Goals of Treatment
Introduction to Level IV
You have been through Level III, in which the goal was to teach you how to provide orthodontic treatment for patients whom you would manage in a typical family practice. There is a hierarchy for clinical knowledge:
Knows: the background for clinical decisions (Levels I and II)
Does: selected clinical procedures (Level III). No practitioner can do everything for everybody, so we all provide selected clinical procedures and refer patients to others for treatment that we do not provide.
Understands: the basis for treatment of more complex treatment (Level IV), so that you can make appropriate referrals for treatment that you do not provide. You will, of course, make your own decisions about the scope of your practice in the future—which may include more or less orthodontics than what you were taught to do in Level III. But whether you are in family practice or a different specialty practice, you will find yourself needing answers to questions about orthodontics and working with orthodontists in treatment of patients who have complex problems that require a multi-disciplinary approach. The goal of Level IV is to provide a level of understanding of orthodontic practice that will enable you to work effectively and efficiently with orthodontists.
The Paradigm for Health Care: Quality of Life vs Disease Control
A discussion of the goals of orthodontic treatment has to begin with a review of the goal of health care more generally. A paradigm is defined as shown in the graphic—and the health care paradigm has changed in recent years. After scientific discovery of the cause of many diseases, it was generally accepted for many years that the major objective of health care was the control if not the elimination of disease. A disease-free life, it was thought, would be the ideal.
But consider the possible impact of controlling disease on other aspects of life. What do you do if the cure is worse than the disease? To put the problem in a dental context, to what extent would you prescribe extensive gingival surgery to treat periodontal problems if it greatly impaired the patient’s appearance and affected his or her ability to keep a job?
It has become clear that the impact of any treatment on the quality of life must be considered. In the modern paradigm, the goal of health care is to obtain for the patient the best quality of life, taking into account the balance between the physical and psychosocial aspects of health.
Goals of Orthodontic Treatment
At one level, it is easy to state the goals of orthodontic treatment. We would like to give the patient the best possible:
- dental and facial esthetics
- dental occlusion
- stability of the result
But that leaves two questions:
- How do you judge what is best?
- What do you do if the goals are incompatible, for example, if the best esthetics would not give the best occlusion and/or stability?
A bit more than 100 years ago, when Norman Kingsley (who was a noted sculptor as well as dentist) began the development of orthodontics in America, the only reason for orthodontic treatment was to improve esthetic problems by aligning the incisor teeth. Alignment of irregular teeth had been done occasionally for that purpose all the way back to at least the 2nd century A.D.
Goals of Orthodontic Treatment, Early 20th Century
Around the turn of the 20th century, Edward Angle, the “father of modern orthodontics”, defined ideal occlusion. It is interesting that the very concept of ideal (normal) occlusion is only a little more than 100 years old.
Having defined ideal occlusion, Angle then was able to define malocclusion as deviations from the ideal. He distinguished three major classes of malocclusion based on the molar relationship. So the Angle classification has four categories: ideal occlusion and Class I, II, and III malocclusion.
Not surprisingly, Angle felt that the major goal of orthodontic treatment was to perfect the dental occlusion. Philosophically, he held that everyone had the potential to be ideal. In his view, the best facial esthetics always accompanied ideal occlusion of all 32 teeth, and he maintained that if the occlusion were perfected, function would cause the teeth to stay in that idealized relationship.
You can still hear echoes of that view in modern dentistry. For instance, some dentists still claim that proper occlusion will maintain teeth in a new position—which is clearly not the case. Occlusion has remarkably little to do with stability.
Goals of Orthodontic Treatment, Mid-20th Century
Angle felt that it was never necessary to extract teeth to obtain space for proper alignment and occlusion of the others. Expansion of the dental arches was always his treatment approach. You already know, from our previous review of equilibrium principles, that if the dental arches are expanded too much, the teeth are likely to be unstable and too prominent.
