A clinical study on the effects of bilateral sagittal split ramus osteotomy on the postoperative condylar positional changes in the mandibular prognathism

ABSTRACT

PURPOSE: This study is aimed to evaluate the clinical efficiency of sagittal split ramus osteotomy by assessing the possible postoperative condylar positional changes and associated temporomandibular joint symptoms after mandibular setback via bilateral sagittal split ramus osteotomy in patients with mandibular prognathism.MATERIALS AND METHODS: Twenty patients(13 male, 7 female) who were taken bilateral sagittal split ramus osteotomy for mandibular prognathism had been assessed in transverse and rotational changes of condylar positions through preoperative and postoperative cephalometric P-A views and submentovertex views. And clinically, patient's subjective symptoms of temporomandibular joints were evaluated at preoperative and postoperative period. The differences between preoperative and postoperative changes in radiographic measurements were evaluated statistically, and also the correlation between the amount of mandibular setback and the condylar positional changes was statistically evaluated.RESULTS: In the pre- and post-operative cephalometric PA view, intercondylar width was increased postoperatively(mean 1.38mm) with statistical significance( p<0.01). Medial ramus angle and intergonial width were also significantly increased by mean value of 1.13.and 1.62mm, respectively( p<0.01). In the pre- and post-operative cephalometric submentovertex view, inward rotation of condyle was observed postoperatively, leading to increase condylar axis angle with statistical significance(mean value 2.29., p<0.01). On the other hands, In the statistical correlation between the amount of mandibular setback and postoperative condylar positional change, there was no statistical significance.CONCLUSION: Although postoperative condylar positional changes occurs significantly, we suggest these changes are within the range of patient's adaptability, and there is no clinical significances in the condylar positional changes.