Class III Malocclusions Flashcards
what is the BSI definition of a class III malocclusion
lower incisor edges occludes anterior to the cingulum plateau of upper central incisors
overjet is reduced or reversed
what are four aetiological links to class III malocclusions
strong genetic link
cleft lip and palate
acromegaly
asian populations
what can the aetiology of class III malocclusions be linked to with regard to AP relationships
small maxilla
large mandible
combination
what alignment in the maxilla is usually associated with class III malocclusions
crowding
what alignment in the mandible is usually associated with class III malocclusions
spacing
what are dento-alvolar compensations of a class III malocclusion
proclined upper incisors
retroclined lower incisors
what are three reasons why class III malocclusions might need to be treated
aesthetics
dental health - attrition
function - speech and mastication
what four aspect may make class III malocclusions more difficult to treat
increase number of teeth in anterior crossbite
skeletal element involved
increase in AP discrepancy
presence of anterior open bite
what are five treatment options for correction of class III malocclusion
accept/ monitor
intercept with URA early
growth modification
camouflage
combined orthognathic/ orthodontic treatment
when is treatment with early URA applicable for class III malocclusions
if class III incisors have developed due to early contact on permanent incisors
when is growth modification used for a patient with class III malocclusion
growing patient to reduce or redirect mandibular growth and encourage maxillary growth
what are examples of growth modification appliances used in treatment of class III malocclusions
chin cup
reverse twin block
frankell III
what is the frankel III
shields labially to upper incisors to hold lip away
palatal arch to procline upper incisors
lower labial bow to retrocline lower incisors
what is used in protraction headgear for treatment of class III malocclusion
have to wear facemask for 14 hours a day
400g per side
best when used in mixed dentition
rapid maxillary expansion used in conjunction
what is the extraction pattern used in camouflaging of class III malocclusions
extract further back in upper arch
extract further forward in lower arch
( eg upper 5s and lower 4s)
