lip form,
• greater prominence of the chin,
• improved relationship of the lips to the chin, and
• improved throat form.

In this case, the skeletal Class II problem was not corrected by lengthening the mandible with ramus surgery. Instead, maxillary surgery to allow the mandible to rotate upward and forward, combined

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{{PAGE_30}} with advancement of the chin, corrected both the malocclusion and the appearance of a long face mandibular deficiency.

Skeletal Class II isn’t always a purely mandibular problem. About 25% of skeletal Class II patients, like Melissa, have excessive maxillary vertical growth. A Class II problem due to rotation of the mandible is very difficult to treat successfully with orthodontic camouflage.

Camouflage vs Surgery

Camouflage vs Surgery

With those camouflage failure cases as background, let’s look at Rita, who was nearly 15 when she was first seen.

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{{PAGE_31}} She complained that her upper teeth protruded and were ugly (image 1). She had not had any previous orthodontic treatment and now wanted it very much.

She was very aware of her mandibular deficiency and postured her jaw forward most of the time. It was difficult to get a photograph with her jaw in its retruded position—she may be posturing forward a little in this image 2. That is a risk factor for long-term TM dysfunction, but she had no TMD symptoms at this age.

She had a classic Class II division 1 malocclusion, with mild spacing in the maxillary incisor area and a deep bite anteriorly (image 3). In the lateral photographs, she was posturing forward somewhat and did not have her teeth tightly together.

The cephalometric radiograph (which was obtained in centric relation, the retruded position of the mandible) and tracing (image 4) show that the malocclusion was due almost entirely to mandibular deficiency.

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{{PAGE_32}} Image 1, full face views: Rita, age 15, prior to treatment. Image 2, profile: Rita, age 15, prior to treatment. Image 3, pretreatment dentition: Rita, age 15, prior to treatment. Image 4, ceph/tracing: Pretreatment ceph and tracing: mandibular deficiency.

Treatment Possibilities

Given Rita’s problem list, there are three possibilities for treatment:

• Class II elastics to pull the teeth together without extraction
• extraction of upper first premolars and retraction of the upper incisors

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{{PAGE_33}} surgery to advance the mandible The first two possibilities, of course, are camouflage. Both of these approaches correct the malocclusion without changing the underlying skeletal problem—and would be successful only if the jaw discrepancy were not noticeable after treatment. Surgery corrects the mandibular deficiency.

It is a great help to both the doctor and patient to predict the outcome of treatment with the various approaches and use the predicted outcome to help select the best approach. It is very difficult to predict growth—but in the absence of growth, treatment changes can be predicted with considerable accuracy.

Class II Elastics for Camouflage? Cephalometric predictions of possible treatment outcomes, based on manipulation of the ceph tracings, have been used since the 1970s to help decide among treatment options. This cephalometric prediction (image 1) shows the probable result of using Class II elastics, without extractions, to correct Rita’s malocclusion. The prediction tracing is on the left and is superimposed (dashed lines) with the original tracing on the right.

Note that the effect of the elastics would be mostly to bring the lower dentition forward, with some retraction of the upper incisors and downward-backward rotation of the mandible from elongation of the lower molars.

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{{PAGE_34}} This has two problems: It would be unstable, because pressure from the lower lip would cause uprighting of the lower incisors after treatment, with crowding and return of the deep bite; and it would be unesthetic because of the effect on the lower lip.

Recently it has become possible to superimpose the profile image on the cephalometric tracing, and use algorithms that relate hard tissue to soft tissue changes to change the profile image, so that the prediction is a facial image, not just a tracing.

Image 2 is the computer image prediction of what Rita would look like after orthodontic treatment with Class II elastics. With the profile image linked to the digitized ceph, changes in the tracing alter the profile image, using algorithms to predict various points on the profile. With the image, It is much easier for the patient to understand the esthetic effect of this treatment approach. For Rita, Class II elastics would make the lower lip more prominent relative to the chin, and would not conceal the chin deficiency. Now she and her parents can see that.

Extraction for Camouflage?

Image 1 is the cephalometric prediction of the effect of orthodontic treatment for Rita with maxillary premolar extraction. The prediction is on the left, and it is superimposed on the original tracing on the right. Note that the upper incisors have been retracted and intruded. This would be difficult tooth movement but is within the limits established by the envelope of discrepancy for incisor retraction and is right at the limit for intrusion. A small amount of downward-backward rotation of the mandible is predicted, because correction of the overbite solely by intrusion of the upper incisors would not be possible.

After this treatment, the lower dental arch would be in about the same place, so stability of the lower incisors should not be a problem. What about the facial change? Would that be satisfactory, or would lack of support for the upper lip and the residual mandibular deficiency put it into the unsuccessful camouflage category?

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{{PAGE_35}} Again, using computer imaging to obtain a predicted profile image (image 2) makes it easier to understand the esthetic effect of the “camouflage by extraction” approach. The linked ceph tracing and photograph are shown on the left, the prediction on the right.

This is better than the Class II elastics, from a stability point of view. Does it flatten her upper lip too much, to the point that it leaves her with an unsatisfactory facial appearance?

Image 1, ceph prediction: Cephalometric prediction, Rita, maxillary premolar extractions.

Image 2, computer image prediction: Computer image prediction: left, linked to digitized tracing; right, image prediction.

Mandibular Advancement?

Image 1 is the cephalometric prediction of surgical advancement of the mandible superimposed on the original tracing. This corrects the skeletal mandibular deficiency and gives her a stronger chin.

If the mandible is advanced, the teeth fit together almost perfectly, and because the relationship of the teeth to the tongue and lips is almost unchanged, the result would be expected to be stable (in the absence of surgical relapse, of course—but mandibular advancement surgery is quite stable). What would the esthetic effect be? Computer imaging (image 2) shows the predicted effect on the soft tissue profile.

For the patient, it is particularly interesting to see the predictions side by side (image 3).

The key question is the esthetic effect of the alternative ways to correct the malocclusion. Is it worth it to do the orthognathic surgery to gain the facial change relative to premolar extraction?

So you’re the doctor. How do you decide among these treatment approaches? The answer (image 4) is very simple: You don’t, the patient does.

It is both a moral principle and now a legal requirement that it’s the patient’s decision, not the doctor’s. The doctor’s role is to provide the information so that the patient can make an informed decision. That’s the heart of informed consent to treatment. Computer imaging is a great help to patients in understanding the esthetic impact of a decision to have orthognathic surgery or to accept orthodontic camouflage.

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{{PAGE_36}} Prediction, Mandibular Advancement

Computer image prediction: Computer image prediction: left, linked to digitized tracing; right, image prediction.

Side-by-side predictions: Side-by- side image predictions: which is best?

How do you choose between the possibilities?

YOU DON’T!

In the modern world, this is the patient’s decision, not the doctor’s • indicated morally and ethically • now required legally in the US Computer imaging helps the patient decide

Image 4, who decides?

Surgical Treatment

When Rita and her family came to discuss the plans for her treatment, she said she had thought about it and expected to be told that her lower jaw needed to be lengthened. The predictions confirmed that for her. That definitely was what she and her family wanted.

So that became the plan (image 1). She would have braces put on her teeth to prepare for surgery, then would have a sagittal split osteotomy to advance the mandible, and would have postsurgical orthodontics to bring the teeth to their final position.

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{{PAGE_37}} Treatment time from braces on to braces off was estimated at 12-15 months. How long the treatment takes is determined largely by how much presurgical orthodontics is required to bring the teeth into proper alignment and arch form, and she didn’t need much presurgical change.

Prior to the surgery, heavy rectangular orthodontic arch wires to stabilize the teeth were placed (images 2,3)—it’s important to have braces on when the surgery is done. Hooks on the arch wires were placed to allow the surgeon to wire the jaws together in the operating room while screws were placed to hold the mandible in its new position. Then the intermaxillary fixation wires were removed.

With rigid internal fixation, using bone screws (image 4), the jaw can be allowed to function while it heals because the screws hold the surgical segments together even when the jaw moves. This makes things much more comfortable for the patient and contributes to better stability.

Rita B. — Age: 14-10 “I thought about it, and I expected you to tell me I needed surgery for my jaw”

Plan:

• Presurgical orthodontics: align without leveling, stabilize
• Sagittal split advancement
• Postsurgical finishing: light round arches, vertical elastics

Image 1, tx plan: Rita, treatment plan.

Image 2, presurgery lateral: Rita, age 15, stabilizing arch wires for surgery.

Image 3, presurgery frontal: Rita, age 15, stabilizing arch wires for surgery.

Image 4, postsurg pan: Panoramic radiograph after sagittal split osteomy, screws in place in the ramus for rigid internal fixation.

Postsurgical Orthodontics

For orthognathic surgery patients, the stabilizing arch wires remain in place after surgery until healing is satisfactory and the patient is comfortable functioning into the splint that was used at

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{{PAGE_38}} surgery to establish the jaw relationship. The splint is tied to either the upper or lower orthodontic arch wires after rigid fixation is established. Typically, the splint and the stabilizing arch wires are removed 3-4 weeks postsurgery and lighter working arch wires are placed, as shown here for Rita (images 1, 2).

Like all orthognathic surgery patients, Rita wore light elastics for a few months postsurgery to control jaw movements and guide her into the correct occlusion. The hooks for these elastics are attached to the brackets on the canines and first molar bands (image 2).

The postsurgical orthodontic treatment was completed and the appliance was removed 6 months after surgery—which is typical postsurgical treatment time. At that point, Rita had excellent occlusion (images 3-5) and normal jaw function. Is this a satisfactory outcome?

Remember, you don’t know until you look at the facial appearance.

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{{PAGE_39}} Image 1, 4 weeks postsurgery, frontal: Rita, age 15-11, 4 weeks postsurgery: splint removed, stabilizing arch wires replaced.

Image 2, 4 weeks postsurgery, lateral: 4 weeks postsurgery, note the hooks for elastics to guide function and bring teeth together.

Image 3, 6 months postsurgery, frontal: Rita, age 16-4, 6 months postsurgery, treatment completed.

Image 4, 6 months postsurg, right lateral: Rita, age 16-4, 6 months postsurgery, treatment completed.

Image 5, 6 months postsurg, left lateral: Rita, age 16-4, 6 months postsurgery, treatment completed.

