Eighteen-month radiographic and histologic evaluation of sinus grafting with anorganic bovine bone in the chimpanzee.

Maxillary sinus grafting procedures are currently the treatment of choice when the alveolar crest of the posterior maxilla is in close approximation to the maxillary sinus. The short-term histologic and radiographic healing following sinus grafting with natural bone mineral (Bio-Oss) in the chimpanzee has been evaluated. We have previously shown by histomorphometric and radiographic analysis that the percentage of vital bone area, the vertical height, and the density of new bone in the maxillary sinus was significantly greater with anorganic bovine bone compared to bovine Type I collagen matrix. The purpose of this in vivo study was to determine the bone mineral density (BMD) of the sinus grafts, the vertical height stability, the vital bone area, and the extent of anorganic bovine bone replacement 18 months postoperatively in 4 maxillary sinuses from 4 different animals. Radiographic analysis of computed tomographic scans taken at 1.5 years revealed an average BMD of 658 mg/mL, which was not significantly different from the values found at 6.5 months. The radiographic vertical height was maintained between the 6.5- and 18-month time points. On average, the grafts were found to have a height of 14 mm. Lateral wall biopsy specimens at 7.5 months were compared to those at 18 months. With the anorganic bovine bone treatment, the percentage of vital bone area increased from 62 +/- 3% to 70 +/- 7% and the percentage of natural bone mineral area decreased from 19 +/- 14% to 6 +/- 3%. The bovine Type I collagen matrix vital bone percentage at 7.5 months was 34 +/- 21%. These results demonstrate that sinus grafting with anorganic bovine bone maintains radiographic evidence of density and height stability of 1.5 years. In addition, histologic evidence supports the hypothesis that anorganic bovine bone is replaced by vital bone.

Residual lateral wall defects following sinus grafting with recombinant human osteogenic protein-1 or Bio-Oss in the chimpanzee.

Sinus grafting procedures are a viable means of ensuring adequate bone for the placement of dental implants in the posterior maxilla. In the quest to improve predictability and accelerate the time line toward receiving a final prosthesis, researchers have turned to recombinant human proteins like osteogenic protein-1 for the potential to therapeutically enhance bone formation. Bilateral sinus augmentations were performed in 15 adults chimpanzees to evaluate treatment with different doses of the osteogenic protein-1 device or natural bone mineral (Bio-Oss). Methods of evaluation included soft tissue healing, radiography (computed tomographic scan), histology, residual lateral wall defect surface area at 7.5 months, and the extent of soft tissue encleftation at 7.5 months. Findings revealed radiographic and histologic evidence of bone formation with all treatment groups and a statistically significant reduction in the depth of soft tissue encleftation and the residual lateral wall defect surface area for both the Bio-Oss and the 2.5-mg osteogenic protein-1 per gram collagen matrix treatments when compared to collagen matrix alone. These results suggest that Bio-Oss and the 2.5-mg osteogenic protein-1 per gram collagen matrix effectively stimulate bone formation in the maxillary sinus.

Maxillary sinus augmentation in the non-human primate: a comparative radiographic and histologic study between recombinant human osteogenic protein-1 and natural bone mineral.

The posterior maxilla has traditionally been one of the most difficult areas to successfully place dental implants due to poor bone quality and close approximation to the maxillary sinus. Sinus augmentation procedures have become a viable means of assuring adequate bone for the placement of dental implants in this area. However, with the techniques currently employed, a considerable variation in the quality of bone attained with the sinus augmentation procedure exists. The purpose of this in vivo study was to evaluate the healing response and bone formation stimulated by 3 doses of recombinant human osteogenic protein-1 (rhOP-1), 0.25, 0.6, and 2.5 mg OP-1 per gram of collagen matrix; natural bone mineral; or collagen matrix alone (control) placed in the maxillary sinus of adult chimpanzees. Results were assessed using clinical, histologic, and radiographic techniques. Radiographic analysis of the computed tomography scans taken at 1 week, and 2.5, 4.5, and 6.5 months revealed a more rapid mineralization with the 2.5 mg OP-1/g collagen matrix and natural bone mineral treatment groups. The incremental bone mineral density (BMD) increase for these 2 treatments from 1 week to 2.5 months was over 2.5 times the increase found with the collagen matrix alone; these 2 treatments also had a higher BMD at the most superior slices evaluated when compared to the other 3 groups. Biopsy specimens were taken at 3.5, 5.5, and 7.5 months and for all 5 treatment groups bone formation was observed at all time points in the majority of the specimens. At 7.5 months the 2.5 and 0.6 mg OP-1/g collagen matrix treatment groups had an increase in the percent bone area when compared to the matrix alone control. In conclusion, these results demonstrate that sinus augmentation with natural bone mineral or 2.5 mg OP-1/g collagen matrix induce comparable radiographic and histologic evidence of bone formation and that both of these treatments performed superior to the control group of collagen matrix alone based upon all methods of evaluation.

Fatal necrotizing fasciitis of dental origin.

Necrotizing fasciitis is a potentially fatal, acute bacterial infection characterized by extensive fascial and subcutaneous tissue necrosis. Four factors that contribute significantly to the morbidity and mortality of necrotizing fasciitis are: 1) delayed treatment, due to difficulty in recognizing the condition; 2) inappropriate treatment; 3) host debilitation; and 4) a polymicrobial infection.