Assessment of the relationship between roots of maxillary first molar to the floor of the maxillary sinus on cone beam computed tomography

Background: The thickness of maxillary sinus floor may reduce markedly because of protrusion of root apices of posterior teeth into the sinus. The possibility of oro-antral communication after extraction is highest for a maxillary first molar, as this tooth erupts first and is frequently extracted early. Aim: To assess the relationships between the roots of the maxillary first molar and the maxillary sinus floor. Materials and Methods: This is a retrospective study in which 29 cone-beam computed tomography scans of maxillary first molar and floor of the maxillary sinus was obtained. The relationship between maxillary first molar teeth and the maxillary sinus floor was analyzed and among three roots which are most likely to be closest assessed. A t-test was used to compare measurements between female and male patients. ANOVA with Tukey test was used to compare between age groups. Results: Totally, 21 (72.41%) mesiobuccal roots, 18 (62.06%) distobuccal roots, and 14 (48.27%) palatal roots showed a Class 1 relationship. Of 8 cases 2 (37.5%) cases which belonged to Class 0 had protrusion of root into the sinus. Conclusion: Any suspected periapical pathologies of maxillary molars needs thorough three-dimensional radiographic assessment to understand the approximation of the maxillary sinus. Clinical Significance: In our study, Class 0 relationship was the highest for palatal root. Most of the root apices had Class 1 relationship with the floor of the sinus. Hence, one should keep this in mind while conducting periapical or pre-prosthetic surgical procedure in the maxillary posterior region to prevent complications.