Correlations between the Thickness of the Mandible and the Bone Mineral Density according to the Dentition

Seo, Youn Kyoung; Chang, Nam Jin; Jeon, Yu Mi; Kim, Kyung Tae; Choi, Yun Young; Paik, Doo Jin

Abstract

The morphometric data which reflect the quality and quantity of the mandible are very important to the surgeon for the mandible. It is very useful clinically to predict the status of the mandible indirectly by other medical examinations. This study was undertaken to clarify the correlations of the mandible and dentition to predict the thickness and bone mineral density of the mandible. Sixty-one mandibles (32 M/29 F, mean age: 66.72 years) obtained from the collection of the Department of Anatomy and Cell Biology of Hanyang Medical College were analyzed. The bone mineral density was measured by dual energy X-ray absorptiometry. In the mandible, bone mineral densities at the mandiblular angle, between molars and premolars, around incisors and the thickness, and the length at the sections through the 1st and the 2nd molars were measured. The data were analysed with SPSS 12.0 program (One-Way ANOVA) according to age, gender and dentition, to verify the statistical significance and the correlation between the thickness and bone mineral densities. The obtained results were as follows. 1. The bone mineral density in the mandibular areas were variable, but statistically insignificant except incisor area. The bone density of the mandible was highly correlated with the thickness of cortical bones and the highest correlation coefficient was shown in sum of the thickness of buccal and lingual cortical bone (correlation coefficient, r=0.622) 2. The thickness of cortical bones at the sections through the molars in the man were greater than those in the woman. The correlation coefficient between the thickness and bone mineral density at the molars were greater in the woman. 3. The bone mineral density of whole mandible, the thickness of lingual and basal cortical bones and the height of alveolar ridge were significantly higher in the specimens with both of the 1st and 2nd mandibular molar teeth. The results of this study represents the significant differences of bone mineral density in the mandible according to gender and dentition and also the significant correlation between the bone mineral density and the thickness of cortical bone.