TY - JOUR T1 - Comparison of Changes of the Gonial Angle in 2 Methods: IVRO and BSSO AU - , J. Yazdani AU - , K. Taheritalesh AU - , M. Ghavimi JO - Research Journal of Biological Sciences VL - 4 IS - 2 SP - 148 EP - 151 PY - 2009 DA - 2001/08/19 SN - 1815-8846 DO - rjbsci.2009.148.151 UR - https://makhillpublications.co/view-article.php?doi=rjbsci.2009.148.151 KW - Mandibular setback KW -gonial angle KW -BSSO KW -IVRO KW -discrepancy AB - The gonial angle plays an important role in ensuring a harmonious facial profile. Changes in this angle especially after surgery may be an aesthetic concern for both the patient and the surgeon. The aim of the present study was to evaluate gonial angles changes after mandibular setback with the BSSO and IVRO techniques. Fifty eight patients with mandibular prognathism referred to zakaria and Emam hospitals were selected from 2004-2006. Patients with other deformities like discrepancy of both jawz which need mandibular setback more then 10 mm, asymmetry, vertical discrepancy syndroms were excluded. Patients were randomly divided into 2 groups. In first group mandibular setback was done with obwegeser technique and wire osteosynthesis with 4 weeks IMF in second group mandibular setback with IVRO technique with wire ostesynthesis with 4 weeks IMF were used. For all patients before the surgery (T0) and one year after surgery (T1) lateral cephalograms were obtained. Gonial angle and occlusal plan-SN in T0 and T1 was evaluated. After the surgery the gonial angle had decreased in all samples. Decrease in IVRO group was more then BSSO group. The average decrease in gonial angle in BSSO group was 2° and in IVRO group was 7° that significantly more than BSSO group (p<0.05). ER -