A histologic evaluation of fracture repair in the midface.

Although much has been written regarding the treatment of facial bone fractures, at the present time there are no available investigations of human microscopic sections to verify the exact nature of the healing process. The consensus in the literature is that following fractures of the midface, the bone segments are united by fibrous union. Biopsies of the healed fracture sites were obtained in 10 consecutive patients who underwent secondary reconstructive procedures to correct residual deformities. Clinical assessment confirmed that the fractures were completely healed and stable. Histologic sections were obtained across the healed fracture sites, sent for H&E staining, and then examined by light microscopy. All specimens showed that the defects between the segments were obliterated by the formation of a mature compact bone. This bridging bone was characterized by concentric lamellae surrounded by a typical bony architecture. From this study it can be concluded that fractures of the midface heal by direct bony union.