1996 年 104 巻 3 号 p. 187-198
The external structure of the mandible is not only under the control of genetic factors, but is also influenced by biomechanical factors such as the masticatory muscles. As is well known, one of the characteristics of the morphology of the mandible which represents the influence of these factors is the gonial angle. It varies from a low angle with strong masseter development to a high angle with reduced muscle activity. The aims of this study were to investigate the internal structures of vertical sections of the mandibular body and to evaluate the relationship between these structures and the gonial angle.
A principal component analysis grouped all cortical thicknesses except for the buccal cortical bone thickness together with large loadings on the ame factor. Buccal cortical bone thickness was more variable than the other variables and showed a different pattern of variation.
The gonial angle was associated with buccal and lingual cortical bone thickness in the second molar section, and was also related to the height of the symphysis and the height and width of the second molar section. These results confirmed the relationship between the gonial angle and the size of the mandibular body at the second molar region.
This study provided evidence that masticatory function influenced on both the internal structure and the size of mandibular body.
