13 - Class 2 Division 2 Malocclusion Flashcards
Identify the Class II div II malocclusion
Class 2 division 2 incisor relationship
Definition
Class 2 division 2 malocclusion
Incidence
Main aetiology:
Examination
Profile assessment -
In class II patients there is an instep in the profile
Can be due to the maxilla or mandible:
- Maxilla could be further forward
- Mandible could be further back
Normally in Class II div II, it’s the mandible that is positioned further back
Mild skeletal II
Examination class 2 div 2 - Anterior Posterior
Anterior Posterior:
- Usually a mild skeletal II
- Convex facial profile
- Prominent chin
- Competent lips – Sometimes the lips mask the malocclusion
Mild mandibular retrusion on right clinical photograph, competent lips
But sometimes cannot tell if pt is class 2 div 2 frmo profile - such as left clinical photo - as lips are masking the malocclusion
Skeletal vertical assessment In class 2 div 2
Decreased vertical dimension -> deep over bite
Examination - vertical:
Lower face height + Frankfort mandibular plane angle reduced (FMPA) -> Deep bite
Reduced lower face height + FMPA (line between lower border of orbit and tragus, and see where intersection is- usu behind occiput)
Skeletal factors - Transverse
- Posterior Crossbites
- Transverse square faces.
- Well developed gonial angle (as tend to have well developed masseter muscles, square appearance )
Examination - Soft Tissue class 2 div 2
Left image - normal lip line 5-6mm of upper incisor shows at rest
Middle image - high lip line
Google labiomental fold - helps understanding
Examination Dental
Extra - Incisors erupt normally but as high lip line, pressure exerted up upper incisors leading them to retrocline and then lower incisors retrocline
Increased curve of Spee - caused by overeruption of the lower incisors
Interincisal angle - angle between u and l incisors should be approx 135 degrees , in class 2 div 2 - angle increases
Examination dental cont
Examination
Mandibular position
Swelling pattern
Growth
Radiographs - Cephalometric values
ANB - usu mild
Typically mandible is retronathic
Upper incisors typically retroclined
Lower incisors to mandibular plane also retroclined
Interincisal angle is larger
Vertical dimension - mmpa is smaller
Face height ratio is reduced
Treatment planning - 3 things required prior :
Why do we treat class 2 Div 2?
Class 2 div 2 Findings
Treatment depends on
3 categories of treatment options for skeletal problem
Most pt are mild - so orthodontic camouflage would be most common
Treatment options: Orthodontic Camouflage
Aims of treatment
MAIN TREATMENT FOR CLASS 2 DIV 2 - used for mild skeletal 2 and reduced vertical skeletal
Crowding correction
Mild crowding:
Moderate - Severe Crowding:
Moderate - severe skeletal 2
Commonly find which 3 things?
Aims of treatment
What 2 things must we do to correct dental problems?
Growth modification
How are skeletal problems corrected?
How are dental problems corrected?
Stages:
Treatment timing:
Which severity of skeletal issue?
Surgery
Used when?
What’s used to correct skeletal issues?
What’s used to correct dental issues?
Stages:
Treatment timing
What severity skeletal?
Not very common in class 2 div 2
Treatemnt of overbite - camouflage treatment
Can reduce overbite with an anterior bite plane - leads to intrusion of lower incisors + gap between upper and lower molars created
Posterior buccal segments erupt - leads to reduced bite
Once the overbite is corrected, if you leave treatment, the lower incisors will over erupt again
You need to correct the interincisal angle (angle between upper and lower incisors - Torque is the type of movement you require
The upper incisor crowns stays in the correct position, but the roots moves in the palatal direction
This torque movement is essential for overbite stability
Treatment of overbite with surgery/ growth modification
Stability and retention in class 2 DIV 2
Proclination of upper incisors without a change in soft tissue environment is not stable and should not do it
Summary
Aetiology:
Treatment depends on:
Stability :
Most need to be:
IOTN?
Do class 2 Div 2 need to be referred?
Why/why not? (4)
Referral for treatment
Why? (4)
When?
Where?
