Abstract
BACKGROUND/PURPOSE: Understanding the relationship between maxillary sinus and posterior root apices is critical in preventing dental treatment complications. This study aimed to analyze and showcase the relationship between the posterior root apices and the maxillary sinus floor, the distance to the buccal cortical bone, and their correlation with age, gender, and sides. MATERIALS AND METHODS: Cone-beam computed tomography images were collected from 94 patients with a total of 478 maxillary posterior teeth and 997 roots. The shortest distance from root apices to the closest border of maxillary sinus and the outer buccal cortical bone margin were measured and grouped for statistical analysis for the differences (P < 0.05). RESULTS: The root apices of maxillary molars and single-rooted second premolars were located closer to the maxillary sinus compared to first premolars (P < 0.01). The buccal root of two-rooted first premolar had the shortest horizontal distance to the buccal cortical bone among all roots (P < 0.01). The lowest position of the maxillary sinus floor was mostly located at the palatal side (P < 0.01) and between the buccal and palatal root apices (P < 0.01) in the maxillary premolars and molars, respectively. Increasing age would lead to longer distances between the root apices and the maxillary sinus (P < 0.01). Additionally, male patients had thicker buccal cortical bone than female patients (P < 0.01). CONCLUSION: Different tooth positions, age, and gender significantly impact the relationships between root apices and the maxillary sinus and buccal cortical plates, informing patient-centered and individually tailored approaches for more effective and safer surgical endodontic treatment.