Department of Maxillofacial Surgery, Plastic Surgery Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China.
Orthod Craniofac Res. 2024 Dec;27(6):860-867. doi: 10.1111/ocr.12827. Epub 2024 Jun 20.
Patients with type IIA craniofacial microsomia (CFM) may benefit from mandibular distraction osteogenesis (MDO) treatment during childhood; however, remodelling of the mandible during the consolidation phase, which may affect the short-term outcomes of MDO, has not yet been quantitatively analysed using computed tomography. Therefore, we aimed to investigate bone remodelling of the mandible in children with type IIA CFM treated with MDO before distractor removal and the factors that influence ramus vertical elongation efficiency.
Twenty-three children with unilateral CFM were studied between 2020 and 2024. Longitudinal computed tomography data (preoperative, end of active phase and at pre-distractor removal) were analysed. Condyle positions and the mandibular cant were analysed using a paired-sample t test. The relapse rates of vertical lengthening and mandibular cant were calculated. The correlation between distraction efficiency and preoperative craniofacial morphology was analysed.
The condyle on the affected side moved upwards and backwards by 28.84 ± 4.08 and 2.85 ± 4.33 mm, respectively during the active phase but lost 7.66 ± 2.64 mm of vertical extension during the consolidation phase. The relapse rates for vertical extension of the condyle and occlusal plane were 27% and 35%, respectively. The ratio of mandibular ramus height was positively related to EV.
In children with CFM, attention should be paid to vertical elongation instability and relapse of mandibular inclination during consolidation. Severe mandibular ramus hypoplasia is a preoperative risk factor for vertical skeletal relapse during consolidation. Further efforts are required to reduce the stress that leads to relapse.
患有 IIA 型颅面短小症（CFM）的患者可能受益于儿童时期的下颌骨牵引成骨术（MDO）治疗；然而，在固位期下颌骨的重塑可能会影响 MDO 的短期结果，尚未使用计算机断层扫描对其进行定量分析。因此，我们旨在研究使用 MDO 治疗 IIA 型 CFM 儿童在去除牵引器之前下颌骨的骨重塑情况，以及影响下颌支垂直伸长效率的因素。
研究了 2020 年至 2024 年间 23 例单侧 CFM 患儿。对纵向 CT 数据（术前、主动期结束时和去除牵引器前）进行分析。采用配对样本 t 检验分析髁突位置和下颌偏斜角度。计算垂直伸长和下颌偏斜角度的复发率。分析牵引效率与术前头面形态的相关性。
在主动期，患侧髁突向上向后移动 28.84±4.08mm 和 2.85±4.33mm，但在固位期失去 7.66±2.64mm 的垂直延伸。髁突垂直延伸和咬合平面的复发率分别为 27%和 35%。下颌支高度比与 EV 呈正相关。
在 CFM 患儿中，应注意固位期垂直伸长不稳定和下颌倾斜复发。严重的下颌支发育不全是固位期垂直骨复发的术前危险因素。需要进一步努力减少导致复发的应力。
