Resorption of microsurgically vascularized bone grafts after augmentation of the mandible

Vascularized bone grafts taken from the iliac crest to augment the extremely atrophied mandible are valued for their ability to maintain their contour. Reliable data on long-term performance, however, is not yet available. The purpose of this study was to investigate the long-term results of this method, evaluating the radiological documentation (lateral cephalograms, orthopantomograms) of six patients. The mean follow-up period was 7.3 years. Dental implants were not inserted into the bone grafts. The average increase in ridge height immediately after surgery was 17.8 mm in the symphyseal area, 17.1 mm above the mental foramen and 13.9 mm in the molar region. In the first postoperative year, the average vertical loss was 3.0 mm in the symphyseal, 2.0 mm in the premolar and 2.9 mm in the molar regions. After that the mean yearly rate of vertical resorption dropped to 0.24 mm in the symphyseal, 0.27 mm in the premolar and 0.34 mm in the molar regions, which corresponded to the physiological loss in ridge height due to aging. The fact that graft resorption was so slight portends a good long-term prognosis with this procedure. However, indication is restricted by the high operative burden for the patient and by the availability of alternative rehabilitation methods.