{{PAGE_1}} LEVEL IV · CLINICAL TREATMENT Unit D Interaction with Orthodontists · Meet Your New Young Patient · Accelerated Tooth Movement

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Interaction with Orthodontists
Meet Your New Young Patient
Accelerated Tooth Movement

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1. Interaction with Orthodontists

Background / Diagnostic Review

Orthodontics as a Dental Specialty

For a variety of reasons, orthodontics developed as the first specialty practice area in dentistry, and one of the first in health care more generally. When the American Board of Orthodontics was established in 1929 to certify specialists in this field, only two medical areas had already established specialty boards.

Why did orthodontics develop as a specialty so early? Edward Angle (image 1), the primary force in the development of modern orthodontics, became frustrated with trying to teach this subject in the dental schools of 100 years ago. He started his own school of orthodontics, with admission limited to those with a dental degree, and maintained it in various locations until just prior to his death in 1930. In 1901, he also established the American Association of Orthodontists, with membership limited to those who had training beyond dental school. In part because of this early tradition of postdoctoral training, orthodontics to this day receives less emphasis in the dental curriculum than most other areas of current dental specialty practice.

What does that mean for the interaction of orthodontists with other dentists? Simply that a higher percentage of patients with orthodontic needs are likely to be treated in a specialty practice, than those with most other types of dental treatment needs. If you practice in another area of dentistry, you would expect to interact with orthodontic specialists on a regular basis—more if you do no orthodontics yourself, less if you do, but regularly in either case.

Let’s explore a familiar situation for all dentists (image 2): You have been asked to look at a child and offer an opinion as to whether orthodontics is needed. It happens all the time in family practice, of course, but you’ll get asked about a friend’s child or patient’s child even if you’re in some other type of specialty practice.

{{PAGE_4}} Facial Examination: Symmetry

In dental education, one of the goals is to equip dentists to recognize problems in dental and skeletal development. Obviously, if you don’t notice a deviation from normal, you won’t be in a position to either treat it yourself or refer it appropriately. Let’s quickly review the diagnostic evaluation of children.

The first, and the key step, in evaluating a child’s potential need for orthodontics is to carefully examine facial proportions. What are you looking for? Two things: symmetry and proportion.

The best way to evaluate symmetry is to look carefully at the patient from the front, drop a line from the forehead through the middle of the face, and look at how the nose and jaws are aligned relative to it (image 1).

A child with an obvious asymmetry is a candidate for immediate referral. Note that this boy’s chin deviates to the left. This reflects a serious growth problem with the potential to become steadily worse if left untreated.

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{{PAGE_5}} Facial Examination: Jaw Proportions

A good way to sharpen your eye in looking at a child’s vertical facial proportions is to apply the “rule of thirds.” In both the frontal (image 1) and profile (image 2) views, the face should have approximately equal thirds from the hairline to the bridge of the nose, from the bridge to the base of the nose, and from the base of the nose to the chin.

Do these have to be exactly the same? Of course not, but if one area is noticeably short or long, you are looking at a potentially serious growth problem that should be evaluated sooner rather than later.

Note that the girl in these images has equal vertical proportions, while the boy has a noticeably short face, especially the lower third. These skeletal proportions predispose him to a deep overbite.

To judge the relative prominence of the mandible to the maxilla, use the profile view (image 2), and drop a vertical line across the front of the face when the patient is in natural head position. Now you can see the the girl’s chin is behind that line, so she has moderate mandibular deficiency, while the boy’s chin is as prominent as his upper lip but his lower lip is behind the upper lip.

She has a skeletal Class II malocclusion, he has a skeletal deep bite. But if face height is short, the mandible rotates upward and forward, which makes his chin more prominent—so he also would be Class II if you rotated his mandible downward to give him normal face height. That rotation also would improve the balance between his lower lip and chin. He’s deficient vertically and anteroposteriorly.

Facial Examination: Lip Prominence

Finally, especially in children who don’t have a jaw discrepancy, look carefully at the lips, and note two things: the amount of lip separation at rest, and the prominence of the lips.

Note that the girl in image 1 has relatively prominent lips, but little or no lip separation, while the one in image 2 also has prominent lips, but lips that are separated at rest.

Why is this important? Because crowding of the anterior teeth and protrusion of the lips are aspects of the same thing. You can’t evaluate crowding without also evaluating protrusion. The guideline is that the teeth are too protrusive, holding the lips too far forward, if two criteria are met: prominence of the lips, and lips that are separated at rest and strained on closure.

{{PAGE_7}} Prominent lips, not separated at rest: incisor protrusion acceptable.

Prominent lips, separated at rest: incisor protrusion excessive.

Lip separation, not lip prominence, is the key to deciding whether the incisors are too protrusive.

Evaluation of Occlusion and Alignment/Crowding

{{PAGE_8}} Only after looking carefully at the face are you ready to examine the occlusion and alignment of the teeth. Look first at the occlusion in three planes of space: transverse [posterior crossbite], a-p [overjet], and vertical [overbite, open bite]. This child (image 1) has problems in all three planes of space. Note the posterior crossbite, excessive overjet, and anterior open bite. You’d have to look at her face (image 2) to know how much of this is due to her jaw relationships and how much is due to displacement of the teeth relative to their own jaw. She has enough mandibular deficiency to be skeletal Class II, and the lower third of the face is long, so there is a skeletal component to the open bite as well. Her face isn’t narrow, so widening the maxillary dental arch should be possible, but you would need to look at dental casts to evaluate the width of the palate. Then you can examine the alignment of the teeth and the amount of space within each dental arch. Space analysis is the best way to quantify how much is available for the permanent teeth, but you can see at a glance whether the amount of space is adequate, a bit short, or seriously short. Of course if the space looks adequate but the teeth are too protrusive, that has to be entered into consideration about the best plan for treatment. It’s obvious that both the lower arches shown in image 3 are crowded despite the reasonably good alignment of the permanent incisors after primary canines were lost prematurely. It’s also obvious that there’s less space in image 2 than image 1. How big is the space discrepancy in each case? You need to do space analysis to verify that.

{{PAGE_9}} Referral: What Cases, When? Referral of Children for Orthodontic Care

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{{PAGE_10}} All right, you have looked at both the face and the teeth, and you note some developmental problems with either the face or the dentition. Now what?

There are two major considerations in the referral of children from family practice to an orthodontist: (1) What type of problem warrants referral? (2) When (at what age) should the child be referred? Let’s consider those one at the time.

Common sense says that the more severe problems should be referred to a specialist, and the less severe ones can be treated in family practice. How do you determine which are the more severe ones?

The term triage describes the sorting of patients by the severity of their problems (and chance of survival) in disaster situations. For orthodontic problems, a similar sorting process, based on problem severity, is needed. This relates closely to the usual diagnostic evaluation that we just reviewed.

What Problems Warrant Referral: Orthodontic Triage

The first step in orthodontic triage for children is to look at the child’s face from the front, and evaluate two thing. First: Is there something so unusual about the child’s facial proportions or general appearance that a craniofacial syndrome may be present?

This boy was seen because of concern about anterior crossbite of retained primary teeth and failure of permanent teeth to erupt. He has the classic facies of cleidocranial dysplasia (short face, maxillary deficiency). He also has the absence of clavicles that is characteristic of the syndrome, so that he can almost bring his shoulders together. Before you even look in his mouth you should expect to find the multiple supernumerary and unerupted teeth that also are characteristic of this syndrome.

Patients with severe problems of this type obviously should be referred. Complete evaluation by a craniofacial team is indicated, because a correct syndrome diagnosis is a key to the planning of future treatment that may involve multiple medical and dental specialties.

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{{PAGE_11}} Orthodontic Triage, Child

SEVERE PROBLEM STEP 1: FRONTAL ANALYSIS OF FACIAL PROPORTIONS MAJOR DISPROPORTION (syndromic deformity?)

Orthodontic Triage, Step 1 (cont.) Looking at the child’s face from the front, the second thing to evaluate is facial symmetry: Is a true facial asymmetry present (not just a deviation of the jaw from initial contact of the teeth to full occlusion)? We have already noticed that this boy’s chin is off to the left. Mentally putting a vertical line down the middle of his face, or using a ruler to establish a line, makes it easier to see that. Often children with asymmetry tilt their head, so you may need to straighten him up to fully appreciate the location of the asymmetry—but it’s important to notice it and surprisingly easy to overlook it. Don’t assume it’s just a shift on closure of the mandible. Is the asymmetry present with the jaws slightly separated in the postural position? Does the asymmetry increase on opening? If so, comprehensive evaluation is needed by a team with experience in treating problems of this type. Growth guidance will be required, either before or after orthognathic surgery depending on the cause of the asymmetry.

ORTHODONTIC TRIAGE, CHILD

SEVERE PROBLEM

STEP 1: FRONTAL ANALYSIS OF FACIAL PROPORTIONS

MAJOR DISPROPORTION (syndromic deformity?)
TRUE FACIAL ASYMMETRY

normal, symmetric (continue)

Orthodontic Triage, Step 2

The second step in orthodontic triage is examination of the facial profile.

If there is an anteroposterior (skeletal Class II/III) or vertical jaw discrepancy (short/long face), a severe problem exists. Cephalometric analysis and probably growth guidance are indicated.

If there is excessive or inadequate support of the lips by the teeth, cephalometric analysis and major tooth movement, perhaps after extraction of teeth, will be required.

Either a jaw discrepancy or abnormal lip support are severe problems that will require complex treatment. These findings from profile analysis suggest early complete evaluation including cephalometric analysis.

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ORTHODONTIC TRIAGE, CHILD

SEVERE PROBLEM

A-P OR VERTICAL JAW DISCREPANCY SKELETAL CLASS II / III SHORT / LONG FACE

STEP 2: PROFILE ANALYSIS

EXCESSIVE INCISOR PROTRUSION OR RETRUSION EVERTED / SEPARATED LIPS CONCAVE NOSE-LIP-CHIN

MODERATE PROBLEM

normal jaw / lip position (continue)

Orthodontic Triage, Step 3

The third step is to examine the dentition and dental (panoramic) radiographs for signs of abnormal development. Congenitally missing permanent teeth and failure of eruption of multiple teeth, which fortunately is rare, are severe problems. Mild asymmetry in the maturation of the teeth is not a problem, but major asymmetry (one side behind the other by a year or more) is.

Supernumerary teeth complicated by number or position constitute a severe problem, because surgical removal can be complex, and multiple teeth may have to be repositioned after the supernumeraries are removed. A single supernumerary in an uncomplicated position is not a severe problem—it can just be extracted, and is not an indication for referral to an orthodontist. In most cases, that’s also true for ankylosed primary teeth and ectopic eruption.

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{{PAGE_14}} Orthodontic Triage, Child

SEVERE PROBLEM ABNORMAL / ASYMMETRIC PATTERN OF DENTAL DEVELOPMENT MULTIPLE / COMPLICATED SUPERNUMERY MISSING TEETH (PERMANENT) ERUPTION FAILURE

STEP 3: REVIEW DENTAL RADIOGRAPHS

MODERATE PROBLEM SINGLE / UNCOMPLICATED SUPERNUMERY RETAINED / ANKYLOSED PRIMARY TEETH ECTOPIC ERUPTION

(continue)

Orthodontic Triage, Step 4 The final step is space analysis. Note that this is done only if the jaw relationships and the pattern of dental development are normal—children with skeletal problems and major dental abnormalities have been separated out previously. Space analysis assumes that skeletal and dental development are normal. It should be used only for children who meet that assumption.

If a primary tooth has been lost prematurely and space is adequate, space maintenance is indicated. If a small space discrepancy has developed, space regaining in the mixed dentition is appropriate treatment in family practice. But a large discrepancy cannot be managed in that way—comprehensive treatment will be required.

If the dentition is intact but the incisors are irregular, the magnitude of the space discrepancy determines how severe the problem is. A small midline diastema is not a severe problem—often it will close spontaneously as the canines erupt—but a large diastema usually requires both careful space closure with control of overbite and long-term fixed retention.

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{{PAGE_15}} So Who Treats Which Problems? So who treats which orthodontic problems? Obviously, that depends in part in the family dentist’s level of interest and expertise in orthodontics. The more you know, and the more you like to do that type of treatment, the more orthodontic patients you will select to treat yourself and vice versa. But there are two explicit guidelines:

Children with skeletal problems in general, and those with facial asymmetry problems in particular, are candidates for referral.
The more severe the crowding and protrusion, the greater the chance that referral to a specialist will be good judgment. Decisions about orthodontic procedures for adults follow a similar logic to the triage for children. The special aspects of orthodontics for adults are reviewed in the companion teaching programs on adjunctive and comprehensive treatment for adults. Now let’s think about the timing of referral. If Referral Is Indicated, At What Age Do You Do It? A second important question is the appropriate age for referral of children.