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{{PAGE_40}} Facial Effects of Surgical Treatment Comparison of the pre- and postsurgery facial photographs (images 1-3) shows the facial change that was created.

Rita’s facial appearance didn’t change dramatically. In her case, orthodontic camouflage with premolar extractions would have damaged her facial appearance. To her, that would have been too high a price to pay for a better bite. Sometimes surgery is needed to make patients look better. Sometimes it’s needed to correct a malocclusion without making them look worse, as in Rita’s case.

Remember—if the esthetic outcome isn’t satisfactory, it isn’t satisfactory treatment.

It is interesting to compare the computer image prediction with the actual treatment result (image 4). The computer predictions are not perfectly accurate, but they come quite close. In general, predictions of chin position are accurate, while changes in lower lip position may not be predicted as well.

Research has shown that both outside observers and patients consistently say that the patient looks better than the prediction. This means there is no great risk of setting up unrealistic expectations by showing the predictions to patients. Patients now routinely are shown computer image predictions to help them decide between camouflage and surgery.

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{{PAGE_41}} Image 1, full face comparison: Rita, presurgery age 15-10 to end of treatment, age 16-4. Image 2, smile comparison: Rita, presurgery age 15-10 to end of treatment, age 16-4. Image 3, profile comparison: Rita, presurgery age 15-10 to end of treatment, age 16-4. Image 4, prediction comparison: Image prediction (at age 14-10), actual profile age 16-4.

Two-Year Recall

On 2-year recall, Rita was away in college. She continued to be pleased with her improved facial appearance (image 1), and had no sign now of her old habit of posturing her mandible forward. Her dental occlusion was excellent (images 2-4), and the occlusal relationship also was stable. Research data show that mandibular advancement of this type is a highly predictable and stable procedure, with a >90% probability of an excellent clinical outcome and a 90% chance that the patient will report satisfaction with the result. For patients who are carefully selected for camouflage, equally good results are obtained—but remember that the surgery and camouflage patients are not the same initially. Patients who choose surgery have more severe problems in their own view.

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{{PAGE_42}} Image 1, facial appearance: Rita, age 18, 2-year recall. Image 2, frontal view: Rita, age 18, 2-year recall. Image 3, right lateral: Rita, age 18, 2-year recall. Image 4, left lateral: Rita, age 18, 2-year recall.

Summary In summary:

• Modern orthognathic surgery allows both jaws, the chin, and dentoalveolar segments to be repositioned in all three planes of space (image 1).
• One major indication for orthognathic surgery is a malocclusion too severe to correct with orthodontics alone—and this changes as growth is completed, so that some problems that could have been corrected with orthodontics during adolescence require surgery later (image 2).
• The other major indication: a jaw discrepancy that cannot be camouflaged satisfactorily with orthodontic tooth movement (image 3).
• Coordinated orthodontic and surgical treatment is necessary for excellent results with orthognathic surgery (image 4): Prior to surgery, orthodontic treatment is used to align the teeth and place them correctly relative to their own supporting bone—which often involves temporarily making the malocclusion worse. At surgery, heavy stabilizing arch wires are used to minimize tooth movement. Postsurgically, lighter working arch wires and interarch elastics are needed to

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{{PAGE_43}} bring the teeth to final position. Like all other orthodontic patients, orthognathic surgery patients require orthodontic retainers.

Image 1, 2-jaw surgery: LeFort I, sagittal split and lower border osteotomies combined for correction of long face, mandibular deficiency problem.

Image 2, envelope of discrepancy: Envelopes of discrepancy: tooth movement/growth modification/surgical possibilities.

Image 3, camouflage?: Too severe for camouflage? That’s for the patient to decide.

Image 4, coordinated treatment: Coordinated treatment: stabilization after presurgical orthodontics, postsurgical orthodontic finishing, 2-year recall after retainers discontinued.

• A – surgical stabilizing arch wires
• B – postsurgical ortho finishing
• C – 2 year recall, after retainers had been discontinued

Self-Test Referral

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{{PAGE_44}} The self-test section of this program is designed to help you be sure you have understood the material. Do the assigned reading (Contemporary Orthodontics, 5th ed., pages 685-709; 4th ed., pages 687-707), then take the test and use it as a guide for further study and review. Copyright 2013, UNC Dept. of Orthodontics

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{{PAGE_45}} 2. Orthodontic Management of Patients with Cleft Lip and Palate

Overview: Treatment/Facial Growth

Overview of Treatment

From birth to late adolescence, a typical child with a cleft of the lip and palate (image 1) undergoes a number of treatments. Ideally, these are coordinated by a cleft palate/craniofacial team serving that area (image 2). It is important for dentists who interact with the patient’s family to understand the treatments and their sequencing—especially since you are very likely to be asked about what is happening and whether it sounds right to you. As an overview (image 3):

• In infancy, to prepare for lip repair, a dental specialist may do presurgical orthopedics to align the maxillary cleft segments. The surgeon repairs the lip and cleft palate and may place an early alveolar bone graft. The social worker counsels parents on future care. The geneticist tests for syndromes in the child and the risk of the parents to have another child with a cleft. The speech pathologist monitors speech development. The audiologist/ENT surgeon monitors middle ear function, because children with a cleft palate may need tubes in the middle ear for fluid drainage.
• During the preadolescent or mixed dentition stage, between the ages of 5 and 8 years old, the patient will have a bone graft placed in the alveolus—alveolar bone grafting. In conjunction with this, there will be an initial phase of orthodontics to align the dentition and expand the maxillary arch.
• Later during adolescence, there will be a second phase of orthodontics, and after the adolescent growth spurt is completed, the patient may need orthognathic surgery. Also, decisions will be made to orthodontically close spaces for missing teeth or maintain space so missing teeth can be prosthetically replaced. Finally, residual soft tissue deficiencies and asymmetries of the lip and nasal regions may need to be surgically revised by the plastic surgeon for improved esthetics.

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{{PAGE_46}} Image 1, cleft patient: Fourteen-year-old girl with typical sequelae of a treated cleft lip and palate. Image 2, cleft team: Meeting of the UNC Cleft Craniofacial Center Team. Members are seen discussing patients’ treatment plans.

{{PAGE_47}} patients have normal midfacial depth and height with obvious dentoalveolar adaptations in the cleft site (image 1).

Repair of an isolated cleft lip usually has little or no effect on facial growth, but repair of a palatal cleft often does. During the palate repair, soft tissue mucoperiosteal flaps are lifted from the cleft halves of the hard palate and are brought together in the midline to close the palatal defect. Scar tissue forms as the tissue heals. This scarring restricts growth of the maxilla (image 2). Modern surgical techniques do not create as much scar tissue as older methods, and the need for orthognathic surgery in adolescence for cleft patients because of maxillary deficiency is decreasing.

Another factor that influences whether a cleft patient will need orthognathic surgery is the patient’s inherited facial profile. In the cleft population as in the general population, individuals have inherited facial profiles that are Class I, Class II, or Class III (image 3). Those with Class II profiles are more able to mask the developing midfacial deficiency, while in those with Class I or Class III profiles, midfacial deficiency will be more apparent. Thus, the patient’s inherent growth pattern may either mask or enhance the midfacial deficiency.

In general, the more severe the cleft of the palate, the worse the midfacial deficiency after it is repaired, but the quality of the initial surgery is the major determining factor. Image 4 provides a summary of these factors.

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{{PAGE_48}} Image 1, adult with unrepaired cleft: Note the normal facial proportions in this Sri Lankan adult with an unrepaired cleft lip and palate. There are dentoalveolar adaptations in the cleft site, but normal jaw growth occurred. Image 2, adult with repaired cleft: Deficiency of the midface, as seen in these two patients—the one on the right is more severe—often occurs once the palate is repaired because scarring limits growth. Image 3, cleft patients, skeletal Class II/III: Patients with Class II profiles are able to mask the midfacial deficiency. On the left, the Class II is due mainly to a retrognathic mandible, and on the right, a prognathic maxilla. Image 4, overview: Overview of growth effects of palate surgery.

OVERVIEW – FACIAL GROWTH ALL SURGICAL TREATMENTS ADVERSELY AFFECT FACIAL GROWTH

1. Adult patients who present with unrepaired cleft palate demonstrate normal midfacial depth and height.
2. Repair of the palate causes scarring and a restriction in growth of the midfacial region that results in a midfacial deficiency in adulthood.
3. The patients’ inherited facial profile (Skeletal Class I, II, III) can mask (Skeletal Class II) or enhance (Skeletal Class I and more so Class III) the developing midfacial deficiency.
4. The midfacial deficiency is worse the more severe the cleft. Patients with cleft lip only do not show these effects.

Infancy/Primary Dentition

Sequence of Cleft Treatment

An important early step in treatment is the surgical repair of the cleft lip. It is performed within the first 12 weeks of life by the plastic surgeon; to facilitate the surgery, either presurgical infant orthopedics or a lip adhesion may be recommended (image 1). Once the displaced cleft segments (image 2) are repositioned, the surgeon can repair the lip under less tension.

{{PAGE_49}} Infant Orthopedics

• For the baby with a unilateral cleft lip and palate, an orthopedic appliance is used to mold and approximate the maxillary cleft segments decreasing the facial asymmetry.
• For the baby with a bilateral cleft lip and palate, a similar appliance is used to expand the maxillary segments and to retract and approximate the premaxillary segment to a more normal position (image 3).

In the 1965-80 era, infant orthopedics was very popular; however, today the treatment is considered less useful than originally thought. Many centers have discontinued the practice. Those still in favor of it cite an improved lip and nasal esthetics, which appears to be true in the short term but is questionable in the long term. There are many different types of appliances. Some are removable and others are fixed to the maxilla with pins (image 4). Newer appliances are designed to mold the nasal cartilage as well as the maxillary segments.

Lip Adhesion An alternative to molding appliances is a lip adhesion. This is a surgical procedure to repair the superficial skin tissues of the lip (image 5). This limited lip repair molds the maxillary segments, and once the segments are approximated, the surgeon then completes the definitive full-thickness repair of the lip muscles.

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{{PAGE_50}}

SEQUENCE OF CLEFT TREATMENT

INFANCY/PRIMARY DENTITION

Weeks

• Lip repair
• Pre-surgical orthopedics?
• Lip adhesion?
• Early alveolar bone graft??

