Cone-Beam Computed Tomography-Derived Alveolar Anatomy for Immediate Implant Planning: Thickness, Concavity, and Angulation Patterns: A Comprehensive Evaluation.

OBJECTIVES: This study aimed to evaluate the buccal and palatal bone thickness, sagittal angulation, and the buccal bone concavity angle of maxillary anterior teeth using cone beam computed tomography (CBCT). MATERIALS AND METHODS: This cross-sectional study included patients ≥18 years with periodontally healthy maxillary anterior teeth (cementoenamel junction (CEJ)-bone crest (BC) ≤3 mm). Scans with artifacts, restorations, implants or pathological bone loss were excluded. Buccal and palatal bone thicknesses were measured at coronal, midroot, and apical levels, along with CEJ-BC distance, sagittal angulation, and buccal bone concavity angle. Data were analyzed using descriptive and parametric statistics, with Pearson correlation analysis. RESULTS: A total of 112 CBCT scans (502 maxillary anterior teeth) were analyzed from 33 men and 79 women (mean age 31.10 years). Of 672 teeth examined, 170 were excluded mainly due to crestal/periapical bone loss, restorations, or imaging artifacts. Mean facial bone thickness was 1.05 ± 0.31 mm, while palatal bone thickness was 4.07 ± 3.07 mm. Mean CEJ-BC distance ranged from 1.65 ± 0.56 to 1.72 ± 0.56 mm. Mean sagittal angulation was 8.70° ± 5.09° for central incisors, 7.86° ± 5.15° for lateral incisors, and 12.23° ± 4.3° for canines. Buccal concavity angles averaged 154° ± 14.6°, 152° ± 9.33°, and 158° ± 7.7° for central incisors, lateral incisors, and canines, respectively. Significant correlations were observed between sagittal angulation and both buccal and palatal bone thicknesses, as well as between concavity angle and selected bone thickness measurements. Sensitivity analysis accounting for within-patient clustering confirmed the robustness of the sagittal angulation correlations, whereas most correlations involving the concavity angle did not remain significant after clustering adjustment. CONCLUSION: The facial bone plate of the anterior maxilla is thin (<1.5 mm), with maxillary anterior teeth frequently positioned buccally within a curved labial plate. As an observational anatomical study, these findings would help in highlighting the importance of individualized CBCT-based evaluation in treatment planning, particularly when considering augmentation needs and implant positioning in the esthetic zone.