Class I Malocclusion

Question 1

British Standards Institute 1983 Class I Incisal Relationship

Answer 1

The lower incisor edges occlude with or lie immediately below the cingulum plateau of the upper central incisor

Question 2

British Standards Institute 1983 Class II Incisal Relationship

Answer 2

The lower incisor edges lie posterior to the cingulum plateau of the upper incisors

Question 3

British Standards Institute 1983 Class II Division 1 Incisal Relationship

Answer 3

1. Upper central incisors are proclined or of average inclination
2. Increase in overjet

Question 4

British Standards Institute 1983 Class II Division 2 Incisal Relationship

Answer 4

1. Upper central incisors are retroclined
2. Minimal overjet or increase in overjet

Question 5

British Standards Institute 1983 **Class III ** Incisal Relationship

Answer 5

1. The lower incisor edges lie anterior to the cingulum plateau of the upper incisors
2. Overjet is reduced or reversed

Question 6

Angle Classification of Class I Molar Relationship

Answer 6

MB cusp of the upper first molar occludes with the MB groove of the lower first molar

Question 7

Angle Classification of Class II Molar Relationship

Answer 7

MB cusp of the upper first molar occludes mesial to the MB groove of the lower first molar

Question 8

Angle Classification of Class III Molar Relationship

Answer 8

MB cusp of the upper first molar occludes distal to the MB groove of the lower first molar

Question 9

Andrew’s Molar Classification Class I

Answer 9

DB cusp of upper first molar contacts MB cusp of lower second molar

Question 10

For Diagnostic Cases, how much incisal overjet and overbite should there be in a BSI Class I Incisal Relationship?

Answer 10

1. Incisor overjet of 2-3mm
2. Incisor overbite ≥ 1mm to a limit where lower incisor crown is still visible

Question 11

What are the components of a Class 1 Malocclusion

Answer 11

1. Skeletal
2. Dental

Question 12

What are the skeletal components of Class I Malocclusion

Answer 12

1. DAC and Steiner’s compromises

2.Vertical excess and deficiency

3. Skeletal asymmetry

Question 13

What are the dental components of Class I Malocclusion

Answer 13

1. Spacing and crowding
2. Displacement
3. Supernumerary or hypodontia
4. Buried teeth, tooth shape anomaly
5. Variation in teeth inclination and angulation, cross bite

Question 14

What is Steiner’s compromises?

Answer 14

Variation in upper and lower incisor inclination (affect ANB value) which may mask a skeletal discrepancy