Prolonging of mandible after loss of periosteum and inferior alveolar vessels in rabbits / 实用口腔医学杂志

ABSTRACT

Objectives: To study the prolonging of mandible by distr ac tion osteogenesis (DO) after severe trauma in rabbits. Methods:O steotomy was conducted in 16 adult rabbits. To simulate severe trauma,periosteum was removed and inferior alveolar vessels were destroyed on left side. The rabb its were randomly divided into 4 groups with 4 in each group and internal distra ctor was applied in each rabbit. In group A1 and A2 the latency time was 1 day,i n group B1 and B2 that was 7 days.In group A1 and B1 the distraction velocity wa s 0.5 mm/d,in group A2 and B2 that was 1.0 mm/d.The distraction length was 10 mm and retention period was 4 weeks. Results:4 weeks after operati on on right side complete new bone formation was found in the distraction area. On left side that was observed in group B1 and B2,but not in A1 and A2.Nonunion was found in 1,4,0 and 0 cases in group A1,A2,B1 and B2 respectively.The bending strength (10 4 N/m 2) of normal bone was 95,that in group A1,B1,B2 was 25,85 and 60 respectively. Conclusion:DO method can be used even after the blood supply of the mandibles has been destroyed, but the latency period sh ould be longer.