Mentalnerver

Mentalnerver, or mental nerves, are paired sensory branches of the inferior alveolar nerve, the mandibular division of the trigeminal nerve (CN V3). They originate within the mandible as the inferior alveolar nerve travels forward and exits the mandible through the mental foramen, which is typically located near the apex of the second premolar. After exiting, the mental nerve divides into anterior and posterior branches that supply the soft tissues of the lower face.

The primary role of the mental nerve is sensory. Its distribution includes the skin of the chin, the mucosa and skin of the lower lip, and the labial gingiva of the anterior mandible. The mental nerve does not directly innervate the teeth; tooth sensation is carried by the inferior alveolar nerve before it gives rise to the mental nerve.

Clinical significance: The mental nerve is a key target in dental anesthesia. A mental nerve block aims to anesthetize the lower lip, chin, and associated mucosa. Anatomical variation—such as differences in the mental foramen’s position, a high or low foramen, or the presence of accessory mental foramina—can affect the success of anesthesia. Injury to the mental nerve during dental procedures, implant placement in the premolar region, or facial trauma can result in numbness, paresthesia, or dysesthesia in its distribution, which is usually temporary but can be permanent in rare cases.

Variations: The number, size, and branching pattern of mental nerves and the presence of accessory foramina vary among individuals, influencing sensory distribution and clinical planning for procedures in the lower jaw.