Higher Contents of Mineral and Collagen but Lower of Hydroxylysine of Collagen in Mandibular Bone Compared with Those of Humeral and Femoral Bones in Human

Abstract

Minerals and collagen are major components of bone. At present, little is known about the material property of the jaw bone compared to other bones of the body. The purpose of this study was to characterize the material property of mandibular bone expressed by the amount of mineral, collagen, and hydroxylysine (Hyl) in comparison with humeral and femoral bones using human cadavers. Mineral and collagen contents were significantly higher in the mandible than in humerus and femur but Hyl was significantly lower in the mandible. Among the three indices, a weak but significantly positive correlation between collagen and mineral contents was observed. On the contrary, Hyl showed a weak but significantly negative correlation with mineral. The three indices were almost not affected by aging, gender, and dental status which were thought to influence bone quantity. These results suggest that human mandibular bone differs in material property from humeral and femoral bones, and may possess a higher mechanical property explained by the hypothesis that adequate and no excessive extent of lysine hydroxylation of collagen leads to optimal collagen fibrillogenesis and matrix mineralization. The assessment of bone property as shown in this study could disclose unknown characteristics which cannot be expressed by bone quantity.