Experimental study on repair of alveolar cleft using distraction osteogenesis by micro-implant and tooth-borne intraoral distractor

PURPOSE: To evaluate the possibility of repairing alveolar cleft with distraction osteogenesis by micro-implant and tooth-borne intraoral distractor and the effects of micro-implant to anchorage tooth. METHODS: Fourteen adult mongrel dogs were divided into A(tooth-borne, n=6), B(micro-implant and tooth-borne, n=6)and C (the control, n=2) group. Alveolar bone resection was made surgically at first. After 2 weeks, the tooth-born complex transport disc was formed by osteotomy. Micro-implant was implanted into the transport disc in group B. Gradual distraction was started after 1-week latency. The dogs were sacrificed at 1 month after completion of distraction(1 month in control group). The samples were evaluated by clinical examination, histology observation. Date was analyzed for Fisher' exact test and t test with SPSS.10.0 software package. RESULTS: The alveolar bone gap disappeared in group A and B. The masculine number showed that there was significant difference between the two groups(P0.05), and the moving distance of anchorage tooth in bone had a significant difference between the two groups(P0.01). CONCLUSIONS: Distraction osteogenesis by micro-implant and tooth-borne intraoral distractor may be used for repair of alveolar cleft. Micro-implant can protect the pulp and periodontal tissues of anchorage tooth, and decrease the moving distance of anchorage tooth in bone.