SINUS ELEVATION PROCEDURES IN THE RESORBED POSTERIOR MAXILLA - COMPARISON OF THE CRESTAL AND LATERAL APPROACHES

Objectives, The purpose of this stud), was to compare three different methods for sinus elevation: (ii the lateral antrostomy as a two-step procedure, (2) the lateral antrostomy as a one-step procedure, and (3) the osteotome technique with a crestal approach, Indication criteria were defined, based on the residual bone height measured from computed tomography scans, for the sake of applying the appropriate technique. Study, In 30 patients designated for implant treatment in the resorbe d posterior maxilla, 79 implants were placed in combination with a bon e-grafting material for sinus augmentation. The final bone heights wer e measured from panoramic radiographs or postoperative computed tomogr aphy scans. Results, The success rate for the osteotome technique was 95% during the 30-month study period; no failures occurred in any site treated with a lateral antrostomy. The gain in bone height was compar able for the one-step (median = 10 mm) and two-step (median = 12.7 mm) lateral antrostomies. These sites exhibited a significantly greater i ncrease in bone height (p < 0.001) than did the sites in which the ost eotome technique was applied (mean = 3.5 mm). The histologic sections showed both bone apposition in intimate contact with the bone-grafting material particles and initial signs oi its remodeling. Conclusions, The results indicate that the osteotome technique can be recommended w hen more than 6 mm of residual bone height is present and an increase of about 3 to 4 mm is expected. In cases of more advanced resorption a one-step or two-step lateral antrostomy has to be performed.