Angle's class III malocclusion is a condition where the mandible is positioned forward in relation to the maxilla, resulting in a reverse overjet. Features include a concave facial profile, mandible appearing well-developed, and a class III molar and canine relationship. Causes may be hereditary, functional habits, or skeletal asymmetries. Treatment depends on the patient's age, including growth modification in pre-adolescents using facemasks or chin cups, orthodontics in adolescents, and orthognathic surgery in adults using procedures like bilateral sagittal split osteotomy.
3. 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
4. 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)
5.
6. 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
8. 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.
9. 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
10. Correction of class iii
• Growth modification
• Orthodontic correction
• Surgery
11. • Should be identified and corrected early
• Treatment is highly dependent on the
patient’s age and hence;
- Preadolescent
- Adolescent
- Adult
12. PRE-ADOLESCENT CHILD
A) 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.
13. 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.
14. C) ANTERIOR FACEMASK
• Promotes maxilla to grow anteriorly and/or rotate
downwards. This causes a reciprocal downward and backward
rotation of the mandible.
15. 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.
16. 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.
17. 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
18. ADULTHOOD
• Emphasis is more on orthognathic surgery.
Bilateral sagittal split osteotomy with retraction of the
mandible
Segmental retraction