[Usefulness of the bodily movement of the tooth into the hydroxyapatite-packed extracted cavity].

Early application of bodily movement of teeth at an unfinished stage of the healing of the extracted wound i.e. ossification is presumed to increase the risk of jiggling. Using adult dogs, an experimental study was made on bodily movement in the case of HAp packing into the extracted wound cavity to avoid jiggling. When tooth movement was performed immediately after extraction and HAp packing, no encapsulation of HAp with fibrous connective tissue was noted. Either for a weak force or for a strong force, the moved tooth lacked alveolar septum on its compressed side, its dental root being in direct contact with the HAp mass. Remarkable enlargement of periodontal cavity on the tension side and strong osteoclastic resorption of proper alveolar bone were noted. When tooth movement was clone one week after extraction and HAp packing, Either for a weak force or for a strong force, the extracted wound surface was sealed and the HAp mass in the extracted wound cavity got encapsulated by fibrous connective tissue. Alveolar septum has disappeared completely on the compressed side of the moved tooth. Fibrous connective tissue lay between the dental root and the HAp mass and presented its partial osteogenesis. Vigorous bone apposition was noted in the proper alveolar bone surface on tension side. When tooth movement was done one month after extraction and HAp packing, definite ossification was noted in fibrous connective tissue which encapsulated the HAp mass in the extracted wound cavity. Alveolar septum on the compressed side of the moved bone presented resorption and disappearance. For a weak force, gradual ossification was noted in fibrous connective tissue which lay in the same region, and for a strong force, osseous adhesion to the HAp mass was noted. On the tension side, bone apposition was remarkable in proper alveolar bone surface either for a weak force or for a strong force. The above findings revealed thus most suitable time to begin tooth movement was one week after extraction and HAp packing.