Three-dimensional observation of internal structure in the region of mandibular deciduous canine using Micro-CT

The objective of this study is to clarify the changes in the internal structure of the surrounding area in deciduous canine and in relation to the development of successive permanent teeth. We observed the mandibles of the dry skulls of Indian children, using Micro-CT, and measured height of the compact bone at the mandibular base. When the first molars reached the occlusal line in addition to the deciduous dentition stage, the superoinferior position of canine bony crypt located lower than that of other permanent teeth. After this eruption stage, the bony crypts of canine showed inferior growth, resulting in compact substance's resorption of the mandibular base. When the central and lateral incisors reached the occlusal line, resorption of compact substance was advanced, but adjunction was observed after deciduous canine shed. Trabecular bone appeared for some directions in the region of sponge bone. The height of compact bone at the mandibular base was measured to elucidate the changes of the compact substance inside of the mandibular base with advancement of the dental eruption stage. The result of measurements quantitatively showed that the bone resorption advanced to the state of central and lateral incisors reached the occlusal line and adjunction occurred after deciduous canine shed.