Variations in bone mass within the cortices of the mandible.

A study of intermandibular variations in bone mass in cortices between regions of the alveolar process and mandibular body and between buccal and lingual cortices in the same region has been carried out. The material consisted of 24 autopsy specimens of half mandibles from normal subjects. Microradiograms of ground sections from incisor, premolar, and molar regions were used. Quantitation of bone mass in percent within the cortices was done by an electronic point-counting system. The analysis indicates that bone mass may lie on nearly the same level all over in the entire lingual cortex. In buccal cortex, bone mass may vary from region to region, as a fall in bone mass from incisor to premolar to molar region in the buccal alveolar cortex, and a rise in bone mass from premolar to molar region in the mandibular body may occur. Bone mass in buccal incisor cortex of mandibular bodies shows great individual variations. Generally, bone mass may lie on a lower level in the buccal than in the lingual incisor and premolar cortec of the mandibular body while bone mass elsewhere lies on nearly the same level in the same part of the two cortices. Bone biopsies should be taken in either the premolar or the molar region of mandibular bodies.