Bone Healing Process of Deciduous Tooth Extraction Sockets

In order to observe objectively the change in the bone trabecula in the upper portion of permanent tooth germs after extraction of deciduous teeth, three-monthold puppies were studied. Macroscopic observation of roentogenograms, quantification of radio opacity in microphotography, and chronological observation were made. The results were as follows: 1. On the 3rd day after the extraction, the concentration curve of the extraction sockets of both the mesial and distal roots rose. For the distal root, the rising trend was more marked for the lower portion than for the middle por- tion. Part of the alveolar bone fell into the high concentration area and the first change after the extraction was observed. 2. On the 7th day after the extraction, the concentration curve of the extraction sockets of both the medial and distal roots rose. In particular the curve for the middle portion was in the high concentration level, which suggested that the osteogenesis was in the most active stage. The alveolar bone and cortical bone were constant in the level of concentration. 3. On the 10th day after the extraction, the concentration curves for the upper and middle portions of the extraction sockets of the mesial root showed a rising trend and the incline for the middle portion was marked. The lower portion of the extraction sockets of the mesial root and the middle portion of the extraction sockets of the distal root were stabilized on the concentration curve. 4. On the 35th day after the extraction, the extraction sockets of both the mesial and distal roots were approximately stabilized in the low concentration level. The concentation curve for the alveolar bone was still rising on the mesial root side and that on the distal root side was restored to normality.