First Permanent Molar Flashcards
When is the best time for XLA first permanent molar?
Age 8.5yrs - 10yrs
When all permanent teeth present
Implications for loss of first permanent molar?
Disturbed occlusion
Orthodontic tx prolonged
Tx maybe more difficult
How can occlusion be disturbed?
Especially if XLA lower arch
If late - 7s may tip/rotate instead of moving
Upper 6s tend to be fine - lower 6s problem
How can XLA lower 6s cause problems?
- Tilt mesial
- Rotate mesio-lingually
- Lean lingually
- Over-eruption (if upper 6 over erupt - stop mesial movement lower 7)
Problems w/ prolonger orthodontic tx?
Higher caries rate
Doubtful cooperation
How would XLA first perm molar be diff in crowded and uncrowded arches?
Uncrowded - high degree of spacing - difficult to close w/ ortho
Crowded - good esp if 8s present and have premolar crowding
Factors to consider for timing of XLA?
Quality of the teeth
If 6s poor prognosis - 7s can replace 6s then used FA
Ideal time to XLA L6s?
Want to achieve spontaneous space closure
Ideal time - bifurcation of lower 7 visible
Possible favourable factor: lower 5 engaged bifurcation of E, lower 7 mesial angulated, lower 8 present
What to do if pt has 1+ poor quality first perm molar?
- Will pt need ortho? - if yes refer for early opinion
- Will affected tooth require crown/ RCT - if yes - consider XLA
- Consider XLA of other first molar
What happens if lower 6s XLA too early or late?
Too early - lower 5s become ectopic/ drift distal
Too late - little spontaneous closure
What is balancing and compensation?
Balancing - extraction same arch on opposite side
Compensation - extraction opposite arch on same side
Should 6s be balanced and compensated
Shouldn’t be balanced
Can compensate e.g consider XLA upper molar if lower XLA
Why must care be taken on XLA 6s?
Prevent alveolar necking = bone loss
Would reduce chance of tooth moving distally
