Xi Tong, Schreurs Ruud, van Loon Bram, de Koning Martien, Bergé Stefaan, Hoppenreijs Theo, Maal Thomas
Department of Oral and Maxillofacial Surgery, Radboud University Nijmegen Medical Centre, Geert Grooteplein 10, 6525 GA, Nijmegen, The Netherlands.
Department of Oral and Maxillofacial Surgery, Rijnstate Hospital, Wagenerlaan 55, 6815 AD, Arnhem, The Netherlands.
J Craniomaxillofac Surg. 2015 May;43(4):462-8. doi: 10.1016/j.jcms.2015.02.006. Epub 2015 Feb 19.
A major concern in mandibular advancement surgery using bilateral sagittal split osteotomies (BSSO) is potential postoperative relapse. Although the role of postoperative changes in condylar morphology on skeletal relapse was reported in previous studies, no study so far has objectified the precise changes of the condylar volume. The aim of the present study was to quantify the postoperative volume changes of condyles and its role on skeletal stability following BSSO mandibular advancement surgery. A total of 56 patients with mandibular hypoplasia who underwent BSSO advancement surgery were prospectively enrolled into the study. A cone beam computed tomography (CBCT) scan was acquired preoperatively, at 1 week postoperatively and at 1 year postoperatively. After the segmentation of the facial skeleton and condyles, three-dimensional cephalometry and condylar volume analysis were performed. The mean mandibular advancement was 4.6 mm, and the mean postoperative relapse was 0.71 mm. Of 112 condyles, 55% showed a postoperative decrease in condylar volume, with a mean reduction of 105 mm(3) (6.1% of the original condylar volume). The magnitude of condylar remodelling (CR) was significantly correlated with skeletal relapse (p = 0.003). Patients with a CR greater than 17% of the original condylar volume exhibited relapse as seen in progressive condylar resorption. Female patients with a high mandibular angle who exhibited postoperative CR were particularly at risk for postoperative relapse. Gender, preoperative condylar volume, and downward displacement of pogonion at surgery were prognostic factors for CR (r(2) = 21%). It could be concluded that the condylar volume can be applied as a useful 3D radiographic parameter for the diagnosis and follow-up of postoperative skeletal relapse and progressive condylar resorption.
使用双侧矢状劈开截骨术（BSSO）进行下颌前徙手术时，一个主要问题是术后可能出现复发。尽管先前的研究报道了髁突形态的术后变化对骨骼复发的作用，但迄今为止，尚无研究客观地明确髁突体积的精确变化。本研究的目的是量化BSSO下颌前徙手术后髁突的术后体积变化及其对骨骼稳定性的作用。共有56例下颌发育不全患者前瞻性纳入本研究，这些患者均接受了BSSO前徙手术。术前、术后1周和术后1年均进行了锥形束计算机断层扫描（CBCT）。在对面部骨骼和髁突进行分割后，进行了三维头影测量和髁突体积分析。下颌平均前徙4.6毫米，术后平均复发0.71毫米。在112个髁突中，55%的髁突术后体积减小，平均减少105立方毫米（占原始髁突体积的6.1%）。髁突重塑（CR）的程度与骨骼复发显著相关（p = 0.003）。CR大于原始髁突体积17%的患者表现出如进行性髁突吸收所见的复发。术后出现CR的高下颌角女性患者术后复发风险尤其高。性别、术前髁突体积和手术时颏点的向下移位是CR的预后因素（r² = 21%）。可以得出结论，髁突体积可作为一个有用的三维影像学参数，用于术后骨骼复发和进行性髁突吸收的诊断及随访。
