Anatomical reasons for the retention of third molars on mandibula

Abstract

To reveal the anatomical reasons for the retention of third molars the complex morphometrical research of mandible and facial skull was conducted with 250 human skulls. All the examined skulls were classified into two series: I - series with intact bite; II - series with impacted third molars. In these series we studied the main morphometrical characteristics of mandible and their correlation with main morphometrical characteristics of facial skull. It was established that the main anatomical preconditions for the complicated teething of third molars are the disproportion between the essential size of its crown and the mandibular size for its appropriate positioning. The complicated teething of third molars can be found more often in leptoprosopes than in meso- and euryprosopes that is caused by smaller sizes of retromolar space in leptoprosopes.