Abstract: PURPOSE: To investigate the labial and palatal bone thickness of the maxillary anterior teeth in normal young adults on different reference lines, in order to provide references for clinical treatment. METHODS: Sixty-seven eligible Han nationality young volunteers were scanned by cone-beam computed tomography (CBCT). The labial and palatal bone thickness and the labial bone morphology of the anterior teeth were measured after reconstruction. Paired-sample t test, independent- sample t test, one-way ANOVA and Chi-square test were performed using SPSS17.0 software package. RESULTS: ①The mean labial bone thicknesses at L1 of canines and L5 of all anterior teeth were more than 1.00 mm, while the thickness of the other labial measurement sites were less than 1.00 mm. The mean palatal bone thickness was more than 1.00 mm. ② The labial bone was thinner than the palatal bone (P<0.001). ③The labial bone was the thinnest at L3 and L4 of the anterior teeth（P<0.001). The thickness of palatal bone gradually increased from the L1 to L5(P<0.001). ④ The frequency of the labial bone thinner than 1.00 mm was less than 50% at L2 of canines and L5 of all anterior teeth; The frequency of the labial bone deficiency at L3 and L4 of lateral incisors and L4 of canines was more than 50% in males. ⑤The mean buccal bony curvature of canines was larger than that of incisors in males. The distance between root apex and the deepest point of buccal bony curvature was the largest in maxillary central incisors zone in males, while there was no significant difference in females. CONCLUSIONS: The alveolar bone thickness of the maxillary anterior teeth in normal young adults are quite thin or even deficient, and there is diversity of the thickness and morphology between labial and palatal bone.

Key words: Maxillary anterior teeth, Bone thickness, Cone beam computed tomography