Grafting of large mandibular advancement with a collagen-coated bovine bone (Bio-Oss Collagen) in orthognathic surgery.

Current principles for correction of dentoskeletal deformities ask to satisfy different treatment goals, making large mandibular advancements a common practice in orthognathic surgery. A main consequence of significant mandibular movements is the potential for unfavorable bone healing of osteotomy sites after traditional sagittal split procedures. This drawback, which mainly occurs at the level of inferior mandibular borders, can affect the stability and support of overlying soft tissues. Whereas the role of bone grafting for upper jaw defects after Le Fort I osteotomy is well addressed in the Literature, until now, just a few articles discussed the potential for grafting of mandibular osteotomy sites. The aim of this study is to evaluate the healing of mandibular bone defects because of large advancement (>8 mm) after sagittal spit procedures. In 20 patients treated for correction of class II dentoskeletal deformities, mandibular osteotomies defects have been grafted with a collagen-coated bovine bone substitute. Clinical, radiological, and histological evaluation of grafted sites showed a good healing of grafted area both in terms of recontouring of inferior mandibular borders and in terms of quality of newly formed bone. This confirms how this procedure could help to avoid the drawbacks related to significant mandibular advancement.