Malocclusion Class 2 Div 1

Question 1

Class 2 div 1

Answer 1

-Lower incisors lies above cingulum plateau of upper central incisors.
- upper central incisors are at normal inclination or proclined
- increased Overjet

Question 2

Incidence

Answer 2

20%

Question 3

Aetiology of class 2 div 1

Answer 3

• Skeletal factors
• soft tissue factors
• Dento alveolar factors
• habits

Question 4

Skeletal pattern class 2 div 1

Answer 4

• sk Class 2 div 1 76%
• sk Class 2 div 2 15%
• sk class 1 Less than 30%
• sk class 3 less than 5 %

Question 5

Sk Factor - AP

Answer 5

• large maxilla
• small mandible
• posterior articulation of mandible with glenoid fossa

Question 6

Sk Factors vertical and lateral.

Answer 6

-All types ( Average, increased , reduced face height)
- facial asymmetry possible

Question 7

Soft tissues factors

Answer 7

-lip morphology - length or tone

• lip competence definition : ( lower lip resting height)- short upper lip or low lower lip
• anterior oral seal
• tongue

Question 8

Lip competency definition

Answer 8

Lips together at rest without muscular activity

Question 9

Lip competency describe?

Answer 9

-Resting height of lower lip should ideally cover Incisal third upper 21-12
- lip competence seems to improve with age due to growth and social acceptability.

Question 10

Habitual competency

Answer 10

Contraction of mentalis muscle alllow lips to meet.

Question 11

Why do lips matter in tx?

Answer 11

• Markedly incompetent lips may cause Relapse of overjet
• Ditto a low lower lip line.
• short upper lip may give an un attractive smile.

Question 12

Anterior oral seal

Answer 12

• Tongue to lower lip
• lower lip to palate

Question 13

Why do we need AOS?

Answer 13

Swallowing

Question 14

Dento alveolar factors
Crowding

Answer 14

Does not cause CLASS 2 div 1

Question 15

Habit

Answer 15

Digit sucking

Question 16

Treatment why?

Answer 16

• Asthetic considerations
• functional considerations
• dental health considerations
• To reduce the risk trauma to upper incisors in children > 10 years

Question 17

Incidence of incisors trauma

Answer 17

Greater than 9 mm 50%

Question 18

Treatment consideration

Answer 18

• dental Camouflage
• Growth Modification (restrained maxillary growth and more mandibular growth)
• correction of underlying sk problem

Pt should be fully informed and involved in decision making process

Question 19

Treatment Aims

Answer 19

• Relieve crowding
• Align the teeth
  -Reduce overbite
• Reduce overjet
• close spacing
• co ordinate upper and lower arch

Question 20

Treatment methods

Answer 20

-Upper removable appliance
- Functional appliance
- Fixed appliance
- Joint orthodontic / orthodonathic (surgical approach)

Question 21

Favourable feature for orthodontic treatment

Answer 21

• small ANB
• no dental compensation
• growing pt
• cessation of habit if present
• greater component of OJ being proclination of ULS

Question 22

Upper removable appliance
Clinical indication

Answer 22

-Overjet less than 8mm
- Proclined upper labial segment
- mesially angulated 3s’

Question 23

Removable appliance for which cases?

Answer 23

• Class 2 div 1 incisor relationship
• upper incisor crowding
• canine mesially angulted
• lower incisor lie anterior to upper root centroid
  -OJ less than 8mm
  -Proclined upper labial segment

Question 24

Removable appliance Aim

Answer 24

• Relief of crowding
• overbite reduction
• Overjet reduction

Question 25

Functional appliance:

Answer 25

- one stage treatment - Two stage treatment folllowed by fixed appliance therapy with or without XTs.

Question 26

When do we use Functional Appliance ? One stage

Answer 26

-One stage treatment - Overjet more than 8mm - well aligned arches - class 2 molar relationship -prepubertal

Question 27

Functional appliance: Clinical indication ?

Answer 27

- Overjet more than 8mm - crowding - class 2 molar relationship

Question 28

Stage two Fixed appliances Clinical indications

Answer 28

- Multiple tooth movement - bodily movement of upper labial segment - correction of rotations - space closure - Arch co ordination

Question 29

Orthognathic treatment when?

Answer 29

- Severe Class 2 sk pattern - tooth movement alone unable to achieve aims in terms of aesthetic, functions and stability - non growing pt

Question 30

General feature of SK

Answer 30

- 76% SK 2 base , If SK1 incisors relationship due to habit - cranial base angle high - mandibular rethrognathia - longer cranial base - prognathic Maxilla - may have small or large maxilla - average lower facial height. Normal cranial base angle 120-125

Question 31

General feature of Soft tissue

Answer 31

Incompetent lips Lower Lip trap Short upper lips

Question 32

General dental features

Answer 32

- class 2 incisor relationship - increased Overjet - OB deep incomplete - buccal segment can be class 2 or 1 - mandibular position : ensure pt not habitually posturing, treat to centric - facial growth - variable, usually favourable growth

Question 33

Which component of upper removable appliance reduce over jet?

Answer 33

- Robert's retractor