Mandible in the context of Temporal bone

Rodents (from Latin rodere, 'to gnaw') are mammals of the order Rodentia (/roʊˈdɛnʃə/ roh-DEN-shə), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for Antarctica, and several oceanic islands, though they have subsequently been introduced to most of these land masses by human activity.

Rodents are extremely diverse in their ecology and lifestyles and can be found in almost every terrestrial habitat, including human-made environments. Species can be arboreal, fossorial (burrowing), saltatorial/ricochetal (leaping on their hind legs), or semiaquatic. However, all rodents share several morphological features, including having only a single upper and lower pair of ever-growing incisors. Well-known rodents include mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs, and hamsters. Once included with rodents, rabbits, hares, and pikas, which also have incisors that grow continuously, are now considered to be in a separate order, the Lagomorpha, distinguished by an extra pair of incisors. Both Rodentia and Lagomorpha are sister groups, sharing a single common ancestor and forming the clade of Glires.

The axial skeleton is the core part of the endoskeleton made of the bones of the head and trunk of vertebrates. In the human skeleton, it consists of 80 bones and is composed of the skull (28 bones, including the cranium, mandible and the middle ear ossicles), the vertebral column (26 bones, including vertebrae, sacrum and coccyx), the rib cage (25 bones, including ribs and sternum), and the hyoid bone. The axial skeleton is joined to the appendicular skeleton (which support the limbs) via the shoulder girdles and the pelvis.

All extant cephalopods have a two-part beak, or rostrum, situated in the buccal mass (mouthparts) and surrounded by the muscular head appendages. The dorsal (upper) mandible fits into the ventral (lower) mandible and together they function in a scissor-like fashion. The beak may also be referred to as the mandibles or jaws. These beaks are different from bird beaks because they crush bone while most bird beaks do not.

Fossilized remains of beaks are known from a number of cephalopod-groups, both extant and extinct, including squids, octopodes, belemnites, and vampyromorphs. Aptychi - paired plate-like structures found in ammonites - may also have been jaw elements.

Incisors (from Latin incidere, "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, whereas armadillos, anteaters and other animals in the superorder Xenarthra have none.

Congenital syphilis is syphilis that occurs when a mother with untreated syphilis passes the infection to her baby during pregnancy or at birth. It may present in the fetus, infant, or later. Clinical features vary and differ between early onset, that is presentation before 2-years of age, and late onset, presentation after age 2-years. Infection in the unborn baby may present as poor growth, non-immune hydrops leading to premature birth or loss of the baby, or no signs. Affected newborns mostly initially have no clinical signs. They may be small and irritable. Characteristic features include a rash, fever, large liver and spleen, a runny and congested nose, and inflammation around bone or cartilage. There may be jaundice, large glands, pneumonia (pneumonia alba), meningitis, warty bumps on genitals, deafness or blindness. Untreated babies that survive the early phase may develop skeletal deformities including deformity of the nose, lower legs, forehead, collar bone, jaw, and cheek bone. There may be a perforated or high arched palate, and recurrent joint disease. Other late signs include linear perioral tears, intellectual disability, hydrocephalus, and juvenile general paresis. Seizures and cranial nerve palsies may first occur in both early and late phases. Eighth nerve palsy, interstitial keratitis and small notched teeth may appear individually or together; known as Hutchinson's triad.

It is caused by the bacterium Treponema pallidum subspecies pallidum when it infects the baby after crossing the placenta or from contact with a syphilitic sore at birth. It is not transmitted during breastfeeding unless there is an open sore on the mother's breast. The unborn baby can become infected at any time during the pregnancy. Most cases occur due to inadequate antenatal screening and treatment during pregnancy. The baby is highly infectious if the rash and snuffles are present. The disease may be suspected from tests on the mother; blood tests and ultrasound. Tests on the baby may include blood tests, CSF analysis and medical imaging. Findings may reveal anemia and low platelets. Other findings may include low sugars, proteinuria and hypopituitarism. The placenta may appear large and pale. Other investigations include testing for HIV.

In vertebrates, the maxilla (pl.: maxillae /mækˈsɪliː/) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxillary bones are fused at the intermaxillary suture, forming the anterior nasal spine. This is similar to the mandible (lower jaw), which is also a fusion of two mandibular bones at the mandibular symphysis. The mandible is the movable part of the jaw.

