The Affect To The Form Of Chin In Mesioclusion With Open Bite Operated By Orthognathic Surgery

ObjectiveFocus on mesioclusion with open bite, reconstruction of three-dimensional skull and simulation of orthognathic surgery on computer, measure the distance of open bite and in-surgery and after-surgery chin angle.Analysis the relation of open-bite distance and chin angle. Provide quantitative reference to the change of chin form before surgery.Materials and MethodsStudy in the 20 mesioclusion with open bite patients in our hospital, count their distance of open bite. Reconstruction of skull with three-dimensional CT image in computer. Simulation of maxillary Lefort I osteotomy and mandibular SSRO Measure the change of NP-FH angle and Y-axis angle, and analysis their relation with open-bite distance.ResultsNP-FH angle of mesioclusion with open bite patients increases after surgery. The open-bite distance and NP-FH angle change have a positive correlation. By the statistics analysis,we get a linear regression equation:Y1=0.82+2.06X.On the other hand,to the Y axis angle change, there is also a positive correlation and Y2=0.68+1.25X.ConclusionMesioclusion with open bite patients after orthognathic surgery, their open-bite distance has correlation with chin form. This correlation can provide quantitative reference for prognosis and analysis of orthognathic surgery.