Improving bony stability in maxillofacial surgery: use of osteogenetic materials in patients with profound (> or =5mm) maxillary advancement, a clinical study.

Purpose: LeFort I osteotomy is a part of the standard surgical regimen in the treatment of patients with Class III dentofacial deformity. Inadequate osteosynthesis between the segments is a problem in patients with profound (> or =5mm) maxillary advancement. In this study an ideal ossification is aimed for by applying a combination of osteoinductive and osteoconductive materials.

Patients And Methods: Ten patients with Class III deformity were included in this study. At least 5mm of advancement was performed on each patient, while mean maxillary advancement was 5.7 mm. Human demineralised bone matrix (DBM, 1 cc) and 20 mg bovine bone collagen-protein extracts (Colloss) were applied in between the segments following rigid fixation. Recurrence rates were calculated via cephalometric analyses. Multislice tomography images were collected after the 3 and 12 months in an effort to document ectopic or abnormal bone growth patterns, if any present. Four patients underwent a second operation for plate removal 12 months postoperatively. Bone biopsies were collected from the anterior maxillary wall.

Results: The cephalometric analyses performed after 3 and 12 months were identical to the analyses calculated 1 week postoperatively for each patient, ruling out recurrences. No abnormal or ectopic bone growth was observed. Peroperative examination of four patients revealed a complete or near to complete osteosynthesis line at the anterior maxillary wall. The microscopic examinations of the bony samples retrieved from these borders revealed abundant osteoblasts, osteocytes, osteoclasts and a bony regeneration mimicking intramembranous ossification with its trabecular organisation.

Conclusions: It is possible to achieve an acceptable line of osteosynthesis in cases in need of profound maxillary advancement by applying DBM and Colloss inbetween the bony segments.