{{PAGE_16}} The general rule is that treatment of Class II and vertical skeletal problems is most effective and efficient if done during the adolescent growth spurt, so you always want to refer children with these problems by the beginning of adolescence. Remember that it’s the stage of physical development that’s important, not the stage of dental development. Get them to the orthodontist before they are sexually mature. Many girls now undergo adolescence at surprisingly early ages.

The girl in image 1 isn’t quite 11, but she’s showing definite signs of puberty. Treatment for her Class II malocclusion, which you can see is largely due to mandibular deficiency, should start now. Waiting for eruption of the remaining permanent teeth would be a serious mistake.

For children with normal jaw proportions but crowding/malalignment, the best time for treatment is just at the end of the mixed dentition, beginning as the second primary molars are ready to exfoliate (images 2,3). Often it is advantageous to maintain leeway space that otherwise would be lost when the second primary molars are lost, and this can be done by beginning treatment just before the remaining permanent teeth erupt. For these patients there is no need to attempt to modify skeletal growth, so the timing can be based on the dentition—but don’t wait until the second primary molars have exfoliated.

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{{PAGE_17}} Image 1, Class II: Refer a child with a skeletal problem before the adolescent growth spurt begins.

Image 2, Class I crowding: Class I crowding: Treatment should begin just at the end of the mixed dentition.

Image 3, Class I radiograph: Class I crowding: Treatment begun just at the end of the mixed dentition.

Jenny M. Age 11-1 End phase 1

Age of Referral (cont.) What types of patients should be referred in the early mixed dentition, well before the beginning of adolescence? In general, those for whom there are special concerns:

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{{PAGE_18}} Psychologic difficulties from being teased at school, as children with protruding teeth often are (most but not all are able to cope with this during preadolescent years) Trauma to the teeth or soft tissues (image 1) Skeletal Class III problems In general also, treatment for children who have both vertical and a-p jaw discrepancies (the short face Class II child, for instance) may be more effective if it starts prior to adolescence. These children should be referred for evaluation early even if the ultimate decision is to delay treatment until the adolescent growth spurt. A particular indication for early referral is a Class III problem due to deficient growth of the maxilla. A child with obvious maxillary deficiency, like the boy shown in image 2, should be referred at age 6 or 7 if possible, because the window of opportunity to change growth of the upper jaw without surgery begins to close at about age 8. In summary: If in doubt, go ahead and refer a preadolescent child for more detailed evaluation. But don’t send them all at age 7, because the majority won’t benefit from treatment until they are approaching adolescence. This important topic is discussed in more detail in the computer program Timing of Orthodontic Treatment.

Image 1, trauma from overbite: Trauma to the soft tissues, as in this 8-year-old with an impinging overbite, is an indication for early (preadolescent) treatment.

Image 2, maxillary deficiency: Maxillary deficiency in a 6-year-old is an indication for early referral and treatment.

How Do You Manage the Referral?

If you’re not in orthodontic practice, you will have orthodontists as colleagues in the local dental community, and will develop a personal relationship with at least some of them. The style of referral will vary depending on that personal relationships, but three things need to happen:

a discussion with the parents as to why and to whom you are making the referral
communication with the orthodontist in advance, so that any pertinent records from your office are available when the orthodontist sees the child

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{{PAGE_19}} feedback from the orthodontist to you as to what he or she is recommending, and why

Referral Interactions

How Do You Manage the Referral?

If you’re not in orthodontic practice, you will have orthodontists as colleagues in the local dental community and will develop a personal relationship with at least some of them.

The style of referral will vary depending on that personal relationships, but three things need to happen:

A discussion between you and the parents as to why and to whom you are making the referral
Communication with the orthodontist in advance, so that any pertinent records from your office are available when the orthodontist sees the child
Feedback from the orthodontist to you as to what he or she is recommending, and why

Before seeing the child for the first time, the orthodontist would like to know from you:

Whether there are special problems with this child/family (including the social setting)
Whether there have been any problems with other dental treatment, especially problems that might affect future orthodontic treatment
Whether you have taken radiographs recently that would be useful during the orthodontic evaluation. If so, of course, copies of those radiographs are needed and should be sent in advance if possible.

What Does the Orthodontist Want From You?

Before seeing the child for the first time, the orthodontist would like to know from you:

whether there are special problems with this child / family (including the social setting)
whether there have been any problems with other dental treatment, especially problems that might affect future orthodontic treatment
whether you have taken radiographs recently that would be useful during the orthodontic evaluation.

Your recent panoramic radiograph would be quite useful, and probably would be used instead of taking another one at the orthodontic office. Previous pans also would be useful, and so would periapical radiographs taken to evaluate possible eruption problems or pathology. Copies of those radiographs should be sent in advance if possible. In the modern world, attaching digital radiographs to an email message makes this quick and easy.

Initial Report from the Orthodontist

What should you expect as feedback from the initial visits to the orthodontist? Three things:

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A report of the findings from the patient’s evaluation and the recommendations for treatment or recall in the specialty practice. This typically goes to both the referring dentist and the parents.
Suggestions for related treatment that you should perform (for example, the removal of primary teeth, placement of a lingual arch to maintain space, etc.).
Copies of radiographs made as part of the orthodontic evaluation that would be useful in your practice (for example, the panoramic radiograph that would be needed if primary teeth are to be removed early).

The report from the orthodontist can be as detailed—or as short and to the point—as the two of you prefer, so long as the above goals are met. It is easy now to include prints of digital photographs in correspondence or as email attachments. Some dentists find this helpful. Others see it as a waste of time and space in charts.

A typical letter to the referring dentist after the orthodontist’s initial evaluation of the patient (taken from the private practice of a UNC faculty member) is shown in images 1 and 2, with the sections of the single page blown up for easier reading.

After a treatment plan is established, it is shared with the referring dentist (images 3-5).

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{{PAGE_21}} Initial feedback letter from orthodontist, top. Initial feedback letter, continued. Treatment plan report. Treatment plan report, top section. Treatment plan report, cont.: Treatment plan report, cont.

David M. Sarver, D.M.D., M.S.P.C. 1705 Vestavia Parkway Birmingham, Alabama 35243 Phone: 205-979-3072 Fax: 205-979-7160 Email: Sarved@juno.com Diplomate - American Board of Orthodontics Practice Limited to Orthodontics

January 8, 2003

Dr. Richard Morgan 2512-D Rocky Ridge Road Vestavia Hills AL 35243

RE: Blayne Ferrell

Dear Dr. Morgan

We have seen Blayne today for an initial orthodontic screening. A summary of our initial findings and recommendations are as follows:

Chief Complaint Frontal Facial at Rest and on Smile

Lip incompetence of 1 mm
Smile arc is flat
Alveolar width is wide.

Profile

Dental Relationships Tooth size discrepancy 1 mm overjet. Mandibular crowding.

Temporomandibular Joints No Deviation on opening

Panoramic Findings No abnormalities were seen on the panoramic film.

Periodontal Evaluation High MX frenum attachment

Recommendations We would like to closes spaces, extrude anterior teeth for more incisor display and improved smile arc.

David M. Sarver, D.M.D., M.S. 1705 Vestavia Parkway Birmingham, AL 35243 205-979-3072

Patient: Blayne Ferrell Dentist: Dr. Richard Morgan

January 9, 2003

ORTHODONTIC TREATMENT PLAN

GOALS OF TREATMENT To eliminate spacing. To correct malpositions and rotations of teeth. To establish proper tooth relations and occlusion. To correct or improve skeletal discrepancy.

TREATMENT PHASE, TYPE/LENGTH OF TREATMENT Estimated time of comprehensive treatment phase is 24 months.

SEQUENCE OF TREATMENT Place fixed appliances. Use archwire. Use class II elastics.

ORTHODONTIC PLAN Place Maxillary and Mandibular fixed appliances. Level and align, progressing to .018 archwires. Close mandibular space with class II elastics. Upper Hawley Lower Fixed Retainer

EXTRactions

SURGICAL OPTIONS

TREATMENT OPTIONS, POTENTIAL PROBLEMS AND LIMITATIONS Headgear may be required. Frenectomy required.

SUMMARY OF CONSULTATION Patient has accepted treatment. Patient has scheduled to begin treatment.

While Blayne has a Class II malocclusion, it is primarily a dental problem rather than a skeletal pattern problem. Therefore, we will retract the upper cusps into the spacing distal to the 7s. Blayne has 80% of incisor display on smile, so retraction of the upper incisors will be designed to rotate the cusp down and back, thus increasing incisor display at rest and on smile. The maxillary frenum is a bit high, and after passive eruption is complete, we can assess whether the frenectomy is indicated.

David M. Sarver, D.M.D., M.S. 1705 Vestavia Parkway Birmingham, AL 35243 205-979-3072

Patient: Blayne Ferrell Dentist: Dr. Richard Morgan

January 9, 2003

ORTHODONTIC TREATMENT PLAN

GOALS OF TREATMENT To eliminate spacing. To correct malpositions and rotations of teeth. To establish proper tooth relations and occlusion. To correct or improve skeletal discrepancy.

TREATMENT PHASE, TYPE/LENGTH OF TREATMENT Estimated time of comprehensive treatment phase is 24 months.

SEQUENCE OF TREATMENT Place fixed appliances. Use archwire. Use class II elastics.

ORTHODONTIC PLAN Place Maxillary and Mandibular fixed appliances. Level and align, progressing to .018 archwires. Close mandibular space with class II elastics. Upper Hawley Lower Fixed Retainer

EXTRactions

SURGICAL OPTIONS

TREATMENT OPTIONS, POTENTIAL PROBLEMS AND LIMITATIONS Headgear may be required. Frenectomy required.

SUMMARY OF CONSULTATION Patient has accepted treatment. Patient has scheduled to begin treatment.

{{PAGE_22}} Reports from the Orthodontist (cont.) What should you expect from the orthodontist while the child is in orthodontic treatment? At least two things:

An emphasis by the orthodontist on regular visits to your office for prevention/control of dental disease
Copies of radiographs or other records that would be useful in your practice, which often will be received with a request to carry out specific treatment procedures

A typical letter reporting progress in treatment and requesting that you see the patient for a specific procedure might look like images 1 and 2. Note that a copy of the orthodontist’s current panoramic radiograph is attached.

Increasingly, instead of a formal letter, communication is in the form of an e-mail message with images attached (images 3 and 4)—which has the advantage of getting the information from one office to another instantly and provides it in digital form that makes it easy to add both text and images to a digital chart.

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{{PAGE_23}} UNC DENTISTRY DEPARTMENT OF ORTHODONTICS

Dr. Robert J. Miller 254 Treewview Lane, #20 Cary, NC 27513

Re: Stephen Jones

Dear Rob:

I have just completed slow maxillary expansion for Stephen to correct his posterior crossbite. He still has significant maxillary deficiency, but the skeletal correction obtained with reverse pull headgear to bring his maxilla forward is being maintained reasonably well. I plan to place a partial fixed appliance on his upper arch in the near future, to reposition the upper incisors and make room for the maxillary canines to erupt.

At this point, I would appreciate it if you would see him to extract the maxillary right and left second primary molars. The right one would probably be lost spontaneously in the near future, but the left side is retreating more slowly, and we need the space to help get the canines into the arch. Our current panoramic radiograph is enclosed.

It is still possible that he will have enough mandibular growth during the adolescent growth spurt that orthognathic surgery ultimately will be required. To this point, however, Stephen has responded well to the treatment he has received. I plan to continue to treat him conservatively, keeping open the options of orthodontics-only treatment.

Thanks for your help and I’ll keep you posted on his progress.

Sincerely yours,

[Signature]

William R. Proffit, DDS, PhD Kenan Professor

cc: Mrs. Jones Chart 0004-7523

School of Dentistry, The University of North Carolina at Chapel Hill, Campus Box 7460, Chapel Hill, NC 27599-7460, USA Phone: (919) 966-6420 • Fax: (919) 966-8064 • Web: http://orthodontics.unc.edu/

UNC DENTISTRY DEPARTMENT OF ORTHODONTICS

Dr. Robert J. Miller 254 Treewview Lane, #20 Cary, NC 27513

Re: Stephen Jones

April 30, 2001

Dear Rob:

Image 2, blow-up of top: Blow-up of top part of letter, for easier reading.

Thanks for your help and I’ll keep you posted on his progress.

