INFLUENCE OF THE PREMOLAR EXTRACTION ON PREDICTING ERUPTION OF THIRD MOLAR

Objective: The aim of this work was to evaluate predictive factors for wisdom teeth impactionin the upper and lowerjaw and to establish two predictive models. Materials and methods:This study was performed on90 patients who had been treated with and without premolars extraction.Lateral cephalograms of pretreatment and post-treatment were evaluated. Logistic regression analyses were performed in order to extract two predictive formulas. Results:The maxillary formula documented that premolar extraction enhance the chance of eruption by more than ten times, 1mm increase in PTM-M increases the risk of impaction by 68%. The mandibular formula revealed that premolar extraction enhances the chanceof third molar eruption by more than 4 times, 1mm increase in posterior space decreases the risk of impaction by 54%. Conclusion:Prediction of third molar impaction can be executed before orthodontic therapybased on the retro-molar space and the extraction decision.