Texas Esthetician License Practice Exam

Which muscle surrounds the upper lip and elevates it, dilating the nostrils?

1. Orbicularis oris

2. Buccinator

3. Levator labii superioris

4. Zygomaticus

The correct answer is: Levator labii superioris

The muscle that surrounds the upper lip and elevates it while also dilating the nostrils is the levator labii superioris. This muscle plays a significant role in facial expressions, particularly those involving the upper lip. It is positioned above the upper lip and, when contracted, lifts the lip and can flare the nostrils, contributing to the expression of emotions such as disdain or contempt. Understanding the function of the levator labii superioris is essential for estheticians, as it relates to facial aesthetics and the overall symmetry and dynamics of facial features during cosmetic procedures and skin treatments. Muscle knowledge enhances an esthetician's ability to perform services that may affect facial structure, such as facial massages, treatments, or product applications targeting specific muscle actions. The orbicularis oris is primarily responsible for movements of the lips, the buccinator is involved in chewing by keeping food between the teeth, and the zygomaticus muscles help in smiling. Although these muscles play important roles in facial movement, they do not specifically elevate the upper lip and dilate the nostrils as the levator labii superioris does.