The factors affecting mandibular third molar angulation during orthodontic treatment / 实用口腔医学杂志

ABSTRACT

Objective:To analyze the factors which affect mandibular third molar angulation changes during treatment of adult orthodontic patients.Methods:80 post-treatment adult patients including 154 mandibular third molars(M3) were selected.The gender,age,clinical classification and treatment methods of the patients were recorded.The pretreatment and post-treatment panoramic radiographs were analyzed.The angulation and the eruption space of mandibular M3 were measured.The root development stages of the mandibular M3 before treatment were evaluated.The factors affecting mandiular M3 angulation changes were analysed by covariance analysis.Results:The results of multi-factors analysis illustrated that the sagittal skeletal classifications,the root development stages of the pre-treatment mandibular M3,the pre-treatment mandibular M3 angulations,the width/space ratios before and after treatment affected the mandibular M3 angulation changes during the orthodontic treatment.Mandibular M3 showed more improvement in angulation in groups of Class I sagittal skeletal classification,the root development stages of the pre-treatment mandibular M3 where the root was fully formed but the foramen apices wasn't closed or the stages where the root less 1/3 was formed,the pre-treatment mandibular M3 angulations 60?,and the more M3 space before and after treatment,the more improvement in M3 angulation.Conclusion:In adult orthodontic patients,the mandibular M3 angulation changes during the treatment can be influenced by many factors,but orthodontic treatment is not the direct factor.