By the middle of the 20th century, it was apparent that if Angle’s prescriptions for treatment were followed, relapse was highly likely for many patients. Tweed in the United States and Begg in Australia independently developed methods of treatment—ironically, adapting Angle’s orthodontic appliance in each instance—to allow proper positioning of teeth after premolar extraction. The goal was to obtain better stability of the result and to overcome esthetic problems created by excessive dental protrusion.
But the problem was that this compromised the occlusion to some extent (it’s not ideal occlusion if some teeth are missing), and could affect facial esthetics for the worse as well as the better.
Goals of Orthodontic Treatment Now
In these early years of the 21st century, in both restorative dentistry and orthodontics, there is an increased emphasis on dental and facial esthetics (image 1). At this point, the goal of treatment still is the best possible esthetics, occlusion, and stability—but if these are incompatible, the best approach now is often to optimize esthetics and accept some compromise in occlusion and stability (permanent retention required). Why?
In the modern age, there are three reasons for doing orthodontics—listed here in their order of importance (image 2):
- primarily, to help patients overcome psychosocial handicaps created by discrimination based on facial appearance
- additionally, to improve function of the teeth and jaws
- occasionally, to improve oral health
Remember that patients seek orthodontic treatment usually and restorative treatment frequently to improve their quality of life. Quality of life, of course, is very much affected by psychosocial handicaps related to dental and facial appearance (though of course if can also be affected by function and health).
That means it isn’t enough to just replace missing teeth, or to bring the teeth into ideal alignment and occlusion without considering the esthetic outcome (image 3). If the dental and facial esthetics are not satisfactory, it’s not satisfactory treatment—because then the desired improvement in quality of life would not achieved.
 Image 1: Esthetic goal. |  Image 2: Why esthetics? |
 Image 3: Quality of life. |
Health Effects
Reasons for Treatment: Health
Let’s look further at the reasons for orthodontic treatment, beginning with the health effects. What’s the relationship of malocclusion and oral disease?
- Hard tissue lesions: little or no relationship
There’s simply no evidence that tooth decay is more likely if teeth are not well aligned (image 1).
- Periodontal disease: a weak relationship
In general, oral hygiene, bacterial types, and immune status are the major factors in whether periodontal disease develops—but there is some evidence that patients with severe malocclusion are more likely to develop periodontal problems. Perhaps this is because good hygiene is more difficult to achieve.
Did the malocclusion (images 2, 3) have anything to do with this man’s development of periodontal disease (image 4)? Probably only to the extent that it discouraged him from taking care of his teeth. There is some evidence that the “bad bugs” related to periodontal disease are more prevalent around malaligned teeth, but malalignment makes it harder to keep the teeth clean and the bacterial flora under control—it doesn’t make it impossible. So motivation is important.
At age 47, as it became apparent that he was in great risk of losing all his teeth, this man wanted treatment to save them if possible.
 Image 1: caries: Caries: little or no relationship to dental alignment and occlusion. |  Image 2: perio: Severe malocclusion: related to development of perio problems? |
 Image 3: perio: Severe malocclusion: related to development of perio problems? |  Image 4: bone loss: Severe malocclusion: related to perio problems? |
Orthodontics and Periodontal Health (cont.)
- Periodontal disease: a weak relationship
Despite this, orthodontics can be an important part of the treatment plan for an adult with periodontal problems. For instance, uprighting a tipped molar often improves the health of the tissues around it (see the program on Adjunctive Orthodontics for more information). A vulnerable tooth that is subjected to occlusal trauma can be stabilized better if other teeth are positioned to take some of the force during bruxism. Successful control of advanced periodontal disease is more likely if the teeth are aligned and brought into more normal occlusion.
This patient decided he wanted to save his teeth and wanted the malocclusion corrected as part of the overall treatment plan. The first step in complex treatment of this type is to bring the periodontal disease under control, and the patient has to demonstrate the motivation to make that possible. The perio treatment includes scaling, curettage, gingivectomy/gingivoplasty—whatever is necessary to stop the progression of the disease (images 1 and 2).
With periodontal disease under control, orthodontics is quite feasible even when severe bone loss is present. Coordinated orthodontic and periodontic treatment can make it easier to manage the periodontal problems. For this patient, splinting of the teeth after they were brought into alignment (note that one lower incisor was extracted and space was closed) was part of the long-term plan (image 3).
