RESUMO
Closed treatment of mandibular condylar fractures has been used for its indications based on the fracture site, fracture status, and patient age. Posttreatment mandibular condyle size is associated with mandibular function; however, a few studies have reported bone remodeling patterns and volume changes in the condyle and glenoid fossa after mandibular condylar head fractures (CHFs). Therefore, volumetric changes in the mandibular condyle and glenoid fossa were analyzed in the present study, and bone remodeling patterns were evaluated after mandibular CHFs. The present study included 16 condyles from 12 patients who received closed treatment for CHF. After reconstruction of a 3-dimensional skull model, including the mandible, using computed tomography data taken immediately after injury and 6 months after treatment, volume changes in the mandibular condyle and glenoid fossa were analyzed. The condylar volume increased by 0.32±0.66 cm3 during the 6-month healing period without statistical significance (P=0.093). Regarding the glenoid fossa, the fossa showed a statistically significant volume increase of 0.41±0.59 cm3 (P=0.021), and 12 glenoid fossae (75%) showed downward bone apposition; however, no change or only mild bone resorption was observed in 4 glenoid fossae (25%). The results of this study indicated that the volume changes in the mandibular condyle after closed treatment of a mandibular CHF are not significant, and the glenoid fossa adapts to the displaced mandibular condyle through downward growth accompanied by volume increase.
RESUMO
PURPOSE: The present study assessed the postoperative bone remodeling after simultaneous sagittal split ramus osteotomy (SSRO) and mandibular angle ostectomy using a 3-dimensional analysis of computed tomography (CT) data. MATERIALS AND METHODS: We designed and implemented a retrospective study that included patients who had undergone SSRO with (study group) or without (control group) mandibular angle ostectomy. Using CT data taken immediately after (T1) and 6 months (T2) after surgery, the vertical and horizontal morphologic changes of the mandibular angle were evaluated and compared between the 2 groups. In the study group, the volumetric changes of the mandibular angle were assessed, and the bone regeneration rate was calculated. RESULTS: A total of 58 mandibular angles were evaluated (32 in the study group and 26 in the control group). The study group exhibited significantly greater vertical bone regrowth at the middle and posterior regions of the mandibular angle ostectomy line compared with that in the control group (middle, P < .001; posterior, P < .001). Both groups showed significant horizontal bone regrowth at 6 months postoperatively (P < .01). In the study group, the postoperative vertical bone regrowth was significantly associated with the extent of exposed bone below the angle ostectomy line at T1 for all regions (P < .001). The percentage of postoperative regenerated bone volume relative to the volume of bone removed intraoperatively was 41.8%. CONCLUSIONS: The present findings suggest that significant bone regrowth could occur after mandibular angle ostectomy with simultaneous SSRO. Therefore, it is necessary to consider bone remodeling patterns in the treatment planning stage for better and more predictable surgical outcomes.
