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 anatomy, the temporalis muscle, also known as the temporal muscle, is one of the muscles of mastication (chewing). It is a broad, fan-shaped convergent muscle on each side of the head that fills the temporal fossa, superior to the zygomatic arch so it covers much of the temporal bone.Temporal refers to the head's temples.
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.
Prognathism, also called Habsburg chin, Habsburg's chin, Habsburg jaw or Habsburg's jaw primarily in the context of its prevalence amongst members of the House of Habsburg, is a positional relationship of the mandible or maxilla to the skeletal base where either of the jaws protrudes beyond a predetermined imaginary line in the coronal plane of the skull. In general dentistry, oral and maxillofacial surgery, and orthodontics, this is assessed clinically or radiographically (cephalometrics). The word prognathism derives from Greek πρό and γνάθος. One or more types of prognathism can result in the common condition of malocclusion, in which an individual's top teeth and lower teeth do not align properly.
Orthognathic surgery, also known as corrective jaw surgery or simply jaw surgery, is surgery designed to correct conditions of the jaw and lower face related to structure, growth, airway issues including sleep apnea, TMJ disorders, malocclusion problems primarily arising from skeletal disharmonies, and other orthodontic dental bite problems that cannot be treated easily with braces, as well as the broad range of facial imbalances, disharmonies, asymmetries, and malproportions where correction may be considered to improve facial aesthetics and self-esteem.
In orthodontics, a malocclusion is a misalignment or incorrect relation between the teeth of the upper and lower dental arches when they approach each other as the jaws close. The English-language term dates from 1864; Edward Angle (1855–1930), the "father of modern orthodontics", popularised it. The word "malocclusion" derives from occlusion, and refers to the manner in which opposing teeth meet.
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 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.
Cherubism is a rare genetic disorder that causes prominence in the lower portion in the face. The name is derived from the temporary chubby-cheeked resemblance to putti, the chubby-faced infants featured in Renaissance paintings, which were often mistakenly described as cherubs.
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 mandibular fossa, also known as the glenoid fossa in some dental literature, is the depression in the temporal bone that articulates with the mandible.
Micrognathism is a condition where the jaw is undersized. It is also sometimes called mandibular hypoplasia. It is common in infants, but is usually self-corrected during growth, due to the jaws' increasing in size. It may be a cause of abnormal tooth alignment and in severe cases can hamper feeding. It can also, both in adults and children, make intubation difficult, either during anesthesia or in emergency situations.
Crossbite is a form of malocclusion where a tooth has a more buccal or lingual position than its corresponding antagonist tooth in the upper or lower dental arch. In other words, crossbite is a lateral misalignment of the dental arches.
Facial trauma, also called maxillofacial trauma, is any physical trauma to the face. Facial trauma can involve soft tissue injuries such as burns, lacerations and bruises, or fractures of the facial bones such as nasal fractures and fractures of the jaw, as well as trauma such as eye injuries. Symptoms are specific to the type of injury; for example, fractures may involve pain, swelling, loss of function, or changes in the shape of facial structures.
Cephalometric analysis is the clinical application of cephalometry. It is analysis of the dental and skeletal relationships of a human skull. It is frequently used by dentists, orthodontists, and oral and maxillofacial surgeons as a treatment planning tool. Two of the more popular methods of analysis used in orthodontology are the Steiner analysis and the Downs analysis. There are other methods as well which are listed below.
Mandibular fracture, also known as fracture of the jaw, is a break through the mandibular bone. In about 60% of cases the break occurs in two places. It may result in a decreased ability to fully open the mouth. Often the teeth will not feel properly aligned or there may be bleeding of the gums. Mandibular fractures occur most commonly among males in their 30s.
A bone cyst or geode is a cyst that forms in bone.
A jaw abnormality is a disorder in the formation, shape and/or size of the jaw. In general abnormalities arise within the jaw when there is a disturbance or fault in the fusion of the mandibular processes. The mandible in particular has the most differential typical growth anomalies than any other bone in the human skeleton. This is due to variants in the complex symmetrical growth pattern which formulates the mandible.
It is estimated that nearly 30% of the general population present with malocclusions that are in great need of orthodontic treatment. However, the term dentofacial deformity describes an array of dental and maxillo-mandibular abnormalities, often presenting with a malocclusion, which is not amenable to orthodontic treatment alone and definitive treatment needs surgical alignment of upper/lower jaws or both. Individuals with dentofacial deformities often present with lower quality of life and compromised functions with respect to breathing, swallowing, chewing, speech articulation, and lip closure/posture. It is estimated that about 5% of general population present with dentofacial deformities that are not amenable to orthodontic treatment only.
Homo longi is an extinct species of archaic human identified from a nearly complete skull, nicknamed 'Dragon Man', from Harbin on the Northeast China Plain, dating to at minimum 146,000 years ago during the Middle Pleistocene. The skull was discovered in 1933 along the Songhua River while the Dongjiang Bridge was under construction for the Manchukuo National Railway. Due to a tumultuous wartime atmosphere, it was hidden and only brought to paleoanthropologists in 2018. The original describers postulated H. longi represents a member of the Denisovans, though this is unconfirmable without genetic testing. They also considered modern humans to be more closely related to H. longi than to the European Neanderthals, but DNA evidence suggests Denisovans are more closely related to Neanderthals than modern humans.