Sincerely yours,

[Signature]

William R. Proffit, DDS, PhD Kenan Professor

cc: Mrs. Jones Chart 0004-7523

Image 3, blow-up of bottom: Blow-up of bottom of letter, for easier reading.

What Does the Orthodontist Expect from You? What does the orthodontist expect from you during active orthodontic treatment? At least three things:

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{{PAGE_24}} Regular recalls in your office to monitor the patient’s health status Treatment as needed for any nonorthodontic problems (for instance, placement of sealants in deep occlusal grooves of second molars as they erupt) Communication about who is to do what. For example, if a fluoride rinse or chlorhexidine application to control decalcification is needed, there should be no doubt about who is providing it and supervising its effectiveness.

Coordination of Orthodontic and Other Dental Treatment

Treatment Coordination for Children: Caries/Decalcification When a child is under orthodontic treatment, three aspects of treatment coordination between the family practitioner and orthodontist require special attention.

1. Control of Caries and Decalcification The orthodontist tells children and parents, “Braces don’t cause tooth decay, but all the stuff that can collect around the braces can cause it. So you have to keep your teeth really clean.” A child should have topical fluoride application before treatment begins and should have regular recalls in the family practice or pediatric practice while under treatment, to monitor oral health. When decalcification is a problem, the family practitioner or pediatric dentist can play an important role in reinforcing the importance of good oral hygiene. He or she also may wish to coordinate the use of additional caries control measures like chlorhexidine or fluoride varnishes. If decalcification is noted (image 1), control measures like fluoride varnish are indicated (image 2).

Treatment Coordination for Children: Extractions

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{{PAGE_25}} Aspects of treatment coordination between the family practitioner and orthodontist that require special attention:

2. Timing and Management of Necessary Tooth Extractions Extraction of retained primary teeth often is required, and the family practitioner or pediatric dentist should expect to be asked to do this for many child patients. A specific extraction order would be sent, along with recent radiographs (typically, panoramic radiograph).

If permanent teeth are extracted for orthodontic reasons, it is important to place appliances and begin controlled space closure soon thereafter. An exception is the removal of premolars so that canines can erupt in severely crowded mouths. Unless a tooth is erupting in an area of the alveolar process, or one is being moved into that area, bone loss begins quite rapidly, so when extraction spaces are to be closed, it is important to start moving teeth with minimal delay to minimize the loss of alveolar bone.

The general guideline is that the orthodontist will need to see the patient for treatment not more than a month after extraction of permanent teeth or primary teeth with no permanent successor. Beginning the active orthodontics sooner than that is ideal.

Image 1, pre-tx: Severely crowded lower arch, 1st premolars to be extracted to provide space for canines.

Image 2, start tx: Three weeks later, during the optimum time period to start treatment: orthodontic appliance in place and tooth movement beginning.

Treatment Coordination for Children: Retainers and Restorations Aspects of treatment coordination between the family practitioner and orthodontist that require special attention:

3. Retainers and Restorations When active orthodontics is completed, retainers are required routinely. Restorations of any type are likely to change the contour of the teeth, and then retainers may not fit.

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{{PAGE_26}} A particular problem exists when a missing tooth is replaced temporarily with a tooth on a removable retainer. This girl had congenitally missing maxillary laterals; space was opened for prosthetic replacements, and when the braces were removed at age 14, she had a retainer with replacement teeth initially. After 4 months, temporary bonded bridges were placed, and a new retainer without teeth (to be worn just at night) was made immediately. It would not be good judgment for her to wear a retainer with replacement teeth all the time for several years, waiting for the end of vertical growth so that implants could be placed.

With this or other types of posttreatment restorations, appointments must be coordinated so that impressions for the new retainer are taken immediately. Either the child goes directly to the orthodontist after the restorations are placed, or the restorative dentist takes the impression and sends it to the orthodontist for retainer design and fabrication. A delay of more than a few days can produce major problems.

Image 1, pre-tx: Age 12, prior to treatment to open space for prosthetic replacement of missing maxillary laterals. Image 2, bonded bridges: Age 14, 4 months after completion of active treatment, new bonded bridges in place, new retainer required immediately at that point.

Treatment Coordination for Adults: Retainers and Restorations

The same points in coordination that are important for children, for example, the timing of orthodontics when space is to be closed after extractions, also are important for adults. As in children, space closure in adults should start within the first month after the extractions, and earlier is better.

An important point in the treatment of adults is the timing of fixed restorative treatment after the orthodontics is completed. Although the orthodontist will make retainers at the time the braces are removed, bridges or crowns that provide permanent retention should be placed as soon as possible. Long delays in making the final restorations greatly increase the chance of problems, because teeth can drift if the patient does not wear removable retainers well or if a temporary fixed retainer is broken.

For this patient, both the maxillary left canine and mandibular left central incisor were extracted when she was a child because the dental arches were crowded—not a good approach to crowding

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{{PAGE_27}} problems. Oversized crowns on two lower incisors were not a satisfactory solution, and the space of the missing maxillary canine was partially open, with drift of the maxillary incisors The orthodontic plan was to open space so that the missing teeth could be replaced. The fixed bridges were placed within a few weeks after removal of the orthodontic appliances. Temporary removable retainers with prosthetic teeth should be replaced with the permanent retainers (bridges or implant- supported crowns) as soon as possible.

Image 1, pre-tx: Prior to treatment, after ill-advised extractions as a child.

Image 2, bridges in place: Bridges in place as permanent retainers.

Summary

In deciding whether a child has a problem that warrants consultation with an orthodontist, you must start with examining facial symmetry/proportions and jaw relationships. The simple rule: If it’s noticeably asymmetric or disproportional, or if the jaw relationships are improper, there’s a skeletal problem that should be evaluated. Then you can examine the dental alignment and occlusion. The more severe the malocclusion, the greater the chance that referring the patient to a specialist would be good judgment.

For treatment of skeletal Class II and vertical problems, the adolescent growth spurt is the best time for treatment. Remember that this may precede the eruption of the canines and premolars, especially in girls. A special indication for early treatment to modify growth is maxillary deficiency that produces a Class III malocclusion. Face mask treatment should start before age 8 if at all possible; Class III elastics to bone anchors should start at age 10/12 to 11, at the very beginning of adolescence.

Good communication in both directions is the key to good patient management when a patient from your practice goes to an orthodontist. It is important for the patient to have regular appointments in the referring dentist’s practice while undergoing orthodontics, to monitor oral health.

Coordinated treatment is needed in several situations:

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{{PAGE_28}} Caries/decalcification control. Guideline: Monitor carefully, use additional control measures if there are signs of problems. Extractions. Guideline: Orthodontic space closure should start within one month after the extractions are done. Retainers/restorations. Guideline: Posttreatment restorations should be done as soon as possible after the braces come off. Temporary retainers are used until the final restorations are completed. New retainers, typically then for part-time wear, should be made as soon as the final restorations are completed, because the previous ones won’t fit satisfactorily any more. For adults, fixed bridges and implant-supported crowns become an effective type of permanent retainer.

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 368-369, 652-660; 4th ed: pages 662-672). Then take the test, and use it as a guide for further study and review.

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{{PAGE_29}} 2. Meet Your New Young Patient

Background

Reading/Links

To get the most advantage of this program, it is highly recommended to have reviewed the following information:

Ackerman-Proffit classification: Computer Module, Level 2: Systematic Description of Malocclusion.

Interaction with orthodontists: Computer Module, Level 4: Interaction with Orthodontic Specialists.

Orthodontic diagnosis: The Development of a Problem List. Contemporary Orthodontics, 3rd ed., pp. 148-195.

Your Next Patient Is Here

After you enter dental practice, a common service to be rendered to the community where you will be practicing is to evaluate the orthodontic needs of a growing patient. Not far in the future, at your busy practice your assistant will be saying:

“Doctor, your next patient is here. She is an 11-year-old named Melissa, and her parents want to know if she needs orthodontic treatment” (video 1).

Orthodontic diagnosis requires a broad overview of the patient’s situation. The essence of the problem-oriented approach is the development of a comprehensive database of pertinent information so that no problems will be overlooked.

Let’s start developing the diagnostic database by going over to meet your new young patient (video 2). You can learn something about her general health and stage of maturity just by watching her walk into the clinic—and you should take the opportunity to do so.

: Patient coming to the dental clinic. https://proffit-instruction.netlify.app/Modules/youngpatient/video/entering.mp4

: Coming in and meeting the doctor. https://proffit-instruction.netlify.app/Modules/youngpatient/video/called.mp4

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Interview

Interview: Initial Questions

The first step in evaluating the patient is an interview with the patient and parent. The objective is to understand the patient’s overall situation and evaluate specific orthodontic concerns. The specific goals are to establish the

Patient’s chief complaint: why are they seeking consultation?
Medical and dental history
Physical growth status
Motivation, expectations, and other sociobehavioral factors

So let’s interview your patient and her mother (video).

Video https://proffit-instruction.netlify.app/Modules/youngpatient/video/waiting.mp4

Chief Complaint

The first step in the interview is to establish the patient’s chief complaint, the reason for seeking this consultation. This usually is done best by direct questions:

Tell me what bothers you about your face or your teeth?
Do you think you need braces? Why? (video 1)

It is important to remember that what the dentist thinks is the major problem may not be what the patient/parent are concerned about (video 2). The major reasons for orthodontic treatment, of course, are to overcome some combination of psychosocial concerns related to dental and facial appearance, concerns about dental/jaw function, and health concerns.

You need to know “where they’re coming from,” in the “why are they here?” sense of that phrase.

** : Video Clip 1, Melissa chief complaint.** https://proffit-instruction.netlify.app/Modules/youngpatient/video/complaint_chief.mp4

** : Video Clip 2, Mother chief complaint.** https://proffit-instruction.netlify.app/Modules/youngpatient/video/complaint_mother.mp4

Medical and Dental History

Young patients interested in orthodontic treatment, like your patient Melissa, often are healthy and have a noncontributory medical history (video). But on occasion positive findings in the medical history can have relevance to orthodontic treatment, as in the following:

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Allergy to metal, especially nickel allergy, can be important if the patient will need fixed orthodontic appliances.
Other allergies can affect growth and treatment response.
Patients with actual or potential heart problems, such as those related to a history of rheumatic fever, need antibiotic coverage during banding and debanding (but not for noninvasive orthodontic procedures like changing an arch wire).
Juvenile arthritis, if it affects the TM joints, can create severe growth problems—and involvement of the TM joints is likely in a child who has multiple affected joints, so this would be an immediate matter of concern in a child with any arthritic joints.
Some children with small stature are treated with growth hormone, which can have implications for growth modification possibilities and treatment timing.
Other medications can affect treatment, so all should be noted carefully.

Orofacial Trauma

“Have you ever injured your teeth, jaws, or face?” (video)

Your patient and mother are reporting a negative history of orofacial trauma, but remember that children frequently sustain injury to their primary and permanent teeth and to their jaws. Twenty-five percent of 17-year-olds in the United States are reported to have sustained some type of trauma to the teeth and face in the past.

Let’s review why orofacial trauma is important in relation to orthodontic treatment.

Trauma to the Teeth

First, think about trauma to the teeth. Why is a history of trauma to the teeth important?

Increased overjet with protrusion of maxillary incisors is a significant predisposing factor for trauma to the teeth. Note that the patient in image 1 traumatized her maxillary left central incisor in the past. That’s more likely if 10 mm of overjet is present, as for her. One reason for beginning orthodontic treatment early (in the mixed dentition), though not a major one for most patients, is to reduce the chance of injury to protruding incisors.
Previous trauma to the permanent incisors, even minor, can produce devitalization of the pulp of the injured tooth. The patient shown in image 2 has history of traumatic injuries in her incisors due to seizures. A negative pulp response was obtained from the maxillary right central incisor, and a periapical radiograph of her maxillary incisors reveals external root resorption, which of course would be exacerbated by orthodontic tooth movement.

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{{PAGE_32}} Severe displacement of the incisors can cause extensive damage to the periodontal ligament, and as that heals, ankylosis of the tooth is quite possible. Ankylosis (image 3) leads to gradual infraocclusion and arrested development of the alveolar process. Remember, an ankylosed tooth cannot be moved orthodontically. Often the best plan is to extract it before it drops well below the plane of the other teeth to minimize the size of the eventual alveolar defect in that area.

Image 1, increased overjet: Increased overjet with protrusion of incisors increases the chance of trauma to the protruding teeth. Image 2, nonvital pulp: A history of dental trauma also increases the chance of external root resorption that would preclude orthodontic tooth movement. Image 3, ankylosed incisor: Ankylosed permanent incisors due to previous trauma. As these teeth fail to erupt, an anterior open bite is developing.

