Lower lip
Labium inferius oris
- Synonym: Inferior lip
Definition
The oral aperture is surrounded by the upper and the lower lips. Both lips unite with each other at the lateral angles of the mouth, forming the right and left oral commissures.
The lower lip covers the anterior surface of the body of the mandible.
Inferiorly, the lower lip is covered over by hairy skin. While, the upper portion of the lower 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.
Muscles such as the depressor labii inferioris and depressor anguli oris play an important role in pulling down the lower lip and opening the oral aperture.
References
Text written by Muhammad A. Javaid, MD, PhD © 2023 IMAIOS.
(2023). Anatomy of the Lips, Mouth, and Oral Region in ‘National Human Genome Research Institute’. Available at URL: https://elementsofmorphology.nih.gov/anatomy-oral.shtml [accessed on Feb 19th, 2023]
