Landmarks for assessing the age-related change in the position of the third molars

Abstract

   To create the landmarks for assessing the age-related change in the position of the third molars 3000 panoramic radiographs of patients in age from 7 to 25 years with different orthodontic anomalies (teeth crowding, teeth arches narrowing, medial and distal occlusion) were studied. The stages of formation of the third molars, angle of inclination of the third molars, position of the third molars relatively to the bisector of the gonial angle, and counterforces of the upper jaw and lower jaw were analyzed. Counterforces of the upper jaw are positioned vertically and do not interfere with the eruption of the upper third molars. If the distance from the counterforce to the third molar germ is more than 2,0 mm and the angle of inclination is more than 700, the eruption of the third molar is possible. But if the distance is not suffi cient enough and the angle of inclination is less than 700, the extraction of third molars is expedient. On behalf of this data, an order for the patent application was accepted and registered in the Russian Federation, registration number 2020144007 (incoming number 082341), on December 28, 2020.The distance from the crowns of the lower third molars to the bisector of the gonial
angle decreases with age. Analysis of the correctional connections of the parameters of the panoramic radiographs showed permanent dependance with age.