Crooked smile

A crooked smile, also referred to as an asymmetrical smile, occurs when one side of the face does not lift or move as effectively as the other side. This results in an uneven or lopsided appearance when a person smiles. The condition is often due to muscle weakness or paralysis, affecting the facial muscles responsible for lifting the corners of the mouth. In the context of myasthenia gravis, a crooked smile is a common manifestation, as the disease causes fluctuating muscle weakness, including those muscles involved in facial expressions. This can lead to difficulties not only in smiling but also in other facial movements and expressions.

Source | Author Doctor Nikas Samuolis, reviewed by Prof. Virginijus Šapoka | Vilnius University | Faculty of Medicine | Head of the Department of Internal Medicine, Family Medicine, and Oncology