Histological Changes in Nasolabial Cutaneous Flaps Employed in Intraoral Reconstruction

Abstract

Nasolabial cutaneous flaps have been routinely used to reconstruct intraoral defects. The purpose of this study was to study histological changes that may occur in the skin flap as a result of its exposure to a new environment. Thirteen patients took part in this study. Fusiform tissue specimens were obtained from the intraoral cutaneous portion of the flap. Biopsy specimens were also taken from the skin of nasolabial region and from the buccal mucosa to serve as control. Thickness of stratum corneum, degree of inflammatory infiltration and number of skin appendages were evaluated. Periodic-acid Schiff (PAS) staining was also performed to identify the presence of hyphae. The characteristic features of the skin are almost always maintained, although the thickness of stratum corneum and the number of skin appendages are often significantly reduced. In two patients the inflammatory infiltration was intense and accompanied by elimination of skin appendages and stratum corneum. These flaps tend to mimic mucosa macroscopically. In four patients fibrosis was histologically demonstrated. These flaps resembled atrophic skin macroscopically. Hyphae could not be identified with PAS staining in this study. Koilocytes, which are indicative of HPV infection, were identified in two flap specimens. Intraorally placed nasolabial flaps may undergo a variety of histological and macroscopical changes. In the majority of cases the intraoral cutaneous flap maintains skin features, except if it becomes heavily infiltrated with inflammatory cells. Inflammation occurs for unknown reasons and results in a mucosa-like microscopic and macroscopic appearance of the intraorally placed flap.