MANAGEMENT OF ANGLES CLASS III MALOCCLUSION

By Collins C. AketchFriday, 19th April 2013

What is Angle’s class iii?

• This condition represents a prenomalcy where the mandible is

in a mesial relation to the upper arch

• According to angle, Class iii molar relationship refers to a

condition where the mesiobuccal cusp of the upper 1st molar

occludes between the mandibilar 1st and 2nd molars

• The lower molar can be in the said mesial relationship to

varying degrees

Features:Extra-oral Features

• A straight to concave profile

• Anteriorly divergent profile

• Long face (increased lower face height), which may

be pointed at the chin

• Mandible appears to be well developed (with an

obtuse gonial angle)

Features cont:

Intraoral Features

• A Class iii molar relationship

• A Class iii canine relationship

• A reverse overjet with possibly labially inclined lower incisors

and lingually inclined upper icisors

• A posterior cross-bite unilateral or bilateral (or functional)

due to a constricted maxillary arch or a more forward

positioned lower arch

Skeletal features:

i. Short retrognathic maxilla

ii. Long prognahtic mandible

iii. combination

Etiology:

• Hereditary (main factor)

• Functional factors and soft tissues (Flat, low, anteriorly placed

tongue that lies low in the oral cavity / macroglossia)

• Compulsive habit of protruding the mandible

• Unilateral or bilateral hyperplasia of mandibular condyle can

cause the Class III malocclusion.

Etiology cont…• Occlusal forces created by the abnormal eruption may

produce unfavorable incisal guidance

• Premature loss of deciduous molars may also cause

mandibular displacement with an occlusal guidance from

teeth

• Anteroposterior deficiency of the maxilla can occur in cases of

cleft lip and palate

• Trauma to the mid-face during the growth phase

Correction of class iii

• Growth modification

• Orthodontic correction

• Surgery

• Should be identified and corrected early

• Treatment is highly dependent on the

patient’s age and hence;

- Preadolescent

- Adolescent

- Adult

PRE-ADOLESCENT CHILDA) FRANKEL III APPLIANCE

• Stretches the soft tissue envelop around the maxilla in an

attempt to stimulate the forward growth of the maxilla. Does

not allow the mandible to advance forward.

B) THE CHIN CUP

• Applies forces, directed along the direction of growth of the

condyle. Inhibits the forward growth of the mandible

• Capable of moving the chin down and back.

C) ANTERIOR FACEMASK

• Promotes maxilla to grow anteriorly and/or rotate

downwards. This causes a reciprocal downward and backward

rotation of the mandible.

D) RME WITH ANTERIOR FACEMASK

• RME is used to split the mid-palatal suture causing a

downward and forward movement of the maxilla.

• During this instance the teeth are disoccluded.

• A facemask is used to pull the maxilla further forward.

E) 3-D SCREWS

• Capable of expanding the maxilla in all the three directions.

• Appliances, both removable and cemented can be used to

correct pseudo Class iii malocclusions and thus prevent their

progression to a full-fledged malocclusion.

THE ADOLESCENT CHILD• Limited to orthodontic camouflage or orthodontic

decompensation in an effort to prepare the patient for

surgery.

• Camouflage can be achieved by proclining the maxillary

anteriors and tipping the mandibular incisors lingually

• Single arch extractions, extraction only in the mandibular

arch, are frequently done to create space for the retraction of

the mandibular anterior segment

ADULTHOOD

• Emphasis is more on orthognathic surgery.

Bilateral sagittal split osteotomy with retraction of the

mandible

Segmental retraction

Thank You!