| Objectives Cleft palate(CP)is one of the most common congenital malformation and in a high incidence of around 2%0 in China's newborn.The bone and soft tissue defects in CP deformity,which has seriously affected children's stomatognathic functions and their sociopsychological health.Currently,the traditional surgery was transferred nearing flaps to close fissures and extended the length of the soft palate,in order to rebuild the anatomical and physiological functions of palate,however,none of these techniques can achieve the reconstruction of the palatal bone and restore the normal muscle attachments.The postoperative scar formation affected children with facial growth,hence cauing the secondary maxillary hypoplasia may create severe influence on the far-reaching social and psychological obstacles for the patients and their families.In recent years,using distraction osteogenesis(DO)to Correcte skeletal deformities and defects became more and more popular.It is simple,less trauma,less scar formation without bone graft.When the new bone was formated,the muscle and other soft tissue attaching to the surface of bone is also increased,for these unique advantages,it is gradually become a favor.In this study we use macaque as laboratory animal,establish cleft palate animal model to observe its feasibility and the effectiveness of clinical treatment for future experimental research platform.Then we try to use DO to closed the cleft and observe the mode and change characteristic of new bone formation.At present,the palate DO has no finished product.They are all researched and elaboratethed by scholars themselves.In our study,we designed a new type of cleft palate distraetor,used it in the DO and evaluated the application of the stability and applicability.Methods1 Using surgical way to cut 25×6mm rectangular bone at one side of hard palate and form an oral and nose perforated defects to establish cleft palate animal model.6 weeks after operation,two animal were sacrificed,check the fissure by the way of X-ray and general observation,thus verifying and judging whether the cleft palate model is established successfully.2 On the basis of the animal model above-mentioned,an osteotomy was formed,we installed the distractor designed by ourselves,5 days following the osteotmy,distraction was started at a rate of 8mm / 24h for 5 to 6 days(distraction phase).After 5 days of distraction,the distractor was held in palace for 6 weeks consolidation phase).After the distraction was completed,3 animals each were sacrificed randomly at the week of 1,2,4,6,8,12,24 which were evaluated by histological,radiological and scanning electron microscopy(SEM)analysis to study the new bone formed in the distraction gap.Result1,All animals survived the surgery and had the performance of food spillage and choking,and this was similar to cleft palate patients.There was no spontaneous bone healing and the bone defect was kept steadily.We established macaque cleft palate animal model successfully.2,The self-developed intraoral pure titanium distractor experienced the traction and fixed period successfully and well preserved to dismantle except of one case of a compacting nut shedding but the main part remained stable.3,The bone defect on CP animal model was corrected by the intraoral distractor.4,X-ray examination showed that at different time points the newly formed bone structure in the gap calcificated gradually near normal bone density.5,We can see the procedure that new bone was produced by osteoid and calcificated to matured gradually by SEM.Conclusion1,The macaque CP model established by surgery is a satisfactory animal model,it could survived all the research procedure.2,The intraoral pure titanium distractor was convenient to use,having good retention and stable effect.3,The stretch rate and speed of 0.8mm/day,6 weeks of consolidation used in this study had good effect for bone formation.4,The changes observed in the stretch gap confirmed that an exclusively intramembranous bone formation was observed during DO.
|
PDF Full Text Request