下颌骨髁突矢状骨折骨碎块移动CT影像分析

CT analysis of bone fragment motion in sagittal fracture of the mandibular condyle

目的通过对下颌骨髁突矢状骨折（sagittalfractureofmandibularcondyle，SFMC）骨块分离和移位程度的分析，了解此类骨折骨碎块移动的类型，指导临床治疗和相关手术器械的研发。方法选择2008年10月一2012年10月收治的髁突骨折患者88例，其中SFMC患者共45例（52侧），男32例（36侧），女13例（16侧）。根据Neff分类标准：A型20侧，B型28侧，M型4侧。对45例SFMC患者进行CT检查，以髁突骨碎块分离和移位的距离及角度为测量指标进行归类分析。结果患者归类：Ⅰ型20侧（ⅠA型14侧，IB型6侧），Ⅱ型27侧（ⅡA型11侧，ⅡB型16侧），ⅢB型1侧Ⅳ4侧。骨碎块位移距离4—16mm，平均12mm；骨碎块偏离度11°～43°，平均34°；骨碎块下降距离6—18mm，平均13mm°结论从CT影像分析，SFMC绝大部分的骨碎块移位较少。

Objective To analyze the separation and displacement of bone fragments in sagittal fracture of the mandibular condyle （ SFMC）, understand the motion type and guide clinical treatment and development of related surgical instruments. Methods Forty-five patients （52 sides） with SFMC trea- ted between October 2008 and October 2012 were enrolled; 32 patients （36 sides） were males and 13 pa- tients （16 sides） were females. According to the Neff classification, there were 20 sides with type A, 28 sides type B and 4 sides type M. All the patients underwent CT scan and were classified based on measurements of distance and angle of displaced bone fragments. Results Patients were categorized in- to type Ⅰon 20 sides （type I A on 14 sides and type Ⅰ B on 6 sides）, type Ⅱ on 27 sides （type ⅡA on 11 sides and type ⅡB on 16 sides） ; type Ⅲ B in 1 side and typeⅣ in 4 sides. Mean displacement of bone fragments was 12 mm （range, 4-116 mm） ; mean deviation angle was 34°（ range, 11 °-43°） ; mean descending distance was 13 mm （range, 6-18 mm）. Conclusion CT analysis results show that, mast bone fragments in SFMC move slightly.