Purpose: This study aimed to evaluate changes in computed tomography (CT) value of ramus bone after sagittal split ramus osteotomy (SSRO) in class II and class III patients using absorbable plates and screws. Patients and Methods: In the retrospective study, the participants were female patients with jaw deformities who underwent bilateral SSRO with Le Fort I osteotomy. Maximum CT values (pixel values) of lateral and medial cortexes at anterior and posterior sites of the ramus were measured preoperatively and 1 year postoperatively by using horizontal planes at the mandibular foramen level (upper level) and 10 mm under the mandibular foramen level (lower level) parallel to Frankfurt horizontal plane. Results: Fifty-seven patients and 114 sides (28 class II: 56 sides and 29 class III: 58 sides) were evaluated. Although CT values decreased at most sites of the ramus cortical bone after 1 year of surgery, they increased at the posterior-medial site at the upper level in class II (P=0.0012) and the lower level in class III (P=0.0346). Conclusion: This study suggested that bone quality at the mandibular ramus could change after 1 year of surgery, and there could be differences between mandibular advancement and setback surgery.

This retrospective study aimed to evaluate the efficacy of support splint treatment for deformities and deviations of the nasal septum after Le Fort I osteotomy (LFI). Patients were divided into two groups: the retainer group wore a nasal support splint immediately after LFI for 7 days, and the no retainer group did not wear a nasal support splint. Evaluation was performed by measuring the ratio of the difference between the left and right sides of the nasal cavity area (ratio of nasal cavity) and the angle of the nasal septum using three computed tomography frontal images (anterior, middle, and posterior) before and one year postoperatively. Sixty patients were included and divided into two groups, the retainer and no retainer group (n = 30 each). Regarding the ratio of nasal cavity on middle images at one year postoperatively, the retainer and no retainer groups differed significantly (0.79 ± 0.13 and 0.67 ± 0.24, respectively; P = 0.012). The angle of the nasal septum on anterior images at one year postoperatively was 164.8 ± 11.7°in the retainer group and 156.9 ± 13.5°in the no retainer group, showing a significant difference (P = 0.019). This study suggests that support splint treatment after LFI is effective in preventing post-LFI nasal septal deformation or deviation.

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