First year

• Feeding plate?

Image 1, overview: Overview of treatment steps in infancy.

Image 2, bilateral cleft infant pre-tx: Collapsed maxillary segments in a baby with a bilateral cleft lip and palate.

Image 3, infant with molding appliance: Orthopedic molding appliance in place to expand the maxillary segments.

Image 4, effect of appliance: Top: Maxillary segments fully expanded. Note the appliance is fixed to the maxilla with pins. Bottom: Premaxilla in position after expansion created room for it.

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{{PAGE_51}} Image 5, lip adhesion: Lip adhesion. Superficial tissues of the lip—skin and mucosa—are sutured together to mold the segments prior to the definitive lip repair.

Sequence of Cleft Treatment, cont’d.

At some centers, a bone graft may be placed in the alveolus around the same time as the lip repair. This bony defect in the alveolar process requires a graft, and an important question is when the alveolus should be grafted. There are three possibilities:

1. Now, very early as an infant (images 1, 2);
2. Late—too late—after the permanent dentition has erupted; and
3. In the mixed dentition before the eruption of the permanent teeth near the cleft site.

Very early grafting in infancy now is rarely used because studies have demonstrated that the practice is detrimental to midfacial growth. Late grafts are very difficult to accomplish successfully. Mixed dentition grafts now are standard practice.

Another treatment that is sometimes considered during infancy is the use of a feeding appliance, which consists of a full-coverage palatal acrylic plate that occludes the palatal cleft. The thought is that occluding the cleft palate will improve swallowing and hence allow the baby to feed more effectively. As the baby grows, these plates must be remade to fit the palate. They are discontinued once the palate is repaired at around one year of age. Except in special circumstances, however, these appliances are not recommended because their effectiveness for this purpose has not been demonstrated. The nutritionist or nurse practitioner affiliated with the team can advise the parents on the use of special nipples and other techniques to maximize bottle feeding without the use of a feeding appliance.

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{{PAGE_52}} Sequence of Cleft Treatment, cont’d.

The cleft of the palate is repaired between one to two years of age (image 1). The exact timing is controversial because the speech pathologist would prefer that the repair occurs early (before one year of age) so that an intact palate is present as speech development occurs. Conversely, the surgeon and orthodontist would prefer to wait until there is sufficient development and maturation of the hard and soft tissues to facilitate the surgical repair and decrease the chance of impaired growth of the maxilla. In most centers,the timing of the surgery has become earlier as surgical techniques have improved and the chance of growth problems has decreased. At present, the palate usually is repaired around one year of age.

The surgery involves lifting soft tissue flaps from the cleft halves of the palate and suturing the flaps in the midline to close the bony defect (image 2). Thus, the defect is closed with soft tissue only—no bone is placed in the midpalatal defect. There are many designs of flaps for lip and palate closure. For further information, see Facial Clefts and Craniosynostosis: Principals and Management (Eds: TA Turvey, KWL Vig, RJ Fonseca. WB Saunders Co., 1996).

At age 3-5 years, there may be the temptation to start orthodontic treatment to expand the maxillary arch. Generally, orthodontics at this age has little long-term effect and for that reason can be considered a waste of time and effort. It is better to wait until the mixed dentition, when the permanent incisors and first molars have erupted.

During the preschool years, the child will attend regular team evaluations and may have other treatments, such as general dental care and surgeries to improve soft palate function, middle ear function (the insertion of ear tubes), and lip function and esthetics.

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{{PAGE_53}} Image 1, schematic of palate repair: Diagrammatic view of palate closure. Soft tissue flaps are lifted from the palatal halves and sutured in the midline. Note a cleft still remains in the bone of the alveolus.

Image 2, steps in palate repair: A. Outline of incisions are drawn on the tissues (broken line). B. Incisions are made and palatal tissues undermined to release the palatal muscles. C. Muscles are sutured in the midline. D. Overlying skin is sutured to complete the operation.

SEQUENCE OF CLEFT TREATMENT INFANCY/PRIMARY DENTITION Weeks Lip repair Pre-surgical orthopedics? Lip adhesion? Early alveolar bone graft? First year Feeding plate? 1-2 years Palate repair 3-5 years Arch expansion? Dental care—if needed Surgery - ear tubes? -speech? -lip revision?

Image 3, overview: Overview of treatment age 1-5.

Preadolescent/Mixed Dentition

Alveolar Graft

At around 6 to 8 years of age, if an early alveolar bone graft (as an infant) was not placed—and most likely it would not have been—then the child is assessed for the proper time to place an alveolar bone graft (image 1). Grafting in the mixed dentition is the most common practice. Support for this practice comes from studies that show minimal effects on midfacial growth from alveolar graft

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{{PAGE_54}} surgery at this age. This is because much of the growth of the maxilla (especially in width) has already occurred, so the surgery has little negative impact.

In the mixed dentition, just about every child with a cleft has malaligned maxillary incisors, and often there is collapse of the posterior segments (image 2). The graft is timed either for the eruption of the permanent lateral incisor near the cleft site—grafting closer to 6 to 7 years of age—or the permanent canine—grafting closer to 7 to 8 years of age. In most cases, the lateral incisor near the cleft is missing, so it is more common to graft for the canine around 7 to 8 years (image 2). The graft must be placed before the specific tooth has erupted through the bone.

Alveolar bone grafting at this time is generally done in conjunction with a first phase of orthodontic treatment. There are two reasons for the phase I treatment:

1. to bring the incisors into position (often they are rotated when they erupt, due to stretching of the tissues during palate repair),
2. and, more important,, to prepare the maxillary arch for the alveolar bone graft.

Tina S., Age 7 1/2 Consider Tina, a 7 1/2-year-old girl with a left unilateral cleft of the lip and palate that was repaired in infancy. In the full face view (image 1), you can see the lip scar and the difference in shape of the nostril between the affected and normal sides. For Tina, both the lip and nose are not major problems. Revision of the lip and/or nostril are major reasons for additional plastic surgery in children with clefts.

In the profile view (image 2), you can see that she has a straight profile, with full lips and less prominence of the midface than is normal for a child of this age. The cephalometric radiograph

{{PAGE_55}} (image 3) and tracing (image 4) confirm moderate midface deficiency due to restricted maxillary growth, which is almost surely the result of scarring after the palate repair.

A periapical radiograph of the cleft area (image 5) shows that the cleft of the alveolus extends through the area where the lateral incisors should be. Both maxillary lateral incisors are missing.

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{{PAGE_56}} Image 1, full face view: Tina, age 7 1/2, after cleft surgery in infancy.

Image 2, profile view: Tina, age 7 1/2, after cleft surgery in infancy.

Image 3, lateral ceph: Tina, age 7 1/2, after cleft surgery in infancy.

Image 4, ceph tracing: Cephalometric tracing: moderate maxillary deficiency.

{{PAGE_57}} Tina S., Age 7 1/2

Intraorally, on the cleft side, the permanent central incisor has erupted rotated nearly 90 degrees (images 1, 2). This often occurs, presumably because of stretching of tissues during repair of the palatal cleft. The cleft through the alveolar process, closed only by soft tissue and extending up into the base of the nose, can be seen clearly. Note that the maxillary dental arch is somewhat V-shaped, because the posterior segment on the cleft side is rotated toward the midline as it approaches the alveolar cleft (image 2).

The dental occlusion on the noncleft side is essentially normal (image 3), but there is a posterior crossbite tendency on the cleft side, more pronounced in the canine region (image 4). This also is related to scar tissue that restricts transverse growth of the repaired palate.

The panoramic radiograph shows that root formation of the permanent canine on the cleft side has begun, with about 1/3 of the root already completed—so eruptive movement of this tooth has started (image 5). Eruption does not occur until root formation begins.

{{PAGE_58}} Image 1, frontal: Severe rotation of the incisors on the cleft side often is noted when these teeth begin to erupt. Image 2, maxillary occlusal: Note the inward rotation of the posterior segment of the dental arch on the cleft side. Image 3, right lateral: Occlusion is normal on the noncleft side. Image 4, left lateral: Posterior crossbite on the cleft side, more in the canine than the molar region.

{{PAGE_59}} Table:

	Image 5, panoramic radiograph: Note the cleft through the alveolar process and the beginning of root development of the permanent canine on the cleft side.

Tina S., Problems/Plan Tina’s problems are summarized in image 1. At this point, alignment of the rotated central incisors and expansion in the canine region are needed, but the key factor is placement of a bone graft to the cleft area of the alveolar process. This must be timed so that the maxillary canine will erupt through it. For Tina, because of the root development of the canine—over 1/3 of the root of the canine was developed—there was not enough time for pregraft orthodontic alignment, and the graft was placed at age 7 years, 11 months. The surgical steps involved in alveolar grafting are shown in image 2.

The bone for the graft can be harvested from either the patient’s hip or cranium, after which it is ground into bone chips. Once the site has been surgically prepared, the bone chips are packed into the area. The postgraft panoramic radiograph shows the material packed into the cleft, with the canine poised to erupt through this area (image 3).

The purpose of any bone graft is to stimulate its own replacement with new bone. As the canine erupts through the grafted area, it brings bone with it so that the graft site is completely remodeled. This creates an intact maxillary arch much more successfully than trying to graft an alveolar defect after the teeth have erupted and also provides sound periodontal support for the erupted canine. Delaying the graft until after the canine has erupted will result in poor periodontal support for the canine. The bone graft also serves to elevate the base of the nose, improving the esthetics of the nasolabial area (images 4, 5).

{{PAGE_60}} PROBLEMS/PLAN FOR TINA S. (AGE: 7 YEARS, 5 MONTHS)

• Typical sequelae of unilateral cleft: rotated central on cleft side, crossbite tendency
• Both laterals missing: plan = close space, canine substitution
• Class III correction?
• Needs alveolar graft soon, so permanent canine can erupt through grafted area

Image 1, problem list/plan

Image 2, steps in alveolar graft: A. Outline of incisions are drawn on the tissues (broken line). B. Flaps are reflected buccally and palatally through the cleft and the nasal mucosa is sutured together to form a base for the bone graft. C. Bone chips are placed in the cleft site and a buccal flap is lifted, the tissues undermined, and the flap is used to close the alveolar cleft. D. The buccal and palatal tissues are sutured to complete the operation.

