Class II Div II Malocclusion

Question 1

What is a class II Div II Malocclusion?

Answer 1

This is where lower incisor edge occludes posterior to cingulum plateau of the upper centrals and the UPPER ICNISORS ARE RETROCLINED

OJ is often reduced and we often see classic flaring of lateral incisors

Question 2

What is the aetiology of a class II Div II maloclusion?

Answer 2

Skeletal cause - Often class II skeletal discrepancy, typically reduced FMPA, reduced lower face hight

Soft tissues - high resinting lower lip, marked labio-mental fold, high masseteric forces, short clinical crown hight of laterals

Dental factors - retrained upper incisors, upper laterals often crowded and can be proclined, laterals having poor cingulum form, increased OB, stripping of lower labial mucosa, class II molars, OJ usually reduced

Question 3

What is the common skeletal pattern of class II Div II pt?

Answer 3

A/P skeletal base relationship - usually class II (this is where A is >2-3mm infront of B), the mandiblee is usually retrognathic and chin retrogenic

Pt usually has reduced FMPA and LAFH is usually reduced and often progrenia of chin

Question 4

What is class II sekelatl pattern often associated with?

Answer 4

forward rotational growth pattern of the mandible which results in lower anterior face hight, forward growth and prominent chin

Question 5

Describe the chin of class II Div II pt

Answer 5

Mandible is often retrognathic (set further back)
Chin is often retrogenic but there is soft tissue prominence and lack of bony chin)

Question 6

Describe 4 soft tissue feauture of a class II Div II pt?

Answer 6

Higher resting lower lip

Marked labio-mental fold

Short clinical crown of upper laterals

High masseter muscle activity

Question 7

What is a high resting lower lip?

Answer 7

This is where the lower lip sits higher up on the crowns of the incisors and contribute to the retroclination of the upper incisors

Question 8

What causes a marked labio-metal fold?

Answer 8

This is due to high activity of mentalis muscle whihch results in retrocline of the lower incisor

Question 9

Why are master forces strong in class II Div II pts?

Answer 9

There is strong, busy muscles which can make space closure hard

Question 10

What is the impact of shorter upper lateral incisors?

Answer 10

Upper laterals are shorter in clinical crown size which means they can escape the effect of the high lower lip resting height and centrals procline whilst laterals done but then the lower lip can catch laterals and cause them to procline

Question 11

What are some dental feautures of class II Div II?

Answer 11

Retroclined upper incisors
Lower incisors can also be retroclined if high activity of metals reulting in force of lower lip retroclining them
Flared lateral incisors - reduced clinical crown height so escape effect of high rising lower lip but often get trapped on lip and retrocline
Poor cingulum form of upper lateral incisors
Upper teeth can traumayise and strip the lower gingiva (esp if deep OB)
Deep OB
Molar normally class II
OJ usually reduced
upper laterals often crowded and can be proclined
Increased OB - can occlude with teeth or palatal mucosa

Question 12

What is ANB of class II Div II pt?

Answer 12

> 4

Question 13

What is the incisor inclination usually like in Class II Div II pt?

Answer 13

Upper incisors - retroclined <110
Lower incisors - can be retroclined <90

Question 14

Why do we tx class II Div II?

Answer 14

Aesthetic reasons
Dental health concerns - traumatic OB stripping gingiva or palate

Question 15

What is IOTN for class II Div II with trauma?

Answer 15

4f

Question 16

What do tx options depend on?

Answer 16

Age of pt
severity of malocclusion
dental health
pt concerns

Question 17

What are the tx options for class II Div II?

Answer 17

Accept/do nothing

Functional appliance/growth mod

camoflague

orthographic surgery

Question 18

When might we accept/do nothing for class II Div II malocclusion?

Answer 18

If pt has no concerns, doesn’t want tx

mild class II Div II case

No dental health implications - ie OB not significant enough to cause trauma or ulceration

Question 19

When might we consider growth modification?

Answer 19

This is when pt ia still growing (ideally around 10-12 years old)

The aim of growth modification is use functional appliances to utilise muscle forces and growth and teeth to correct a malocclusion

we use a twin block appliance to procline the upper teeth and promote mandibular growth

Question 20

When do we use camoflague for class II Div II pts?

Answer 20

This can be used if mild skeletal discrepancy and we choose to accept this and instead change teeth to treat to class I incisor relationship

we want to procline the oupper incisors and lowe rincisors
reduce OB
palatal root torque upper incisors

Question 21

Do we need to XLA for class II Div II camouflage?

Answer 21

Sometimes we extract upper 4 and sometimes lower 5

Question 22

What is orthographic tx for class II Div II?

Answer 22

This is where pt has severe skeletal discrepancy and we carry out surgery once growth has stopped - at least 18 usually

we start with Otho to make pt class II Div I with OJ
then surgery
the post surgery ortho