Abstract: To explore clinical features of vertical root fracture (VRF) and analyze the possible causes of VRF. MethodsA total of 51 cases of vertical root fracture in nonendodontically treated teeth in 48 patients were investigated. Age and gender, tooth type and root distribution, as well as clinical manifestations and radiographic findings of vertical root fracture were presented. ResultsThe average age of patients was 52.16 years and the ratio of male to female stood at 2.2:1. The most frequently （54.90%）affected teeth were mandibular first molars. 88.24% of affected roots were mesial roots in the mandibular molars and mesialbuccal roots in the maxillary molars. Clinical manifestations of VRF were similar to pulp disease, periodontal disease, and dull discomfort or pain when biting. Unusual widening of apical and middle parts of the root canals may be accompanied by vertical and horizontal resorption and bone destruction of the furcation area. ConclusionClinical manifestations of VRF are varied. Xray examination is necessary in diagnosis. Anatomy of roots and canals and occlusal force may play main roles in the development of vertical root fracture.

Key words: Tooth diseases, Tooth root, Etiology