MORPHOLOGICAL-CHARACTERISTICS OF VERTICAL SECTIONS OF THE MANDIBLE OBTAINED BY CT SCANNING

The external structure of the mandible is not only under the control o f genetic factors, but is also influenced by biomechanical factors suc h as the masticatory muscles. As is well known, one of the characteris tics of the morphology of the mandible which represents the influence of these factors is the genial angle. It varies from a low angle with strong masseter development to a high angle with reduced muscle activi ty. The aims of this study were to investigate the internal structures of vertical sections of the mandibular body and to evaluate the relat ionship between these structures and the gonial angle. A principal com ponent analysis grouped all cortical thicknesses except for the buccal cortical bone thickness together with large loadings on the same fact or. Buccal cortical bone thickness was more variable than the other va riables and showed a different pattern of variation. The genial angle was associated with buccal and lingual cortical bone thickness in the second molar section, and was also related to the height of the symphy sis and the height and width of the second molar section. These result s confirmed the relationship between the genial angle and the size of the mandibular body at the second molar region. This study provided ev idence that masticatory function influenced on both the internal struc ture and the size of mandibular body.