Trauma to the Face and Jaws Why is a history of trauma to the face and jaws important? The condylar neck of the mandible in childhood is vulnerable when there is a blow to the face, and a fracture of this area can result in a growth deficit that causes facial asymmetry as the injured side lags behind. A condylar fracture often goes undiagnosed. Remember that this is the most likely cause of a mandibular asymmetry with deficient growth of one side, even if the child and family don’t remember the traumatic event.

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At age 5, the patient in images 1 and 2 suffered a subcondylar fracture of his left condyle in a car accident. Note in the panoramic radiograph that the condylar fragment is displaced. It will remodel and regenerate in most instances. A removable appliance was fabricated to reposition his mandible and guide jaw movement during healing, to maximize the chance of normal growth afterward.
When the mandible can’t translate after an injury (remember, the condyle must be able to move out of the fossa to grow), there’s a major growth problem. The patient in images 3 and 4 suffered a subcondylar fracture as an infant. The asymmetric and reduced growth noted at age 9 is severe enough to require early mandibular surgery to improve the skeletal problem.

Image 1, panoramic and frontal cephalometric radiograph, subcondylar: A subcondylar fracture on the left can be seen in the panoramic radiograph taken soon after the accident. Note the displacement of the fractured condyle.

Image 2, subcondylar fracture: Following the accident, a removable appliance was fabricated, to reposition his mandible and facilitate growth on the affected side.

Image 3, old fracture, asymmetric growth: Young patient with reduced mandibular growth as a result of early mandibular fracture and restriction of translation of the condyles. Early orthognathic surgery (at age 9) was indicated.

Image 4, old fracture, early mandibular advancement: Cephalometric radiographs before/after mandibular advancement at age 9. Additional surgery later probably will be required—subsequent normal growth cannot be expected.

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Physical Growth Status

The child’s physical growth status (where is he or she relative to the adolescent growth spurt?) is an important factor in determining the timing of orthodontic treatment. How do you evaluate that in an interview? The appropriate questions:

How rapidly have you grown recently? (video)
Have your clothes sizes changed?
(For girls) Have you reached menarche?

In addition, of course, you would look for signs of sexual maturation. Before sexual maturity, continuing growth of the face and jaws can be expected; after it, much less growth is anticipated.

Why is it important to evaluate physical growth status? Young patients, those who still have significant growth remaining, can be treated using growth modification. The patient in images 1 and 2 has a Class II malocclusion due to mandibular deficiency, and the patient in images 3 and 4 has a concave profile and a Class III malocclusion due primarily to a shift from centric relation to maximum intercuspation (if the Class III is mostly due to a shift, it’s called pseudo-Class III). For both, treatment during active growth offers the best possibility to correct the skeletal and dental discrepancy. The Class III patient needs treatment as soon as possible because the constant forward shift can displace erupting teeth and make the malocclusion worse. The Class II patient is best treated during the adolescent growth spurt and must be evaluated relative to his level of physical maturity rather than his dental age.

Video, Physical Growth Status https://proffit-instruction.netlify.app/Modules/youngpatient/video/growth.mp4

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{{PAGE_35}} Motivation, Expectations, and Compliance As the final step in the interview, it is important to explore two related but different factors: the motivation for treatment, and what the patient/parents expect as a result of treatment. Why? Because both relate strongly to cooperation with treatment and therefore to the chance of a successful treatment outcome.

Melissa shows genuine interest for treatment and demonstrates now that she understands a lot of what it is like to wear orthodontic appliances when she talks about her friends wearing braces (video). This suggests that she would cooperate with treatment.

Increased patient compliance has been associated with:

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{{PAGE_36}} more severe malocclusions and a greater desire to have treatment positive parental attitude regarding the value of effective orthodontics whether or not the child likes the dentist

The patients in images 1 and 2 really wanted treatment and were very motivated to use extraoral appliances like the face mask or headgear. The patient in image 2 had a personal diary in which she recorded the hours she wore her headgear.

Cooperation is likely to be much better if the child genuinely wants treatment, rather that just putting up with it to please a parent. Indifferent patients, of course, are not likely to cooperate, and occasionally a child overtly refuses to cooperate with treatment, often because it is being forced on him or her by the parents and becomes a focus of adolescent rebellion. Sometimes orthodontic treatment has to be delayed until the patient is ready to accept it.

Video, Motivations and Expectations https://proffit-instruction.netlify.app/Modules/youngpatient/video/motivation.mp4

Image 1, Face mask to treat maxillary deficiency: This young patient was very conscious of her facial appearance and was highly motivated to cooperate with reverse pull headgear (face mask) to bring her upper jaw and teeth forward.

Image 2, Headgear to treat skeletal Class II: This girl wanted her protruding teeth corrected and cooperated very well with headgear.

Summary of Interview So what did we learn about Melissa from the interview?

She and her parents think she needs orthodontic treatment, and their primary concern is the protrusive appearance of the teeth.
There’s nothing significant in the history—no history of trauma, no allergies/habits, no medications.

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{{PAGE_37}} She has obvious secondary sexual characteristics and reports recent growth, so she’s entering the adolescent growth spurt even though she’s only 11. Her expectations are realistic, and she appears to be motivated to be a cooperative patient. Now we are ready to perform the clinical exam.

Video https://proffit-instruction.netlify.app/Modules/youngpatient/video/complaint_mother.mp4

Clinical Evaluation

Step 1: Oral Health

In the clinical examination, look at the patient from general to particular (video, image 1). It’s a serious error to characterize the dental occlusion while overlooking a jaw discrepancy, developmental syndrome, periodontal problem, or systemic disease. It helps to have a mental checklist to avoid overlooking things. If you don’t see it, usually it’s because you are not looking for it.

This is the suggested checklist—look at these four things, in this order:

Oral health
Jaw function
Facial proportions
Dental relationships

For the prospective orthodontic patient, what are you looking for in the category of oral health? The same things you would be in any dental patient. Is there any oral pathology? What is the periodontal status? Is caries present? Are there missing teeth, tooth discoloration, enamel fractures, and or enamel defects?

Remember that even if the question is only whether the patient needs orthodontic treatment, any active disease or problem in the soft and hard tissues must be under control before any recommended orthodontic treatment can begin.

Video, clinical exam https://proffit-instruction.netlify.app/Modules/youngpatient/video/chair.mp4

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{{PAGE_38}} Step 2: Evaluation of Jaw Function and Habits

The key questions in evaluation of jaw function:

What is the maximum voluntary opening?
Normal lateral/forward movements?
TMJ sounds?
Tenderness on palpation?
History of pain and habits?

The answers should be recorded on an appropriate clinical form (image 1).

The most important single indicator of joint function is the amount of maximum opening (video 1). If any joint has reasonably normal motion, there is not a great deal wrong with it. If the mandible moves normally, the TM joint is unlikely to be significantly impaired.

It also is important to palpate the muscles of mastication and TM joints and to note any joint sounds or pain. In a patient with limitation of motion, looks for a scar in the chin as a sign of previous orofacial trauma that may have not have been thought to be important at the time.

Find out if the patient has any oral habits like thumb sucking (video 2) or nail biting or a forward posture of the tongue. Both can disturb the development of the orofacial complex.

{{PAGE_39}} 3. MASTICATORY AND FUNCTIONAL EXAM | Maximum Voluntary Opening: | 40 mm | Deviation: No | Yes | Pain: No | Yes | | Maximum Forced Opening: | 45 mm | Deviation: No | Yes | Pain: No | Yes | | Protrusion: | 7 mm | Rt Lateral: | 7 mm | Lt Lateral: | 7 mm | | Sounds: | No | Yes | If yes, | Rt Click | Lt Click | Crepitus | | Tenderness on Palpation: | No | Yes | If yes, where? | Temp | Mass | Lat Lig of TMJ | | History: | No | Yes | If yes, | Pain | Dysfunction | (Specify) _________________________

Step 3: Evaluation of Facial Proportions and Esthetics

A critically important step in the clinical examination is the evaluation of facial proportions and esthetics. The goal is to detect disproportions and asymmetries that are major contributors to facial esthetic problems. Start by looking at your patient in the frontal view to evaluate the transverse proportions (image 1). Remember that a small degree of bilateral asymmetry exists in essentially all normal individuals. One way to show this is by creating an image of what the face would look like with the right and left sides duplicated (image 2). This “normal asymmetry” should be distinguished from a chin or nose that deviates enough to produce an esthetic problem. The guideline is that a deviation of more than 3-4 mm is enough to be noticed and therefore potentially a problem.

The relationship of height to width establishes the overall facial type. Robin Williams (relatively wide) and Dustin Hoffman (relatively narrow) illustrate the different types within the normal range (image 3). The width of the dental arches, not surprisingly, is related to the width of the face.

The relationship of the midline of each dental arch to the facial midline also should be noted during the clinical examination (image 4). Melissa’s dental and skeletal midlines are exactly coincident. It’s not enough to just note whether the midline of the upper and lower arches coincide—you need to know how the dentition fits into the face.

It is important to note the relationship of the dentition to the lips when a patient smiles (video). A video clip of the patient’s smile rapidly is becoming a standard part of the diagnostic records for orthodontics, as it becomes easy to include video in the digital record file for the patient. Melissa’s smile exposes all of her upper incisors and some gingiva, which is normal at her age but makes the upper incisor protrusion quite apparent.

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Video, smile animation

https://proffit-instruction.netlify.app/Modules/youngpatient/video/smile.mp4

Image 1, Melissa, frontal view: Melissa, frontal view.

Image 2, Melissa, frontal facial composite views: Melissa, actual view (left) and composite faces with 2 right and 2 left sides (center, right) showing normal asymmetry.

Image 3, Facial types: Facial types: extremes of normal.

Image 4, Melissa, dental / skeletal midlines: Melissa, dental / skeletal midlines.

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{{PAGE_41}} Evaluation of Facial Proportions and Esthetics (cont’d.)

The next step in examining facial proportions is to look at your patient from the profile view. The goal now is to evaluate the anteroposterior jaw relationship, the vertical jaw relationship, and the lip prominence.

Let’s start by evaluating the relative prominence of the mandible to the maxilla. Put the patient in natural head position (relaxed, looking into the distance) (image 1). Then visualize where the maxilla is positioned in relation to the forehead. Normally we would see it slightly in front. Now what about the mandible? Locate the most anterior point of the chin and see how it relates to the forehead and the maxilla. Melissa’s chin is behind that line, so she has moderate mandibular deficiency. That’s why her profile is convex (image 2).

Another important aspect is the prominence of the lips and their relationship to each other (image 3). Note that Melissa’s lower lip is behind a line from the nose to the chin and well related to her chin (only slightly forward from the chin). So she doesn’t have protrusion of her lower teeth relative to the mandible that compensates for the skeletal mandibular deficiency.

Last but not least, look at the vertical proportions of her face. The easiest way to do this is to check to see if the facial thirds are proportional. The distances from the hairline to the bridge of the nose, bridge of nose to base of nose, and base of nose to chin should be very close to the same. Do you see any disproportions?

It also helps to visualize the mandibular plane (image 3) and relate it to the true vertical line. If the lower face is long, the mandibular plane angle usually is steep—so if you see a high mandibular plane angle, you should look again at lower face height. For Melissa, both the facial thirds and mandibular plane angle appear to be close to normal.

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{{PAGE_42}} Image 1, Profile convex: Profile evaluation in natural head position Image 2, Lip posture: Lip position in reference to natural head position

<table border="1" cellpadding="8" cellspacing="0">
	<tr>
		<td><i>Image 3, Vertical thirds: Vertical thirds proportion and mandibular plane inclination</i></td>
		<td></td>
	</tr>
</table>
 
<h2>Step 4: Evaluation of Crowding/Alignment</h2>
<p>Now evaluate the dental relationships, starting with the alignment of the teeth and the amount of space within each dental arch (image 1). At a quick look you can estimate the amount of crowding present. Is it mild (&lt;2 mm), moderate (2-4 mm), or severe (&gt;4 mm)? Look carefully at Melissa’s mandibular arch, where are the permanent canines related to the first primary molars? . . . No first primary molars present! space between canines and second primary molars nearly closed! So it looks as if at least moderate, probably severe crowding is likely. In the maxillary arch, in contrast, even though the incisors are somewhat crowded, it looks as if there should be enough (or nearly enough) room for the permanent teeth.</p>
<p>Mixed dentition space analysis at this point would quantify the space available for the permanent teeth. To interpret it, remember that you have to look again at the profile and evaluate lip protrusion (image 2). Is there excessive separation of her lips at rest? Is there any strain in bringing her lips together? How prominent are the lips relative to nasolabial and mentolabial concavities?</p>
<p>Since Melissa’s upper lip is a little protrusive, space analysis might understate her upper arch crowding. The lower lip isn’t at all protrusive relative to the chin, perhaps is a little retrusive, so crowding in the lower arch is fully expressed or even a little overstated by space analysis.</p>
<p>The bottom line: She’s short of space in both arches, and some of the potential crowding in the upper arch is concealed by protrusion of the upper incisors.</p>
 
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{{PAGE_44}} Image 1, occlusal views: Melissa, mild maxillary, moderate to severe mandibular crowding. Image 2, profile: Melissa, profile: reasonably normal lip prominence, mandibular deficiency.

