The mandibular symmetry evaluation of total temporomandibular joint replacement on developing sheep

ObjectiveTo evaluate the mandibular symmetry effect of temporomandibular joint (TMJ) replacement by surgicase5.0 software.MethodsSix developing sheep were included in our study. Spiral computed tomography (CT) data of all sheep was obtained and transformed into 3-dimensional model by surgicase5.0 software preoperatively. 3-dimensional resin skull models were obtained and total TMJ prostheses were made. The right sides of all sheep were carried out operation based on preoperative planning as the experimental group, while the left sides were as the control group. CT scanning was performed one, four and twelve weeks after operation. Ramus heights (RH), mandibularbody length (ML), condyle-incisor (CI) and supramental-condyle (BC) of both experimental and control group were measured to be compared by Wilcoxon Signed Rank. Meanwhile those measurements were also compared with preoperative counterpart by Wilcoxon Signed Rank respectively.ResultsAll animals were alive to the end of this experiment with normal eating. There were significant differences for RH, CI, BC between the experimental and control group after twelve weeks. The comparison before and after operation on experimental group showed that there was significant difference on ML, CI and BC after four and twelve weeks. The comparison on control group showed that there was significant difference on ML, CI, BC after four weeks and RH, ML, CI, BC after twelve weeks.ConclusionIn conclusion, we deduce that sheep carried out by custom-made TMJ prosthesis can eat well. However the long term results of total TMJ replacement on developing sheep may not be very good.