 Image 1: After initial scaling/clean-up. |  Image 2: Further disease control in preparation for orthodontics. |
 Image 3: At the completion of active orthodontics. |
Third Molars in Post-Orthodontic Patients
What to do about third molars that often do not have enough space to totally erupt is an important question for most patients in late adolescence, whether or not they have had orthodontic treatment. You already know that third molars really can’t be blamed for the development of lower incisor crowding in late adolescence—that is much more a response to late mandibular growth than pressure exerted by third molars that are trying to erupt. Are there health considerations in the decision to retain or extract third molars? Yes, there are.
Third molars can be put into three categories:
(1) those that erupt and become a functional part of the dental arch;
(2) those that erupt into the mouth, but are only partially exposed and are not in occlusion;
(3) those that have not entered the oral cavity.
Those in the first category usually are not a problem, with one important exception. They are more likely to be seen in individuals who have large jaws, particularly a large mandible, and therefore in those who have a skeletal Class III tendency or bimaxillary protrusion. Extraction of third molars before surgery to reposition the mandible may be needed.
Those in the third category produce health risks related to the bacterial flora around them and development of chronic inflammation; those in the third category are a lesser health risk but may become cystic and damage other teeth or produce significant bone lesions (image 4). Follow-up radiographs to monitor their status are needed if they are retained.
Let’s look more closely at the second category, for which new information about the effects of chronic inflammation and about their role in the development of periodontal disease has changed recommendations for their management.
Partially Erupted Third Molars
Partially erupted third molars, particularly mandibular third molars, are problematic because when the crown of the tooth breaks through the soft tissue and is exposed to the oral environment, bacteria can and do penetrate deeply along the crown. Even though periodontal bone loss does not occur quickly when this happens, an increased probing depth is found, and this is a hospitable area for the anaerobic bacteria that now are now known to be the cause of periodontal disease. The result is that periodontal disease tends to develop initially around third molars and spread anteriorly from there, and that chronic inflammation in this area can be the source of cardiovascular disease and complications of pregnancy. You have, of course, learned about this in other courses, so we do not need to go that again—but we do need to provide recommendations about management of partially erupted third molars.
Is orthodontic treatment related to partially erupted third molars? It seems logical that expansion of the dental arches to correct crowding of the anterior teeth would decrease space for third molars, and that if the second molars move mesially during orthodontic space closure, this would increase space. Extraction of first molars is rarely done for orthodontic purposes, but major mesial movement of the second and third molars does occur after first molar extraction in children or adolescents, and functional third molars in occlusion often is the outcome. Extraction of second premolars tends to bring the molars forward, though not nearly as much as first molar extraction. The extent to which it decrease partial exposure of third molars has not been documented—it helps somewhat, but often not enough.
Should partially erupted third molars be extracted routinely? What about watchful waiting to see if they will eventually come into occlusion? The current guidelines:
- removal of exposed 3rd molars decreases the chances of early periodontal disease
- if a partially erupted 3rd molar is retained, monitoring that includes probes for evaluation of the bacterial flora is needed
- an episode of pericoronitis is an indication for extraction
- recovery after 3rd molar extraction is faster and less problematic in teen-agers
Function
Orthodontics and Function
There are two aspects to the relationship between dental occlusion and function:
(1) Masticatory Efficiency
It is difficult to demonstrate that patients with normal occlusion can chew and eat better than those with malocclusion, although it is obvious that patients with severe malocclusion have difficulty in eating many foods.
Perhaps this difficulty comes from the fact that occlusion as dentists view it really does not come into play during eating. The upper and lower teeth almost never contact each other during chewing. So if normal jaw movements are possible and the jaws and teeth are reasonably well related, perhaps the details of occlusion do not matter very much for mastication.
