Sinus elevation procedures in the resorbed posterior maxilla. Comparison of the crestal and lateral approaches

Abstract

Objectives: The purpose of this study was to compare three different methods for sinus elevation: (1) 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 resorbed posterior maxilla, 79 implants were placed in combination with a bone-grafting material for sinus augmentation. The final bone heights were measured from panoramic radiographs or post-operative computed tomography 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 comparable for the one-step (median = 10 mm) and two-step (median = 12.7 mm) lateral antrostomies. These sites exhibited a significantly greater increase in bone height (p < 0.001) than did the sites in which the osteotome 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 of its remodeling.

Conclusions: The results indicate that the osteotome technique can be recommended when 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.