Integrated correlation analysis of the thickness of the buccal bone and gingiva of the maxillary incisors

Objective: The purpose of this study was to validate the integrated correlation between the thickness of the buccal bone and the gingiva of the anterior maxilla and to gain insight into the reference plane selection when measuring these two tissues before treatment with implants. Methodology: CBCT and model scans of 350 included human subjects were registered in coDiagnostiX software to obtain sagittal maxillary incisor sections. The buccal bone thickness was measured at the coronal (2, 4 and 6 mm apical to the cementoenamel junction (CEJ)) and apical (0, 2 and 4 mm coronal to the apex plane) regions. The buccal gingival thickness was measured at the supra-CEJ (0, 1mm coronal to the CEJ) and sub-CEJ regions (1, 2, 4 and 6 mm apical to the CEJ). Canonical correlation analysis was performed for intergroup correlation analysis and the investigation of key parameters. Results: The mean thicknesses of the buccal bone and gingiva at different levels were 0.64~1.88 mm and 0.66~1.37 mm, respectively. There was a strong intergroup canonical correlation between the thickness of the buccal bone and that of the gingiva (r=0.837). The thickness of the buccal bone and gingiva at 2 mm apical to the CEJ are the most important indices with the highest canonical correlation coefficient and loadings. The most and least prevalent subgroups were the thin bone and thick gingiva group (accounting for 47.6%) and the thick bone and thick gingiva group (accounting for 8.6%). Conclusion: Within the limitations of this retrospective study, the thickness of the buccal bone is significantly correlated with that of the buccal gingiva, and the 2 mm region apical to the CEJ is a vital plane for quantifying the thickness of these two tissues.