But some patients comment that they can eat better after orthodontic treatment. It makes sense that correcting severe deviations from the normal relationships would make a difference. We can’t yet measure improvements in masticatory efficiency—there are no good tests. But there’s another aspect of being able to chew better: often patients with severe malocclusion learn that there are some things they can’t eat in a socially acceptable way, and they avoid eating those things when other people are around. For instance, pizza often offers a challenge is you have an open bite or large overjet. Perhaps what we need is an evaluation of how patients feel about eating pizza (or other things) in public and what reactions they get from others when they do, not an evaluation of how many chews it takes to get to the point that swallowing is OK.
TM Joint Function and Malocclusion
(2) TMD/Occlusion
What’s the relationship between TM pain/dysfunction and malocclusion? That, too, is a difficult question to answer, for the same reason: Remember that there is almost no occlusion during mastication. The teeth are brought lightly together at the end of most swallows, but otherwise are separated. Occlusion, as viewed by bringing dental casts together, is only a minor part of normal function with the natural teeth.
Occlusal relationships, therefore, become important in the etiology of TM dysfunction only to the extent that patients clench and grind their teeth, and neuromuscular adaptation to the occlusion during bruxism determines whether pain develops. In the absence of parafunctional activity, TM pain/dysfunction related to the occlusion simply does not develop. Perhaps the way to look at it is that some arrangements of the teeth make it easier to hurt yourself by bruxing and grinding than others.
Effects of a Lateral Shift
There is a relationship between some types of malocclusion and TMD.
The strongest correlation is with crossbite with a lateral shift. The correlation coefficient between the two conditions is about 0.4. If you square any correlation coefficient, you get the chance of successfully predicting one thing from the presence of the other. What’s the chance that TMD will be found when there is a crossbite and lateral shift? The correlation coefficient is 0.4: (0.4) squared = 0.16, so there is a 16% chance that a patient with a crossbite and lateral shift will have symptoms of TMD. It works in reverse, too, so there also is a 16% chance that a patient with TMD will have a crossbite with a lateral shift.
Does having a crossbite with a shift predispose you to TMD? Yes, but remember that if you have such a crossbite, there is only 1 chance out of 6 that you have or will develop TMD and 5 chances out of 6 that you won’t.
TMD and Other Types of Malocclusion
The correlation coefficients are even lower for other types of malocclusion. The coefficients are about 0.3 for Class III and Class II deep bite, meaning there’s only about a 10% chance of correctly predicting that TMD will develop in a patient with these malocclusions. Perhaps this reflects the fact that some (but by no means most) individuals with either of these malocclusions have to shift to avoid incisor interferences when they bring their teeth together.
It’s pertinent that the severity of Class III malocclusion is inversely related to the prevalence of TMD (image 1). With a mild Class III, incisor interferences are likely to force a shift on closure, whereas a severe Class III puts the incisors beyond occlusal contact. It makes sense, therefore, that patients with mild Class III who are forced to shift on closure are more likely to develop TMD symptoms than those with severe Class III, who don’t have to shift.
For several other types of malocclusion, some investigators report a weak correlation with TMD; others do not find a relationship. Anterior open bite falls into this category of controversy. If there is a relationship to TMD, it is very weak (image 2).
Perhaps the best way to look at it is this: Some types of malocclusion make it easier to generate muscle spasm and pain/dysfunction by clenching and grinding your teeth. No matter how good your occlusion is, you can still hurt yourself with parafunctional activity if you do it enough. So perfect occlusion decreases the chance of TMD but doesn’t eliminate it. And if you don’t clench and grind, it’s easier to tolerate a malocclusion that predisposes you to TMD without developing it.
 Image 1: Class III patients with a CO-MI shift have a greater chance of developing TMD. |  Image 2: Other malocclusion types related to TMD? |
TMD and Malocclusion: The Bottom Line
Orthodontic treatment changes the occlusion, but it neither causes nor cures TMD.
With orthodontic treatment, preexisting TMD often gets better—the sore teeth created by treatment takes all the fun out of clenching and grinding. But you can’t count on long-term improvement—if the patient goes back to bruxism, the TMD is likely to recur.
