172 Embryological and Developmental Understanding in Improving Outcomes of Canine Exposure
A Gupta, K Ganesan- Surgery
Abstract
Aim
85% cases of canine impaction are palatal. This presentation reviews the surgical factors to consider in predicting outcomes for canine exposure.
Age - Apexogenesis of the canine root completes by 16 years. Exposures should be considered before root completion. Where the patient is over 16y, a bracket & chain should be considered.
Vertical level of impaction - Mcsherry’s rule of thirds suggests the Orthopantomogram can be used to grade the vertical level of impaction. Grade 2 and 3 impactions will most likely require a closed approach.
Role of the follicle – The follicle is a source of RANK, CSF-1 and progenitor cells involved in bone remodelling and formation of root-bone surface. Therefore, during surgical exposure, the follicle should not be stripped. Ankylosis may occur from radical removal of dental follicle as bone deposition occurs in the created space. Orthodontic mobilisation should be considered within 4-6 weeks of exposure whilst the woven bone is to mineralise.
Method
Surgical outcomes were reviewed to assess these theories. Data was collected for the canine exposures done in the department over a 7-year period. The re-exposure rates is compared to the National re-exposure rate reported by Spencer et al.
Results
Over 500 palatal canines were exposed. 90% were successfully aligned. 0.6% cases required re-exposure. Spencer et al. reported a re-exposure rate of 3% for open exposures.
Conclusions
By applying the follicle preservation theory and considering age and level of impaction in surgical decision making, our service demonstrates that canine exposure can be carried out with predictable outcomes.