Tridimensional analysis of maxillary sinus anatomy related to sinus lift procedure.

Purpose: To evaluate the angulation of the maxillary sinus walls at the apical sinus region.
Materials and Methods: Using preoperative computerized tomographies of 15 patients selected for sinus lift procedures, the angulation of the maxillary sinus floor was measured drawing straight lines tangential to the mesial and lateral walls. The measurements were taken from sagittal images at specific areas (i.e., second bicuspid, first molar, and second molar).
Results: The results showed that the second bicuspid sites have a sharper angulation than the second molar sites, and these second molar sites have a sharper angle than the first molar sites.
Conclusion: The sharper angle observed in the second bicuspid area can influence the feasibility of schneiderian membrane evaluation when compared to the molar areas.