CBCT research on the alveolar bone morphology in the maxillary anterior teeth area of the adults with the low-angle skeletal class II malocclusion

Objective To study the alveolar bone morphology in the maxillary anterior teeth area of the low-angle skeletal Class Ⅱ malocclusion subjects, and to analyze the correlation between morphological features and the incisor labial inclination. Methods 60 adults with low-angle skeletal Class Ⅱ malocclusion ( experimental group ) and 20 adults with normal occlusion (control group) were included. The maxillary alveolar bone structure of the anterior teeth were observed using CBCT. Then the experimental group were divided according to the upper middle incisor labial inclination and were analyzed. Results The thickness and height of the maxillary anterior alveolar bone in experimental group were lower than those in control group (P<0.05). There was a negative correlation between the thickness of palatal and total apical alveolar bone and the incisor labial inclination. The distance between the labial alveolar ridge crest and cemento-enamel junction(CEJ) had a positive correlation with the incisor labial inclination (P<0.05). Conclusions The thickness and height of the anterior alveolar bone of low-angle skeletal Class Ⅱ malocclusion were lower than those of the normal teeth. There was a significant correlation between the thickness and height of the alveolar bone in upper incisor area and the incisor labial inclination. There was no significant correlation between the thickness and height of the alveolar bone in upper canine regions and the incisal inclination. Key words: Adults; Low-angle; Skeletal classⅡ malocclusion; The alveolar bone morphology; CBCT