Comparison of Rigid and Semirigid Fixation for Advancement Genioplasty

To compare the skeletal stability of rigid versus semirigid fixation for advancement genioplasty by the assessment of vertical and horizontal measurements pre-operatively and post-operatively on lateral cephalometric radiographs. The study comprised of patients who underwent standard advancement genioplasty by inferior osteotomy of the chin with broadest musculoperiosteal pedicle with either rigid fixation or wire fixation. The displacements of vertical and horizontal measurements resulting following surgery was derived by calculating the difference between preoperative, immediate post-operative and 1 year post-operatively on lateral cephalometric radiographs. Preoperative measurements were marked as T1, immediate post-operative as T2, 1 year follow up post-operative as T3. In the semirigid group a mean horizontal advancement of 5.97 mm was accompanied by a relapse of 1.623 mm during a period of minimum 1 year. The mean superior repositioning of menton was 0.7 mm. This was accompanied by a relapse of 0.325 mm during a period of 1 year. In the rigid group a mean horizontal advancement of 4.815 mm was accompanied by a relapse of 0.2 mm during a period of 1 year. The mean superior repositioning of menton was 0.975 mm. This was accompanied by a relapse of 0.1 mm during a period of 1 year. This study confirms the findings of several previous studies that contribute data specific towards the use of rigid fixation in advancement genioplasty. In our study we also observed that, in cases where large advancements are necessary, wire fixation may offer insufficient means of fixation particularly if the movement is complex and asymmetrical, in which case rigid fixation devices are more helpful.