Which factors affect the risk of membrane perforation in lateral window maxillary sinus elevation? A prospective cohort study.

It was the aim of this prospective cohort study to assess the various anatomical and other patient-related factors that increase membrane perforation risk. Patients underwent cone-beam computed tomography (CBCT) before surgery. The presence of septa, presence of mucous retention cyst, lateral wall thickness, membrane thickness, and residual bone height were predictive factors. Age, gender, and smoking were covariates for the study. The presence or absence of membrane perforation was the study outcome. In total, 140 subjects were studied. The hazard ratio (HR) for the presence of septa with membrane perforation was 8.07 (2.93-22.29) (p < 0.001). The HR for perforation with a single edentulous area relating to two or more teeth was 68.09 (9.52-49.16). The risk of membrane perforation in smokers was 25 times more than in non-smokers - HR 25 (7.58-82.51) (p < 0.001). The HR for membrane perforation in subjects with mucous retention cysts compared with subjects without retention cysts was 27.75 (8.73-88.23) (p < 0.001). Within the limitations of the study it seems that anatomical, habitual, and pathological factors may increase the risk of Schneiderian membrane perforation when a lateral window approach is used for sinus floor augmentation.