CBCT evaluation of buccal bone thickness, ridge dimensions, and root position in the maxillary anterior region: a retrospective study

Abstract

Accurate assessment of alveolar bone morphology is essential for implant treatment planning in the anterior maxilla, where anatomical characteristics may influence surgical procedures and aesthetic outcomes. This study aimed to evaluate alveolar crest height and width, buccal bone thickness, buccal undercut depth, and root position around healthy maxillary anterior teeth using cone-beam computed tomography (CBCT), while investigating the influence of age, gender, and tooth type on these parameters. CBCT images of 1,668 maxillary anterior teeth from 278 periodontally healthy individuals aged 20–79 years were retrospectively evaluated. Alveolar crest height and width, buccal bone thickness, buccal undercut depth, and the root-crest angle were measured using a standardized CBCT protocol. Data were analyzed using robust mixed ANOVA with Holm-adjusted post hoc comparisons. Intraobserver and interobserver reliability were assessed using intraclass correlation coefficients (ICC). Age group and tooth type significantly affected all evaluated parameters (all p  < 0.001). The greatest alveolar crest height and root-crest angle were observed in the 70–79-year age group, whereas the alveolar crest width was greatest in the 20–29-year age group. Buccal bone thickness and buccal undercut depth peaked in the 50–59-year age group. Canines exhibited the greatest alveolar crest width and root-crest angle. Conversely, lateral incisors displayed the thickest buccal bone, the deepest buccal undercut, and the narrowest alveolar crest width. Males generally presented with greater alveolar crest width than females, whereas buccal bone thickness was significantly greater in males only for lateral incisors and canines. No significant interaction effects were identified between age group and tooth type or between gender groups and measurement point. Intraobserver agreement ranged from 0.709 to 0.991, and all interobserver ICC values exceeded 0.90. Morphological characteristics of the anterior maxilla vary significantly by age, gender, and tooth type. The lateral incisor region demonstrates the least favorable anatomy due to its thin buccal bone and pronounced buccal undercut, highlighting the necessity of a comprehensive CBCT evaluation for individualized implant treatment planning to minimize potential surgical complications. This study was retrospectively registered on August 18, 2025, at ClinicalTrials. gov. Registration number: NCT07133503.