Scientific Reports / Morphometric analysis of sinus depth in the posterior maxilla and proposal of a novel classification

The aim of this study was to analyse the posterior maxillary sinus based on its extension into the alveolar process and to provide a simple clinical classification. A retrospective cohort study was conducted in CT scans of 200 dentate and 200 edentulous patients (100 women and 100 men, respectively). After manual placement of 12 reference points morphometric analysis was performed and sinus depth, residual alveolar ridge height (RH) and the sinus opening angle were calculated. Sinuses were classified according to the quartiles of sinus depth: class I (above the hard palate), class II (06mm below the hard palate) and class III (>6mm below the hard palate). Sinus depth was found to be a reliable anatomical landmark and did not vary significantly between gender (p=0.8940) or dentition groups (p=0.9723). Alveolar height varied significantly between sinus classes (p<21016) and dentition groups (p<21016) but not between genders (p=0.5178). The sinus opening angle was significantly different between sinus classes (p