Class III Malocclusion Flashcards
Define class III
Lower incisal edge occludes anterior to the Cingular plateau of the upper central incisor
Overjet is reduced or reversed
What AP discrepancy makes it harder to treat class III?
Greater AP discrepancy = more complex to treat
What vertical discrepancies make class III the most difficult to treat?
Increased FMPA and anterior open bite
What transverse discrepancy is often seen in class III? Why?
Bilateral cross bites and retrognathic maxilla sits on wider part of mandible
What dental features are commonly found in class III?
Reduced / reversed overjet
Reduced overbite / AOB
Crossbites
Crowded maxilla
Spaced or aligned mandible
What factors of class III make treatment more difficult
> number of teeth in crosbsite
AP discrepancy
Presence of AOB
early age - mandible grows for longer
- so nothing irreversible until growth stopped
When could one accept a class III?
No concerns
No dental health indications
- no displacements or attrition
Very mild cases
When would interceptive tx be an option for class III?
Mild class III
- mandibular displacement to achieve ICP
- anterior crossbite
When may growth modification be used in class III?
Growing patient
Reduce mandibular growth and encourage maxillary growth
Good for functional appliances like twin block
How may orthodontic camouflage be achieved in class III cases?
Extract further back in upper arch and further forward in lower arch
Upper 5’s and lower 4’s
Aim to procline upper incisors and retrocline lowers while correcting overjet
What patient would be a good candidate for orthodontic camouflage?
Where we can accept underlying skeletal base
Growth stopped
ANB not less than 0
Average or increased overbite
Able to reach edge to edge incisor relationship
WHAT CLASS III PATIENTS WOULD TYPICALLY REQUIRE ORTHOGNATHIC SURGERY?
Growth completed
Moderate or severe skeletal discrepancy in all planes
