因素在牙根纵裂发生过程中的作用分析

The role of occlusal factors in the occurrence of vertical root fracture

目的：分析牙根纵裂患牙的咬合特征，观察牙根纵裂患牙的牙体磨耗情况，并从猞学角度探讨牙根纵裂的病因及咬合异常、牙体磨耗与牙根纵裂之间的关系。方法：选择确诊为牙根纵裂的患者277例．患牙309颗．对其牙周情况、耠面磨耗及形态、袷接触区、袷干扰或袷创伤及X线片进行评价，采用SPSSl3．0软件包对数据进行X2检验。结果：牙根纵裂多发生于40～60岁患者第一磨牙的近中根或近中颊根，患根牙周组织破坏明显大于无纵裂的牙根．形成局限性牙周袋。患牙袷面磨耗严重，出现非工作尖高陡，工作尖磨平，深猞面凹及远中边缘嵴低平等改变。牙根纵裂的程度与深袷面凹的部位有关。患牙存在袷干扰或拾创伤，并存在咬合不协调的易感因素。结论：本组患者牙根纵裂的发生与咬合异常和牙体磨耗有关，患牙猞关系改变，导致过大的袷力与异常方向的袷力．可能是牙根纵裂发生的重要因素．

PURPOSE： To investigate the occlusal characteristics and the condition of tooth abrasion in patients with vertical root fracture and to discuss the etiology of the vertical root fracture and the relationships between occlusal disorder, tooth abrasion and vertical root fracture of molars. METHODS： Two hundred and seventy-seven cases of root fracture patients were included in the study, with 309 involved teeth. The periodontal status, occlusal wear, occlusal contact area, occlusal interference, occlusal trauma and the X-ray film were observed and evaluated. All statistical analyses were performed using SPSS13.0 software package. Date was expressed as n （%）.Differences between groups were compared using X2 test with SPSS 13.0 software package. RESULTS： Vertical root fracture occurred in patients aging 40 to 60 years, the first molar mesial root or buccal root was mostly involved. Periodontal tissue destruction was significantly greater than roots without vertical fracture, with formation of localized periodontal pocket. Severe occlusal surface wear, high and steep non-work tip, working tip abrasion, deep occlusal surface concave and lower distal edge were seen in the affected teeth.The degree of vertical root fracture was related to the site of deep occlusal surface concave. Occlusal interference or occlusal trauma was the predisposing factors of vertical root fracture. CONCLUSIONS： Vertical root fracture is associated with malocclusion and tooth abrasion. Changes of occlusion leads to over occlusal force and abnormal direction of occlusal force, which may be important factor of vertical root fracture. Supported by Scientific Research Project of Bureau of Science and Technology of Changsha City（K10ZD033-13）.