ABSTRACT
Objective@#To compare the influence of extraction and retention of the intruded dogs' teeth on permanent successors.@*Methods@#Nine healthy 45-days-old Chinese rural puppies were selected, and six were submitted to the intrusion of the bilateral canine. Intruded teeth on the left side were extracted 30 minutes later and the teeth on the right side were kept in their sockets. After 8 months, all dogs were sacrificed. General observation, periapical radiograph and cone beam CT were used to observe the preoperative and postoperative deciduous teeth, permanent germs and permanent teeth development. The structure and content of successors' enamel were observed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS).@*Results@#In the extraction groups, the enamel hypoplasia was found in 19 permanent successors, ectopic eruption in 2 cases and abnormal teeth were in 19 cases in total (79%). In the retention groups, enamel hypoplasia of the permanent successors occurred in 2 cases, root dilaceration in 6 cases, and ectopic eruption in 5 cases, retained deciduous teeth in 3 cases, and there were 22 abnormal teeth in total (92%). In blank control group, there was no abnormal teeth. The major effect of intruded deciduous teeth on the permanent successors exhibited enamel hypoplasia [85% (41/48)], presented as enamel coloration and enamel defect (P=0.416).@*Conclusions@#The intruded deciduous teeth should be removed early in order to reduce the effect on the permanent teeth.
ABSTRACT
Objective: To observe morphological change and diversity of periodontium and alveolar bone after tooth transplantation into artificial tooth socket. Methods: 6 dogs were divided randomly into 2 groups: 2 dogs were used as the controls and 4 used for the experiment. In the control group 4 teeth were autotransplanted into the inherent sockets. In the experiment group 4 teeth were autotransplanted into the artificial sockets. The dogs were sacrificed at the 16th week after operation. The healing condition of periodontal tissue and the remodeling of alveolar bone were examined. Results: None of the transplanted teeth in both groups was loosen or dropped. Mircro-CT examination showed that cancellous bone and bone trabecula around the transplanted teeth lined tightly,no significant difference of bone trabecula thickness was observed between the 2 groups. Hard tissue slice examination revealed that parodontium of both groups grew and adhered to the teeth,and the quantity of new-born bone between the top of alveolar ridge and the neck of transplanted teeth was fundamentally the same in the 2 groups. Conclusion: Autotransplantation of teeth into the artificial socket is similar to that into inherent socket.