Image 3, postgraft pan: Postgraft panoramic radiograph. The canine now is beginning to erupt toward the grafted area.

Image 4, facial change: Facial appearance pre- and postgraft. The improved contour of the nostril on the cleft side is due to better support of its base.

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Tina S., Treatment Sequence

Following the placement of the graft, at age 8 1/2, phase 1 orthodontic treatment was started for Tina, with the goal of correcting the severe rotation of the maxillary right central incisor and bringing the central incisors to the midline. Initially, a flexible rectangular wire (NiTi) attached to the central incisors and molars was used (images 1-4).

Incisor alignment may occur either before or after the grafting. During incisor alignment prior to grafting, care must be exercised to avoid uprighting the root of the permanent incisor near the cleft so that it contacts the bony lining of the cleft. This would induce root resorption. Excessive orthodontic force will move the root into the cleft where there is no bone—an even worse situation. If there is any doubt, the incisors should be aligned after grafting to minimize iatrogenic damage to the root of the incisor near the cleft. In general, postgraft orthodontic treatment can be started soon after the graft has been placed and as long as the patient is comfortable enough to tolerate it.

{{PAGE_62}} Image 1, frontal view: Tina, age 8 1/2 yrs, phase 1 orthodontic treatment. Image 2, maxillary occlusal: Tina, age 8 1/2 yrs, phase 1 orthodontic treatment. Image 3, right lateral: Tina, age 8 1/2 yrs, phase 1 orthodontic treatment. Image 4, left lateral: Tina, age 8 1/2 yrs, phase 1 orthodontic treatment.

Tina S., Treatment Sequence

At age 9 years, 9 months, the permanent canine was erupting through the graft site, and the cleft already was obliterated (image 1). With the position of the central incisors corrected, the brackets on the central incisors were removed (images 2-3) and the molar bands were left in place to help stabilize the removable retainer needed to control the position of the incisors (image 3). Soon afterward, the maxillary primary canines were extracted to relieve crowding and allow the permanent canines to erupt mesially, so that they would replace the missing lateral incisors. This usually is the preferred approach to the treatment of cleft patients with missing laterals.

In a patient like Tina, because eruption of the canine will occur over the next few months, a prosthetic tooth may be attached to the acrylic of the retainer for esthetic purposes. In such a situation, the retainer must be adjusted regularly to clear the acrylic to allow the canine to erupt.

For some patients, the graft placement may be timed for the eruption of the lateral incisor near the cleft site (image 4). This tooth often is missing, but if it is present grafting is needed earlier—typically, at 6 to 7 years of age and certainly before the root is 2/3 formed—so that it erupts through the graft site. Having a tooth erupt through the grafted area is the key to obliterating the alveolar defect.

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{{PAGE_63}} Therefore, to reemphasize, it is important to refer a cleft patient to the orthodontist by the time the permanent central incisors are erupting. Then the final decisions can be made on the timing of graft placement, and the need for pregraft orthodontic treatment. The family dentist should not assume that surely someone else is taking care of this.

TINA S. — TREATMENT SEQUENCE
Age

Image 1, treatment sequence

Image 2, intraoral views: Tina, age 9-9, end phase 1.

Image 3, occlusal with retainer: Occlusal view, retainer in place.

Image 4, early graft indication: Panoramic radiograph, lateral incisor developing: indication for early graft

Adolescence/Early Permanent Dentition Adolescence/Early Permanent Dentition

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{{PAGE_64}} Despite all the treatment provided previously, adolescent cleft patients almost always have some combination of three problems: (1) posterior crossbite, (2) spacing/crowding, and (3) skeletal problems of the long face and/or maxillary deficiency types. As a result, a second phase of orthodontic treatment is needed once the permanent teeth have erupted (image 1). If the early surgeries have been atraumatic with minimal scarring, the patient will have a minor crossbite and reasonably normal midfacial growth. Then routine orthodontic treatment would be undertaken.

This was exactly the situation for Tricia, who had a right unilateral cleft of the lip and palate repaired as a baby and had an alveolar bone graft placed at age 9 1/2 years. She presented to her orthodontist at age 11 years with a convex profile, and a very mild midfacial deficiency and asymmetry of the alar rims (image 2). Intraorally (image 3), she had an increased overjet and overbite, transposed maxillary right canine and first premolar, a supernumary right maxillary lateral incisor, and crowding in both arches. Her maxillary left permanent first premolar had been extracted previously to relieve the crowding.

One consideration was the region of the grafted cleft site. Because the canine and first premolar were transposed—an uncommon situation—the first premolar erupted close to the supernumary lateral incisor. However, there was still space remaining. The orthodontist had to decide whether to extract the supernumary tooth and close the space by substitution of the premolar or reopen the space for a prosthetic lateral incisor. A decision like this is based largely on the morphology of the premolar crown and its suitability to serve as an esthetic replacement—but in fact, a premolar with the lingual cusp removed can look remarkably like a lateral incisor from the facial view. It should be noted that it is far more common for the canine to be substituted for the lateral incisor.

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{{PAGE_65}} SEQUENCE OF CLEFT TREATMENT INFANCY/PRIMARY DENTITION Weeks 1-2 years Lip repair Palate repair PREADOLESCENT / MIXED DENTITION 6-8 years Phase 1 orthodontics Alveolar bone graft ADOLESCENT / EARLY PERMANENT DENTITION 11-14 years Phase 2 orthodontics Nose / lip revision surgery?

Image 1, overview

Image 2, full face and profile views: Facial appearance at age 11, after alveolar bone grafting at age 9, showing mild asymmetry of the nasal alae and a moderate skeletal Class II.

Image 3, occlusion: Intraoral views at age 11, after alveolar bone grafting.

Adolescence/Early Permanent Dentition, cont’d.

The plan for Tricia was to extract the supernumary right lateral incisor and use the maxillary right first premolar as a lateral incisor, and finish with Class II molars. In addition, the mandibular arch was expanded to relieve the mild crowding.

Eruption of the premolar in the lateral incisor position completely obliterated the alveolar cleft site (image 1). At the end of orthodontic treatment, Tricia had excellent facial symmetry and balance (image 2). Intraorally, she finished with an ideal overjet and overbite and Class II molars (image 3). A Hawley retainer was used for retention in the maxillary arch and a bonded lingual retainer in the mandibular arch (image 4).

The lateral cephalometric radiograph (image 5) showed no evidence of maxillary deficiency, with slight elongation of face height and a mild skeletal Class II due to downward-backward rotation of the

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{{PAGE_66}} mandible. Superimposition of the pre- and posttreatment cephalograms show that little growth occurred during treatment. The major treatment change during this time was that the mandibular incisors were uprighted as the anterior crossbite tendency was corrected.

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{{PAGE_67}} Image 1, dental relationships during treatment: Tricia, age 12-4. Note the obliteration of the alveolar cleft with good dental health. Note wire segments in auxiliary molar tube to bring maxillary 2nd molars into position Alveolar cleft has vanished after tooth erupted into the area

Image 2, post-treatment facial views: Tricia, age 13-1, at the end of treatment. She has good facial esthetics, with no sign of maxillary deficiency.

Image 3, post-treatment occlusal views: Occlusion at the end of treatment. With closure of the space of the missing lateral incisors, a Class II molar relationship is necessary and functionally acceptable.

Image 4, post-treatment dental relationships: Occlusal views. Note the reversed positions of the canine and first premolar.

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{{PAGE_68}} Image 5, post-treatment ceph and superimposition tracing: Lateral cephalometric radiograph showing a mild skeletal Class II jaw relationship and superimposition showing that minimal growth occurred during the period of treatment.

Adolescence/Early Permanent Dentition, cont’d.

If the early surgeries resulted in enough scarring to significantly restrict growth, patients will have a greater midfacial deficiency and posterior crossbite, and orthognathic surgery to advance the maxilla and/or set back the mandible may be required (image 1). For these cases, orthodontics and orthognathic surgery are timed for late adolescence, when growth is essentially completed. This timing is important because surgery to reposition the jaws before facial growth is completed may be negated by later mandibular growth, so that a second surgery would be required later to correct the discrepancy. Generally, the age for surgery is between 16 to 18 years for females and 17 to 19 years for males.

This was the situation for Tina, whose phase 1 treatment we saw previously. Here she is at age 13 years 4 months (images 2, 3) . She had been followed without additional treatment after she discontinued the upper retainer at about age 11. By age 13, she was quite mature physically and in the permanent dentition. She was concerned about the appearance of her face and teeth, and anxious to get her treatment completed. Her chin was prominent and moderately deviated to the left, and the midface was deficient.

The maxillary left canine had erupted to the occlusal plane but remained to the lingual, out of the line of the dental arch. The lower incisors were mildly crowded and tipped lingually. The maxillary arch was V-shaped, quite narrow across the premolars and canines. With teeth missing in the upper but not the lower arch, the molar relationship needed to be Class II to provide normal occlusion, but the molars were Class I, and she had minimal overjet (image 4).

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{{PAGE_69}} The panoramic radiograph showed normal bone in the alveolar cleft area, with the canine in that area having erupted down to the occlusal plane (image 5).

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SEQUENCE OF CLEFT TREATMENT

INFANCY/PRIMARY DENTITION Weeks: Lip repair 1-2 years: Palate repair

PREADOLESCENT / MIXED DENTITION 6-8 years: Phase 1 orthodontics Alveolar bone graft

ADOLESCENT / EARLY PERMANENT DENTITION 11-14 years: Phase 2 orthodontics Nose / lip revision surgery?

POST-ADOLESCENT / PERMANENT DENTITION 15-19 years: Orthognathic surgery? Nose / lip revision surgery?

Image 1, overview

Image 2, full face / profile view: Tina, age 13-4, full face and profile. A skeletal Class III relationship exists.

Image 3, oblique facial views: The oblique facial views show the maxillary deficiency more clearly.

Image 4, occlusion / alignment: The maxillary arch was quite V-shaped, constricted in the canine- premolar region, and she was in crossbite anteriorly and posteriorly as far as the first molars.

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{{PAGE_71}} Image 5, panoramic radiograph: Note the excellent obliteration of the alveolar cleft, with good bone support for all teeth and good dental health.

