下颌骨髁状突纵形骨折CT三维重建分析

目的：探讨下颌骨髁状突纵形骨折（SFMC）的影像学改变及其机制。方法：对47例（94例）疑有髁状突骨折的患者进行常规CT和三维重建检查，根据CT三维重形态学并结合解剖学，就SFMC的好发部位及特点作了分析。结果：检出各型髁状突骨折70例，其中纵形骨折22例（31．4％）位于髁状突中、外1／3交界段的内撕脱骨折18例，位于髁状突内1／3段的内极撕裂4侧，8例同时伴发下颌骨其他部位骨折，结论：由于髁状突的解剖特点，当正中颌面部或颏部受撞击时，其髁头内极具有较高的张应力和较弱的承受力而导致SFMC。三维CT的重要意义在于可立体观察解剖结构及其空间关系。

Three dimensional CT for mandibular condyle sagittal fracture

Objective To probe into the image features and the mechanism of sagittal fracture of the mandibular condyle(SFMC) by using three dimensional CT. Methods Three dimensional CT and routine CT were performed for 47 cases (94 sides) with clinically suspected SFMC . The predilection location and image characteristics of SFMC were discussed and analyzed based on three dimensional CT morphology and anatomy. Results Mandibular condyle fractures were found in 70 sides, among them, 22 (31.4%) were SFMC. SFMC occurred at the conjunction segment lateral 1/3 and middle 1/3 of the mandibular condyle in 18 sides, and at middle 1/3 of the mandibular condyle in 4 sides. SFMC accompanied with fractures in other parts of mandibular condyle were found in 8 cases. Conclusions There is a high tensile stress at the segment inside the condyle under an impact to the face or chin because of the anatomical characteristics of the mandibular condyle. SFMC occurs often at the medial process of mandibular condyle. Three dimensional CT has the advantage of observing the solid anatomical structure and its space relationship.