TMD may develop after orthodontic treatment, but it’s hard to be sure whether the treatment had anything to do with it. Certainly it is possible that orthodontic treatment could create an occlusion that would lead to a shift on closure, or a greater awareness of the occlusion that would predispose a patient to bruxism. The best evidence that this rarely happens is that the chance of developing TMD as you get older is the same whether you had orthodontic treatment or didn’t.
The bottom line: As a general rule, orthodontics doesn’t cause TMD—and it doesn’t cure it.
Psychosocial Effects
Psychosocial Impact of Malocclusion
Now let’s examine the psychosocial impact of malocclusion. In a sense, we already took that into account in thinking about chewing efficiency in the context of how other people react if you have trouble managing some kinds of food. Let’s look at the reaction to your facial appearance.
What difference does your facial appearance make, really? Begin by understanding that every time you meet a new person, their first impression is based largely on your facial appearance. He or she looks like … a good person, a hard case, whatever.
We all size people up in that way, instinctively. Fortunately, as people get to know each other better, appearance isn’t so important, but it’s a considerable handicap to have to overcome an unfortunate appearance every time you meet somebody new.
What do you think of the person in this image? Just based on her appearance, you will immediately have some ideas about what you’d find if you met her.
![[whyortho_20.webp|Initially, you would assume about this person [what?] …]]
Effect of Protruding Incisors
Three caricatures drive home the point:
(1) Protruding upper incisors suggest that you’re an idiot.
You can’t draw a proper idiot without giving him protruding teeth—like Zero in the comics, for example (image 1). If you want him to look smarter, you’ll have to correct those teeth.
What’s your initial reaction to this girl (image 2) and young woman (image 3)? You’re likely to assume that neither is very smart, because their dental appearance suggests that—but that’s not correct, for either one.
The caricature associated with protruding upper incisors creates a social handicap that’s hard to overcome. It’s a terrible problem to have to convince every new person you meet that you’re not stupid.
 Image 1: Protruding teeth = stupid. |  Image 2: Protruding teeth = stupid (??). |
 Image 3: Protruding teeth = stupid (??). |
Effects of Dental Appearance and Chin Prominence
Three caricatures drive home the point:
(2) Bad teeth (decayed, broken, missing, obviously crowded, or protrusive) suggest that you’re from a lower socioeconomic class, probably aren’t well educated, and don’t take good care of yourself.
The patient we looked at in Section 2 of this module wanted treatment more to keep from being judged unfavorably than to improve his health, though both were reasons for treatment. In an adolescent, crowded and irregular incisors can create a social problem at a time in life when it’s particularly difficult to cope successfully (images 1, 2). This boy’s complaint: “I try not to smile and show my teeth.” That reflect his awareness of possible social discrimination based on dental/facial appearance.
(3) Chin prominence (strength) means a lot.
In a male, a strong chin is associated with a more powerful personality, while a weak chin is associated with general weakness and doubtful intelligence (your upper incisors will protrude, of course, if your mandible is deficient).
When you first met him, would you expect the boy in image 3 to be a leader in his group? Not likely. It’s hard to be elected class president if you have a weak chin.
In a female, a strong enough chin makes you a witch. This girl’s chin (image 4) isn’t that strong, but it detracts, makes her look as if she might be unpleasant, unhappy, hard to get along with.
Bottom line: It’s not just your teeth, it’s jaw proportions as well.
 Image 1: Poor dental appearance implies neglect. |  Image 2: Protruding/irregular incisors imply poor socioeconomic status as well as questionable intelligence. |
 Image 3: A weak chin in males implies general weakness. |  Image 4: A strong chin in females implies an unpleasant level of aggressiveness. |
Social Limitations
What’s the benefit of treatment? Click on the icon and consider the impact of this clip from the classic movie Casablanca:
Would the girl have looked like that (and become a movie star), without braces on her teeth at an early age? Probably not. A nice idea to have planted in the public mind in 1943.
: Clip from Casablanca.
Psychosocial Benefit of Treatment
Let’s be sure you understand the psychosocial problem that malocclusion can create for a child or an adult:
- Stereotypes determine long-term performance to a surprising degree.
