Abstract: Objective: To study the feasibility of maxillary anterior root tip region as autologous bone donor region based on cone beam CT. Methods: A total of 158 patients admitted to our hospital from September 2022 to July 2024 were selected as the study objects. All patients underwent CBCT examination. According to tooth position, the patients were divided into group A: central incisor group (n=88) and group B: lateral incisor group (n=70). After 1∶1 orientation matching, the last two groups each contained 60 patients. CBCT parameters and the occurrence of CS were compared between two groups. The relationship between CBCT parameters and CS opening diameter and branches was analyzed by multivariate Logistic regression. Threshold effect was used to analyze the relationship between CBCT parameters and CS occurrence. Results: There were no significant differences in all indexes between two groups after propensity matching (P>0.05), which was comparable. The height of labial bone, the width of infrasasal square bone, the thickness of labial cortical bone above the root tip, and the thickness of infrasasal cortical bone above the root tip in group B were higher than those in group A, and the height of palatine bone and the width above the root tip were lower than those in group A, and the differences between two groups were statistically significant (P<0.05). The incidence of CS was 13.33% in group A and 33.33% in group B, which was significantly higher than that in group A, and the difference in the incidence of CS between two groups was statistically significant (P<0.05). The number of CS pipeline branches in group B was more than that in group A, the diameter of CS opening and the distance between CS opening on the palatal side and alveolar crest were greater than that in group A, and the distance between CS opening on the nasal base and alveolar crest was smaller than that in group A. The differences in CA pipeline branches and CS opening and the distance between two groups were statistically significant (P<0.05). There were statistically significant differences in tooth position, labial bone height, palatine bone height, labial cortical bone thickness above the root tip, and nasal cortex bone thickness between CS developing group and non-developing group (P<0.05). The height of labial bone, the width of subnasal quadrate bone, the thickness of labial cortical bone above the root tip, and the thickness of subnasal cortical bone were risk factors for CS duct branch, the distance of nasal CS opening from alveolar crest and the diameter of CS opening, and were protective factors for the distance of palatal CS opening from alveolar crest. The risk of CS increased with the increase of the height of labial bone, the width of subnasal quadrate bone, the thickness of labial cortical bone above the root tip, and the thickness of subnasal cortical bone. The risk of CS decreased with the increase of palatine bone height and apical bone width. Conclusion: The apical area of maxillary anterior tooth can be used as the bone donor area to satisfy the small and medium bone defects. CS mainly occurs in the lateral incisor, and the palatal opening of the central incisor is closer to the crest of the alveolar ridge. Attention should be given to maintaining a safe distance when bone extraction is performed.

Key words: cone beam computed tomography, apical area of maxillary anterior teeth, autogenous bone