Purpose: The aim was to classify the relationship of the sagittal root positions of the maxillary central incisor to alveolar bone using cone beam computed tomography (CBCT).
Methods: CBCT images of 934 maxillary central incisors were retrospectively reviewed included 542 men and 392 women. The sagittal root position in the alveolar bone was classified as buccal, middle, or palatal. The sagittal buccal type was further classified into 3 subtypes: I, II, and III.
Results: The root position type was buccal in 95.4% of the 934 incisors, middle in 4.4%, and palatal in 0.2%. In the buccal type, 47.5%, 44.2%, and 8.3% were subtypes I, II, and III, respectively. There was no significant difference in the major and subtypes of root position between the male and female subjects (both P > 0.05).
Conclusions: In Chinese adults, the predominant type of sagittal root position of the maxillary central incisor is buccal. This classification system is useful in planning the implant site for immediate placement in the maxillary esthetic zone.