ABSTRACT
Bone is a remarkable connective tissue that possesses the quality to undergo the process of remodeling to maintain its mass and structure depending on mechanical loading, however not all bones are subjected to mechanical loading yet they don't show disuse osteoporosis. In oral biology, tooth removal leads to alveolar bone resorption due to reduced mechanical load [like limb bone], however basal bone does not resorb so quickly on disuse despite the fact that there is less mechanical load on it [like calvaria]. So in this respect, mandible display features of both the limb bone and calvaria. Therefore the aim was to compare the amino acids composition of mandible with ulna and calvaria and the objective was to compare the bone samples with collagen standard. The commercial collagen type I from the rat tail tendon [sigma Aldrich, UK] was used as a reference to be compared with the bone samples. These samples were subjected to carbon-13 NMR spectroscopy. Results showed that the carbon-13 spectra of ulna and calvaria were almost similar, while mandibular spectra showed the most distinct results. Carbon-13 NMR study showed increased proline content in calvaria then ulna. However mandible showed greater hydroxyproline content and lower glycine content than other spectra. Furthermore, an important finding was the presence of additional amino acids particularly aspartate, leucine and isoleucine in mandible, and glutamate, phenylalanine and methionine in other bone spectra, that might suggests non-collagenous proteins in bone. Additional work is required using new techniques in the NMR that can separate collagenous proteins from the non-collagenous proteins to further explore the complex dynamics of bone