Prevalence, location and morphology of maxillary sinus septa: systematic review and meta-analysis.

AIM: To gain further insights and resolve conflicting results in the literature regarding prevalence, predominant location and morphologic variability of maxillary sinus septa. MATERIAL AND METHODS: Electronic and hand searching of English literature identified 33 investigations published from 1995 to 2011. Septa were defined as at least 2-4 mm in height. RESULTS: Septa were present in 28.4% of 8923 sinuses investigated (95% confidence interval: 24.3-32.5%). Prevalence was significantly higher in atrophic sinuses compared with dentate maxillae (p < 0.001). Septa were located in premolar, molar and retromolar regions in 24.4%, 54.6% and 21.0% respectively. Orientation of septa was transverse in 87.6%, sagittal in 11.1% and horizontal in 1.3% of cases. Septa height measured 7.5 mm on average. Complete septa (dividing the sinus into two separate cavities) were found in only 0.3%. Other rare conditions included multiple septa in one sinus (4.2%) and bilateral septa (17.2%). Septa diagnosis using panoramic radiographs yielded incorrect results in 29% of cases. CONCLUSIONS: In view of their high overall prevalence and significant morphologic variability, 3D radiographic imaging prior to sinus floor augmentation may help to reduce complication rates in the presence of maxillary sinus septa.