[Distribution characteristics of the root apices of multirooted teeth in the mandible].

Changes in the mandibular height and thickness of its alveolar part have been studied, with special reference to the relation existing between the apices of the molar teeth roots and the external and internal surfaces of the mandible and the mandibular canal. The investigation was carried out in 148 male and female sculls having the lower jaw, in 115 maxillodental cuts. It has been stated that the greatest mandibular height is in males at the level of the first premolar teeth (23.4+/-0.82 mm) and the smallest -- at the level of the second molar (32.01+/-0.52 mm). The thickness of the alveolar part at the level of the root apices of the first premolar is the smallest both in males and females (9.578+/-0.301 mm -- 11.068+/-0.69 mm); the greatest -- at the level of the third molar (13.0+/-0.632 mm -- 15.5+/-0.55 mm). The distance between the root apex and the external surface of the alveolar part is the least at the level of the first premolar, at an average 3.12 mm. The mandibular osseous structure and the relation of the tooth root with the mandibular canal are clearly seen in electroroentgenograms.