Volumetric evaluations of the maxillary sinus before and post regenerative surgery

Objective: The purpose of this study was to investigate possible differences in the filling of the various recesses of the maxillary sinus after the procedure of sinus floor elevation in relation with the initial volume of the same and if the sinus volume can influence long-term graft dimensions, by using cone beam computed tomography (CBCT) as diagnostic analysis device. Patients and methods: This study included 32 sinuses corresponding to 16 patients referred for bilateral maxillary sinus augmentation procedures needing to increase the volume of the surgical site with the porcine cortical bone for dental implant placement in the posterior maxilla. The sinuses were analyzed by preoperative and postoperative (15 days and 6 months after sinus surgery) cone beam computed tomography. Results: No statistically significant relations were observed between initial sinus dimensions and the entity of the contraction of the graft between T1 (15 days after surgery) and T2 (180 days after surgery). The behavior was the same either for the large sinus (> 15.65 cm3) and for the small one (< 15.65 cm3). Instead, about the filling of the various sinus recesses, a linear regression model was used to explain the difference between the mean preoperative and postoperative surgical spaces; in most of the samples, the filling of the anterior recess was ~15% of the total volume of the graft, i.e., the minor one among the main recesses. Conclusions: Our findings suggest that: (1) in the procedure of sinus floor augmentation by a lateral approach with deproteinized porcine bone there are no relations between the initial dimensions of the sinus and the long-term dimensional changes of the graft, and (2) that, among the main recesses of the sinus, the anterior one is generally the less filled.