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. This joint is unique in that it is a bilateral joint that functions as one unit. Since the TMJ is connected to the mandible, the right and left joints must function together and therefore are not independent of each other.
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 buccinator is a thin quadrilateral muscle occupying the interval between the maxilla and the mandible at the side of the face. It forms the anterior part of the cheek or the lateral wall of the oral cavity.
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 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 deep cervical fascia lies under cover of the platysma, and invests the muscles of the neck; it also forms sheaths for the carotid vessels, and for the structures situated in front of the vertebral column. Its attachment to the hyoid bone prevents the formation of a dewlap.
The masseteric fascia and parotideomasseteric fascia are fascias of the head varyingly described depending upon the source consulted. They may or may not be described as one and the same structure.
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.
Mouth infections, also known as oral infections, are a group of infections that occur around the oral cavity. They include dental infection, dental abscess, and Ludwig's angina. Mouth infections typically originate from dental caries at the root of molars and premolars that spread to adjacent structures. In otherwise healthy patients, removing the offending tooth to allow drainage will usually resolve the infection. In cases that spread to adjacent structures or in immunocompromised patients, surgical drainage and systemic antibiotics may be required in addition to tooth extraction. Since bacteria that normally reside in the oral cavity cause mouth infections, proper dental hygiene can prevent most cases of infection. As such, mouth infections are more common in populations with poor access to dental care or populations with health-related behaviors that damage one's teeth and oral mucosa. This is a common problem, representing nearly 36% of all encounters within the emergency department related to dental conditions.
Inferior alveolar nerve block is a nerve block technique which induces anesthesia (numbness) in the areas of the mouth and face innervated by one of the inferior alveolar nerves which are paired on the left and right side. These areas are the skin and mucous membranes of the lower lip, the skin of the chin, the lower teeth and the labial gingiva of the anterior teeth, all unilaterally to the midline of the side on which the block is administered. However, depending on technique, the long buccal nerve may not be anesthetized by an IANB and therefore an area of buccal gingiva adjacent to the lower posterior teeth will retain normal sensation unless that nerve is anesthetized separately, via a (long) buccal nerve block. The inferior alveolar nerve is a branch of the mandibular nerve, the third division of the trigeminal nerve. This procedure attempts to anaesthetise the inferior alveolar nerve prior to it entering the mandibular foramen on the medial surface of the mandibular ramus.
The sublingual space is a fascial space of the head and neck. It is a potential space located below the mouth and above the mylohyoid muscle, and is part of the suprahyoid group of fascial spaces.
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.
The submandibular space is a fascial space of the head and neck. It is a potential space, and is paired on either side, located on the superficial surface of the mylohyoid muscle between the anterior and posterior bellies of the digastric muscle. The space corresponds to the anatomic region termed the submandibular triangle, part of the anterior triangle of the neck.
The submental space is a fascial space of the head and neck. It is a potential space located between the mylohyoid muscle superiorly, the platysma muscle inferiorly, under the chin in the midline. The space coincides with the anatomic region termed the submental triangle, part of the anterior triangle of the neck.
The mental space is a fascial space of the head and neck. It is a potential space, bilaterally located in the chin, between the mentalis muscle superiorly and the platysma muscle inferiorly. These spaces may be created by pathology, e.g., the spread of odontogenic infection. Commonly the origin of the infection is an anterior mandibular tooth with associated periapical abscess which erodes through the buccal cortical plate of the mandibular at a level below the attachment of the mentalis muscle. The mental space also has the mental foramen located laterally on both the right and left sides. This is important as many mandibular nerves pass through these foremens.
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 submasseterric space is a fascial space of the head and neck. It is a potential space in the face over the angle of the jaw, and is paired on each side. It is located between the lateral aspect of the mandible and the medial aspect of the masseter muscle and its investing fascia. The term is derived from sub- meaning "under" in Latin and masseteric which refers to the masseter muscle. The submasseteric space is one of the four compartments of the masticator space. Sometimes the submasseteric space is described as a series of spaces, created because the masseter muscle has multiple insertions that cover most of the lateral surface of the ramus of the mandible.
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.
The canine space, is a fascial space of the head and neck. It is a thin potential space on the face, and is paired on either side. It is located between the levator anguli oris muscle inferiorly and the levator labii superioris muscle superiorly. The term is derived from the fact that the space is in the region of the canine fossa, and that infections originating from the maxillary canine tooth may spread to involve the space. Infra-orbital is derived from infra- meaning below and orbit which refers to the eye socket.
The Infratemporal space is a fascial space of the head and neck. It is a potential space in the side of the head, and is paired on either side. It is located posterior to the maxilla, between the lateral pterygoid plate of the sphenoid bone medially and by the base of skull superiorly. The term is derived from infra- meaning below and temporal which refers to the temporalis muscle.
