Introduction to Orthodontics

Question 1

Malocclusion

Answer 1

Variation from ideal occlusion which has dental or psychosocial implications for the individual
Variation NOT disease

Question 2

Orthodontics

Answer 2

Branch of dentistry concerned with growth of teeth, jaws and face
Orthodontics moves teeth to improve occlusion and appearance thus correcting malocclusion

Question 3

Appliances

Various types

Answer 3

Fixed - brackets
Functional - dentofacial orthopaedics - modify growth of different facial bones to function together better - no teeth removed
Removable - interceptive orthodontics - small changes to dentition - single tooth movements

Question 4

Benefits

Answer 4

Improved aesthetics
Improved occlusion –> for masticatory fx and trauma
Caries risk reduced
Speech
Removal of unerupted or topic teeth –> resorption of surrounding teeth
Psychosocial wellbeing
Overjet linked to poor periodontal health, poor lip seal, increased likelihood of trauma

Question 5

Treatment of overjet

Answer 5

Functional appliance or headgear

Two phase tx between 8-10 or observe until adolescence

Question 6

Risks

Answer 6

Cost
Convenience 
discomfort and pain after first fitting 
Incomplete tx 
Interference with medical conditions 
OH - gingival health and PD health 
Demineralisation/caries 
Root resorption 
Relapse

Question 7

Root resorption

Patient factors

Dental factors

Answer 7

Unerupted or ectopic teeth
Genetic, nutrition, age
Short roots, ectopic growth and trauma

Short roots, ectopic growth, trauma
Tx factors

Question 8

Occlusal indices

IOTN

Answer 8

Index of orthodontic treatment priority 
5 grades 
4+ indicates Tx need 
4 (overjet over 6.5mm) 
Aesthetic component - 10 photographs compared to models 
Peer assessment rating

Question 9

Classification of malocclusion

Incisor

Answer 9

Class I - Lower tip occludes with or below cingulum plateau of upper incisor
Class II - div 1 and div II - tip behind cingulum

Div 1 - average inclination or proclined
Div 2 - retroclined

Class III - lower tip occludes in front of cingulum plateau - reverse overjet

Question 10

classification of Malocclusion

Molar relationship

Answer 10

Class I - MB cusp of U6 in mid buccal groove of L6

Class II - MB cusp of U6 anterior to mid buccal groove of L6 - half unit exists - cusp to cusp

Class III - MB cusp of U6 posterior to mid buccal groove - half unit exists