Evaluation of bone formation after sagittal split ramus osteotomy using different fixation materials

PurposeThe purpose of this study was to evaluate bony change between the proximal and distal segments after sagittal split ramus osteotomy (SSRO) using different fixation materials.Subjects and methodsThe subjects consisted of 74 patients (21 male and 53 female; 148 sides) who underwent SSRO with and without Le Fort I osteotomy.They were divided into five groups: (1) an MT group, mono-cortical titanium plate fixation (26 sides); (2) an MA group, mono-cortical absorbable plate fixation (48 sides); (3) a BA group, bi-cortical absorbable plate fixation (22 sides); (4) an MAα group, mono-cortical plate absorbable fixation with α-tricalcium phosphate (36 sides); and (5) a BAα group, bi-cortical plate absorbable fixation with α-tricalcium phosphate (16 sides).Ramus square (RmS), ramus width (RmM-RmL) and ramus length (RmA-RmP) at the horizontal plane under the mandibular foramen were assessed pre-operatively, immediately after surgery, and at 1 year after surgery by computed tomography (CT).ResultsThere were significant differences among the groups regarding change over time in RmS (p = 0.0126) and RmM-RmL (p = 0.0001). However, there was no significant difference among the groups regarding change over time in RmA-RmP.ConclusionThese results suggest that the use of different fixation materials leads to significant differences in the bone healing process after SSRO.