Evaluation of Occlusion

Then (image 1) look at the occlusal relationships in the three planes of space:

transverse (posterior crossbites),
anteroposterior (overjet, molar and canine relationships), and
vertical (overbite or open bite).

The objectives are to accurately describe the occlusion and then distinguish between skeletal and dental contributions to malocclusion.

Melissa has no posterior crossbite, so the transverse relationships are acceptable. She has 8 mm overjet, well above the normal 1-3 mm. Her overbite is 1-2 mm, normal. Her molars are Class I, but the canines are nearly Class II.

In her case the Class I molar relation was created by the mesial drift of her mandibular molars after premature loss of the first primary molars (image 2). Reference to her profile (image 3) confirms mandibular deficiency, so this is a skeletal Class II problem.

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{{PAGE_45}} Image 1, occlusal views: Melissa, 8 mm overjet and 2 mm overbite, Class I molars but Class II canines. Image 2, posterior drift: Mesial drift of molars after early loss of mandibular primary first molar. Image 3, profile: Melissa, profile: lack of chin prominence = mandibular deficiency.

{{PAGE_46}} Give Your Recommendations

Which Diagnostic Records Are Needed?

After interviewing your patient and performing the clinical evaluation, you should be thinking about whether any diagnostic records are needed to provide more information before you give your recommendations about orthodontic treatment.

For this patient, which diagnostic records do you really need to provide an opinion? 1. No further records needed 2. Panoramic radiograph ✓ 3. Cephalometric radiograph 4. Dental casts plus radiographs

Correct That is correct, you need a panoramic radiograph. In the mixed dentition, a panoramic radiograph is the screening tool to evaluate pathology (for an orthodontic opinion, especially missing teeth and supernumerary teeth) and gain further insight into the timing of treatment.

Incorrect No, that’s incorrect. You really need, and should obtain, a panoramic radiograph to offer an informed opinion. In the mixed dentition, a panoramic radiograph is the screening tool to evaluate pathology (for an orthodontic opinion, especially missing teeth and supernumerary teeth) and gain further insight into the timing of treatment. The other records would be part of the complete set of records needed to plan orthodontic treatment but aren’t needed to give the parents a recommendation about treatment.

Which Diagnostic Records Are Needed? (cont’d.)

Let’s review Melissa’s panoramic radiograph. She doesn’t have any pathologies, missing teeth, or supernumerary teeth. Look where the unerupted teeth are, and think further about whether there is enough space for them. The crowding in the lower arch looks pretty severe, doesn’t it?

How long will it be before the second premolars would be ready to erupt? You’d judge that by the amount of root development: They’re about a year away, given that they have half or less of their root formation, and normally would erupt when 2/3 of the root is formed.

Using the panoramic radiograph as a visual aid to explain space problems to the parents is an excellent way to help them understand. It doesn’t require a lot of training to see that space for the second premolars just isn’t going to be there.

Orthodontic Problems?

From your findings during the interview and the clinical evaluation, which of the following need to be discussed with Melissa and her parents? a. Melissa’s concerns about her teeth and appearance

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{{PAGE_47}} b. Facial proportions and esthetics c. Alignment and space d. Dental relationships e. Radiographic findings 1. a, c, and e 2. b, c, and d 3. b, d, and e 4. a, b, c, e 5. all of the above ✓

Correct That’s right, your findings relative to all these areas should be discussed.

Incorrect No, that’s incorrect. Your findings relative to all these areas should be discussed.

Orthodontic Problems? (cont’d.)

What should you tell them about each area?

Melissa’s concerns are appropriate: The protrusive appearance of her front teeth can cause problems in social interactions.
One reason that her upper teeth appear protrusive is a problem with the growth of her lower jaw. It hasn’t grown forward as much as it should.
The crowding in the lower arch is worse than it appears clinically. This needs to be explained to the parents with the aid of the panorex, showing the lack of space for the succedaneous teeth.
All the upper teeth are too far forward relative to the lower teeth. This is part of the reason that she will need braces on all her teeth, not just the protruding front ones.
Melissa has a healthy mouth, which is necessary before you can have orthodontic treatment, so she is in good shape to go ahead with treatment if she wants it.

To Refer or Not To Refer?

Would you refer Melissa to an orthodontist? 1. Yes ✓ 2. No

Correct That’s correct, referring Melissa to an orthodontist is recommended.

Incorrect No, that’s probably not good professional judgment. She certainly is a candidate for orthodontics, and her problems are severe enough to require extensive and prolonged treatment. Referring Melissa to an orthodontist is recommended.

To Refer or Not To Refer? (cont’d.)

Melissa is a candidate for orthodontics for three reasons:

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the skeletal component of her Class II malocclusion,
the severity of the crowding, which is at least borderline for extraction, and
the excessive lip support in the upper arch, decreased lip support in the lower arch, and lip incompetence (lip separation at rest). She will need comprehensive treatment with a complete fixed orthodontic appliance.

When Would You Refer Her?

When would you refer her? 1. Now ✓ 2. When menarche makes it definite that she is in the adolescent growth spurt 3. In another 12 months or so, when the premolars erupt 4. Between ages 12 and 13, depending on her level of maturity

{{PAGE_49}} evaluation 3. That she has a Class II crowded malocclusion 4. No referral letter with information is needed, the orthodontist will find out all the information

Correct That is correct. Before seeing the child for the first time, there are a few things the orthodontist would like to know from you.

Incorrect No, that is incorrect. All the things you discussed with the parent are things you should share with the orthodontist.

Referral Letter (cont’d.) Before seeing the child for the first time, the orthodontist would like to know from you:

Anything useful about the child/parent’s expectations, social setting, etc.
What the orthodontic problems appear to be.
Whether you have taken radiographs recently that would be useful during the orthodontic evaluation. If so, of course, copies of those radiographs are needed and should be sent in advance if possible.
Your recommendations for treatment or recall in your practice. For Melissa, an appropriate referral letter might look like the one in the attached images, which show the sections of the letter (separated for greater enlargement and easier reading on the screen).

What Treatment Do You Expect? What treatment do you expect the orthodontist to suggest? a. No treatment at this time, he or she will wait for all the teeth to erupt b. Orthodontic treatment soon using headgear or a functional appliance growth modification c. Comprehensive orthodontic treatment with possible extractions when the permanent teeth erupt d. Orthognathic surgery in the future 1. a and c 2. b and c ✓ 3. b and d 4. a and d 5. b, c, and d

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{{PAGE_50}} Correct That is correct. Because of her skeletal maturity relative to the eruption of the permanent teeth, growth modification treatment in the mixed dentition will be indicated in the near future. That could be either headgear to the maxillary arch or a functional appliance. It may be desirable to use a partial fixed appliance in the mixed dentition to reposition and align the incisors. If so, headgear might be the choice—and in fact, for Melissa it was (image 1).

After the permanent teeth are available, a second phase of comprehensive treatment to deal with the alignment/space problems definitely will be needed. Orthognathic surgery, however, is not needed for a patient with moderately severe problems like Melissa’s.

Incorrect No, that’s incorrect. Because of her skeletal maturity relative to the eruption of the permanent teeth, growth modification treatment in the mixed dentition will be indicated in the near future. That could be either headgear to the maxillary arch or a functional appliance. It may be desirable to use a partial fixed appliance in the mixed dentition to reposition and align the incisors. If so, headgear might be the choice—and in fact, for Melissa it was (image 1).

Length of Treatment How long do you think Melissa’s orthodontic treatment will take? That’s almost surely something the parents will ask you, so you need to have an answer—what will you tell them? 1. Less than 12 months 2. 12-15 months 3. 15-24 months 4. More than 24 months ✓

Correct That is correct, treatment for Melissa almost surely will take more than 2 years. The first phase of treatment, still in the mixed dentition, needs to start now, but the second phase of treatment can’t start until the remaining permanent teeth erupt. That won’t be for at least a year (image), and phase 2 will take more than a year, so the total will be greater than 24 months.

Incorrect No, that’s wrong. Treatment for Melissa almost surely will take more than 2 years. The first phase of treatment, still in the mixed dentition, needs to start now, but the second phase of treatment can’t start until the remaining permanent teeth erupt. That won’t be for at least a year (image), and phase 2 will take more than a year, so the total will be greater than 24 months.

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{{PAGE_51}} Feedback from the Orthodontist What feedback do you expect the orthodontist to provide after he or she sees Melissa? a. acknowledgment of the referral and thanks for it b. summary of problems c. recommendations for treatment d. copies of photographs e. copies of cephalometric radiographs 1. all the above 2. a, b, c, d 3. a, b, c ✓ 4. only what I have asked for

Correct That is correct. Let’s look at the specifics of what to expect from the referral.

Incorrect No, that’s incorrect. Let’s look at the specifics of what to expect from the referral.

Feedback from the Orthodontist (cont’d.) You should expect a letter acknowledging the referral, with a summary of the patient’s problems and the orthodontist’s recommendations for treatment. A copy of that letter, or one in simpler language providing the same information, goes to the parents. If the orthodontist took panoramic, bitewing, or periapical radiographs, you also should expect to receive copies of those.

You may or may not get copies of photographs, depending on whether you have told the orthodontist you want them. Unless you specifically request them, you won’t get copies of the cephalometric radiographs, simply because they are of minimal use in family practice—but you can have them if you want them.

A typical feedback letter is shown in the attached images (with the parts separated for greater enlargement on the computer screen).

Melissa’s Recall Schedule While Melissa is in orthodontic treatment, on what schedule will you recall her for evaluation in your office? 1. No need to see her during orthodontic treatment 2. When the orthodontist indicates it 3. Every 10-12 weeks 4. Normal 6- or 12-month recall schedule as with any other young patient ✓

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{{PAGE_52}} Correct That’s correct. Melissa needs to be seen in a normal recall schedule like any of your other regular patients, to check for the development of caries or other problems, and to reinforce the importance of oral hygiene during orthodontic appliance wear (image).

If hygiene becomes a particular problem, the orthodontist may ask for your help, and then Melissa might need to be seen in your office more often. Other special problems—which Melissa does not have at this point—also could be the reason for a modified recall schedule when one of your patients is in orthodontic treatment.

Incorrect That is incorrect. Melissa needs to be seen in a normal recall schedule like any of your other regular patients, to check for the development of caries or other problems, and to reinforce the importance of oral hygiene during orthodontic appliance wear (image).

Summary Yes indeed. It will happen: In the near future you’ll be asked to look at a friend’s child or patient’s child to offer an opinion as to whether orthodontics is needed.

To answer such questions, you need to

analyze the patient’s problems,
decide whether orthodontic treatment is needed, and
apply the triage method based on problem severity to make the decision as to whether a child has a problem that warrants consultation with an orthodontist.

Specifically, you need to

interview the parent and patient, asking about their concerns, the medical/dental history, and growth status;
perform a clinical exam with emphasis on facial symmetry/proportions and jaw relationships, then the dental alignment and occlusion; and
obtain a panoramic radiograph in most circumstances, so that you can evaluate pathology, anomalies in eruption dental development, missing teeth, and supernumerary teeth.

Good communication in both directions is the key to good patient management when a patient from your practice goes to an orthodontist. It is important for the patient to have regular appointments with the primary dental health provider while undergoing orthodontics, to monitor oral health.

3. Accelerated Tooth Movement

Principles of Orthodontic Tooth Movement

Objectives

From a broad perspective, there are two ways to speed up orthodontic tooth movement: (1) improve the engineering of orthodontic materials and appliances, so that orthodontic force is delivered more efficiently, and (2) modify the underlying biology of tooth movement, which has the potential both to delay and accelerate it—so you would want to be sure the modification was on the acceleration side.

Faster treatment with better orthodontic appliances was the “hot topic” in recent years for the companies that manufacture brackets, wires and other supplies. New materials, especially brackets, were marketed aggressively as making treatment faster and easier, unfortunately with claims that were well beyond reality. Dentists, and the orthodontists with whom they work, have no choice but to critically evaluate new materials and appliances—a subject that we covered in an earlier module in this course and will review now.

