The impact of anatomic, patient and surgical factors on membrane perforation during lateral wall sinus floor elevation.

OBJECTIVES This retrospective study aimed to evaluate the influence of anatomical, patient and surgical factors on the occurrence of membrane perforation (MP) during lateral window sinus floor elevation (LWSFE). MATERIAL AND METHODS A review of LWSFE patient records between 2014 and 2019 accounted for MP occurrence, window surface area (WSA), intravenous sedation use, osteotomy instrument type and clinician experience. Preoperative cone beam computed tomography (CBCT) scans were analyzed for lateral wall thickness (LWT), LFM and LAM angles formed between lateral and medial walls at the floor and anterior wall, respectively, sinus width at 5-, 10- and 15-mm (LM-5, LM-10 and LM-15) from the floor, residual bone height (RBH), sinus pathologies, septa and arterial anastomoses. The generalized estimating equation (GEE) approach with a sandwich variance-covariance estimator was used to evaluate the associations with MP. RESULTS MP occurred in 25.74% of 202 LWSFE procedures (166 patients). Mean 1.6 mm-LWT, 3.2 mm-RBH, 95°-LFM, 75.5°-LAM, 12 mm-LM-5, 20.79% septa, 16.83% arterial anastomosis, 37.62% sinus pathology and 29.21% intravenous sedations, 85.24% WSA ≥ 40 mm2 and 57% >10 procedures/clinician were reported. Greater MP rates were encountered as follows: 38.3% (LWT ≥ 1.5 mm), 38% (LFM   80 mm2 ), with statistically significant associations with all these outcomes (p < .05). The presence of pathologies was also associated with MP (p = .013). Associations between MP and the presence of septa and arterial anastomoses, age/gender, right/left sinus, RBH, clinician's experience, instrument type and intravenous sedation use could not be demonstrated. CONCLUSIONS MP is significantly associated with thicker lateral walls, narrower sinuses, larger windows and existing sinus pathology.