Evaluation of palatal mucosal thickness in maxillary posterior teeth using cone-beam computed tomography combined with intraoral scanning: a cross-sectional study on correlating factors

Cone-beam computed tomography (CBCT) combined with intraoral scanning (IOS) technology was used to measure and analyze the variation patterns of the palatal masticatory mucosa (PMM) in the maxillary posterior region and its correlation with gender, gingival biotype (GB), and the palatal bone thickness (PBT), thereby establishing a theoretical foundation for autogenous soft tissue augmentation procedures.

A total of 57 Han Chinese patients and 342 affected teeth were included in the study. CBCT and IOS data were obtained for all participants, and 3D models were constructed by segmenting CBCT images based on standardized parameters, followed by alignment with IOS data using reference points. Measurements were conducted at predetermined intervals to evaluate PMM, PBT, and GB. The variability of PMM from the first premolar to the first molar was analyzed bilaterally by gender, age, and GB using t-tests and Games-Howell post-hoc analysis. Pearson's correlation test examined the relationship between PMM and PBT, while linear regression models were utilized to evaluate associations between PMM and clinical factors such as gender, age, and PBT.

There was no statistically significant difference in PMM between the left and right sides of the maxilla (P > 0.05). Overall, PMM increased with greater distance from the gingival margin, and statistically significant differences were observed between specific measurement points at different tooth positions. The second premolar exhibited the greatest thickness at 6 mm, 8 mm, and 10 mm. Gender had a relatively minor impact on PMM. Significant differences in PMM were observed across age groups, with the middle-aged group showing greater PMM compared to the younger group (P < 0.05). At 2 mm from the first molar's gingival margin, significant PMM differences were identified between different GB (P < 0.05). The correlation between PBT and PMM was weak. Regression analysis revealed age as a primary determinant of PMM, with gender and PBT exerting site-specific effects.

CBCT combined with IOS proved effective in measuring maxillary PMM. The maxillary posterior region exhibited a symmetrical distribution of PMM, with premolar areas identified as optimal for soft tissue graft harvesting. While no significant correlation was found with gender, GB, or PBT, the mucosa was notably thicker in middle-aged individuals.

This study presents comprehensive data on PMM thickness across various tooth positions and distances from the gingival margin, facilitating the identification of optimal donor sites for autologous grafts. It highlights regional and ethnic variations in PMM thickness among Han Chinese patients and validates the combined use of CBCT and IOS for accurate, non-invasive measurements.