Increased Overbite & Class II Div 2

Question 1

Definition of increased overbite (deep bite)

Answer 1

overlapping of the upper anterior teeth over the lowers in a vertical plane

Question 2

Describe increased overbite

Answer 2

upper incisors overlap lowers by more than 4mm

Question 3

Describe reduced overbite

Answer 3

less than 3mm overlap

Question 4

Significance of Increased overbite
Why to refer patient for treatment?

Answer 4

•Trauma – soft tissues of anterior palate

•Prevents overjet reduction during treatment

•Dentofacial aesthetics

•Restorative difficulties

Question 5

Typical extraoral features of increased overbite ?

Answer 5

•Reduced lower face height

•Often Class II

Question 6

Incidence of Increased Overbite

Answer 6

•Common in many malocclusions

•Most Class II Div 2 malocclusions

•Many Class II Div 1 malocclusions

•Some Class III and Class I malocclusions

Question 7

Aetiology of Increased Overbite

Answer 7

•AP skeletal discrepancy (Class II, III)

•Increased interincisal angle (Class II Div2)

•Reduced lower face height

•Unopposed lower incisors

Question 8

Treatment of increased overbite: Why?

Answer 8

•Allow overjet reduction

•Facilitate a Class I incisor
relationship

•Improve post-treatment stability

•Facilitate restorative treatment

Question 9

Reducing an Increased Overbite
1. Growing patients (ie. <14 years old)

Answer 9

•Anterior Biteplane

•Functional Appliance (eg. Andresen, Twinblock)

•Fixed appliances

Question 10

Reducing an Increased Overbite
2. Non-growing patients (>14 years old)

Answer 10

•Orthognathic surgery often required

•Sometimes fixed appliances alone

•Therefore refer deep bite patients early

Question 11

Anterior Biteplane – how does it work for growing patient?

Answer 11

•Biteplane only contacts with lower incisors

•Posterior mandibular rotation

•Eruption of molars

Question 12

Use of Functional Appliances in treatment of deep overbites …
What malocclusion are they used to treat ?

Answer 12

Class II Div 1 malocclusions

Question 13

How do functional appliances help to treat Class II div 1 malocclusions (deep overbite)

Answer 13

. Anterior biteplane effect, the posterior teeth are separated vertically when wearing the appliance

•Trimming posterior inter-occlusal acrylic allows eruption of posterior teeth

•This also facilitates full overjet reduction

Question 14

How to fixed appliances help to treat deep overbites?

Answer 14

Reduction in overbite is

•Mostly due to molar extrusion

•Some incisor intrusion is possible

Question 15

Increased Overbite: Summary
•Increased overbite is a …

Answer 15

common feature

Question 16

Correction of increased overbite allows …

Answer 16

full overjet reduction

Question 17

Correction of increased overbite is easiest in

Answer 17

growing patients, usually in the late mixed or early permanent dentitions

Question 18

Correction of deep overbites in .. is most difficult and often requires …

Answer 18

Adults
Surgery

Question 19

When to refer patients with deep overbites ?

Answer 19

Early

Late mixed or early permanent dentitions best time (age 10 to 13 years)

Question 20

The diagnosis of a Class II Div 2 malocclusion is based on

Answer 20

the incisor relationship

Question 21

Definition of class II div 2

Answer 21

Lower incisor edges are palatal to the cingulum plateau of the upper incisors and the upper central incisors are retroclined.

The overjet is usually average but may be increased

Question 22

Incidence of Class II div 2 incisor relationship ?

Answer 22

5-10 percent of population

Question 23

Class II Div 2: extra-oral features

Answer 23

•Skeletal II

•Reduced lower face height

Question 24

Class II Div 2: intra-oral features

Answer 24

. Retroclined upper (and lower incisors)

•Increased inter-incisal angle

•Deep overbite

Question 25

Class II Div 2: Cephalometry upper incisors/ Mx angle

Answer 25

UI Retroclined UI/Mx < 105º

Question 26

Skeletal relationship and ANB for Class II div 2?

Answer 26

Skeletal class II
ANB >4•

Question 27

Class II Div 2
Overbite ?
Lower facial proportions ?

Answer 27

Increased overbite
Reduced lower facial proportions

Question 28

Significance of Class II Div 2V

Answer 28

•Poor dental appearance

•Traumatic overbite

•Reduced lower face height

Question 29

Treatment of II Div 2: Aims

Answer 29

. Relieve crowding and align arches

•Reduce overbite

•Produce a stable incisal relationship

•Improve facial profile

Question 30

Treatment Options for class II div 2

Answer 30

•Fixed appliances
•Often also use URA to help overbite reduction

•Fixed Appliances + Surgery

Question 31

Treatment II Div 2: Fixed appliances- how ?

Answer 31

•Root control required to upright and then bodily retract upper incisors
•This type of tooth movement is called “torqueing”

Question 32

II Div 2: Fixed appliances: which cases?

Answer 32

•Crowded upper arch requiring extractions

•Crowded lower arch requiring extractions and alignment

•Acceptable facial profile

•Only in growing patients if there is a deep overbite

Question 33

II Div 2: Fixed appliances- clinically how

Answer 33

•Anterior biteplane usually used with fixed appliances to reduce the overbite

•Usually extract upper 1st premolars

Question 34

Class II Div 2: Fixed Appliances
Stage 1

Answer 34

Overbite reduction …

An upper removable biteplane and lower fixed appliance is an efficient way to reduce a deep overbite

Question 35

Class II Div 2: Fixed Appliances
Stage 2 …

Answer 35

Torquing upper incisors

Question 36

II Div 2: Surgery. Which cases?

Answer 36

•Adult patients (non-growing)
•too old for functional appliances

•Poor facial profile
•vertical: reduced lower face height
•AP: Class II skeletal pattern

•Deep overbite

Question 37

II Div 2: Surgery

Answer 37

Correction of incisor inclinations
using fixed appliances

Surgical correction of jaw relationship

Question 38

Prognosis, Retention and Stability of Class II Div 2

Stability depends on …
Must achieve …

Answer 38

•Stability depends on correction
of the inter-incisor angulation

Must achieve Class I incisors

Question 39

How to ensure good prognosis retention and stability for Class II div 2

Answer 39

Usually a lower fixed retainer

Question 40

Class II div 2 (increased overbite)

Treatment is ?
What is important ?
What is often required ?

Answer 40

Difficult
Overbite reduction
Fixed appliances

Question 41

Class II div 2: who may require surgery ?

Answer 41

Severe skeletal discrepancies or non-growing patients

Question 42

When to refer patients for II/2 ?

Answer 42

Refer patients early (late mixed or early permanent dentition). Age 10-11