Class II Div I Flashcards
What is a class II div I?
Lower incisal edges lie posterior to the cingulum plateau of the upper incisors
There is increased overjet and proclination / average inclination of maxillary incisors
What % of people are class II div I?
15-20%
What are the main causes for concern of Class II div I
Concerns over aesthetics
Trauma concern due to increased overjet and proclined incisors
Overjet >9mm is twice as likely to suffer dental trauma
What often causes a class II skeletal base?
Most commonly a retrognathic mandible
Maxillary prognathism is less common
What Eastman values typically present in those with a class II div I?
Decreased SNB angle due to retrognathic mandible
SNA usually average but can be increased if prognathic maxilla
ANB angle > 5
How do the soft tissues often present in a class II div I case?
Often lips are incompetent due to proclination of upper incisors
Lip trap
What dental factors often present for a CII DI?
Increased overjet regardless of proclination of incisors
Overbite variable
Alignment, crowding or spacing
Incompetent lips can lead to xerostomia and more pronounced gingivitis
Give occlusal features of digit sucking habit
AOB
Proclined MI
Retroclined MI
Unilateral posterior crossbite due to narrowing of arch
What are the possible management options for class II div I?
Accept
Attempt growth Modification
Simple tipping of teeth
Camouflage?
Orthognathic surgery
When is accepting a CII DI ok?
What must you do if they accept?
Mild overjet
Significant overjet but not unhappy
Give advice regarding a mouth guard for trauma protection
How would growth modification fix a class II div I?
Headgear can be used to restrain growth of prognathic maxilla
Use of a functional appliance twin block to position mandible anteriorly and use of a Roberts retractor to retract proclined maxillary centrals
When should a functional appliance be used?
Early use around 10 years old
- 2 phase treatment
Later use in late mixed or early permanent dentition
- 1 phase treatment
What are some disadvantages of early treatment with functional appliances for class II div I?
Time for treatment increased to 2 phase tx
- early functional
- fixed later
Early skeletal effects from functional appliances or headgear not maintained in long term
Possible benefits of early treatment in CII DI with functional appliances?
Improve aesthetics sooner which can provide possible psychological benefit to pt
Reduce risk of trauma earlier
Often better compliance if exposed to tx earlier
When is orthognathic surgery usually indicated in a class II div I case?
When growth is complete
When there is a severe AP skeletal discrepancy
