Relationship between maxillary posterior molar roots and the maxillary sinus floor: Cone-beam computed tomography analysis of a western Chinese population

OBJECTIVE: This study aimed to assess the positional relationships between the maxillary sinus and the first and second molars in a western Chinese population by using cone-beam computed tomography. METHODS: This study included 212 patients (652 maxillary molars and 1956 roots). Patient demographics (sex and age) and cone-beam computed tomography data regarding the relationship between molar roots and the maxillary sinus were obtained. This relationship was stratified into four types for statistical analysis. RESULTS: Sex and side did not significantly influence the distance between maxillary molar roots and the maxillary sinus. However, the distance between maxillary molar roots and the maxillary sinus increased with age. The mesiobuccal root of the second molar was nearest to the maxillary sinus. The most common relationship type involved absence of root contact with the sinus border and presence of a maxillary sinus cross-section above the root apex. CONCLUSIONS: Compared with other teeth, the maxillary posterior teeth have a complex anatomical structure and are closely related to the sinus. These findings may serve as reference information for root canal treatment, tooth extraction, dental implant, and other dental clinical procedures among patients in western China.