Transcrestal Window Approach For Sinus Floor Elevation: A Case Series

To evaluate the clinical outcome of transcrestal window approach (TWA) for sinus floor elevation with severe bone resorption in maxillary posterior region. Ten partial edentulous patients with an available bone height (ABH) of less than 2 mm in the maxillary posterior region were included. TWA for sinus floor elevations were performed. Cone-beam computed tomography (CBCT) images were taken before surgery (T0), immediately after surgery (T1) and 6 months after surgery (T2). Endo-sinus bone gains (ESBG) were measured at T1 and T2. The alveolar crest positions of soft tissue were evaluated by oral scanning at T0 and T2. The new crestal cortical bones were observed by HE staining through harvesting bone columns before implant placement. The average ABHs were 1.61mm, 11.04mm and 10.31mm at T0, T1 and T2. ESBGs were 9.43±3.02mm and 8.70±2.80mm at T1 and T2. The alveolar crest position of soft tissue increased approximately 0.5 mm at T2. The alveolar ridge cortical bones were osteogenesis under microscope by HE staining. No implant failure and only slight discomfort were reported by the patients. TWA for sinus floor elevation showed a favorable clinical and radiographic outcome in severe atrophic posterior maxilla. TWA technique is less invasive and can reduce postoperative complications (No. 202103).