class III malocclusion Flashcards
definition of class III malocclusion
lower incisor edge occludes aterior to the cingulum plateau of the upper central incisor
the overjet is reduced or reversed
what condition can contribute to a large mandible
acromegaly - overproduction of growth hormone by the pituitary
most common skeletal cause of class III malocclusion
maxillary hypoplasia
name 2 environmental factors that increase risk of class III malocclusion
- cleft lip and palate patients
- acromegaly (contribute to large mandible)
why is a bilateral crossbite common in class III malocclusion
hyposplastic maxilla tends to be set back against mandible - narrower portion of maxilla set against wider portion of mandible
what should be checked if a crossbite is identified
check for mandibular displacement
why should no irreversible treatment of a class III malocclusion be done until the patient has stopped growing
mandibular growth continues for longer than maxilla - there is a chance malocclusion will worsen
Anything irreversible prior to growth stopping could impact future surgery
what feature of a class III malocclusion may indicate that URA alone would be acceptable treatment
they can achieve an edge to edge occlusion
what type of functional appliance may be used for a class III malocclusion
reverse twin block
aim of growth modification when treating class III patients
aims to reduce and / or redirect mandibular growth and encourage maxillary growth
name 3 favourable features for camouflaging a class III malocclusion
- growth has stopped
- average or increased overbite
- able to reach edge to edge incisor relationship
- ANB not < 0
- little to no dentoalveolar compensation already present
3 common dental features of a class III maloccusion
crowded maxilla and spaced mandible
reverse OJ
dentoalveolar compensation
AOB