Modification of the biology of tooth movement now is becoming the hot topic, again with aggressive marketing of new methods and devices to produce faster tooth movement. It is difficult to evaluate things that you don’t understand. The objectives of this module are to:

Review and clarify the principles of conventional tooth movement
Review changes in orthodontic appliances that can contribute to faster tooth movement
Discuss the possible ways to accelerate tooth movement by changing the biologic response
Provide information as to currently marked treatment modalities, drugs and devices to accelerate or, in some instances, decrease the rate of tooth movement.

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{{PAGE_54}} Objectives of this Module: Review, evaluate and put into perspective:

Principles of tooth movement
Changes in orthodontic appliances to produce faster tooth movement
Changing the biologic response to produce faster (or slower) tooth movement
Currently promoted methods to alter the speed of tooth movement

Sequence of Events in Tooth Movement (light force) Tooth movement is primarily a periodontal ligament (PDL) phenomenon, in the sense that the bone remodeling necessary to allow tooth movement is created by sustained pressure that compresses the PDL in some areas while stretching it in others. By now you should be familiar with the sequence of events when a spring that delivers light force is activated to remove a tooth:

immediately, the alveolar bone bends and a short-acting piezo-electric signal is created
in 1-2 seconds, the bone springs back (one more piezo-electric signal) (Figure 1) and the PDL is compressed on the side opposite to the spring and stretched on the side adjacent to it. After that, piezo-electric signals are inhibited. They are not part of the process that leads to tooth movement.
in 3-5 seconds, changes in pressure and tension in affected areas of the PDL alter blood flow, and cells and fibers are mechanically distorted
within a minute or so (Figure 2) blood flow decreases in the compressed area and increases in the stretched area
chemical signals, especially prostaglandins and cytokines, are released from mechanically distorted cells in both areas
in about 4 hours, secondary messengers (m-RNA) appear as differentiation of monocytes into osteoclasts (on the compressed side) and osteoblasts (on the stretched side) begins within the PDL (Figure 3)
within 2-3 days, remodeling of the alveolar bone adjacent to the tooth begins

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{{PAGE_55}} over the next days (how many days depends on how quickly the force from the spring declines as the tooth moves), the tooth moves at a rate of about 1 mm/month

Image 1 Bioelectricity: Bone Health and Tooth Movement Tooth Displacement in Function → Bone Bending → Piezo-electric Signal Current Flow Bend Relax

Image 2 PDL Compression/Tension: The Cascade of Events < 1 Sec PDL fluid incompressible, alveolar bone bends, piezo- electric signal 1-2 Sec PDL fluid expressed, tooth moves within PDL space (bone springs back) 3-5 Sec Pressure/tension affects blood flow; cells/fibers mechanically distorted Minutes Blood flow altered, O2/CO2 tension change; prostaglandins, cytokines released

Image 3 PDL Compression/Tension: The Cascade of Events If the pressure is light: Minutes Blood flow, O2/CO2 tensions change; cellular activity affected, prostaglandin, cytokines released ~4 hrs Chemical messengers affect cell activity, enzyme levels increase

Sequence of Events (heavy force) If the force is heavy enough to totally cut off blood flow in the compressed area, the sequence changes after the first few seconds:

within 30-60 seconds, blood flow stops in the compressed area (the increase in the stretched area is about the same as with light force)
within an hour or so, cell death is occurring in the compressed area, so there are no viable cells to respond to the prostaglandins and cytokines that were released, no secondary messengers appear in that area and there is no cell differentiation to produce osteoclasts and osteoblasts
over the next days, viable cells in the PDL adjacent to the necrotic area are stimulated by initial messengers that diffuse from the necrotic area and remodeling begins at the edge of the necrotic area, but osteoclast differentiation in the bone marrow beside the necrotic area requires diffusion

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{{PAGE_56}} of chemical signals all the way through the lamina dura of the adjacent bone, which can take a 5-7 days

eventually, osteoclast differentiation in the bone marrow leads an attack on the underside of the lamina dura, and tooth movement begins 10-14 days after the heavy pressure was applied. Perhaps this would be a good time to go back to Level III, Module 3 and look at the text and figures there, which present this material in greater detail.

PDL Compression/Tension: The Cascade of Events

If the pressure is heavy: Minutes Blood flow is cut off in compressed regions, cell death begins ~2 Days Cell differentiation in adjacent PDL no cells left in the compressed area 5-7 Days Cell differentiation in adjacent PDL ~10 Days Undermining resorption complete, tooth movement begins

Importance of Force Magnitude It is obvious that light force for tooth movement is more physiologic and more desirable. Unfortunately, it is very difficult—in fact, almost impossible—to prevent the development of at least some small necrotic areas in the PDL even when light force is used. If that is true, is the magnitude of the force really important?

The answer is yes, for two reasons: (1) the amount of pain associated with tooth movement is linked to the size of the necrotic areas, and the heavier the force, the larger the area of necrosis; (2) heavy force becomes a greater stress on the anchor teeth that shouldn’t move. So using heavy force both increases the amount of pain and makes it harder to control the tooth movement. You have already seen the graph below in the context of controlling anchorage—but you need to remember its importance in determining the amount of tooth movement.

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Orthodontic Mechanics as a Factor in the Rate of Tooth Movement

Importance of Force Duration

In Level III, you have already seen that the amount of tooth movement will be a function of how quickly the force from a spring declines as tooth movement occurs. Let’s review that concept. What does it mean, exactly?

There is no such thing as a perfect spring—the force any spring delivers will decline as the tooth moves and the stretch or compression of the spring changes. You have seen the graphs below before. Now look at them again as you think about force duration as a factor in the speed of tooth movement.

If there were a perfect spring, the force it delivered would not change as tooth movement occurred (the dashed green line in Figure 1). A good spring would show some reduction in force as a tooth moved, but would still produce a continuous force the force that would not decline to zero between activations. If a poorer spring produced no force soon after it was activated (Figure 2), this would be described as interrupted force. And if the force was produced by a removable appliance (remember, any appliance that can be removed will be) (Figure 3), the force would be described as intermittent. Light continuous force, not surprisingly, produces the fastest tooth movement.

Sequence of Orthodontic Appointments: Repair Time

In clinical practice, orthodontic patients usually are seen no more frequently than once a month. Why? Couldn’t you move teeth faster if you saw them every two weeks to re-activate springs and archwires? In fact, you probably could move teeth faster with more frequent appointments, but that would not be good judgment. At least a few necrotic areas in the PDL are almost inevitable, so it is prudent to give enough time for repair of injured and inflamed areas.

The importance of doing that is magnified by the fact that it’s not just adjacent alveolar bone that’s being remodeled. Cementum on the tooth root adjacent to a necrotic PDL area also is marked in some way, so that it is attacked by the clast cells that are part of the remodeling process. Cementum, like alveolar bone, is repaired as part of the remodeling process, so there’s no permanent damage to the side of the root unless repair is inhibited—but you would not want to apply new force that would do just that until the repair process is complete.

The attached figure, from human autopsy material, is a coronal section through the root of a premolar that is being moved to the left. Remodeling of alveolar bone can be seen on both sides. Note the areas of root resorption on the left side of the root that will be repaired by later deposition of cementum. In some places, resorption has penetrated through the cementum into the dentin, leaving craters that will filled with cementum and would not be visible unless the root was sectioned as this one was.

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{{PAGE_59}} Sequence of Appointments (cont.) You might say, “Enough time between appointments for repair makes sense if heavy force is used, but with light force, would that be necessary?” It’s correct that when heavy interrupted force is used, a month or even 6 weeks for repair is important to prevent permanent damage to bone and teeth. But flexible springs or wires can be active over a period of a month or longer, and there is no need to re-activate them at shorter intervals. In fact, longer appointment intervals are quite feasible if modern NiTi or TMA wires are used, simply because they can provide light continuous force. That doesn’t necessarily move teeth faster, but it does reduce the number of appointments, which benefits both the patient and the doctor.

Now you know that light continuous force is best because it produces less damage to soft tissue (PDL) and hard tissues (tooth, alveolar bone). Heavy intermittent force is acceptable, but only if re-activation is not done until there has been time for repair. Heavy continuous force is not acceptable. There has to be time for repair.

Summary, Orthodontic Mechanics and Speed of Tooth Movement Let’s summarize the relationship between orthodontic mechanics and the speed of tooth movement.

It’s important to remember that wires and springs move teeth. In contrast, brackets just provide an attachment to the tooth, and excellent evidence now shows that the way a wire is held in a bracket is not a major influence on the speed of movement.
Light continuous force is ideal for tooth movement. Superelastic nickel-titanium (NiTi) and beta-titanium (TMA) wires and springs, which are more flexible than stainless steel wires, do allow

{{PAGE_60}} faster tooth movement because they provide light force with a considerable range of activation; 3. Stiffer wires and springs generate heavier force that is likely to decay quickly. This makes it particularly important to provide enough time between appointments for repair of damaged soft and hard tissues. More frequent adjustments of stiff wires might produce faster tooth movement, but at too high a risk of damage to the teeth and their bony support.

Mechanical Considerations in Speed of Tooth Movement

Modern materials for wires and springs - reduction in treatment time
Type of bracket ligation design - little or no effect on treatment time
Light continuous force is ideal
Heavy intermittent force is OK if there is enough time for repair between activations
Heavy continuous force is destructive and unacceptable

Effect of Electro-Magnetic Fields and Drugs on Tooth Movement

Electro-Magnetic Fields We have already noted that piezo-electricity is critical for maintenance of bone but does not seem to be important for orthodontic tooth movement. It has been observed in orthopedics that small electric currents applied to casts over a fractured bone can increase the rate of healing, but how this effect is mediated remains unclear. In orthodontics, delivering an electric current to the alveolar bone is difficult, and to this point, experiments have not shown any increase in the speed of tooth movement. Electrical currents create an electro-magnetic field in the area, and the reverse also is true: imposing an electro-magnetic field (EMF) creates electrical current flows. So perhaps creating an EMF around

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{{PAGE_61}} the teeth and alveolar bone would alter the response to orthodontic force. How could you do that? One way would be to place magnets close to the targeted area of the jaws.

Small magnets that produce a relatively large EMF now can be produced using rare earth elements (ytterbium, etc.). For intraoral use they must be carefully packaged to insure that corrosion products are not ingested, and that can be accomplished. If such magnets are attached to an orthodontic appliance and placed in attraction or repulsion, they can generate enough force to move teeth (Figures 1 and 2). But the non-linear force system is far from ideal—the amount of force changes as the square of the distance between the magnets. Nonetheless, magnets would be potentially valuable in orthodontics if the magnetic fields changed the biology.

Unfortunately, the best evidence shows little if any effect of these small fields on the biologic response. So from an orthodontic perspective, magnets can be best viewed rather simply as bad springs. They have essentially disappeared from modern orthodontic treatment.

Image 1: Magnets in attraction: Small rare-earth magnets can be bonded to teeth to produce tooth movement. Image 2: Magnets in attraction, progress: Note the space closure as the magnets moved together. Magnets now have been positioned to move the root of the mandibular canine distally into contact with the first premolar.

Drugs to Accelerate Tooth Movement: Prostaglandin?

Orthodontists rarely use drugs, even local anesthetics—but the possibility of drug therapy to accelerate the rate of tooth movement is intriguing. Think back to the cascade of events when sustained force is applied to a tooth. What are the chemical agents involved in that? That’s right, prostaglandins and cytokines are the initial signals. Could you increase their amount and thereby get faster tooth movement?

Prostaglandins have the almost unique ability to simultaneously stimulate differentiation of both osteoclasts and osteoblasts, and of course an increase in both is needed for bone remodeling. The drug would have to be delivered locally, because prostaglandins have a wide range of effects beyond bone remodeling. Could you increase the rate of tooth movement by injecting prostaglandin E or one of its chemical cousins into the PDL space? Interestingly, there is some evidence that you could.

