Abstract: PURPOSE: To measure the morphological parameters of the incisive canals in the middle-aged and elderly population using CBCT, to analyze the age-related changes in the position and morphology of the incisive canals, and to investigate the relative position between the incisive canals and the surrounding anatomical structures, in order to provide reference for the design of aesthetic anterior dental implant restorations in this population. METHODS: CBCT data from 69 patients over 50 years of age were measured in the sagittal and coronal planes for the incisal foramen(W_IF) along the long axis of the incisal canal, the width of the incisal canal from the median (W_m) to the Stetson's foramen (W_SF), the diameter of the incisal canal along the long axis of the incisal canal(D_IF), the diameter of the incisal canal from the median (D_m) to the Stetson's foramen(D_SF), and the distance from the most concave part of the bone on the labial side to the anterior wall of the incisal canal (A), and the distance from the top of the alveolar ridge to A (B) were measured, respectively. The patients were grouped according to gender and whether or not they were missing upper anterior teeth, and the data were analyzed using SPSS 19.0 software package. RESULTS: The mean width of the incisal canal(W) was (3.93±0.83) mm, the mean diameter(D) was (3.03±0.83) mm, the mean distance from the most concave part of the bone on the labial side to the anterior wall of the incisal canal was (6.15±1.53) mm, and the mean distance from the top of the alveolar ridge to A was (11.98±2.50) mm. D_IF in male group [(3.61 ± 0.79) mm] was higher than that in female group[(3.14±0.94) mm], D_SF in male group [(2.96±1.22) mm] was higher than that in female group[(2.31±0.92) mm], A value in male group [(6.76±1.43) mm] was higher than that in female group [(5.48±1.36) mm], A value in the edentulous group [(5.73±1.55) mm] was lower than that in the edentulous group [(6.41±1.48)mm], B value in the edentulous group[(10.73±2.64)mm] was lower than that in the edentulous group [(12.78±2.06)mm]. All the differences were statistically significant(P<0.05). CONCLUSIONS: Gender has an influence on the diameter of the incisal canal, the thickness of the alveolar crest bone. The height of the alveolar crest was related to with or without missing upper anterior teeth; and in middle-aged and elderly patients with missing anterior teeth, a more precise control of the implant direction at depth is needed.

Key words: Nasopalatine canal, CBCT, Dental implant, Thickness of the alveolar crest bone, Height of the alveolar crest