Labial commissures

Labial Commissures are the corners of the mouth where the upper and lower lips meet. They play a significant role in facial expressions and speech.

Anatomy

The anatomy of the labial commissures involves several structures, including the orbicularis oris muscle, which encircles the mouth and controls the movements of the lips. The labial commissures are also connected to the buccinator muscle, which assists in mastication and facial expression.

Function

The primary function of the labial commissures is to facilitate the movement of the lips during speech, eating, and facial expressions. They also play a role in maintaining oral continence, preventing saliva and food from leaking out of the mouth.

Clinical Significance

Changes in the appearance or function of the labial commissures can be indicative of certain medical conditions. For example, drooping or sagging of the labial commissures can be a sign of Bell's palsy, a condition that causes temporary weakness or paralysis of the facial muscles. Angular cheilitis, a condition characterized by inflammation and cracking of the corners of the mouth, can also affect the labial commissures.

See Also

• Oral anatomy
• Facial expression
• Speech production