New Bone Formation in Nongrafted Sinus Lifting With Space-Maintaining Management: A Novel Technique Using a Titanium Bone Fixation Device

Purpose Sinus lifting without graft materials allows new bone formation in the sinus, but the amount of bone formation varies. This study aimed to investigate whether nongrafted sinus lifting using a titanium bone fixation device can promote bone formation in the sinus. Materials and Methods Patients with atrophic posterior maxillae jeopardizing implant stability were included. After nongrafted sinus lifting in combination with implant placement, repositioning of the bone window and additional space-maintaining management were performed by use of the bone fixation device. The primary variables recorded retrospectively included implant survival and preoperative and postoperative alveolar crest height with and without Schneiderian membrane perforation. Independent variables included patient demographics, position and dimension of the implants, complications, and follow-up period. The t test was used for comparing differences in bone levels. The implant survival rate was estimated by uses of Kaplan-Meier statistics. Results The study included 11 patients (4 men and 7 women) and a total of 21 implants. Radiographically, new bone formation around the implant was generally observed in accordance with the implant apex. Postoperative alveolar crest height (mean, 10.9 ± 2.2 mm) was significantly higher compared with residual alveolar crest height (mean, 4.7 ± 1.4 mm), and no significant difference in bone formation was seen according to membrane perforation. The cumulative survival rate was 95.2%. Conclusions This nongrafted sinus-lifting procedure using a bone fixation device could attain predictable bone formation. Additional space-maintaining management using a bone fixation device in a nongrafted sinus lift offers a useful technique for promoting bone formation in the sinus.