This study presents new data on maxillary sinus mucosal thickening derived from a carefully defined data set; however, there were some limitations in the study. One limitation was the limited sample size. However, as discussed, our stringent case selection criteria yielded a more uniform data set for analyses. Other limitations were related to the actual measurements of the maxillary sinus. In order to normalize the data, specific planes were used as the basis for measurements. However, due to anatomical variations in patients, it was not always possible to orient each plane in the exact position. In those instances, the plane of orientation was set as close to ideal as possible. For example, it was not possible to orient the entire hard palate horizontally in some patients if it had a curvature. In addition, since the maxillary sinus is a three-dimensional structure with many variations among patients, situations arose where mucosal thickening extended from the septa or lateral walls instead of just on the floor of the sinus. In these situations, best judgment was utilized in order to decide if these areas of thickening would have an impact on the implant placement area. Also, variations in the anatomical features made orienting CBCT scans at times challenging, and this may have influenced the study outcomes.

Our study found that the largest tissue thickening was present in the middle section of the maxillary sinus. This tissue thickening did not vary based on gender, age, or smoking status, nor did it relate to the underlying alveolar ridge height. However, patients with a history of periodontal diseases demonstrated a significant association with mucosal thickening. A mucosal thickening index was proposed as a guide for future studies and clinical practice. A high implant and grafting success rate (100%) in the maxillary sinus was noted despite large and varied physiologic sinus mucosal/tissue thickening.

CBCT:

Cone-beam computed tomographic

PHI:

Protected Health Information

SFE:

Sinus floor elevation