Le Fort I osteotomies using Bio-Oss® collagen to promote bony union: a prospective clinical split-mouth study.

The purpose of this study was to evaluate whether a bone substitute can be used to promote bony union in patients undergoing maxillary advancement after Le Fort l osteotomy. Nine patients were treated bilaterally with Le Fort I osteotomies and maxillary advancements of 5mm or less. In each patient, one gap was grafted with the bone substitute Bio-Oss(®) Collagen (BOC). The contralateral site was left empty and served as control. After 6 months there were still empty gaps in the control sites of three patients, while in the grafted sites all gaps were completely filled with bone. The histomorphometric analysis performed with biopsies from the region of the original gap showed a similar amount of new bone in both groups, however, in the test group the mean overall amount of the mineralized fraction was higher compared to the control group (test site 65.0±6.2%, control site 38.9±32.6%). The bone substitute seemed to be a suitable material to promote bony union in Le Fort I osteotomies. Further studies are needed to analyse whether this technique is efficient in preventing relapse and promoting bony union in larger advancements.