Adolescence/Early Permanent Dentition, cont’d. Tina and her parents agreed that her concerns could not be met without orthognathic surgery. The plan was orthodontic treatment to align and coordinate the dental arches, while waiting for the completion of growth. The surgical plan was to advance the maxilla and set back the mandible more on the right than the left side, so as to bring the chin to the midline. At age 14 years 6 months, because of her level of maturity and lack of recent growth, she was judged to be ready for surgery. Her maxillary deficiency and prominent/asymmetric chin were more apparent after the lower teeth were aligned and positioned properly relative to the mandible (images 1, 2). The maxillary arch had been expanded to make its arch form compatible with the lower arch and the teeth in both arches aligned. The maxillary canines now substituted bilaterally for the missing maxillary lateral incisors (image 2). The cephalometric radiograph shows the extent of her skeletal Class III problem (image 3). A superimposition tracing from the beginning of phase 1 treatment (solid lines) shows the downward but not forward growth of the maxilla, with considerable downward-forward growth of the mandible during adolescent growth (image 4). A note of caution: Surgical advancement of the midface in a cleft palate patient can result in leakage of air through the nose during speech, creating nasal “cleft palate speech” that was not present previously. This occurs because as the hard palate moves forward along with the rest of the maxilla, the soft palate is pulled forward and away from the pharyngeal wall. The potential for speech problems should be investigated by the craniofacial team before maxillary advancement surgery. For some patients, moving the deficient maxilla forward has such a positive effect on facial esthetics that it is worth doing even if secondary pharyngeal surgery to control speech problems might be necessary afterward. Tina was judged to be a minimal risk for speech problems.

{{PAGE_72}} Image 1, facial views: Tina, age 14-4, presurgery. Image 2, intraoral views: Tina, age 14-4, presurgery. Image 3, presurg ceph: Tina, age 14-4, presurgery. Image 4, superimposition tracing: Lateral cephalometric superimpositions show the Class III growth pattern from age 7 to 14, with downward growth of the maxilla and downward-forward growth of the mandible.

Adolescence/Early Permanent Dentition, cont’d.

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{{PAGE_73}} At surgery, a LeFort I osteotomy was used to move the maxilla forward with onlay graphs to the maxilla, and the mandible was moved back more on the left than the right sides (image 1). The screws and plates used for rigid internal fixation can be seen in the postsurgical radiograph. The cephalometric superimposition (image 2) shows the forward movement of the maxilla, with downward rotation anteriorly to increase the display of the maxillary incisors, and moderate backward movement of the chin.

Finishing orthodontics began 4 weeks postsurgery, and flexible arch wires and light elastics were used to bring the teeth into final occlusion (image 3). The braces were removed 3 months later, at age 14 years 10 months (image 4), with a Class II molar relationship because of the maxillary space closure but good occlusion.

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{{PAGE_74}} Comparison of facial views before and after surgery make the improvement in her facial proportions clearly evident (images 1-3).

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{{PAGE_75}} At the completion of phase 2 orthodontics (with or without orthognathic surgery), surgery to improve the esthetics of the lip and nose and to correct any residual distortions and asymmetries in these regions is considered. For Tina, it was not necessary. On 2-year recall (image 4), there was slight transverse collapse of the maxilla and a mild posterior crossbite tendency, but the dental alignment and skeletal relationships were nicely maintained. She enjoyed an active social life and was quite pleased with the outcome of treatment.

Image 1, smile view: Tina, age 14-4 presurgery and age 16-9, 2-year recall. Image 2, oblique view: Tina, age 14-4 presurgery and age 16-9, 2-year recall. Image 3, profile view: Tina, age 14-4 presurgery and age 16-9, 2-year recall. Image 4, dentition, 2 year recall: Tina, age 16- 9, 2-year recall

Summary Summary In summary, patients with cleft lip and palate require numerous treatments during the first 20 years of life, which are summarized in the accompanying image.

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{{PAGE_76}} Treatment procedures required by every patient are shown in yellow; procedures that may or may not be needed are shown in white. To maximize the benefits and minimize any negative consequences, it is important to properly sequence the various treatments. Obtaining an alveolar bone graft before the permanent teeth erupt in that area is particularly important and is something that the family dentist should keep in mind, especially if the patient’s family is not in close contact with a cleft palate team at that time.

Coordination of treatment among the group of specialists who are needed in the treatment of a cleft patient is best achieved by a cleft palate team. Such a team, a group of specialists who work together for short- and long-term treatment planning, exists in most metropolitan areas, usually in connection with the local dental school or, if there is no school, a major local hospital. Patients who are not being followed by a team should be referred to one in your area.

In this review you have been provided with the sequencing of treatments from a general perspective. It must be emphasized that your responsibility is to provide treatment that is in compliance with the team’s recommendations, and for this, you must keep in contact with the team. All teams provide their members, and those doctors participating in the care of their patients, with reports that are generated after each patient’s visit to the team. Recall that patients visit the team on a regular basis for follow-up—generally either annually or biannually. You, as the general dentist, should feel comfortable contacting either the team coordinator, director, or any member on the team for clarification of treatment and advice concerning the management of your patient.

{{PAGE_77}} Self-Test Referral

The self-test section of this program is designed to help you be sure you have understood the material. Take it now, and use it as a guide for further study and review.

Copyright 2003, UNC Dept. of Orthodontics

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{{PAGE_78}} 3. The Best Time for Orthodontic Treatment

Background

Treatment Timing Controversy: How Early? A debate within the dental profession on the timing of orthodontic treatment went public in the early 2000s, as several major newspapers ran lengthy stories about whether early (preadolescent) orthodontic treatment really benefited patients. Excerpts of those stories appeared in papers all over the country, and almost all dentists were asked about it. Sporadic news reports on that subject continue because there still is controversy within the dental profession. As with any controversy, some see it one way, some another.

It doesn’t matter whether you’re a specialist in that aspect of dentistry or not; whenever a controversy about the best way to treat some type of dental problem comes up, you’re going to get asked about it if you’re in dental practice. You don’t have to know the details of exactly how to treat the problem, but you have to know enough about it to give an intelligent opinion. That’s especially true when it’s a child from your practice who receives contradictory opinions from different specialists. Nothing gets a mother’s attention like the treatment that is planned for her child.

What do you say to a parent with questions about the best time for her child to have orthodontic treatment? Even closer to home, when should your child start orthodontic treatment?

Even prior to starting school? — primary dentition Preadolescent, elementary school years? — early mixed dentition Adolescent, junior high/high school years? — late mixed/early permanent Even later, for best results? — late permanent dentition

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{{PAGE_79}} The New York Times Science Times December 5, 2000 Early Intervention Dentistry: Going to Work on Baby Teeth By CLARA HEMPHILL William Morrison is only 8 years old and still has most of his baby teeth, but he is already a veteran of the orthodontist’s office. He recently completed a 6-month course of treatment … Story introduction

The New York Times Science Times December 5, 2000 Early Intervention Dentistry: Going to Work on Baby Teeth By CLARA HEMPHILL “I’ve treated hundreds of preschool children with lots of success,” said Dr. David Hamilton, past president of the American Assn. of Orthodontists who often starts treatment when children are 4 years old. “You can create minor miracles.” Minor miracles

The New York Times Science Times December 5, 2000 Early Intervention Dentistry: Going to Work on Baby Teeth By CLARA HEMPHILL “There is a growing body of literature that says the benefits of early treatment aren’t as much of a given as people once thought,” said Dr. Lysle E. Johnston Jr., chief of pediatric dentistry and orthodontics at the University of Michigan, a leading critic … Critical view

The New York Times Science Times December 5, 2000 Early Intervention Dentistry: Going to Work on Baby Teeth By CLARA HEMPHILL “Are children having treatment that is unnecessary? No,” said Dr. William R. Proffit, chairman of orthodontics at the University of North Carolina. “Are they having treatment done sooner that just as well might have been done later? Maybe.” Sooner than later?

Effectiveness and Efficiency in Treatment There are two important things to consider in the timing decision: Effectiveness: How well does the treatment work? To what extent does it solve the patient’s problems? The more improvement it produces, and the more ideal the result, the more effective it is. Is effectiveness different at different stages of growth? Efficiency: How much effort does it take to achieve a satisfactory result? How does the benefit of treatment relate to risk and cost? For equivalent results, the more it costs, the less efficient it is. Is efficiency different different at different stages of growth? Remember that there are two kinds of costs when efficiency is evaluated:

1. The economic cost, in dollars, which reflects the amount of time and effort for the doctor and staff.
2. The burden of treatment, which is its impact on the patient and the parent. The greater the risk associated with the treatment, the more the child experiences discomfort and complains to the

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{{PAGE_80}} mother, the more appointments that have to be kept even if they interfere with school or soccer practice, the greater the inconvenience of travel, a whole series of things like that: the greater the burden of treatment.

The best treatment has the best combination of effectiveness and efficiency.

Obviously, the best time for treatment would be when it is most effective and most efficient. Timing is important when the patient’s growth will affect the treatment outcome, as it almost will in orthodontic treatment for children and adolescents.

Principles That Affect Treatment Timing

Some important principles affect the timing of treatment:

1. Growth modification often is desirable.

For example, in a growing patient with a skeletal Class II jaw relationship, guiding growth so that the mandible grows forward more than the maxilla is the best way to solve the problem.

One approach is to use a fixed functional (Herbst) appliance, illustrated here. The appliance holds the mandible forward, which tends to accelerate its growth, and the reaction creates some restraint of growth of the upper jaw. There are a number of alternative approaches in Class II growth modification, but the goal is the same: differential forward growth of the mandible.

Treatment of this type

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{{PAGE_81}} is most effective during the adolescent growth spurt should be completed about the time the growth spurt ends, otherwise much of the effect can be lost to rebound growth If you start too late, it doesn’t work—you can’t modify growth that isn’t happening, and the treatment would not be effective. If you start too soon, it takes too long—you can’t quit until the growth spurt ends. So even if the treatment were effective, it would not be efficient. Both the burden of treatment and the economic cost would be unnecessarily high.