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<table>
  <tr>
    <td>Then why isn’t prostaglandin injection used for that purpose? There are two problems: (1) the PDL space is small, and injecting anything into it hurts; and (2) prostaglandins create intense and painful inflammation when injected. When a wasp or bee stings you, what it really does is inject prostaglandin subcutaneously. So injecting prostaglandin into the PDL would be quite painful, and certainly wouldn't be a practice builder.</td>
  </tr>
  <tr>
    <td><b>Drugs to Accelerate Tooth Movement: Relaxin?</b></td>
  </tr>
  <tr>
    <td>Another drug possibility for moving teeth faster is Relaxin, a hormone discovered in the 1980s that increases collagen breakdown and decreases collagen synthesis, both of which are needed in bone remodeling. Relaxin is considered a pregnancy hormone because it facilitates birth by softening the cervix and loosening the pelvic symphysis. It almost surely is involved in more than that, because in pregnant women its blood levels are highest well before birth, but its larger role has not been well defined.</td>
  </tr>
  <tr>
    <td>Preliminary animal experiments indicated that Relaxin injected near teeth that were being moved did increase the rate of tooth movement. That led to a double-blinded human randomized clinical trial at the University of Florida, in which one maxillary central incisor was moved with a clear aligner, and Relaxin or a saline control was injected mesial and distal to the tooth. Although there were differences between patients in the rate of movement of the tooth, there was no difference between the control and experimental teeth (McGorry SP et al, Am J Orthod Dentofac Orthop, Feb. 2012). Future clinical trials have been delayed.</td>
  </tr>
  <tr>
    <td>Relaxin may not be the drug that becomes useful as an accelerator of tooth movement, but it seems likely that such a drug will be discovered and used in the future—probably in your professional lifetime.</td>
  </tr>
</table>
 
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{{PAGE_63}} PDL Compression/Tension: Can you alter the effects?

Relaxin clinical trial: Univ. of Florida (Wheeler)

Double-blinded: move one tooth (maxillary central incisor) with plastic aligner
Relaxin injected mesial and distal to tooth; compare with untreated controls
Great variability among subjects - but no difference between treated and control

Further clinical trials now delayed.

Drugs to Impede Tooth Movement: Prostaglandin Inhibitors

Drugs are almost never used to deliberately impede tooth movement, but widely used medications can do that. You need to understand this because patients and parents are going to ask you about it, whether or not you are doing any orthodontics.

Most current over-the-counter analgesics (aspirin, ibuprofen, naprosyn) are prostaglandin inhibitors, and of course if increasing the amount of prostaglandin increases the rate of tooth movement, inhibiting it certainly could slow treatment down. There is an alternative pain reliever that isn’t a prostaglandin inhibitor: acetaminophen (paracetomol in Europe), which acts centrally rather than peripherally. Acetaminophen has no anti-inflammatory action, however, and inflammation in the PDL is a component of orthodontic pain.

Fortunately, orthodontic pain is (usually) not severe, and medication is needed for only 3-5 days after activation of springs or wires. Clinical data show that low doses of both ibuprofen and acetaminophen are effective in managing orthodontic pain, and which one you choose makes no difference in the rate of tooth movement.

If there is a problem due to prostaglandin inhibitors, it occurs in adults who are taking large doses day after day, usually to control pain from arthritis. Both the strength of the inhibitor and the duration of use are important factors, but if orthodontic treatment is to succeed, these adults will need another approach to pain control.

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{{PAGE_64}} Drugs to Impede Tooth Movement: Bisphosphonates

Osteoporosis becomes a problem for many post-menopausal women and, less frequently, for aging men. Estrogens were used to treat this until recent studies showed a risk of cardiovascular and related problems; now, bisphosphonates of moderate potency are widely used to control osteoporosis, and adults seeking orthodontic treatment often have been exposed to these drugs.

Bisphosphonates are osteoclast inhibitors, and it is easy to see how this could help to control osteoporosis. Bone remodeling occurs all the time, and inhibiting osteoclasts but not osteoblasts would change the equilibrium between bone formation and resorption toward a net increase in the amount of bone and bone quality.

Active bisphosphonate treatment, even with the less potent drugs used to treat osteoporosis (Fosamax, Actonel, Atelvia, several others), makes tooth movement essentially impossible. Bisphosphonates are incorporated into bone, and so have the potential to inhibit tooth movement for some time after they were first used. Fortunately, most of the drug remains on the surface of bone, where it can be “washed out” after treatment is discontinued. The best guideline is that tooth movement will be very difficult for the first 3 months after a bisphosphonate is discontinued, and teeth will begin to respond, perhaps still slowly, after that.

Orthodontics in Bisphosphonate Patients

It must be remembered that treatment for osteoporosis can’t be just discontinued when the patient wants orthodontics. A hip fracture during orthodontic treatment would be too high a price to pay for straight teeth and a better bite. There is an alternative to bisphosphonates: replacing them with an estrogen like Evista, which has a maximum effect on bone and minimal estrogenic side effects. Consulting with the patient’s physician to see if bisphosphonates can be discontinued temporarily may make orthodontics possible (Figure 1).

Extraction of mandibular teeth in some bisphosphonate patients has led to progressive necrosis of bone around the extraction site. Fortunately, that is much more likely in patients taking the potent bisphosphonates that are used in patients with metastatic bone cancer—but elective extractions for orthodontic purposes after any bisphosphonate exposure carries a high (and probably unacceptable) risk with it (Figure 2).

Guidelines for orthodontic treatment of patients with a history of bisphosphonate treatment are shown in Figure 3.

{{PAGE_65}} PDL Compression/Tension: Can you alter the effects? Pharmacologic intervention

Decreased tooth movement - a threat in some adults
Bisphosphonates (osteoclast inhibitors) for osteoporosis
- Alendronate (Fosamax) - potent effects
- Risedronate (Actonel) - potent effects

Substitute Evista® during orthodontic treatment.

PDL Compression/Tension: Can you alter the effects? Pharmacologic intervention

Decreased tooth movement - a threat in some adults
Bisphosphonates (osteoclast inhibitors) for osteoporosis
- Alendronate (Fosamax) - potent effects
- Risedronate (Actonel) - potent effects

Be careful about extracting teeth in these patients.

Guidelines for Orthodontic Treatment of Patients Taking Bisphosphonates

Active bisphosphonate treatment should be discontinued - physician substitutes Evista®?
It takes about 3 months after stopping bisphosphonates to get tooth movement
Limited treatment objectives and short treatment times are prudent
Tooth extraction, especially in the mandible, should be avoided - the risk of bone necrosis is small but not acceptable for elective treatment

Non-Bisphonate Drugs Newer drugs that can have adverse effects on tooth movement, not classified as bisphonates, have recently been introduced to fight osteoporosis.

Prolia (Denosumab) is a RANK ligand inhibitor. As you already know, RANK ligand plays a significant role in osteoclast development and function. The clinical effect of Prolia on tooth movement has not been well explored yet, but the biologic basis for the interaction of this drug with tooth movement is essentially the same as bisphosphonates: inhibition of the osteoclast activity needed for teeth to move.

It is important to ask your patients about all the medications they might be taking for bone health, not just bisphosphonates.

Alveolar Bone Injury to Accelerate Tooth Movement

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{{PAGE_66}} Development of Corticotomy

The idea that making cuts into the bone between teeth would make it possible to move them faster is an old one. It was tried in the early 20th century and abandoned as too dangerous (that was, after all, the pre-antibiotic era).

The German surgeon Köle in the late 1950s proposed doing rapid orthodontics in an interesting way that he called corticotomy. The method was to make cuts into the alveolar bone between and around the teeth so that each tooth was supported on a relatively small bony pedicle, then use heavy force from stiff orthodontic archwires to green stick-fracture the remaining bony support for each tooth and pull it into position against the arch wire. That was instant orthodontics, if you saw no need to reposition the roots. Fortunately, the blood supply to teeth is so good that the teeth usually didn’t lose pulp vitality. This approach was briefly advocated in the American northwest at that time, but again abandoned as not worth the morbidity and risk.

Corticotomy (Images 1 and 2) was revived in the US in the 1990s, originally with only a slight modification of the Köle approach. It was heavily promoted by periodontist-orthodontist brothers who gave courses on how to do this. As you can see in these images, large flaps are reflected both facially and lingually to expose the alveolar bone, and cuts are made almost all the way through the interdental bone are made. (All images in this section of the module, courtesy Dr. S. Dibart)

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{{PAGE_67}} Image 1: Maxillary corticotomy: After reflection of a gingival flap, cuts have been made through the interdental alveolar bone adjacent to each tooth to be repositioned. The bone over the roots has been scored to induce remodeling there—that was not part of the original technique. Image 2: Maxillary corticotomy, lingual: Cuts also are made lingual to the involved teeth.

Changing Rationale for Corticotomy

The rationale for corticotomy, and the technique for doing it, changed as three things were realized: fracturing the teeth into position often did not give satisfactory occlusion; teeth could be moved orthodontically after corticotomy (and perhaps more quickly); and loss of alveolar bone height often occurred in corticotomy patients. The concept became that faster tooth movement could be achieved if remodeling of the bone around the teeth was stimulated by the bone healing in adjacent areas, i.e., no more bone fracture as part of the tooth movement, and if application of a bone graft slurry was added to the technique. The current corticotomy technique, now called AOO (Accelerated Osteogenic Orthodontics) is illustrated in the images here.

The method now uses bone cuts as previously, with the addition of scoring of the bone facial to the roots to induce remodeling there (Images 1 and 2). Light (normal orthodontic) force instead of heavy force is used for the tooth movement. The theory is that remodeling associated with bone healing at the osteotomy sites will lead to faster remodeling of the bone immediately adjacent to the teeth.

{{PAGE_68}} A bone graft slurry now is placed over the facial surface before the gingival flaps are sutured back into position (Images 3 and 4). The slurry contains ground-up human cadaver bone, bovine bone or synthetic bone mineral. It has two purposes: to (1) prevent loss of alveolar bone height, and (2) facilitate dental arch expansion and prevent fenestration of the alveolar bone with expansion. How well it accomplishes either of these goals has not been verified. For this patient, treatment was completed in 6 months, with good healing (Image 5).

{{PAGE_69}} Image 1: Just before corticotomy to accelerate tooth movement. Image 2: Maxillary corticotomy surgery: After reflection of the maxillary gingival flap, interdental cuts and scoring of the facial bone can be seen. Image 3: Mandibular surgery (same patient): Similar cuts and scoring of facial bone surfaces in the mandibular arch. Image 4: Maxillary bone graft: A bone graft slurry is placed over the surgical area. Image 5: Mandibular bone graft: As in the maxillary arch, a bone graft slurry is placed over the surgical area. Image 6: Surgical area 11 months later: Orthodontic treatment for this patient was

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{{PAGE_70}} completed in 6 months. The surgical area shows excellent healing.

Outcomes of Corticotomy and AOO

Although corticotomy and AOO have been advocated since the 1990s, there is a remarkable dearth of outcome reports. The published literature consists almost totally of before and after photographs and the amount of time needed to align crowded teeth in selected cases. Based on that, one can conclude that faster tooth movement soon after the surgery does occur (always? sometimes?). No data from a series of consecutive patients has been made available, and there is no good information as to the prevalence of problems related to the surgery or the percentage of patients with good / fair / poor outcomes. In short, the advocates of corticotomy and AOO offer no good evidence to support the claims of greatly reduced treatment times and no complications or problems. A complete report of at least 25 consecutive cases, including all patients and data for occurrence and management of problems, is badly needed.

It is apparent, however, that this is not incidental surgery. The large flaps and extensive bone cuts require one-two hours of surgery, and there is enough morbidity to mean that there is an effect on quality of life (for how long?). An obvious question is whether this extent of injury to the alveolar bone is necessary to obtain faster movement, and many clinicians have thought about possibilities to decrease the amount of injury and associated morbidity.

Piezocision as a Less Invasive Alternative

In recent years, piezocision has been offered as an alternative to corticotomy by both Japanese and American periodontists. Piezocision is based on cuts through the interdental gingiva that penetrate into the bone, without raising extensive soft tissue flaps and with significantly less bone injury. The American technique has four steps:

“micro-incisions” instead of reflecting the gingiva (Image 1)
use of a piezo-electric (vibrating) knife to penetrate into the interdental bone (Image 2)
tunneling beneath the gingiva in preparation for a bone graft (Image 3), and
use of a syringe to inject a bone graft slurry over the facial alveolar bone (Images 4 and 5).

In contrast to AOO, there is minimal morbidity, but orthodontic treatment does not start for 1-2 weeks with both methods. There are no good comparative data, but it appears that orthodontic treatment time with piezocision is similar to corticotomy / AOO.

Gingival “micro-incisions”

Piezocision incisions are made only on the facial, without reflecting flaps.

Piezo-electric knife

A piezo-electric knife, which vibrates, is used to penetrate into the alveolar bone.

Tunneling in preparation for bone graft

A tunnel beneath the facial gingiva is created for placement of a bone graft.

Syringe to inject the bone graft slurry

The bone graft material is injected into the tunnel, from both ends.

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{{PAGE_72}} Image 5: End of procedure: Appearance immediately after surgery and injection of bone graft material.

Image 6: 10 months later: Appearance 4 months after end of orthodontic treatment, with good healing. Orthodontic retainers are needed—the gingival fibers that contribute to relapse were not sectioned during the surgery.

