Yan Shunchao, Qiao Chongxu, Miao Junyan, Shi Zai, Xu Jingyi, Yan Kaili, Qu Yuming, Wu Guoping
Department of Plastic Surgery, The Affiliated Friendship Plastic Surgery Hospital of Nanjing Medical University, 146 Hanzhong Road, Nanjing, 210029, Jiangsu province, China.
Aesthetic Plast Surg. 2025 Sep 19. doi: 10.1007/s00266-025-05272-2.
Bilateral sagittal split ramus osteotomy (BSSRO) is the gold-standard surgical treatment for mandibular prognathism and facial symmetry restoration in class III malocclusion. However, it remains unclear whether asymmetric and symmetric mandibles exhibit differential relapse patterns that impact both functional stability and aesthetic outcomes. This study aims to compare intraoperative displacement and postoperative skeletal relapse between asymmetric and symmetric mandibles following BSSRO.
This retrospective cohort study analyzed class III malocclusion patients who underwent BSSRO between January 2018 and December 2023. Three-dimensional CBCT datasets were obtained at three time points: preoperative (T0), immediately postoperative (T1), and at least 6 months postoperative (T2). Translational and rotational changes in mandibular segments (distal and proximal) were quantitatively assessed during surgical correction (T0-T1) and relapse (T1-T2).
Intraoperatively, the asymmetric group (AG) exhibited greater displacement toward the non-deviated side of the distal segment (P=0.001) and movement of the non-deviated proximal segment toward the deviated side (P=0.044) compared to the symmetric group (SG). Rotational analysis revealed increased clockwise yaw in AG's distal segment (P=0.009) and enhanced clockwise roll in the non-deviated proximal segment (P=0.021). Postoperatively, AG demonstrated significant relapse toward the deviated side in both proximal segments (non-deviated side: P<0.001; deviated side: P=0.027), counterclockwise yaw in the distal segment (P=0.020), and a counterclockwise rolling tendency in the non-deviated proximal segment (P=0.050).
Asymmetric and symmetric mandibles exhibit distinct relapse patterns following BSSRO, involving both translational and rotational movements across all segments. These findings highlight the importance of individualized surgical planning and postoperative management in asymmetric cases. Further validation through prospective multicenter studies with long-term follow-up is recommended.
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双侧矢状劈开下颌支截骨术（BSSRO）是治疗Ⅲ类错牙合畸形下颌前突及恢复面部对称性的金标准手术方法。然而，不对称和对称下颌骨是否表现出不同的复发模式，从而影响功能稳定性和美学效果，目前尚不清楚。本研究旨在比较BSSRO术后不对称和对称下颌骨的术中移位及术后骨骼复发情况。
这项回顾性队列研究分析了2018年1月至2023年12月期间接受BSSRO的Ⅲ类错牙合畸形患者。在三个时间点获取三维CBCT数据集：术前（T0）、术后即刻（T1）和术后至少6个月（T2）。在手术矫正期间（T0-T1）和复发期间（T1-T2），对下颌骨段（远心段和近心段）的平移和旋转变化进行定量评估。
术中，与对称组（SG）相比，不对称组（AG）远心段向非偏斜侧的移位更大（P = 0.001），非偏斜近心段向偏斜侧移动（P = 0.044）。旋转分析显示，AG远心段顺时针偏航增加（P = 0.009），非偏斜近心段顺时针滚动增强（P = 0.021）。术后，AG在两个近心段均向偏斜侧出现明显复发（非偏斜侧：P<0.001；偏斜侧：P = 0.027），远心段逆时针偏航（P = 0.020），非偏斜近心段有逆时针滚动趋势（P = 0.050）。
BSSRO术后，不对称和对称下颌骨表现出不同的复发模式，涉及所有骨段的平移和旋转运动。这些发现凸显了不对称病例个体化手术规划和术后管理的重要性。建议通过前瞻性多中心长期随访研究进一步验证。
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