Perforation of the sinus membrane during sinus floor elevation: a retrospective study of frequency and possible risk factors.

PURPOSE To analyze the frequency of perforation of the sinus membrane during maxillary sinus floor elevation (SFE) and to assess possible risk factors. MATERIALS AND METHODS Seventy-seven cases of SFE performed with a lateral window approach were evaluated retrospectively. Clinical and radiographic variables potentially influencing the risk of sinus membrane perforation were evaluated and divided into patient-related factors (age, sex, smoking habit); surgery-related factors (type of surgical approach, side, units, sites, and technique of osteotomy); and maxillary sinus-related factors (presence and height of septum, height of residual ridge, thickness of lateral sinus wall, width of antrum, and thickness and status of sinus membrane). RESULTS The following factors presented with at least a 10% difference in rates of perforations: smokers (46.2%) versus nonsmokers (23.4%), simultaneous (32%) versus staged (18.5%) approach, mixed premolar-molar sites (41.2%) versus premolar-only sites (16.7%) versus molar-only sites (26.2%), presence of septa (42.9%) versus no septa (23.8%), and minimum height of residual ridge ≤4 mm (34.2%) versus > 4 mm (20.5%). These same parameters, except minimum height of residual ridge, also showed an odds ratio above 2. However, none of the comparisons reached statistical significance. CONCLUSION The present study failed to demonstrate any factor that statistically significantly increased the risk of sinus membrane perforation during SFE using the lateral window approach