Dental vs. Skeletal Maturation Some important principles affect the timing of treatment: 2. Tooth eruption correlates—but not too well—with the skeletal growth status and the timing of the adolescent growth spurt. This graph shows the variation in adolescent growth for American girls with early, midrange, and late maturation, and the variation in timing of eruption of the mandibular canines and premolars. Because tooth eruption correlates with skeletal growth, early maturing girls are likely to also have early eruption of their teeth. But because the correlation is not as high as you might think, tooth eruption can and does occur over a wide range of physical development. Some children (especially girls) have almost completed their

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{{PAGE_82}} growth before they lose the last baby teeth. Others (especially boys) have all their permanent teeth almost before their growth spurt starts. So the dentist has to judge physical maturation, not just the stage of dental development, to decide when treatment should start. What does that mean?

• For skeletal problems (Class II/III), choose when to send a child for orthodontic treatment by the physical maturation level, not the dentition.
• If the problem is only dental (Class I crowding), judge by the dentition.

Position of Primary vs. Permanent Teeth 3. Permanent teeth often do not erupt where their primary predecessors were. The patient shown here had early expansion of the maxillary arch to make space for the teeth. Note that the canines and premolars aren’t erupting into ideal arch form, although the primary canines and primary molars were in the ideal position after the early treatment. To obtain good occlusion, further treatment to align these teeth will be needed. The result: If early (mixed dentition) treatment was done, a second phase of treatment after the permanent teeth erupt usually is necessary to obtain normal occlusion.

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{{PAGE_83}} Adolescent Treatment: The “Gold Standard” Based on those principles, we can conclude that the best time to treat most orthodontic problems is during the adolescent growth spurt.

Why? Because for most patients this gives the best combination of effectiveness and efficiency.

• The permanent teeth are available for final alignment.
• Effective growth modification can be obtained if needed.
• The treatment ends as adolescent growth slows to the low rate of later life (growth doesn’t totally stop—adults continue to grow, very slowly).
• One stage of treatment, rather than a first phase during the mixed dentition and a second phase later, gives a shorter treatment time and maximum efficiency.

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{{PAGE_84}} Based on those principles:

Treatment timing: the “gold standard”

very late mixed dentition or early permanent dentition

Why Deviate from the Gold Standard?

Why would you deviate from the gold standard, treating earlier or later? Obviously, because treatment at a different time would be more effective, more efficient, or perhaps both.

Let’s start by asking when it might be wise to delay treatment beyond the adolescent growth spurt. Why would you do that? Primarily if prolonged growth (after the adolescent growth spurt) would cause relapse after treatment at the usually optimal time.

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When does it make sense to plan later treatment?

[after the adolescent growth spurt]

The primary indication: prolonged growth in an unfavorable pattern

Indications for Later Treatment

The major indication for delaying treatment until after adolescence:

• Class III due to excessive mandibular growth.

Class III patients with excessive mandibular growth differ from the norm in two ways: Their mandibles are large, and their mandibular growth doesn’t stop at the end of the adolescent growth spurt.

Continued mandibular growth in this girl between age 16 and 19 is obvious from examining her profile. Sometimes these patients look reasonably normal until they just don’t stop growing at puberty. There is no good way to stop excessive mandibular growth—attempts to modify growth in that way, including early orthognathic surgery, just doesn’t work reliably—so the best plan is to wait until growth stops, then treat it. For this girl, that meant delaying treatment until she finally stopped growing at age 19.

Severe long face problems also may have to be treated after adolescence, because often vertical growth in these patients doesn’t stop when it should. But growth modification aimed at restricting downward growth of the maxilla and controlling eruption of posterior teeth can help some long face patients and is worth trying during adolescence.

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Indications for Earlier (Preadolescent) Treatment

Whether to start treatment before adolescence and if so, when, are the controversial issues at present. What would be the indications for early treatment? It should be either:

• More effective: produces a result that could not have been obtained with later treatment, or
• More efficient: produces as good a result with less cost/burden of treatment.

Let’s look at treatment timing for the major types of malocclusion from this perspective, starting with Class I crowding/protrusion.

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When does it make sense to plan earlier treatment?

(before the adolescent growth spurt)

Obvious indication: treatment is more effective or more efficient

When is that?

Class I Problems

Background Concept

For treatment of Class I crowding/protrusion problems, first, an important concept:

• There’s no need to modify growth in patients who have a normal jaw relationship. So for these patients, the stage of dental development rather than skeletal maturation is more important.
• But erupting teeth often become a demonstration of the “law of the perversity of inanimate objects,” erupting in poor positions even though they had every opportunity to erupt in the correct place. That’s why a second stage of treatment in the early permanent dentition usually is necessary after mixed dentition treatment of Class I patients.

It is extremely unlikely that two phases of treatment would be more efficient than one. Only if early treatment eliminated or significantly shortened the later second phase could it be more efficient. The reason for early treatment for crowding and/or protrusion, therefore, would have to be that it produced a better result, and thus was more effective.

There are two approaches to crowding/protrusion (which are discussed in detail in the program To Extract Or Not To Extract, Part 1. These are expansion of the arches or extraction of some permanent tooth or teeth, usually first premolars.

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{{PAGE_88}} Let’s look at the timing of expansion first.

Class I Crowding/Protrusion: Early Expansion?

Keep the definition in mind: Early treatment is done in the mixed dentition, prior to the adolescent growth spurt, before the canines and premolars erupt. There is no doubt that early expansion is effective—it works. The question is whether it works better than later expansion that does not require such prolonged treatment time.

Early expansion often is done with a jackscrew device, which widens the upper arch by opening the midpalatal suture. If treatment started in the primary dentition (image 1), it would still have to continue through adolescence, so expansion in the primary dentition almost never is a good idea. If it were done in the primary dentition, light force is sufficient. A jackscrew device like the one shown in image 1 is unnecessary and should not be used in a young child. This child suffered an injury because of excessive force from the screw device.

In the mixed dentition (image 2), the expander often is bonded to the primary and permanent molars, as shown in the lower image. By this age, a jackscrew device is acceptable if it is not activated too rapidly. It’s generally accepted that this is appropriate treatment for a child with a posterior crossbite due to a narrow maxilla.

What if the child has crowded teeth but no crossbite? Then the maxillary expansion would produce a buccal crossbite. It has been claimed, but not demonstrated, that this makes it possible to expand the lower arch more than would have been possible with a fixed appliance later (image 3). No evidence exists to verify this claim.

The bottom line: Compared to later expansion during adolescence, early expansion is

• probably no more effective
• certainly less efficient

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Class I Crowding/Protrusion: Early (Serial) Extraction

The other possibility for treating crowding/protrusion, of course, is extraction.

Early extraction (usually referred to as serial extraction) was used widely in the mid-20th century in the hopes that it would simplify or even eliminate the need for later treatment. The objective was to systematically move the crowding in each quadrant of the dental arches around to the point where a permanent tooth—almost always the first premolar—would be extracted.

Typical serial extraction has three stages:

• Removal of primary canines to provide enough space for the permanent lateral incisors as they erupt (image 1).

{{PAGE_90}} Removal of the primary first molars before they would normally be lost, to encourage eruption of the first premolars (image 2). Extraction of the first premolars before the canines and second premolars erupt (image 3). Usually the second primary molars also are extracted at this point. This allows the canines and second premolars to share the space of the first premolars as they erupt, and if the potential crowding was severe, the space would be totally closed (image 4). In an ideal world, further eruption of the teeth would lead to proper positioning of the roots and excellent occlusion (image 5). Since this is not an ideal world, often the final result is not so good.

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{{PAGE_91}} Image 1, 1st stage, serial extraction: 1st step, serial extraction: extract primary canines.

Image 2, 2nd stage: 2nd step: extract primary 1st molars when 1st premolars are nearly through the alveolar bone.

Image 3, 3rd stage: 3rd step: extract permanent 1st premolars before canines/2nd premolars erupt.

Image 4, 4th stage: Eruption of canines/2nd premolars into 1st premolar space.

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Problems with Serial Extraction

There are two problems with serial extraction:

1. It requires accurate prediction that the crowding is severe and that extraction really will be necessary for an individual patient. Since extraction is irreversible, even if the probability of an error is small, a mistake is a serious problem.

2. A second phase of treatment is needed after the permanent teeth erupt. A typical serial extraction result, in a child who did have so much crowding (10 mm space discrepancy in each arch) that extraction was necessary, is shown here in the accompanying images. The typical findings are:

• alignment is improved but not perfect
• some extraction space remains
• excessive overbite has developed

For this reason, a second stage of fixed appliance treatment almost always is needed. The deepening of the bite can be difficult to correct, but the length of the fixed appliance treatment is less than it would have been with late extraction.

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{{PAGE_93}} Image 1, frontal view: Serial extraction result: note anterior deep bite (excessive overbite).

Image 2, right lateral: Right lateral view: overbite, imperfect alignment.

Image 3, left lateral: Left lateral view: overbite, good alignment.

Image 4, upper occlusal: Upper occlusal: rotations, extraction space not totally closed.

Image 5, lower occlusal: Lower occlusal: small space on left, mild incisor crowding.

Serial Extraction: The Bottom Line

Serial extraction is not a cheap way to avoid orthodontic appliance therapy for most children. It was hoped at one time that properly timed extractions would make conventional orthodontic treatment

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{{PAGE_94}} unnecessary for most children with crowding/protrusion. It now is well documented that this is not the case. On the other hand, because it does have the potential to reduce phase 2 treatment time, it isn’t necessarily less efficient than later one-phase treatment. A similar number of total visits can be spread over a longer period of time if phase 2 is shortened sufficiently. What about the effectiveness of serial extraction? If a child really is severely crowded, serial extraction has advantages that can lead to a better result than later extraction. It eliminates incisor crowding during the mixed dentition, which can make both the parent and child happier during that period. reduces phase 2 treatment time. may also reduce the chance that crowded-out canines will erupt through mucosa instead of gingiva, thus improving long-term periodontal health. may also improve long-term stability. It seems reasonable that if the incisors were never allowed to become malaligned, they should be more stable in the long term, but the evidence for this is questionable. Modern guidelines restricts serial extraction to children with 10 mm or more crowding in both arches predicted by space analysis normal facial proportions (not skeletal Class II/III, short/long face) phase 2 treatment definitely available Most children with crowding/protrusion are excluded by those restrictions. For the small group who are candidates for it, serial extraction can be judged to be both effective and reasonably efficient.

