Anatomical proximity of upper teeth and local factors associated with the thickness of the maxillary sinus membrane: a retrospective study

Aim: This cross-sectional study aimed to assess the proximity of root apexes to the maxillary sinus and to verify the correlation between sinus mucosal thickening with the distance from the root apex to the sinus floor, endodontic treatment, age, tooth, sex, and presence of periapical lesion. Methodology: 169 cone-beam computed tomography images were selected, and 696 teeth were assessed, 600 without endodontic treatment, and 96 endodontically treated. The images were initially classified according to the study conducted by Kwak et al. (2004) to assess the proximity of the tooth roots to the maxillary sinus, and multiple logistic regression was subsequently applied to identify probable factors influencing the thickening of the sinus mucosa. Results: The vertical relationships between tooth roots and the sinus floor among the second premolars indicated a predominance of classification I (57.7%); whereas, in the first and second molars there was a predominance of types II (48.4%) and III (34.2%), respectively. The logistic regression did not indicate significant relationships between sinus mucosal thickening and the distance from the root apexes to the sinus floor, presence of endodontic treatment, and type of tooth (p>0.05). Age, presence of periapical lesions, and sex were associated with the presence of sinus thickening (p<0.05; odds ratio=1.03, 2.99, and 5.11, respectively). Conclusions: The presence of thickening in maxillary sinuses was correlated with the following factors: age, sex, and presence of periapical lesions.