Objectives: We aimed to demonstrate our modified osteotome sinus floor elevation (OSFE) technique for placing two implants in multiple maxillary posterior edentulous spaces with residual bone height (RBH) < 5 mm, to evaluate the clinical effect and explore the prognosis. Methods: We identified 18 appropriate patients with RBH < 5 mm and 12 patients with RBH ≥ 5 mm. After drill preparation, variously shaped curettes were applied to adequately release the tension of the membrane around the cavity and between two implants by blunt dissection. Then, an osteotome was used to elevate the membrane to the desired height. After filling bone graft into the elevated space, dental implants were inserted. Cone-Beam Computed Tomography (CBCT) was performed after surgery and 6 months later. Results: The implant survival rate was 100%, and after the 6-month resorption, the height of the graft apically between the two implants gradually stabilized at 8.92 mm. Compared with 12 patients with RBH ≥ 5 mm, their graft bone resorption demonstrated no significant difference. Conclusions: It can be suggested that the modified OSFE technique could yield predictable clinical results for placing adjacent implants in patients with RBH less than 5 mm after six months of follow-up. Clinical Significance: Our modified OSFE technique could be applied to place adjacent implants in patients with RBH less than 5 mm, especially for elderly patients or patients with bone crests and vessels on the lateral wall, owing to its advantages including less trauma and fewer complications, minimizing the risk of membrane perforation, shortening the treatment period, avoiding another surgery area or second-stage surgery, improving not only the bone around the implant apex but also between implants, etc.
Keywords: Schneiderian membrane; dental implants; residual bone height; simultaneous implant placement; sinus floor augmentation.