Sinus Width Analysis and New Classification with Clinical Implications for Augmentation

To measure the distances between the medial and lateral sinus wall (sinus width [SW]) at different levels on cone beam computed tomography (CBCT) and apply those SW values to formulate a new sinus classification.

Edentulous sites adjacent to maxillary sinuses with inadequate residual bone height (RBH) were included from the CBCT database. SW was measured at the heights of 1, 3, 5, 7, and 9 mm from the sinus floor. Mean SW was stratified into different groups by RBH, study sites (first and second premolars and molars), and measurement levels. Statistical analyses were conducted with commercially available software (IBM SPSS Statistics 19, SPSS Inc., Chicago, IL, USA).

A total 186 patients (mean age 50.4 years) with 267 edentulous sites were included. Mean SW was wider at molar sites, higher measurement levels, and sites with less RBH. Narrow, average, or wide sinuses were classified based on the 33rd and 67th percentile SW values at 1-, 5-, and 9-mm measurement levels, respectively.

SW at different levels relating to sinus floor elevation was measured. The proposed classification could contribute to estimate the difficulty of sinus augmentation, useful for the selection of surgical approaches. Further studies are required to testify its clinical implications.