Propel: A Commercial System for Bone Injury The most recent (2013) approach to bone injury as way to speed up tooth movement is to screw a device (which is about the size of a typical bone screw for skeletal anchorage) into the interdental bone and then immediately remove it, leaving a bone defect to heal. This is done at 3 locations adjacent to each tooth (near the alveolar bone crest, at the middle of the root and near the root apex). A sterile kit with the removable equivalent of a bone screw and a driver for the device are provided.

As with the other bone injury approaches described above, the marketing for Propel has greatly outstripped the data (Image 1,2). Does it work? Probably. Is it as effective as piezocision or corticotomy? There are simply no data to provide information of that type.

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{{PAGE_73}} Treatment Time with Bone Injury Techniques The critical question about the bone injury techniques is “How much time does it really save?” The answer, of course, would come from data for total treatment time, not for time to initial alignment, but some insight comes from considering the rate of time for healing after injury more generally.

How long does it take for bone to heal after a fracture? That depends on the extent of the injury and the age of the patient, but for a typical uncomplicated fracture of a limb in an adolescent or young adult, there is enough formation of new bone in about 6 weeks that casts can be removed, and bone in the healing area is relatively mature in another 6 weeks or so. Remodeling is essentially complete in 4 months.

Based on that, you would need to accomplish essentially all the tooth movement in 3-4 months after the bone injury in order to obtain an acceleration. If treatment took longer than that, the latter part would be at the usual speed. So if movement was twice as fast in those four months, you would expect to reduce total treatment time by 2 months. Is the benefit of saving that amount of time worth the expense and morbidity of the surgery?

Answers to several additional questions are needed:

Are there specific indications for using injury to accelerate tooth movement? Should it be limited to mature adults, or is it useful in adolescents and perhaps even in children?
Does the bone graft slurry really allow greater facial movement of teeth without creating bone dehiscence?
How does long-term stability compare to stability without bone injury?

Bone Injury Conclusions

The bottom line on bone injury to speed up orthodontic tooth movement:

Anecdotal case reports and selected patient samples indicate that the amount of time for alignment of crowded incisors decreases after corticotomy, piezocision and creation of empty bone screw sites
The injury effect decreases as healing progresses, and any acceleration of tooth movement would be expected to disappear after 3-4 months
The effect of injury with these techniques while a patient is still growing is unknown, but other types of injury do tend to decrease subsequent growth, so using this approach in adolescents should not be done until the end of the growth period
If one assumes that the alignment phase of treatment in adults is cut in half by bone injury, and there is no decrease in time after that, the saving in total treatment time would be about 2 months. No data for actual treatment times in a controlled study are publicly available.

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{{PAGE_74}} Bone Injury to Speed Up Tooth Movement

Anecdotal data - time for alignment of crowded incisors in adults decreases, healing is good
Injury effect lasts 3-4 months only
Bone injury in younger patients has the potential to decrease subsequent growth, so it is not indicated for children or early adolescents
Decrease in total treatment time is unknown, but probably would be about 2 months in alignment, no decrease in later stages of treatment

Non-Invasive Methods

Acceledent: High-Energy Vibration

As we noted earlier, piezo-electric current flow generated by bending of bone during function is a key element in maintaining bone health. For astronauts in reduced or zero gravity situations, there is less bone bending, and loss of bone is inevitable unless piezo-electric currents can be induced. At first this was done by vigorously pedaling an exercise bicycle. NASA scientists discovered that vibration could produce the same bone-sparing effect, and a bulky exercise bike in the space station has been replaced by a vibrating platform on which the astronauts can stand.

Based on this experience, the idea was advanced that faster tooth movement could be produced by high-energy vibration of the teeth, and a device to do this is now marketed as Acceledent (Images 1 and 2). Preliminary data suggested that with a regimen of 20 minutes of vibration every day, the teeth would move more quickly. A randomized clinical trial conducted at the Univ. of Texas-San Antonio showed faster closure of a maxillary premolar extraction site in patients who used the vibration device, and on that basis the US Food & Drug Administration approved its sale.

FDA approval rarely has been sought for an orthodontic device, and seeking and obtaining it certainly is a positive step. Based on this, an aggressive marketing program has moved forward. The clinical

{{PAGE_75}} trial data, however, have not yet appeared in the orthodontic literature (as of mid-2013) because journal reviewers have expressed concerns about the interpretation of the outcomes.

It is interesting to note that although the focus of the clinical trial was the time to close an extraction space and malalignment was not quantified, claims of reduction in time for alignment and total treatment time are included in current advertisements. It is fair to say that the marketing is far ahead of the evidence to support it.

Image 1: Acceledent device: The device consists of a mouthpiece that is activated by batteries in the extraoral part into which the mouthpiece is inserted.

Image 2: Acceledent in use: The recommendation is 20 minutes per day of vibration.

High-energy Vibration (cont.)

In comparison to bone injury methods, there is one great advantage of vibration as a way to accelerate tooth movement: no surgery is required, and the morbidity associated with it is avoided. Patients in the Acceledent trial did not report pain beyond what orthodontic patients normally experience—mild to moderate pain lasting only a few days after appliance adjustment.

There are, however, two types of problems. The first is that the mechanism of action with vibration is not understood. Is that important? As part of the reaction to the 2012 “discovery” of neutrinos moving faster than light (which was retracted after further evaluation of the data), the interesting cartoon shown in Image 1 accompanied a NY Times story about it. The astrophysicist’s comment was

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{{PAGE_76}} “No experiment should be believed until it has been confirmed by theory.” The orthodontic analogue would be “No experimental result should be completely accepted until the underlying mechanism is understood.” Why? Because if you don’t understand the mechanism, you have no way to identify exactly what outcomes you should be looking for.

What is the mechanism for high-energy vibration? We simply do not know—but especially since its effect seems to be similar to that of bone injury, one can wonder if the device is creating micro-fractures in the alveolar bone that lead to greater bone remodeling. If that is the mechanism, however, an appropriate concern would be the long-term effect of repeated injury during a year or more of treatment. The surgical bone-injury approaches produce injury once and then it is allowed to heal. What would repeated injury do? At this point that is not known.

New York Times, March 26, 2012 Out There The Trouble With Data That Outpaces a Theory

Practical Considerations with Vibration The other type of problem with vibration is best labeled a series of practical considerations. These include

If you want to move only some of the teeth (which is the case for the great majority of orthodontic patients), can the vibration effect be restricted to only one part of the dental arch without altering the effect elsewhere?
Is the frequency / intensity of the vibration optimal? The objective is to deliver enough vibrational energy to alter the response to orthodontic force, in 20 minutes per day. What happens if these

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{{PAGE_77}} variables change? Importantly, what happens if the patient uses the device more or less than 20 minutes per day?

For adults, is there a maximum duration of safe use? Can it be used safely in adolescents? in younger patients who are still growing?
Does the device work equally well with all types of appliances? It has been suggested that it may be particularly useful with Invisalign, and it seems reasonable that this might help in fully seating the aligners—but there are no data yet to support that idea.

High-Intensity Light

High-intensity light in the 800-900 nanometer range (just outside the visible range for humans) penetrates through soft tissues. It has been hypothesized that it could be used to activate cells in the PDL and alveolar bone and thereby lead to faster tooth movement. With vibration the mechanism could still be injury in the form of micro-fractures; with light, it is hard to see how the mechanism could be injury.

That leaves the same problem as with vibration: if you don’t know the mechanism, you don’t know what to look for as outcome parameters beyond the desired effect. It is known that light of this type can produce some tissue heating that would increase blood flow, and in studies of tooth eruption, it has been shown that increasing blood flow does affect the rate of eruption. So there is some reason to believe that the light could increase blood flow, and perhaps that would be a way to accelerate tooth movement.

At this point (mid-2013) Biolux, the company that is working with high-intensity light, has obtained encouraging preliminary data and a randomized clinical trial has just begun. The first efforts with humans used an extra-oral device like the one shown in Images 1 and 2, with illumination for 20 minutes per day. Although most of the light (97%, according to the company) was absorbed before it reached the alveolar bone, the remaining 3% was thought to be intense enough to affect cells there. Currently, an intra-oral device to supply the light (Image 3) is being used, with illumination for only 3 minutes per day.

Is light really going to accelerate tooth movement (Images 4,5,6)? If so, will patients be willing to wear a device like either of the ones in these images? That simply is not known at present, although the devices already are being promoted commercially. But light does seem to offer a non-injurious way to possibly affect tooth movement by increasing blood flow in the PDL and adjacent alveolar bone. Is the primary effect on the PDL or the bone? That also is not known.

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{{PAGE_78}} Image 1: Experimental extra-oral device: With this device, light-emitting diodes are placed so that light penetrates through the cheeks to the gingival area of both arches.

Image 2: Infra-red image of light from extra-oral device: In this image from an infra-red camera, the nose is at the top and the lips in the center. Note that light does penetrate to (and presumably into) the PDL and alveolar bone adjacent to the teeth.

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{{PAGE_80}} Therapeutic Ultrasound There is no doubt that therapeutic ultrasound (which has much greater intensity than diagnostic ultrasound) can increase blood flow in targeted tissues. For that reason, therapeutic ultrasound is widely used in physical therapy, typically to increase blood flow in deep muscles that are contracted and painful.

A possible application of therapeutic ultrasound to orthodontics would be to increase blood flow in the PDL, as a way to decrease the formation of necrotic areas and the size of those that do form. That would have the potential to decrease the amount of root resorption, and if increasing blood flow leads to accelerated tooth movement, it might be another non-injury way to accomplish this also.

At this point, intra-oral devices to supply ultrasound to the teeth have been developed, and the possibilities of decreased root resorption and /or faster tooth movement are being evaluated. This technology has not yet been marketed.

Non-injury Methods: Summary To summarize what is known about possible physical methods to accelerate tooth movement:

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{{PAGE_81}} High-intensity vibration has been shown to accelerate the rate of tooth movement in humans in closure of extraction spaces. Devices to supply high-energy vibration now are for sale in most countries, including the United States. The marketing claims go beyond the supporting evidence, and it is not yet clear whether this will become an important adjunct to orthodontic therapy. The mechanism of action for vibration is not known, but it may be a less invasive way to induce alveolar bone injury. The magnitude of change in tooth movement is similar to what is seen with more overt injury procedures. High-intensity light that penetrates soft tissues also seems to have the potential to increase tooth movement, and clinical trial data are being gathered now. The mechanism of action for light is not known, but does not seem to be another way to injure the bone, and may be related to its ability to increase blood flow in the PDL and alveolar bone. Therapeutic ultrasound definitely increases blood flow in areas targeted with it. It will be interesting to see if increased blood flow in the PDL and adjacent alveolar bone decreases root resorption and/or alters the rate of tooth movement.

Referral to Self-Test At this point, review the assigned reading for this module (Chapter 8, pages 278-295, Contemporary Orthodontics, 5th edition) (much of the information in this module is new, not in the 4th edition). Then take the self-test and use it to direct your re-examination of parts of the teaching module and the reading.

Quartz 4

Explorer

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Contents

1. Interaction with Orthodontists

Background / Diagnostic Review

Orthodontics as a Dental Specialty

Facial Examination: Lip Prominence

Evaluation of Occlusion and Alignment/Crowding

ORTHODONTIC TRIAGE, CHILD

SEVERE PROBLEM

Orthodontic Triage, Step 2

ORTHODONTIC TRIAGE, CHILD

Orthodontic Triage, Step 3

How Do You Manage the Referral?

Referral Interactions

How Do You Manage the Referral?

What Does the Orthodontist Want From You?

Initial Report from the Orthodontist

Interview

Interview: Initial Questions

Chief Complaint

Medical and Dental History

Orofacial Trauma

Trauma to the Teeth

Physical Growth Status

Clinical Evaluation

Step 1: Oral Health

Step 3: Evaluation of Facial Proportions and Esthetics

Video, smile animation

Evaluation of Occlusion

Orthodontic Problems? (cont’d.)

To Refer or Not To Refer?

To Refer or Not To Refer? (cont’d.)

3. Accelerated Tooth Movement

Principles of Orthodontic Tooth Movement

Objectives

Orthodontic Mechanics as a Factor in the Rate of Tooth Movement

Importance of Force Duration

Sequence of Orthodontic Appointments: Repair Time

Changing Rationale for Corticotomy

Outcomes of Corticotomy and AOO

Piezocision as a Less Invasive Alternative

Gingival “micro-incisions”

Piezo-electric knife

Tunneling in preparation for bone graft

Syringe to inject the bone graft slurry

Graph View

Table of Contents