Timing Guidelines, Class I Crowding/Protrusion

So how do we summarize the timing guidelines for Class I patients? Unless crowding is very severe as the lateral incisors are erupting and the serial extraction criteria exist, don’t extract mandibular primary canines prematurely. No treatment is needed at that point, unless extraction of maxillary primary canines is needed to decrease the chance of canine impaction.

It takes a lot more potential crowding than is seen in image 1 to justify the extraction of primary canines to make space for lateral incisors.

If one or both primary canines are lost spontaneously as the lateral incisors erupt, some early treatment is indicated: Keep it symmetric: extract the other primary canine if only one was lost. Use a lingual arch to maintain space unless the strict criteria for serial extraction are met.

One of the patients shown in image 2 needs extraction of the other mandibular primary canine and both need a lingual arch to maintain space—but neither needs anything else now. This keeps the option open for long-term expansion or extraction and prevents the development of major asymmetry in dental arch.

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• Arrange for orthodontic treatment to begin just before the second primary molars are lost, so that leeway space (the difference between the size of 2nd primary molars and 2nd premolars) can be used to help resolve any space discrepancy. The patient in image 3 is close to the ideal time to start fixed appliance treatment for mild/moderate crowding. If crowding had been more severe, placing an appliance on the lower arch before leeway space was lost would have been indicated.

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{{PAGE_96}} Image 1, no serial extraction: Moderate crowding, not enough to indicate early treatment.

Image 2, lingual arch needed: More severe crowding: maintain space and symmetry.

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{{PAGE_97}} Class II Problems Background Concept, Growth Modification Important concepts in treatment of skeletal (jaw relationship) problems:

• The major reason for early treatment is to modify growth. Tooth movement (as for camouflage of a skeletal problem) can and should be done later.
• Growth modification at an early age tends to wear off as uncontrolled later growth occurs, so what looked successful in the short term may not be so successful in the long term.

Dentists’ opinions about the effectiveness of early Class II treatment have changed back and forth over time. Recently, many have been enthusiastic about early (preadolescent) treatment, on the theory that growth modification would be more successful at that time. Others have doubted that two phases of treatment would produce a better outcome than later one-phase treatment.

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{{PAGE_98}} EARLY vs LATE TREATMENT OF CLASS II MALOCCLUSION A RANDOMIZED CLINICAL TRIAL

J.F.C. Tulloch Ceib Phillips William R. Proffit

Department of Orthodontics University of North Carolina School of Dentistry

Class II Clinical Trial: Research Design

The UNC clinical trial, like the other major trials, was designed to answer two major questions:

• Did preadolescent treatment really modify growth?
• Was there any difference in the final outcome between children who had early (preadolescent) treatment followed by a second phase of treatment at adolescence, and those who had only one phase at adolescence?

In the trial, preadolescent Class II children were randomly assigned to one of three groups:

• No treatment until adolescence
• Headgear treatment
• Functional appliance treatment

{{PAGE_99}} Class II Clinical Trial: Phase 1 Outcomes

At the end of the first phase, there was a small but statistically significant difference in jaw growth between the children who had treatment and the untreated controls—so now there is good evidence that early treatment is effective.

But the variability in results was perhaps the most impressive finding. This graph shows the percentage of patients whose jaw relationship improved greatly, improved somewhat, stayed the same or got worse with or without treatment. The ANB angle, of course, is one measure of the difference between the position of the maxilla and mandible. If it decreases, the jaw relationship is improving. A highly favorable response would be a large decrease, unfavorable would be an increase.

Note that a few of the untreated children improved, most showed no change, and some got worse. In the treated groups, some improved impressively, the majority improved a little, and 25% showed no response or got worse. Cooperation obviously was a factor in treatment response, but it did not explain all the variability.

With this variability, if you were an advocate of a particular approach, it would be easy to select the right children to illustrate that your point of view was correct. Many published case reports, in fact,

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{{PAGE_100}} demonstrate different outcomes in different children from similar treatment procedures. Clinical impressions obviously can be misleading.

The conclusion from the first phase of the trial: Although early treatment is effective in general, it does not improve the jaw relationship every time. Things change for some children in both directions, in the absence of treatment.

Class II Clinical Trial: Phase 2 Outcomes The first phase of treatment was effective—it produced the desired change in most (but not all) patients.

That brings us to the second major question: Did early treatment produce a better (different) outcome at the end of phase 2, after both the treated children and untreated controls had fixed appliance treatment during adolescence?

The factors that would need to be considered would include

• dental occlusion
• jaw relationship
• type of treatment needed in phase 2 nonextraction orthodontics extraction orthodontics orthognathic surgery
• treatment time

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{{PAGE_101}} Let’s look at these one at the time, using the phase 2 data. Class II Clinical Trial:

At the end of phase 2, did early treatment make any difference in

• Dental occlusion
• Jaw relationship
• Type of phase 2 treatment
  • Premolar extraction for camouflage
  • Orthognathic surgery
• Treatment time

Clinical Trial Phase 2: PAR Scores

Perhaps the best way to measure the quality of the dental occlusion is to use PAR scores. These scores are derived from a weighted system (in which overjet is emphasized) to evaluate

• Overjet, overbite, midlines
• Alignment of maxillary and mandibular teeth
• Right and left buccal occlusion

PAR scores are like golf—low score wins. A PAR score of 5 or lower is nearly perfect occlusion, under 10 is good. A patient with a typical Class II malocclusion would have a score in the 25-40 range before treatment.

Data for changes in mean PAR scores for the three groups of patients are shown in image 1, and the percentages of children with excellent, good and disappointing scores at the end of phase 2 are shown in image 2.

The objective of phase 1 treatment was growth modification, not improvement in the occlusion, so it is not surprising that PAR scores changed very little in phase 1 (image 1). Phase 2 treatment greatly reduced the mean PAR scores for each treatment group, and at the end of Phase 2 there was no difference in the mean scores for those who did and did not have a first phase of early treatment. The distribution of children by phase 2 PAR scores also was the same for the three groups.

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{{PAGE_102}} The bottom line: Early treatment didn’t make any difference in the extent to which the Class II malocclusion was corrected.

Clinical Trial Phase 2: Jaw Relationships The goal of phase 1 treatment was to improve jaw relationships, and on average, it did. What happened to jaw relationships during phase 2? In this table (image 1), look at the amount of decrease in ANB for the three groups during early (phase 1) treatment, during phase 2, and the total for both phases.

The interesting result: The difference between the previously treated and untreated control children nearly disappeared during phase 2. The ANB angle decreased more for the previous controls during phase 2, and they almost caught up with the children who had early treatment, even though phase 2 treatment did not focus on the jaw relationship. The same effect is observed when other indicators of jaw relationship are measured.

The bottom line: Early treatment made very little long-term difference in jaw relationships. At the end of phase 2, the differences between the children who had two phases of treatment and those who had only one were no longer statistically significant.

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{{PAGE_103}} Class II RCT Skeletal effects: ANB angle

Visit	Control	Bionator	Headgear
Initial	6.29 (1.98)	6.26 (2.06)	6.04 (1.82)
End Ph 1	6.11 (1.90)	5.14 (1.99)	4.72 (1.82)
Ph 1 change	-0.17	-1.12	-1.31
End Ph 2	4.28 (2.04)	3.93 (1.94)	4.10 (1.97)
Ph 2 change	-1.83	-1.21	-0.62
Total change	-1.83	-2.43	-1.93

Clinical Trial Phase 2: Extraction Percentage

One of the possible advantages of early treatment would be a reduction in the number of patients who would need premolar extraction during phase 2 (for camouflage—see To Extract Or Not To Extract, Part 2). It seems reasonable that if growth modification were successful during phase 1, the extraction percentage should be lower in children who had early treatment.

In phase 2 treatment, the orthodontist was instructed to do whatever it took to produce the best outcome for that individual patient—so extractions were used if they were needed, in the doctor’s opinion. The data show differences among doctors, as would be expected.

But as the chart shows, for the three groups of patients who did or did not have early treatment, the differences in the number of patients with extractions during phase 2 were small and not statistically significant. It often has been claimed that early functional appliance treatment decreased the need for later extractions. The data clearly did not support that contention.

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{{PAGE_104}} Class II RCT: Extractions by doctor and group

	Total treated	Number of extractions Control	Bionator	Headgear	Total extracted
Dr. P	40	3	3	2	8 20%
Dr. T	40	4	6	4	14 33%
Dr. B	35	3	3	1	7 20%
Dr. O	32	0	2	0	2 6%
Total	147	10 20%	14 30%	7 15%	31 21%

Clinical Trial Phase 2: Orthognathic Surgery Percentage It also seems reasonable that taking advantage of growth at an early age might reduce the number of patients with severe Class II problems who ultimately would need orthognathic surgery. All patients enrolled in the clinical trial had to have at least a moderately severe Class II malocclusion, but there was no upper limit on severity, so some of the children had quite severe problems. It would be expected that some of them eventually would require orthognathic surgery.

As the chart shows, if early treatment decreased the chance that orthognathic surgery ultimately would be needed, the change was small. The small difference between early and later treatment is suggestive but not statistically significant.

The bottom line: The results for orthognathic surgery were the same as for other indicators of effectiveness. The clinical trial data did not support two-phase treatment with a first phase prior to adolescence as being more effective (producing a better result) than one-phase treatment during adolescence.

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{{PAGE_105}} Class II RCT: Phase 2 Surgery

	Total	Control Bionator Headgear
Finished Treatment	147	51
Surgery Completed	11 (7.5%)	5 (7.8%)
Surgery Needed, declined	3 (0.7%)	1 (1.9%)
Percent	9.5%	11.8%

Clinical Trial Phase 2: Treatment Time

Finally, one would hope that at least some of the time spent on early treatment would be recovered by shorter phase 2 treatment time later.

The clinical trial data, however, show no significant difference in phase 2 treatment time with or without early treatment. As the graph demonstrates, the median treatment time in phase 2 was very similar for the three groups, and the distribution of phase 2 treatment times was nearly identical.

The conclusion: For most patients with Class II problems, a first phase of treatment prior to adolescence is

• No more effective then later treatment
• Considerably less efficient

An important caveat: Children with severe skeletal vertical problems (severe short or long face) were not included in the clinical trial. Its conclusion, therefore, applies to children with a skeletal Class II malocclusion and reasonably normal face height.

