Myofascial flap without skin for intra-oral reconstruction. 1: Animal studies

Although myofascial flaps are already used clinically in intra-oral reconstruction, the source and process of epithelialization remain unclear. The process of epithelialization of grafted myofascia in the oral cavity was investigated using the latissimus dorsi muscle of Wistar strain rats. The use of myofascial tissue to fill in defects may maintain the space by preventing shrinkage and contracture of the wound, and this myofascial tissue may induce regeneration of the mucosal epithelium. Myofascia itself did not have the potential to epithelialize. Epithelialization progressed gradually along the surface of the granulated myofascia from the surrounding incised mucosal margin of the recipient site to the central portion. Immunohistochemical staining showed that keratinocyte growth factor-expressing cells were found mainly in the granulated myofascia. Within the study period, regenerated epithelium with orthokeratosis consisting of stratified squamous cells was thin and had scanty rete pegs, but it was similar to normal epithelium. Grafted myofascia in the oral cavity may play a space-making role, and induce regeneration of the mucosal epithelium, associated with the production of keratinocyte growth factor.