Condylar and disc positions after sagittal split ramus osteotomy with and without Le Fort I osteotomy

Abstract

Purpose. The purpose of this study is to examine the changes in temporomandibular joint (TMJ) morphology and clinical symptoms after sagittal split ramus osteotomy (SSRO) with and without a Le Fort I osteotomy. Subjects and Methods.Of 45 Japanese patients with mandibular prognathism, 23 underwent SSRO and 22 underwent SSRO in combination with a Le Fort I osteotomy. The TMJ symptoms and joint morphology, including disc tissue, were assessed preoperatively and postoperatively by magnetic resonance imaging (MRI) and axial cephalography.Results. There were significant differences between pre-and postoperative horizontal changes in the condylar long axis on the right side in the group undergoing SSRO (sagittal split ramus osteotomy) alone. However, there were no other significant differences in preand postoperative measurements in this group as compared with the group receiving SSRO plus Le Fort I osteotomy, and the preoperative disc position could not be changed in either group. Conclusion.These results suggest that SSRO, either with or without Le Fort I osteotomy, could not change the preoperative disc position or correct anterior disc displacement, although these procedures did improve the symptoms associated with TMJ dysfunction.

Horizontal changes in the condylar head after sagittal split ramus osteotomy with bent plate fixation

“…20 However, here there were no differences between the pre and postoperative angle of the condylar long axis, and we found no medio-lateral or antero-posterior displacement. This result suggests that even if the condylar repositioning device was not used, the condylar position and angle would not change significantly, even though we did not strive to maintain the preoperative condylar position.…”

“…8 SSRO improved TMJ symptoms despite being unable to change preoperative disc position or correct anterior disc displacement. 20 Using CT here, we also did not observe significant changes in condylar position or angle, but the gap between the proximal and distal segment created by the bent plate might reduce the stress on TMJ.…”

A hypothesis on the desired postoperative position of the condyle in orthognathic surgery: a review

“…77 However, there were no differences between the pre and postoperative angles of the condylar long axis, and we found no medio-lateral or antero-posterior displacement. This result suggests that even if the condylar repositioning device was not used, the condylar position and angle would not change significantly, even though we did not strive to maintain the preoperative condylar position.…”

TMJ response to mandibular advancement surgery: an overview of risk factors

“…But the major evidence with regard to clicking after orthognathic surgery points to the fact that there is greater likelihood of improvement rather than deterioration 6,55,67,107,120,146 , even if such improvement is temporary 89 . For these reasons, there is no individual guarantee for the evolution of clicking, in contrast to disc displacement and crepitus which do not seem to be affected by SSRO for mandibular advancement or setback 6,80,133 , unless a specific surgical intervention is undertaken to recapture the disc in TMJ 57 .…”