Abstract
BACKGROUND: This study aimed to evaluate the relationship between maxillary sinus volume (MSV) and alveolar bone trabeculation using fractal dimension (FD) analysis across different vertical skeletal patterns, and to assess its potential implications for orthodontic mini-implant (OMI) stability. METHODS: CBCT images of 84 skeletal Class I individuals (47 females, 37 males; mean age 20.08 ± 2.25 years) were analyzed and categorized into three vertical skeletal groups (28 normodivergent, 28 hyperdivergent, 28 hypodivergent). MSVs were measured bilaterally using 3D Slicer, and FD analyses were conducted on alveolar bone regions of interest (ROIs) located between the roots of teeth #14-15, #15-16, #16-17, and #24-25, #25-26, #26-27. MSV and FD values were analyzed within and between groups using one-way ANOVA, Kruskal-Wallis test, paired t-tests, Wilcoxon signed-rank tests, and Spearman's correlation test at a significance level of p < 0.05. The effects on OMI stability were then evaluated. RESULTS: Both right and left MSVs, as well as FD values in the ROIs between teeth #14-15, #15-16, #24-25, and #25-26, were found to be significantly higher in hypodivergent individuals. The posterior increase in FD values was significant only in the normodivergent group. In hypodivergent individuals, right MSVs were significantly correlated with FD values at the 14-15 ROI, and left MSVs with those at the 24-25 ROI, while no such correlation was found in other vertical patterns. CONCLUSIONS: In hypodivergent individuals, increased trabecular complexity between the maxillary second premolar and first molar may enhance OMI stability; however, the MSV, which correlates significantly with FD values in this region, necessitates caution due to the potential risk of sinus perforation during insertion.