Treatment class III malocclusion Flashcards
What is the british standard classification for class II malocclusion?
Lower incisor occludes in front of upper incisor cingulum plateau
How can the skeletal pattern of class III be corrected?
Dento-alveolar compensation
Can the patient acheive edge-to-edge incisors?
Why is it a problem if the patient has no overbite?
retention if a problem if there is no overbite
What is the class III skeletal pattern aetiology?
mandibular protrusion 26%
Maxillary retrusion 34%
Both 40%
What would you expect if have dento-alveolar compensation?
if their teeth are compensating for skeletal pattern would expect the upper incisors to be proclined and lowers to be upright or retroclined
What is the problem if incisors already proclines and lowers upright/retroclined?
If already compensated, then little that can be done to uppers - cant procline more
Causes the tooth to tip ar mid 1/3 of the root - this reduced the overbite further
How do you treat normal overbite and mid skeletal III?
Check where they are in RCP
No extractions
How do you treat moderate Class III skeletal?
Loss of overbite - no overlap Poor prognosis for stability Need upper and lower fixed appliances Consider extractions in lower arch, take out 2nd premolar as dont want lower anteriors to move too far back Then use class III elastics
How do you treat severe skeletal class III
Surgery
Limited compenstation
Teeth in right place then surgery to get teeth in right place
Pre-surgical - remove any compensation - may need to extract in upper arch to bring the incisors back
What can happen if class III and dont have an overbite?
Can end up with an anterior openbite
How do you treat mild class III skeletal pattern and reduced overbite?
Accept the skeletal pattern and just align the teeth
Need to accept there will be less of an overbite at the end
Need to wear retainer forever
May need to just alingn and not correct the anterior cross-bite
What is the treatment for reduced overbite, skeletal pattern moderate and severe class III
Surgery or align teeth and have indefinite retention
What treatment cant be done to correct cass III malocclusion in mised dentition?
Skeletal pattern growth modification:
Set the mandible back using a chin-cup; no evidence that mandible is affected, retroclines lower incisors, leads to possible TMD problems
Maxilla forwards usina face mask; worn full time (20 hours per day) for 4-6 months, if get early enough 9/10 can be effective
Class III functional appliance - doesn’t work because when patient in RC, cant move their jaw back any further - Frankel 3 appliance
What are the problems with class III functional appliances?
Only small amount activation possible
Maxillary retrusion possible
Continued growth
What is the potential problems checklist for correcting class III malocclusion?
Class III skeletal pattern Overbite Space interference from primary canines Position of permanent canines Growth