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{{PAGE_106}} Phase 2 Treatment Time Short (< 18 months) Expected (18-33 mo.) Long (>33 months)

60% 50% 40% 30% 20% 10% 0%

Mean 27.1 S.D. 10.1 Mean 26.7 S.D. 11.4 Mean 29.6 S.D. 11.7

Control Functional Headgear

Class II Treatment Timing: Summary/Recommendations The data for the clinical trials of preadolescent vs. adolescent treatment of children with skeletal Class II problems have been reviewed by an expert group, using the criteria of the Cochrane Collaboration that evaluate the quality of the research. The bottom line: “For most Class II children, there is no advantage in beginning treatment before the adolescent growth spurt.”

Does that mean early treatment is never indicated for a Class II patient?

No—but it does mean there should be a good reason for early treatment and that early treatment is not indicated for the majority of Class II children.

Remember, treatment timing is related to skeletal development, not dental development, so a rapidly maturing girl who still is in the mixed dentition as she enters her adolescent growth spurt should start treatment (for her, it’s not really early), and a slowly maturing boy whose teeth have erupted probably should wait for the growth spurt (for him, it’s still early).

What characteristics should lead you to recommend orthodontic consultation for a preadolescent Class II patient in your practice? The current guidelines, based on an interpretation of the clinical trial results:

• Evidence of major social problems from teasing, etc. Problem severity should be determined by its effect on the patient’s quality of life, not characteristics like mandibular deficiency or overjet.
• Evidence of damage to teeth or soft tissues that is related to the malocclusion.

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{{PAGE_107}} Since data from a randomized clinical trial involving children with combined vertical and anteroposterior problems are not yet available, it is possible that early treatment might be advantageous for children with a short-face or long-face Class II problem. On that point, clinical opinions still are the best available information.

How many Class II children meet these guidelines for early treatment? Except that it obviously isn’t the majority, we still don’t know with any precision.

Class III Problems

Background Concepts

Class III problems can arise from maxillary deficiency, mandibular excess, or their combination. Important background concepts:

• Excessive mandibular growth is almost impossible to control. Devices that put force against the chin to restrain the mandible (like the chin cup shown in image 1) are not effective in most circumstances, probably because children will not tolerate the amount of force and time required.
• In contrast, deficient maxillary growth can be stimulated with force to pull the maxilla forward. As we have described previously, there are two ways now to do that: reverse pull headgear or face mask (image 2), or Class III elastics to bone anchors (image 3). But the window of opportunity for non-surgical face mask treatment closes around age 10, so treatment should start at age 8 or 9; therefore, referral for early treatment is critically important. Treatment with bone anchors is possible in the early part of the adolescent growth spurt but also should start as early as possible (when there is enough bone maturation to hold the bone screws), ideally at age 10 1/2 or 11.

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{{PAGE_108}} Image 1, chin cup: Devices to place force against the chin do not succeed in restraining mandibular growth.

Image 2, face mask: Devices to pull the maxilla forward to reduce skeletal maxillary deficiency can succeed—but only if used very early.

Chin Cup to Restrain Mandibular Growth

The image you see here is from a textbook published in 1890. The caption under the picture described the use of this chin cup device to inhibit mandibular growth, then said, “Unfortunately, it doesn’t work very well.” More than 100 years later, that is still the best summary.

There are two problems with chin cups:

• Mandibular growth restraint requires a level of cooperation (and tolerance of pain) that is very difficult to obtain in children.
• Patients with excessive mandibular growth differ from the norm in two ways: Their mandibles grow too much, and as we noted previously, They don’t stop growing at the end of the adolescent growth spurt.
• So any restraint or redirection of growth tends to be canceled out by “rebound” growth afterward unless the treatment is continued well into adolescence.

The bottom line: Early treatment with a chin cup is neither effective nor efficient.

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{{PAGE_109}} Face Mask to Stimulate Maxillary Growth

Until the 1970s, it was thought to be impossible to stimulate forward growth of the maxilla. Then it was discovered that if force to bring the maxilla forward is employed at quite young ages, it is possible to obtain skeletal change. The original guideline, from the French surgeon who pioneered this method, was that the treatment had to be done before age 8 to be effective.

The treatment is done with a face mask (reverse pull headgear) (image 1), placing relatively heavy force against the maxillary teeth that is transmitted to the maxilla. Skeletal change, not tooth movement, is the goal. The teeth must be splinted to minimize tooth movement. Treatment can start in the primary dentition, but to control tooth movement, it helps to have the maxillary first molars available, so age 7 is the preferred time.

This boy wore his face mask for 12 hours per day for a year, between ages 7 and 8. The improvement in the prominence of his maxilla is apparent (image 2).

The upper age limit for success with face mask treatment has moved up a little recently, but it remains clear that if a face mask is used when a patient is approaching adolescence, the only effects are tooth movement and downward/backward rotation of the mandible, not forward growth of the maxilla.

Bottom line: If face mask treatment is going to help a maxillary deficient Class III child, it must start early, preferably before age 8.

{{PAGE_110}} Image 1, face mask: Reverse pull headgear (face mask), to provide force against the maxilla to bring it forward. Image 2, profile change: Profile effect of 12 months of face mask treatment.

Face Mask to Stimulate Maxillary Growth (cont.)

Does that mean all Class III children should have face mask treatment early?

No, only those whose problem is largely due to maxillary deficiency and who would prefer face mask treatment to bone plates that would require (relatively minor) surgery to place them. The moment of truth for the former face mask patients is the adolescent growth spurt. If excessive mandibular growth occurs then, the Class III problem will recur, no matter how much it was improved earlier.

The only solution for excessive mandibular growth is orthognathic surgery, and the best estimate (based on similar results from three studies of long-term outcomes) is that 20-25% of children who responded well initially to face mask treatment will eventually need surgery.

You saw the impressive improvement for this boy with early face mask treatment (image 1). But at age 16 (image 2) he was on the borderline for surgery and mandibular growht was continuing. At age 19 (image 3), he was concerned about his reverse overjet and jaw asymmetry, and was told that orthognathic surgery was the only way to correct it. His problem was a combination of maxillary deficiency, which was significantly improved, and excessive mandibular growth that led to a need for surgery in spite of the favorable face mask response.

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{{PAGE_111}} Image 1, after face mask: Age 9, one year after face mask therapy was discontinued. Image 2, 7 years later: Age 16, recurrence of the skeletal Class III problem. Image 3, comparison: Change from age 9 to 16, with continued mandibular growth.

Class III Elastics to Skeletal Anchorage

As you have seen in earlier modules on temporary anchorage devices (TADs), growth modification is one of the possible uses for skeletal anchors. The technique is built around the use of bone plates in the maxilla at the base of the zygomatic arches that are held by 3 screws, and bone plates mesial and

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{{PAGE_112}} inferior to the mandibular canines that are held by 2 screws (see Level III, . Recent data show that on average, about twice as much maxillary advancement is obtained as with a face mask, even if the force from the face mask is applied to bone screws in the anterior maxilla.

The patient shown in image 1 was treated with this approach, with a treatment duration of 12 months and a gratifying short-term outcome (image 2). What’s the best time to do this type of treatment? The answer still is, as early as possible, which turns out age 10 1/2 to 11, significantly later than the age for face mask treatment. By the time a child’s jaws have matured to the point that bone screws are reliably retained, he or she is already too old to expect a good face mask response—which means that there is a way now to modify Class III growth in children who have entered adolescence.

At what age is a patient too old to expect a favorable response to this type of treatment? It appears that significant advancement of the maxilla is less likely after age 12 or 13, depending on the patient’s maturity. Since the response does include a component of restraint of mandibular growth, it is possible that this might, for the first time, be a way to control excessive growth during adolescence—but that has not yet been demonstrated in enough patients to be sure it would work.

Class III Treatment Timing: Summary/Recommendations

So what should you recommend to the parents of the Class III child in your practice?

• The child should have an early orthodontic evaluation including cephalometric radiographs, so that later cephs could be superimposed to determine the pattern of growth and suitability for early growth modification treatment.
• Early referral means age 7 to 8, earlier if possible.
• If the problem is primarily excessive mandibular growth, a chin cup appliance is unlikely to be effective treatment and orthodontic / surgical treatment should be delayed until after the adolescent growth spurt and a decline in mandibular growth to the very slow adult level.
• If the problem is primarily maxillary deficiency, there are two possibilities:for younger children: face mask (reverse pull headgear) to a splint on the maxillary teeth, with treatment starting by age 8. Class III elastics to maxillary and mandibular bone anchors, with treatment starting at age 10 1/2 to 11
• Be sure the parents understand that this is a growth problem and that even if it’s corrected early, it may recur during adolescent growth.

Treatment Timing Conclusions

The best time for most orthodontic treatment is during the adolescent growth spurt, which usually coincides with the transition from the late mixed dentition to the early permanent dentition.

For children with no skeletal component to their malocclusion (Class I problems), treatment timing is based primarily on the dentition. Early treatment (early mixed dentition) is indicated primarily for

• very severe crowding (serial extraction)
• early loss of primary teeth, especially primary canines (maintain space if serial extraction criteria not met)

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{{PAGE_113}} For children with Class II malocclusion, early (preadolescent) treatment has been shown to be of limited benefit in most cases. It is primarily indicated a child with

• psychologic problems produced by teasing, etc.
• trauma to the soft tissues or teeth during function (usually from deep overbite)

For children with Class III malocclusion, maxillary deficiency can be improved with face mask treatment, but only at very early ages, well before adolescence. Class III elastics to skeletal anchors can bring the maxilla forward in older children, perhaps up to ages 12 or 13. Mandibular excess, in contrast, is almost impossible to control, and so may better be treated late in adolescence.

Any Class III child is a candidate for early diagnostic evaluation to determine the extent to which the problem is maxillary deficiency, and therefore whether early treatment is appropriate.

Self-Test Referral

The self-test section of this program is designed to help you be sure you have understood the material. Do the assigned reading (Contemporary Orthodontics, 5th ed: pages 472–475 and 480–497; 4th ed: pages 497–498 and 502–516). Then take the test, and use it as a guide for further study and review.

Copyright 2013, UNC Dept. of Orthodontics

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