Assessment of the anatomical relationship of the roots of maxillary molars and the floor of maxillary sinus using cone-beam computed tomography (CBCT) in the Saudi sub-population

BACKGROUND: This study aimed to assess the relationship between the roots of the maxillary molars and the maxillary sinus floor in a Saudi subpopulation using cone-beam computed tomography (CBCT). METHODS: The study was conducted at the Dental University Hospital of King Saud University in Riyadh, Saudi Arabia. A sample of 220 Saudi patients who attended the Dental University Hospital between January 2009 and January 2024 and had CBCT images was included. The vertical relationship between the maxillary sinus floor and the root apices of the maxillary molars was assessed using the classification of Kwak et al. Vertical distances were recorded on both sides for each maxillary molar root. RESULTS: A total of 880 maxillary molars and 2640 individual roots were analyzed. The linear mixed-effects model showed a significant effect for tooth root on root-to-sinus distance (p < 0.001). Age group demonstrated a significant overall effect in the model; however, no pairwise comparisons between age groups remained statistically significant after Bonferroni correction. No significant effect of gender was observed. The roots of the maxillary second molars are closer to the maxillary sinus. Type 2 was the most frequently observed relationship among maxillary molars in both genders. CONCLUSIONS: The shortest root-to-sinus distance was observed among the roots of the maxillary second molars. These findings highlight the value of CBCT imaging in preoperative clinical assessment for identifying high-risk cases, thereby modifying treatment planning and reducing the likelihood of sinus-related complications.