后牙根折的临床及CBCT影像学研究

目的：探讨非外伤根折后牙的临床特点及锥形束CT（Cone beam computed tomography,CBCT）上的影像学表现。方法：收集经CBCT明确诊断的47名患者的60颗非外伤根折后牙的下列临床资料：患者性别、年龄、根管治疗情况。同时对CBCT图像上根折的部位、方向、根折移位情况,伴发的其它病变进行分析研究,使用卡方检验进行统计学分析。结果：不同年龄段及男、女性根折牙发生比例均具有显著性差异。根管治疗与非根管治疗根折牙数目之间没有显著差异。根折最常见于下颌第一磨牙近中根（36.2%）,其次为上颌第一磨牙腭根（29.3%）。51.7%的根折表现为牙根全长根折。牙根颊舌向根折是最常见的根折方向（41.7%）。51.7%的根折牙伴发根尖周骨质吸收。结论：患者的年龄、性别是影响根折的重要因素。CBCT可以对根折牙的根折部位、方向,根折移位情况及伴发病变进行精确的定位和评价,是一种可以明确诊断根折牙的诊断方法并为我们探讨非外伤根折后牙的临床特点提供了很好的影像学支持。

Clinic Study and Radiographic Features on CBCT Images of Root Fractures of Posterior Teeth.

Objective： To study the clinic and radiographic manifestation on the CBCT images of non-traumatic root fractured tooth. Methods： 47 patients with 60 root fractured teeth were collected in this study. The age, sex and history of root canal therapy were recorded. The position, direction, displacement of the fractured slice and the associated lesions were observed on the CBCT images. The Chi-square test was used for statistical analysis. Resuits： Age and sex significantly effected the incidence of root fracture. However, no significant differences were found between the root canal treatment group and non-root canal therapy group. Root fractures were most commonly found in mesial roots of the mandibular first molars（36.2 %）, followed by the palatal roots of the maxillary first molars（29.3%）. 51.7% root fractures were through the whole length of the teeth. Buccolingual root fracture was the most common direction of root fracture（41.7%）. The most common lesion accompanied the root fracture was resorption of periapical bone. Conclusion： The patient＇s age and sex were important factors affecting root fracture. CBCT could display the position, direction, displacement of the fractured slice and the associated lesions accu- rately and clearly. It was a useful tool to diagnose the root fracture and supplied a great amount of useful information to explore the clinical characteristics of root fracture teeth.