Sokmen, KevserKarci, Bilge2026-01-242026-01-242025https://doi.org/10.15311/selcukdentj.1625562https://hdl.handle.net/20.500.12868/4502Background: This study aimed to retrospectively analyze the influence of the upper posterior teeth roots' interaction with the maxillary sinus (MS) on sinus lateral wall thickness (SLWT) as observed in cone beam computed tomography (CBCT) images. Methods: This retrospective study analyzed 234 MS cone beam computed tomography (CBCT) images from 117 patients. Tooth roots were examined in 4 groups (Type 1, Type 2, Type 3, Type 4) according to their relationship with MS. SLWT was evaluated at a distance of 5 mm from the sinus floor. Results: In the 2nd premolar (P2), 1st molar (M1), 2nd molar (M2) tooth alignment; no statistically significant difference was found between women and men in terms of SLDK (p>0.05). Only in the M1 tooth alignment; SLWT of the 60 years old and over group was found to be significantly higher than the other age groups (p<0.05). SLWT at the alignment of P2 teeth was found to be significantly higher than the alignment of other teeth (p<0.05). The incidence of Type 1 sinus relationship in P2 teeth and Type 4 sinus relationship in M2 teeth was found to be significantly higher than the other teeth (p<0.05). SLWT in regions with Type 1 sinus relationship was found to be significantly higher than in regions with other sinus relationships (p<0.05). Conclusions: SLWT decreases from P2 teeth to M2 teeth. Type 1 sinus relationship is most common in P2 teeth, and Type 4 sinus relationship is most common in M2 teeth. SLDK decreases as the close contact of the upper posterior teeth with the MS increases. © 2025, Selcuk University. All rights reserved.trinfo:eu-repo/semantics/openAccessCone beam computed tomographyMaxillary sinusSinus lateral wall thicknessUpper posterior teethArticle10.15311/selcukdentj.1625562121991032-s2.0-105007570398N/A