Histomorphometric analysis of intraoral split-thickness skin grafts.

Transposition of split-thickness skin grafts from the anterior thigh to the oral cavity is an ideal method for reconstruction of selected defects following major oncologic ablative surgery. This alternative potentially allows for tongue mobility, deglutition, and articulation superior to that obtained with bulky adynamic myocutaneous flaps. We have examined the adaptive responses of split-thickness skin grafts to the intraoral environment with biopsies from 10 patients 11 to 90 months following oral cavity reconstruction. Histologic examination of intraoral skin grafts shows preservation of the cytoarchitecture of the epidermis, an absence or atrophy of skin appendages, and a statistically significant thinning of the keratin layer. A "junctional zone" between the normal oral cavity mucosa and the skin graft was identified. This zone is characterized by an abrupt transition from keratinized stratified squamous epithelium with a prominent granular layer, to nonkeratinized stratified squamous epithelium lacking a granular layer. This study clearly demonstrates that split-thickness skin, when transposed to the oral cavity, maintains the epidermal phenotype and does not assume the histologic characteristics of mucosa.