Marginal mandibular branch of the facial nerve | |
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![]() Plan of the facial and intermediate nerves and their communication with other nerves. (Labeled at center bottom, second from bottom, as "Mandibular".) | |
![]() The nerves of the scalp, face, and side of neck. | |
Details | |
From | Facial nerve |
Identifiers | |
Latin | ramus marginalis mandibularis nervi facialis |
TA98 | A14.2.01.113 |
TA2 | 6305 |
FMA | 53365 |
Anatomical terms of neuroanatomy |
The marginal mandibular branch of the facial nerve arises from the facial nerve (CN VII) in the parotid gland at the parotid plexus. It passes anterior-ward deep to the platysma and depressor anguli oris muscles. It provides motor innervation to muscles of the lower lip and chin: the depressor labii inferioris muscle, depressor anguli oris muscle, and mentalis muscle. [1] It communicates with the mental branch of the inferior alveolar nerve.[ citation needed ]
The marginal mandibular nerve may be injured during surgery in the neck region, especially during excision of the submandibular salivary gland or during neck dissections due to lack of accurate knowledge of variations in the course, branches and relations. An injury to this nerve during a surgical procedure can distort the expression of the smile as well as other facial expressions. The marginal mandibular branch of the facial nerve is found superficial to the facial artery and (anterior) facial vein. Thus the facial artery can be used as an important landmark in locating the marginal mandibular nerve during surgical procedures. [2] Damage can cause paralysis of the three muscles it supplies, which can cause an asymmetrical smile due to lack of contraction of the depressor labii inferioris muscle. [3] This may be corrected with resection of the muscle, which tends to be successful. [3]
The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue. The nerve typically travels from the pons through the facial canal in the temporal bone and exits the skull at the stylomastoid foramen. It arises from the brainstem from an area posterior to the cranial nerve VI and anterior to cranial nerve VIII.
The parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the mandibular ramus, and secretes serous saliva through the parotid duct into the mouth, to facilitate mastication and swallowing and to begin the digestion of starches. There are also two other types of salivary glands; they are submandibular and sublingual glands. Sometimes accessory parotid glands are found close to the main parotid glands.
The lips are a horizontal pair of soft appendages attached to the jaws and are the most visible part of the mouth of many animals, including humans. Vertebrate lips are soft, movable and serve to facilitate the ingestion of food and the articulation of sound and speech. Human lips are also a somatosensory organ, and can be an erogenous zone when used in kissing and other acts of intimacy.
The auriculotemporal nerve is a sensory branch of the mandibular nerve (CN V3) that runs with the superficial temporal artery and vein, and provides sensory innervation to parts of the external ear, scalp, and temporomandibular joint. The nerve also conveys post-ganglionic parasympathetic fibres from the otic ganglion to the parotid gland.
The platysma muscle is a superficial muscle of the human neck that overlaps the sternocleidomastoid. It covers the anterior surface of the neck superficially. When it contracts, it produces a slight wrinkling of the neck, and a "bowstring" effect on either side of the neck.
The depressor labii inferioris is a facial muscle. It helps to lower the bottom lip.
The mentalis muscle is a paired central muscle of the lower lip, situated at the tip of the chin. It originates from the mentum of the mandible, and inserts into the soft tissue of the chin. It is sometimes referred to as the "pouting muscle" due to it raising the lower lip and causing chin wrinkles.
The depressor anguli oris muscle is a facial muscle. It originates from the mandible and inserts into the angle of the mouth. It is associated with frowning, as it depresses the corner of the mouth.
The facial artery, formerly called the external maxillary artery, is a branch of the external carotid artery that supplies blood to superficial structures of the medial regions of the face.
In facial anatomy, the modiolus is a dense, compact, mobile, fibromuscular tissue mass of facial muscles formed by the interlacing of a number of muscles just lateral to the angle of the mouth opposite the second upper premolar tooth.
The lingual nerve carries sensory innervation from the anterior two-thirds of the tongue. It contains fibres from both the mandibular division of the trigeminal nerve (CN V3) and from the facial nerve (CN VII). The fibres from the trigeminal nerve are for touch, pain and temperature (general sensation), and the ones from the facial nerve are for taste (special sensation).
The maxillary artery supplies deep structures of the face. It branches from the external carotid artery just deep to the neck of the mandible.
The masseteric nerve is a nerve of the face. It is a branch of the mandibular nerve (CN V3). It passes through the mandibular notch to reach masseter muscle. It provides motor innervation the masseter muscle, and sensory innervation to the temporomandibular joint.
The buccal branches of the facial nerve, are of larger size than the rest of the branches, pass horizontally forward to be distributed below the orbit and around the mouth.
The submental artery is the largest branch of the facial artery in the neck. It first runs forward under the mouth, then turns upward upon reaching the chin.
The buccal space is a fascial space of the head and neck. It is a potential space in the cheek, and is paired on each side. The buccal space is superficial to the buccinator muscle and deep to the platysma muscle and the skin. The buccal space is part of the subcutaneous space, which is continuous from head to toe.
The facial muscles are a group of striated skeletal muscles supplied by the facial nerve that, among other things, control facial expression. These muscles are also called mimetic muscles. They are only found in mammals, although they derive from neural crest cells found in all vertebrates. They are the only muscles that attach to the dermis.
Lip reconstruction may be required after trauma or surgical excision. The lips are considered the beginning of the oral cavity and are the most common site of oral cancer. Any reconstruction of the lips must include both functional and cosmetic considerations. The lips are necessary for speech, facial expression, and eating. Because of their prominent location on the face, even small abnormalities can be apparent.
The buccal fat pad is one of several encapsulated fat masses in the cheek. It is a deep fat pad located on either side of the face between the buccinator muscle and several more superficial muscles. The inferior portion of the buccal fat pad is contained within the buccal space. It should not be confused with the malar fat pad, which is directly below the skin of the cheek. It should also not be confused with jowl fat pads. It is implicated in the formation of hollow cheeks and the nasolabial fold, but not in the formation of jowls.
The following outline is provided as an overview of and topical guide to human anatomy:
This article incorporates text in the public domain from page 905 of the 20th edition of Gray's Anatomy (1918)