Upper lip

The oral aperture is surrounded by the lower and the upper lips. Both lips unite with each other at the lateral angles of the mouth, forming the right and left oral commissures.

The upper lip covers the anterior surface of the body of the maxilla.

Superiorly, the upper lip is covered over by hairy skin. Here, a central depression can be found directly underneath the nasal septum, called the philtrum.

The lower portion of the upper lip is reddish in appearance, called the vermillion. The vermillion is covered by a specialized stratified squamous epithelium that continues with the oral mucosa inside the oral cavity.

The vermillion region is separated from the hairy skin by a rim of paler skin called the vermillion border. The contour of the vermillion border resembles that of an archer’s bow, hence, sometimes called as the Cupid’s bow.

Muscles such as the Levator labii superioris and levator anguli oris play an important role in lifting up the upper lip and opening the oral aperture.