What is the most common cause of lower lip paresthesia in a patient with a lower denture?

The most common cause of lower lip paresthesia in a patient with a lower denture is due to pressure on the mental foramen. The mental foramen is an opening on the mandible where the mental nerve, a branch of the mandibular division of the trigeminal nerve, exits. When a lower denture fits poorly or exerts excessive pressure on this area, it can irritate or compress the mental nerve, leading to sensations of tingling, numbness, or pain in the lower lip area.

Ill-fitting dentures can certainly contribute to various oral issues, but the direct impact on the mental foramen makes pressure on it the primary reason for paresthesia. Other causes like pressure on the genioglossi mylohyoid muscles or neuropathy are less likely to specifically relate to lower lip discomfort associated with dentures.