The oral region of the face is unique, with three different epithelial zones: the cutaneous lips, the vermillion and the mucosa of the oral cavity. The skin of the cutaneous vermillion is similar to the rest of the face. There are typical features such as sebaceous glands, sweat glands and hair follicles. However, the vermillion is non-keratinized. Specifically, areas in this region are considered “non-keratinizing” and therefore lack the typical stratum corneum barrier, including the labial mucosa and wet surface of the vermillion, ventral tongue, floor of mouth, soft palate and buccal mucosa.