Children placed into a classroom labeled as low- or high-performing tend to perform at the predicted level—so if you’re thought to be stupid, you’re likely to conform to the prediction.
- Nearly half the Class II children report being teased at school about their protruding teeth. *“*Yeah, yeah, Buck-toothed dummy!”
- Both incisor irregularity and incisor protrusion are predictors of teasing.
- The effect on self-esteem created by this type of social discrimination also affects future performance.
The more you’re treated as if you are stupid, the more you may come to believe that it’s not worth trying to do better—and people don’t achieve more than they try to accomplish.
Benefit of Treatment (cont.)
This man returned at age 50, 20 years after treatment (which in his case involved orthodontics and orthognathic surgery) to say, “Now I have my own successful business—and without the treatment I would never have had the confidence to quit my job years ago and go out on my own. I’m so grateful for what it did for me.”
The bottom line regarding psychosocial effects of malocclusion:
Dental and facial appearance is not “just esthetics,” it affects your whole life. Because the psychosocial handicap of an unfortunate facial appearance is the biggest problem for most orthodontic patients, it’s the major reason for orthodontic treatment.
 Image 1: Age 29, prior to treatment. |  Image 2: Age 50, 20 years after treatment was completed. |
 Image 3: Comparison of pre- and long-term posttreatment. |
Summary: Quality of Life
So why do we do orthodontics? To help a patient with his or her particular problem.
The goal of treatment should be to provide the greatest possible benefit to that particular patient—which means, of course, that what is most important to the individual patient should receive the emphasis. That might be esthetic improvement to help with psychosocial problems, improved occlusion to solve functional problems, or an improvement in oral health. Is esthetics the most important thing? For some patients, generally the majority, yes, but certainly not for all.
Orthodontics represents particularly well the type of health care that focuses on improving the quality of life, not on controlling or preventing disease. Not surprisingly, it has become increasingly valued worldwide as the health care paradigm has changed to emphasize quality of life.
Self-Test Referral
The self-test section of this program is designed to help you be sure you have understood the material. Before you take the self-test, read the assigned material in Contemporary Orthodontics (5th ed., pages 50-64; 4th ed, pages 58-70). Then use the self-test as a guide to further study of this important material.
Copyright 2013, UNC Dept. of Orthodontics
Self-Test
Question 1
Which of the following attributes of treatment are important when health care is structured around the quality of life paradigm?
a. Prevention of disease
b. Neuromuscular adaptation and function
c. Self-esteem
d. Positive social interaction
- a and b
- b and c
- a, b, and c
- b, c, and d
- all of the above ✓
Correct
That’s right, all of these are important from the perspective of quality of life. Putting the emphasis on broader aspects of quality of life doesn’t mean that prevention of disease is not important or that neuromuscular adaptation should receive less emphasis. The quality of life paradigm does say that it’s incorrect to assume that if you don’t have a specific disease, everything is fine. Good health and absence of disease are not necessarily synonymous.
Incorrect
No, that’s wrong. All of these are important from the perspective of quality of life. Putting the emphasis on broader aspects of quality of life doesn’t mean that prevention of disease is not important or that neuromuscular adaptation should receive less emphasis. The quality of life paradigm does say that it’s incorrect to assume that if you don’t have a specific disease, everything is fine. Good health and absence of disease are not necessarily synonymous.
Question 2
Why, in the mid-20th century, did the emphasis in orthodontics change toward stability of the result from the previous emphasis on ideal occlusion?
a. Relapse toward crowding after expansion of the dental arches
b. Return of deep bite tendencies
c. Return of incisor protrusion
d. Concern about esthetics
- a and b
- a and c
- b and d
- a, b, and c ✓
- all of the above
Correct
That’s right, the shift toward emphasizing stability was based on concern about relapse in dental relationships, not on concerns about esthetics. The assumption remained for a time that if the occlusion were maintained at a near-ideal level, esthetics would take care of itself, and the risk of impaired esthetics if incisors were retracted to improve stability was not recognized at first. Experience showed that there was a potential risk to esthetics with excesive incisor retraction, just as there is with excessive protrusion. This led to the current emphasis on tooth position and jaw relationships as important factors in facial esthetics.
