[The prevalence of dehiscence and fenestration on anterior region of skeletal Class III malocclusions:a cone-beam CT study].

PURPOSE: To investigate the prevalence and distribution of alveolar bone dehiscence and fenestration in anterior region of skeletal Class III malocclusions. METHODS: The sample consisted of 19 males and 25 females with skeletal Class III malocclusions selected from consecutive patients of Department of Oral and Cranio maxillofacial Science from May 1st to June 1st, 2012. Five hundred and twenty-three teeth were examined by cone-beam CT (CBCT) in total while alveolar bone dehiscences and fenestrations were detected and measured using a new method. The data was processed using SAS8.02 software package. RESULTS: The prevalence of dehiscence was 61.57% in all teeth, while fenestration was 31.93% and the prevalence of defect (dehiscence or fenestration) was 77.44%. More defects were found in the mandible (58.52%) especially. The tooth site which was most commonly affected was lower canine, while the least was upper central incisor. No significant difference was found between both genders on most tooth sites of anterior region but more defects was found in lower central incisor and lower lateral incisor in male subjects. CONCLUSIONS: Alveolar defect is an extremely common finding in this sample. Whether alveolar defects such as dehiscence and fenestration are potential factors of root resorption and addition bone loss is still unclear, and further researches are needed.