In anatomy, the temporomandibular joints (TMJ) are the two joints connecting the jawbone to the skull. It is a bilateral synovial articulation between the temporal bone of the skull above and the mandible below; it is from these bones that its name is derived. The joints are unique in their bilateral function, being connected via the mandible.
In neuroanatomy, the trigeminal nerve (lit. triplet nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for sensation in the face and motor functions such as biting and chewing; it is the most complex of the cranial nerves. Its name (trigeminal, from Latin tri- 'three', and -geminus 'twin') derives from each of the two nerves (one on each side of the pons) having three major branches: the ophthalmic nerve (V1), the maxillary nerve (V2), and the mandibular nerve (V3). The ophthalmic and maxillary nerves are purely sensory, whereas the mandibular nerve supplies motor as well as sensory (or "cutaneous") functions. Adding to the complexity of this nerve is that autonomic nerve fibers as well as special sensory fibers (taste) are contained within it.
In neuroanatomy, the mandibular nerve (V3) is the largest of the three divisions of the trigeminal nerve, the fifth cranial nerve (CN V). Unlike the other divisions of the trigeminal nerve (ophthalmic nerve, maxillary nerve) which contain only afferent fibers, the mandibular nerve contains both afferent and efferent fibers. These nerve fibers innervate structures of the lower jaw and face, such as the tongue, lower lip, and chin. The mandibular nerve also innervates the muscles of mastication.
The four classical muscles of mastication elevate the mandible and move it forward/backward and laterally, facilitating biting and chewing. Other muscles are responsible for opening the jaw, namely the geniohyoid, mylohyoid, and digastric muscles.
The middle meningeal artery is typically the third branch of the first portion of the maxillary artery. After branching off the maxillary artery in the infratemporal fossa, it runs through the foramen spinosum to supply the dura mater and the calvaria. The middle meningeal artery is the largest of the three (paired) arteries that supply the meninges, the others being the anterior meningeal artery and the posterior meningeal artery.
In anatomy, the masseter is one of the muscles of mastication. Found only in mammals, it is particularly powerful in herbivores to facilitate chewing of plant matter. The most obvious muscle of mastication is the masseter muscle, since it is the most superficial and one of the strongest.
The lateral pterygoid muscle (or external pterygoid muscle) is a muscle of mastication. It has two heads. It lies superior to the medial pterygoid muscle. It is supplied by pterygoid branches of the maxillary artery, and the lateral pterygoid nerve (from the mandibular nerve, CN V3). It depresses and protrudes the mandible. When each muscle works independently, they can move the mandible side to side.
The buccal nerve is a sensory nerve of the face arising from the mandibular nerve. It conveys sensory information from the skin of the cheek, and parts of the oral mucosa, periodontium, and gingiva.
The tensor veli palatini muscle is a thin, triangular muscle of the head that tenses the soft palate and opens the Eustachian tube to equalise pressure in the middle ear.
The nasociliary nerve is a branch of the ophthalmic nerve (CN V1) (which is in turn a branch of the trigeminal nerve (CN V)). It is intermediate in size between the other two branches of the ophthalmic nerve, the frontal nerve and lacrimal nerve.
The pharyngeal arches, also known as visceral arches, are structures seen in the embryonic development of vertebrates that are recognisable precursors for many structures. In fish, the arches are known as the branchial arches, or gill arches.
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 pterygoid processes of the sphenoid, one on either side, descend perpendicularly from the regions where the body and the greater wings of the sphenoid bone unite.
The greater wing of the sphenoid bone, or alisphenoid, is a bony process of the sphenoid bone, positioned in the skull behind each eye. There is one on each side, extending from the side of the body of the sphenoid and curving upward, laterally, and backward.
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 infratemporal fossa is an irregularly shaped cavity that is a part of the skull. It is situated below and medial to the zygomatic arch. It is not fully enclosed by bone in all directions. It contains superficial muscles, including the lower part of the temporalis muscle, the lateral pterygoid muscle, and the medial pterygoid muscle. It also contains important blood vessels such as the middle meningeal artery, the pterygoid plexus, and the retromandibular vein, and nerves such as the mandibular nerve (CN V3) and its branches.
The following outline is provided as an overview of and topical guide to human anatomy:
In jawed vertebrates, the mandible, lower jaw, or jawbone is a bone that makes up the lower – and typically more mobile – component of the mouth.
Fascial spaces are potential spaces that exist between the fasciae and underlying organs and other tissues. In health, these spaces do not exist; they are only created by pathology, e.g. the spread of pus or cellulitis in an infection. The fascial spaces can also be opened during the dissection of a cadaver. The fascial spaces are different from the fasciae themselves, which are bands of connective tissue that surround structures, e.g. muscles. The opening of fascial spaces may be facilitated by pathogenic bacterial release of enzymes which cause tissue lysis. The spaces filled with loose areolar connective tissue may also be termed clefts. Other contents such as salivary glands, blood vessels, nerves and lymph nodes are dependent upon the location of the space. Those containing neurovascular tissue may also be termed compartments.
The pterygomandibular space is a fascial space of the head and neck. It is a potential space in the head and is paired on each side. It is located between the lateral pterygoid muscle and the medial surface of the ramus of the mandible. The pterygomandibular space is one of the four compartments of the masticator space.