Incorrect
No, that’s wrong. The shift toward emphasizing stability was based on concern about relapse in dental relationships, not on concerns about esthetics. The assumption remained for a time that if the occlusion were maintained at a near-ideal level, esthetics would take care of itself, and the risk of impaired esthetics if incisors were retracted to improve stability was not recognized at first. Experience showed that there was a potential risk to esthetics with excesive incisor retraction, just as there is with excessive protrusion. This led to the current emphasis on tooth position and jaw relationships as important factors in facial esthetics.
Question 3
(A) For most patients, the primary motivation for orthodontic treatment is concern about dental/facial esthetics because (B) Diminished self-esteem nearly always is due to discrimination related to esthetic problems.
- A true, B true, A and B related
- A true, B true, A and B not related
- A true, B false ✓
- A false, B true
- A and B false
Correct
That’s right, the first statement is true, but the second one is false. Those who seek orthodontic treatment often do so because of concern about facial esthetics, but low self-esteem is by no means always a part of the problem, and self-esteem problems can arise from many causes other than dental and facial appearance. Adolescent and adult patients who seek treatment, in fact, tend to score higher on self-esteem and related psychological scales than those with similar esthetics who don’t seek treatment. It appears that you have to have reasonably high self-esteem to seek treatment. Those with low self-esteem tend to feel that treatment wouldn’t do any good anyway.
Incorrect
No, that’s wrong. The first statement is true, but the second one is false. Those who seek orthodontic treatment often do so because of concern about facial esthetics, but low self-esteem is by no means always a part of the problem, and self-esteem problems can arise from many causes other than dental and facial appearance. Adolescent and adult patients who seek treatment, in fact, tend to score higher on self-esteem and related psychological scales than those with similar esthetics who don’t seek treatment. It appears that you have to have reasonably high self-esteem to seek treatment. Those with low self-esteem tend to feel that treatment wouldn’t do any good anyway.
Question 4
Which of the following are reasons why orthodontic treatment for patients with malocclusion can improve the prognosis for their periodontal disease?
a. Crooked teeth are harder to keep clean
b. The biologic response to orthodontics includes stimulation of the immune system
c. Improved occlusion can decrease the force felt by some vulnerable teeth during bruxism
d. The presence of orthodontic appliances tends to change the bacterial flora in a desirable way
- a and b
- a and c ✓
- a, b, and c
- b, c, and d
- all of the above
Correct
That’s right, orthodontics can improve the prognosis for some patients by making it easier to keep the teeth clean and by decreasing the force felt by vulnerable teeth during bruxism. Although bacterial and immune phenomena are the major determinants of periodontal disease, orthodontics doesn’t affect the immune system or bacterial flora, at least in ways that decrease the risk of periodontal problems.
Incorrect
No, that’s wrong. The correct answer is a and c. Orthodontics can improve the prognosis for some patients by making it easier to keep the teeth clean and by decreasing the force felt by vulnerable teeth during bruxism. Although bacterial and immune phenomena are the major determinants of periodontal disease, orthodontics doesn’t affect the immune system or bacterial flora, at least in ways that decrease the risk of periodontal problems.
Question 5
(A) Poor masticatory efficiency is highly correlated with malocclusion because (B) The occlusal surfaces of the teeth must fit together precisely for efficient mastication.
- A true, B true, A and B related
- A true, B true, A and B not related
- A true, B false
- A false, B true
- A and B false ✓
Correct
That’s correct, both statements are false. It seems reasonable that severe malocclusion should decrease masticatory efficiency, but even a weak correlation between the type of occlusion and masticatory efficiency has not been established. Patients with severe malocclusion often learn not to try to eat some things in public, not so much because they can’t but because it is hard for them to be socially acceptable while doing so. During mastication occlusal contact of the teeth is rare, so if normal jaw movements are possible, it may not make much difference exactly how the teeth would fit if they were in contact.
