Objective To study the changing feature of massester muscle by measuring expression of myosin heavy chain mRNA after ostectomy of the mandibular angle along arc line.Methods Ostectomy of the left mandibular angle were performed on 25 New Zealand female rabbits aged three months.The unoperated right lateral was taken as the control.5 rabbits were sacrificed at the following intervals: 2nd,4th,8th,12th and 24th week.Massester immediately was dissected out and stored at-70?℃,subsequently the mRNAs of MHCⅠ,MHCⅡ and GAPDH were measured by RT?PCR.Results The amount of MHCⅠ mRNA on the left massester significantly decreased at the first 8 week.The amount of MHCⅡ mRNA was significantly decreased at the 2nd week,and then recovered after 4 weeks.MHCⅡ/MHCⅠ on the left masseter was significantly increased at the 2nd,4th,8th week.Conclusion The reconstruction of massester muscle after ostectomy of the mandibular angle is beneficial for reforming new balance of gnathostomatic system,thus restoring chewing function. |