Clinical And Experimental Studies On The Isotension Continuous Sutural Distraction Osteogenesis For Maxilla Complex Advancement

【objective]1. To study the mechanism of bone formation by observing thehistology changes and bFGF,TGF-β1,VEGF expression inzygomatico- maxillary suture and new bone tissue2. To investigate the advantages of the sutural distractionosteogenesis in young children by evaluating the distracting effect of theimprovement we made in sutural distraction implements and distractingmethod through clinical observation and clinical test.【Methods】1. Animal experimentUse the goat as experimental animals, place the self-designed internalnickel-titanium shape memory metal brace on maxillary surface whichbridge zygomaticomaxillary suture and place titanium nail on the surfaceof the maxillary as a signal point which evaluate the distance the suturewas enlarged ,by taking X-ray regularly after operation to know thedistance maxilla moved, and get the new bone and suture tissue in4weeks,6weeks and 8weeks after distraction ,stain the specimen with HE,Toluidine Blue and Sirius red , observe the histology changes and collagen changes through the normal microscope and polarizationmicroscope, the expression of bFGF,TGF-β1,VEGF is investigatedby means of immunohistochemistry.2. Clinical researchwe design nickel-titanium shape memory metal spring andnickel-titanium shape memory metal hook, use the rigid externaldistracting device and continuous sutural distraction technical to treat 8patients with midface displasia and maxillary retrusion after cleft lip andpalate operation, taking the photos, x-ray, CT, dental cast andnasopharyngeal fiberscope to investigate the result after distraction andto estimate the effect by cephalometry.【results】When the time goes by, all goats' maxillary complex advancesuccessfully, theⅠtype collagen in sutural tissue and new boneincreases,and theⅡandⅢtype collagen decrease little by little ,atlast ,it is made up ofⅠandⅢtype collagen ,six weeks afterdistraction,the cartilage cell group appears ,we can observe bonetrabecula between the cartilage cell group and the new bone formation inthe suture tissue and subperiosteum on the surface of the maxilla, bFGF,TGF-β1,VEGF expressed in all groups and varies with distractingtime.In clinical study , 8 patients involved who has midface displasia after cleft lip and palate operation company with maxillary retrusion ,werectified the deformity by distracting the maxilla complex withcontinuous, isotension strength , the maxilla complex advance enoughdistance as we predict, the occluding relation of the patient becomenormal,midface concave has been rectifed, the relation of the organs onthe face become nice and harmony.【conclusions】①Cartilaginous osteogenesis is a kind of boneformation in the sutural tissue ,three kinds collagen take part in the boneformation during the distraction and play a important role ,on the surfaceof the maxilla, mechanism of bone formation is intramembranousosteogenesis, bFGF,TGF-β1,VEGF play a important role in boneregeneration.②The sutural distraction osteogenesis is a kind of safe,effective method to cure the midface displasia deformity of the children,it can offer the children an opportunity to rectify the midface displasiawho suffer from the cleft lip and palate operation early without too muchoperation injury, ensure they build self-confidence and get rid of theproblems come from the deformity.