Which muscle helps in expressing doubt by wrinkling the chin?

The mentalis muscle is primarily responsible for the movement of the chin and is specifically associated with expressing emotions such as doubt or irritation. When the mentalis contracts, it causes the skin of the chin to wrinkle and protrude the lower lip, creating a facial expression that conveys skepticism or uncertainty. This subtle movement is a key indicator of non-verbal communication, illustrating how facial muscles contribute to emotional expression.

The other muscles listed serve different functions. For instance, the risorius muscle is involved in smiling or grinning, the platysma handles tension and movements of the neck and lower face, while the buccinator assists in actions related to chewing and blowing, such as keeping food positioned between the teeth. Each muscle has its unique role in facial expressions, but the mentalis is specifically linked to the expression of doubt due to its anatomical position and function.