Incorrect
No, that’s wrong. Both statements are false. It seems reasonable that severe malocclusion should decrease masticatory efficiency, but even a weak correlation between the type of occlusion and masticatory efficiency has not been established. Patients with severe malocclusion often learn not to try to eat some things in public, not so much because they can’t but because it is hard for them to be socially acceptable while doing so. During mastication occlusal contact of the teeth is rare, so if normal jaw movements are possible, it may not make much difference exactly how the teeth would fit if they were in contact.
Question 6
What is the chance that TMD symptoms will accompany posterior crossbite with a shift?
- 1 in 10
- 1 in 6 ✓
- 1 in 4
- 1 in 2
- unpredictable, no relationship established
Correct
That’s right, there’s about a 16% chance, or 1 in 6, that TMD symptoms will accompany a posterior crossbite with a shift, given a 0.4 correlation coefficient between the two conditions. That is the highest correlation between any type of malocclusion and TMD, but it isn’t very high. Another way to say the same thing is that the data indicate that 5 times out of 6, TMD will not become a problem for a crossbite patient.
Incorrect
No, that’s wrong. There’s about 1 chance in 6 that TMD symptoms will accompany a posterior crossbite with a shift, given a 0.4 correlation coefficient between the two conditions. That is the highest correlation between any type of malocclusion and TMD, but it isn’t very high. Another way to say the same thing is that the data indicate that 5 times out of 6, TMD will not become a problem for a crossbite patient.
Question 7
(A) The chance that a Class III patient will have TMD symptoms is directly related to the severity of the Class III malocclusion because (B) Severe Class III patients have to shift their jaw on closure.
- A true, B true, A and B related
- A true, B true, A and B not related
- A true, B false
- A false, B true
- A and B false ✓
Correct
That’s correct. Both statements are false. In fact, patients with mild Class III problems are more likely to have TMD symptoms, probably because they have to shift to avoid incisor intereferences. Patients with severe Class III don’t have incisor interferences and don’t have to shift on closure. So there’s an inverse relationship between Class III severity and TMD, not a direct one.
Incorrect
No, that’s wrong. Both statements are false. In fact, patients with mild Class III problems are more likely to have TMD symptoms, probably because they have to shift to avoid incisor intereferences. Patients with severe Class III don’t have incisor interferences and don’t have to shift on closure. So there’s an inverse relationship between Class III severity and TMD, not a direct one.
Question 8
What’s the chance that a child with Class II malocclusion will be teased because of his or her protruding teeth?
- 10-15%
- 20-30%
- 40-50% ✓
- 50-70%
-
75%
Correct
That’s right, nearly half of Class II children report being teased by other children about their protruding teeth; that is more than we would like but not quite the majority. If the teeth protrude badly enough, adults are likely to assume that child isn’t very smart and may treat him or her accordingly. That isn’t teasing, but it can be psychologically damaging.
Incorrect
That’s wrong. Nearly half of Class II children report being teased by other children about their protruding teeth; that is more than we would like but not quite the majority. If the teeth protrude badly enough, adults are likely to assume that child isn’t very smart and may treat him or her accordingly. That isn’t teasing, but it can be psychologically damaging.
Question 9
(A) Patients often are reluctant to admit that they are seeking treatment because of concerns about dental/facial appearance because (B) They think physical and functional problems are more likely to impress doctors.
- A true, B true, A and B related ✓
- A true, B true, A and B not related
- A true, B false
- A false, B true
- A and B false
Correct
That’s right. These statements are both true and related. For sure, patients often are reluctant to admit esthetic concerns. Why that’s true varies, but often it relates to the feeling that psychosocial concerns shouldn’t be admitted, especially since the doctor probably wouldn’t take them seriously anyway.
Incorrect
No, that’s wrong. These statements are both true and related. For sure, patients often are reluctant to admit esthetic concerns. Why that’s true varies, but often it relates to the feeling that psychosocial concerns shouldn’t be admitted, especially since the doctor probably wouldn’t take them seriously anyway.