Increased Overbite

Question 1

Overbite

Answer 1

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

Question 2

Increased overbite

Answer 2

Upper incisors overlap lowers >4mm

Question 3

Reduced overbite

Answer 3

<3mm overlap

Question 4

Significance of increased overbite

Answer 4

Trauma - soft tissues ant palate
Prevents overjet reduction during tx
Dentofacial aesthetics
Restorative difficulties

Question 5

E/O features

Answer 5

Reduced lower face height
Class II

Question 6

Incidence of increased overbite

Answer 6

Increased overbite is a feature of many malocclusions
Most Class II Div II malocclusions
Many Class II Div I malocclusions

Question 7

Aetiology

Answer 7

AP skeletal discrepancy (Class II, III)
Increased interincisal angle (Class II, Div II)
Reduced lower face height
Unopposed lower incisors

Question 8

Why treat

Answer 8

Allow overjet reduction
Facilitate class I incisor relationship
Improve post tx stability
Facilitate restorative tx

Question 9

Reducing an increased overbite - growing pts (<14 yrs)

Answer 9

Anterior biteplane
Functional appliance e.g, CTB/Andresen
Fixed appliance

Question 10

Reducing an increased overbite - non-growing pts (>14yrs)

Answer 10

Orthogathnic surgery required
Fixed appliance alone
Refer deep bite pts early

Question 11

Anterior biteplane - growing pts

Answer 11

Biteplane only contacts lower incisors
Posterior mandibular rotation
Eruption of molars

Question 12

Functional appliances

Answer 12

Class Div I malocclusions
Anterior biteplane effect, the posterior teeth are separated vertically when wearing the appliance
Trimming posterior inter-occlusal acrylic allows eruption of posterior teeth
Facilitates full overjet reduction

Question 13

Fixed appliance

Answer 13

Overbite reduction is mostly due to molar extrusion
Some incisor intrusion is possible