Orthodontics Level 4 unit A:

Question 1

What are the goals of orthodontic treatment?

Answer 1

In the modern age, there are three reasons for doing orthodontics—listed here in their order of importance:

Primarily, to help patients overcome psychosocial handicaps created by discrimination based on facial appearance

To improve function of the teeth and jaws

To improve oral health

Question 2

True or false. Bringing teeth into the correct occlusion and ideal alignment is enough for orthodontic treatment?

Answer 2

False, it isn’t enough to just replace missing teeth, or to bring the teeth into ideal alignment and occlusion without considering the esthetic outcome

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.

Question 3

Is there a relationship between malocclusion and oral health?

Answer 3

Hard tissue lesions: little or no relationship

Periodontal disease: a weak relationship

Question 4

How do third molars typically erupt?

Answer 4

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.

Question 5

What kind of problem can unerupted 3rd molars develop? How should they be managed?

Answer 5

They can produce health risks related to the bacterial flora around them and development of chronic inflammation; they are a lesser health risk but may become cystic and damage other teeth or produce significant bone lesions. Follow-up radiographs to monitor their status are needed if they are retained.

Question 6

What problem can partially erupted third molars lead to?

Answer 6

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.

An increased probing depth is found, and this is a hospitable area for the anaerobic bacteria that are now known to be the cause of periodontal disease. (not necessarily causative of periodontal disease)

Question 7

Should 3rd molars be extracted if they only erupt partially?

Answer 7

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

Question 8

What factors are influenced by dental occlusion?

Answer 8

Masticatory efficiency (although no need for perfect occlusion as teeth barely even touch during chewing)

TMD/occlusion

Question 9

What food is hard to chew with an open bite or large overjet?

Answer 9

pizza often offers a challenge is you have an open bite or large overje

Question 10

What kind of malocclusion is associated with crossbite?

Answer 10

lateral shift, however, 1 in 6 people with lateral shift have RMD

Question 11

What is the chance of developing TMD with class 3 and class 2 deep bites?

Answer 11

there’s only about a 10% chance of correctly predicting that TMD will develop in a patient with these malocclusions.

Question 12

Perfect occlusion decreases the chance of tmd but doesn’t eliminate it

Answer 12

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Question 13

What do protruding upper incisors give as an impression to other people?

Answer 13

That a person is stupid.

Question 14

psychosocial impacts of dentition

Answer 14

Protruding upper incisors suggest that you’re an idiot

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.

(3) Chin prominence (strength) means a lot.n 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).

Question 15

What are the reasons where orthodontic extractions is indicated?

Answer 15

2 main reasons:

Correcting crowding/protrusion

Camouflage of jaw discrepancy

Question 16

When are extractions done for crowding/protrusion?

Answer 16

As a general rule, extraction for crowding/protrusion is done for patients with Class I malocclusion

Question 17

When is extraction for camouflage done?

Answer 17

Class II or III problems.

Question 18

What determines whether teeth protrude or are crowded?

Answer 18

if there’s not enough room for the teeth, soft tissue characteristics of individual patients determine whether they’re crowded, are protrusive, or have some aspects of both.

Question 19

What determines whether or not teeth are too protrusive?

Answer 19

Lips are separated at rest and are strained/everted on closure.

Question 20

What is the purpose of extraction in the treatment of crowding/protrusion?

Answer 20

Providing space to align crowded teeth without protruding them

Provide space to retract protruded teeth to normal relationship with the lips and the jaw

Or both.

Question 21

Why did extractions increase and decrease in orthodontics over the years?

Answer 21

In the early 20th centures expansion of the arches was the usual treatment and by mid 20th century extractions increased in frequency to create a more stable result.

Increased use of bands in the mid 20th century also meant more patients needed extractions.

Question 22

Why in recent times is extraction much less common than it used to be in the id 20th century?

Answer 22

Too much incisor retraction can harm facial aesthetics in some patient

Research data in the 1970s showed that relapse into crowding still occurred in some patients after extractions were done reducing enthusiasm for extraction.

Bonding of attachments largely replaced banding so band space wasn’t a consideration anymore

some practitioners linked premolar extraction–wrongly–to the development of TMD. Those claims, though false, led to a widely reported lawsuit and a more defensive approach by some practitioners.

most clinicians agree that it is more difficult and takes longer to treat extraction cases well, which tends to reduce enthusiasm for extraction in borderline cases.

Question 23

Why is orthodontic expansion more successful now than it was many years ago when extractions were more common?

Answer 23

If you can keep the first permanent molars from shifting forward into the leeway space then that space can be used for anterior teeth.

Transverse expansion of the dental arches has been shown to be more stable than antero-posterior expansion. In current treatment transverse expansion is emphasized.

Question 24

How much expansion can be tolerated?

Answer 24

Lower incisors can be moved forward 2mm if they’re not already protrusive

Very little expansion across canines is stable

2 - 3mm expansion across the premolars and molars is tolerated.

Question 25

Which of the following are reasons for the decline in the percentage of patients with premolar extraction to treat crowding/protrusion?

a. Effects on facial esthetics
b. Instability even after extractions
c. Introduction of bonded brackets to replace bands
d. Considerations of treatment efficiency

Answer 25

All of the above