Is the relationship of maxillary molar roots to the floor of the maxillary sinus associated with antral pseudocysts? A retrospective study using cone beam computed tomography.

Objective: The aim of this study was to examine the relationship between molar root positions and antral pseudocysts (APs).

Study Design: The retrospective study included 160 patients. Vertical relationships of the molar roots and the maxillary sinus floor were divided into 4 categories. Root relationships were compared for the presence and dimensions of APs overlying teeth. The root relationships and the presence of APs were also compared for differences in gender, right versus left side, and age groups.

Results: APs were significantly more likely to occur in areas where 1 root extended through the sinus floor from the first molar (P = .004) or second molar (P = .014) and where more than 1 root of the first molar extended through the floor (P = .002). The extension of roots into the sinus was associated with a 9.900 to 25.300 times increase in APs compared with areas with no root contact. The height and width of APs were significantly greater in areas of root penetration into the sinus but gender, side, and age had no effect on the distribution of these root relationships.

Conclusions: Root apices that transmit occlusal force to the Schneiderian membrane might induce the formation of APs and increase the dimensions of the lesions.