Mentolabial sulcus

The mentolabial sulcus is the anatomical groove or depression located between the lower lip and the chin. It marks the transition from the labial (lip) region to the mental (chin) region and is formed by the underlying soft tissue and muscular anatomy, particularly the mentalis muscle and adjacent structures. The prominence and curvature of the mentolabial sulcus can vary based on age, sex, and individual anatomical differences.