Radiological Changes Associated with New Bone Formation Following Osteotome Sinus Floor Elevation (OSFE): A Retrospective Study of 40 Patients with 18-Month Follow-Up

BACKGROUND: Osteotome sinus floor elevation (OSFE) is used to increase the bone volume at the site of the maxillary sinus through the transalveolar approach, and may require support with bone grafting. The aim of this retrospective study was to evaluate the radiological changes associated with new bone formation following OSFE during an 18-month follow-up period. MATERIAL/METHODS: Forty patients (including 51 implants) underwent OSFE with final dental reconstruction with a single crown, six months after surgery. Of the 51 dental implants, 24 were implanted with bone grafts, and 27 were implanted without bone grafts. All patients were reviewed using preoperative cone beam computed tomography (CBCT) and panoramic radiographs in postoperative follow-up immediately after OSFE, at six-month follow-up, at 12-month follow-up, and at 18-month follow-up. The degree of new bone formation following OSFE was measured by endo-sinus bone gain (ESBG) in the digital radiographs, and the related factors were analyzed. RESULTS: At 18-month follow-up, the mean ESBG was 2.55±2.24 mm (range, 0.1–8.6 mm). Partial correlation analysis showed that there was no significant correlation between residual bone height (RBH) and ESBG (partial correlation coefficient −0.143) (P=0.328). There were significant positive correlations between the implant protrusion length (IPL) and ESBG (partial correlation coefficient 0.560) (P=0.000), and whether to perform bone grafts and ESBG (partial correlation coefficient 0.596) (P=0.000). CONCLUSIONS: Following OSFE combined with a short implant, the IPL and the performance of bone grafts were significantly associated with new bone formation.