intro to ortho

Question 1

What is malocclusion?

Answer 1

Variation from ideal occlusion which has dental health +/ psychosocial implications for the individual

Question 2

What is orthodontics?

Answer 2

Branch of dentistry concerned with the growth of the teeth, jaws and face

Improves occlusion and appearance by moving teeth

Question 3

What are the 3 types of appliances?

Answer 3

Fixed appliances
Functional appliances
Removable appliances

Question 4

What is dentofacial orthopaedics?

Answer 4

Modify growth to improve relationships between facial bones

Question 5

What are the benefits (or possible disadvantages of no treatment)?

Answer 5

Dental health (caries, perio, trauma, function [masticatory/speech], unerupted/ectopic teeth)
Social well being (removes social handicap, positive judgements by others, increased self esteem)

Question 6

What is the correlation between overjet and trauma?

Answer 6

14% w OJ 0-3mm
39% w OJ >6mm

70% of boys have OJ by age 10

Question 7

How can overjet be treated?

Answer 7

HEADGEAR/FUNCTIONAL
2 phase treatment
(Age 8-10 then again in adolescence)
Less incisal trauma

OBSERVE
1 phase in adolescence
More economical to restore trauma?

Question 8

What is the correlation between TMJ disorder and malocclusion?

Answer 8

Low correlation and unlikely to be of direct clinical significance

Question 9

Can alteration of tooth position improve function?

Answer 9

No definitive proof that it can improve articulation disorders

Severe AOB correction can improve mastication

Question 10

How might treatment affect unerupted/ectopic teeth?

Answer 10

Up to 50% case w ectopic maxillary canine shows root resorption
3 times more common in girls than boys
Rarely there can be cyst formation

So treatment can prevent this

Question 11

What are the reasons for ortho treatment?

Answer 11

Health is a state of complete physical, mental and social well being and not merely the absence of disease or infirmity

Question 12

What are the problems/risks of ortho treatment?

Answer 12

Cost/inconvenience
Pain and discomfort (pain 6hrs after first fitting, lasts 2-4 days)
Incomplete tx
Medical disorders (bleeding, epilepsy, allergy etc)
OH and status
Demineralisation—> caries
Root resorption (mean is 0.9mm for all max incisors and 17% >2.5mm for one or more)
Relapse

Question 13

What are causes of root resorption?

Answer 13

Patient factors- genetic, systemic disease, nutrition, age, gender, habits

Dental factors- short/blunt/pipette shaped roots, hx of trauma, ectopic canines, OJ, endo tx, alveolar bone density

Tx factors- length of tx, fixed a., rectangular arch wires, class II elastics, continuous forces, degree of force, jiggling forces, type of movement

IMPOSSIBLE TO PREDICT

Question 14

What is the index of Ortho tx need?

Answer 14

2 part index to measure priority
DHC and AC
dental health component and aesthetic component
Grades 1-5
Grade 3 is borderline so needs AC
Grade 4 and 5 is great need

Question 15

What are the occlusal indices?

Answer 15

IOTN
PAR- peer assessment rating (measures success of outcome)

Question 16

What is the classification of malocclusion?

Answer 16

Descriptive (incisors [class I, II div 1and 2, III] and buccal segments)

Question 17

What is incisor classification?

Answer 17

Assess the position of the lower incisor tip in relation to where it occludes w the upper incisor cingulum plateau

Class I- occludes with or below
Class II div 1- occludes behind (upper incisor are inclined/proclined)
Class II div 2- occludes behind (upper incisor retroclined)
Class III- occludes in front

Question 18

What is the molar relationship?

Answer 18

Occlusion of upper and lower first permanent molars

Class I- mesiobuccal cusp tip of upper 6 occludes in mid buccal groove of lower 6

Class II- mesiobuccal cusp tip of upper 6 occludes anterior to mid buccal groove of lower 6

1/2 unit class II- mesiobuccal cusp tip of upper 6 occludes cusp to cusp w mesiobuccal cusp tip of lower 6

Class III- mesiobuccal cusp tip of upper 6 occludes posterior to mid buccal groove of lower 6

1/2 unit class III- mesiobuccal cusp tip of upper 6 occludes cusp to cusp w distobuccal cusp tip of lower 6