The gums or gingiva (pl.: gingivae) consist of the mucosal tissue that lies over the mandible and maxilla inside the mouth. Gum health and disease can have an effect on general health.

The Mauer 1 mandible is the oldest-known specimen of the genus Homo in Germany. It was found in 1907 in a sand quarry in the community Mauer, around 10 km (6.2 mi) south-east of Heidelberg. The Mauer 1 mandible is the type specimen of the species Homo heidelbergensis. Some European researchers have classified the find as Homo erectus heidelbergensis, regarding it as a subspecies of Homo erectus. In 2010 the mandible's age was for the first time exactly determined to be 609,000 ± 40,000 years. Previously, specialist literature had referred to an age of either 600,000 or 500,000 years on the basis of less accurate dating methods.

The Boxer is a medium to large, short-haired dog breed of mastiff-type, developed in Germany. The coat is smooth and tight-fitting; colors are fawn or brindled, with or without white markings. Boxers are brachycephalic (they have broad, short skulls), have a square muzzle, mandibular prognathism (an underbite), very strong jaws, and a powerful bite ideal for hanging on to large prey. The Boxer was bred from the Old English Bulldog and the now extinct Bullenbeisser, which became extinct by crossbreeding rather than by a decadence of the breed. The Boxer is a member of both The Kennel Club and American Kennel Club (AKC) Working Group.

The first Boxer club was founded in 1895, with Boxers being first exhibited in a dog show for St. Bernards in Munich the next year. Based on 2013 AKC statistics, Boxers held steady as the seventh-most popular breed of dog in the United States for the fourth consecutive year. According to the AKC's website, though, the boxer is now the 11th-most popular dog breed in the United States.

Gular skin (throat skin), in ornithology, is an area of featherless skin on birds that joins the lower mandible of the beak (or bill) to the bird's neck. Other vertebrate taxa may have a comparable anatomical structure that is referred to as either a gular sac, throat sac, vocal sac or gular fold.

The alveolar process (/ælˈviːələr, ˌælviˈoʊlər, ˈælviələr/) is the portion of bone containing the tooth sockets on the jaw bones (in humans, the maxilla and the mandible). The alveolar process is covered by gums within the mouth, terminating roughly along the line of the mandibular canal. Partially comprising compact bone, it is penetrated by many small openings for blood vessels and connective fibres.

The bone is of clinical, phonetic and forensic significance.

Ambondro mahabo is a mammal from the Middle Jurassic (Bathonian) Isalo III Formation (about 167 million years ago) of Madagascar. The only described species of the genus Ambondro, it is known from a fragmentary lower jaw with three teeth, interpreted as the last premolar and the first two molars. The premolar consists of a central cusp with one or two smaller cusps and a cingulum (shelf) on the inner, or lingual, side of the tooth. The molars also have such a lingual cingulum. They consist of two groups of cusps: a trigonid of three cusps at the front and a talonid with a main cusp, a smaller cusp, and a crest at the back. Features of the talonid suggest that Ambondro had tribosphenic molars, the basic arrangement of molar features also present in marsupial and placental mammals. It is the oldest known mammal with putatively tribosphenic teeth; at the time of its discovery it antedated the second oldest example by about 25 million years.

Upon its description in 1999, Ambondro was interpreted as a primitive relative of Tribosphenida (marsupials, placentals, and their extinct tribosphenic-toothed relatives). In 2001, however, an alternative suggestion was published that united it with the Cretaceous Australian Ausktribosphenos and the monotremes (the echidnas, the platypus, and their extinct relatives) into the clade Australosphenida, which would have acquired tribosphenic molars independently from marsupials and placentals. The Jurassic Argentinean Asfaltomylos and Henosferus and the Cretaceous Australian Bishops were later added to Australosphenida, and new work on wear in australosphenidan teeth has called into question whether these animals, including Ambondro, did have tribosphenic teeth. Other paleontologists have challenged this concept of Australosphenida, and instead proposed that Ambondro is not closely related to Ausktribosphenos plus monotremes, or that monotremes are not australosphenidans and that the remaining australosphenidans are related to placentals.

The four classical muscles of mastication elevate the mandible (closing the jaw) 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 lateral pterygoid may play a role).

Glaucabalaena is an extinct genus of gray whale that lived during the Pliocene epoch. The genus is known from a single species, Glaucabalaena inopinata, which was described in 2024 by Michelangelo Bisconti and colleagues based on the holotype specimen MGPT-PU 19512. This specimen consists of fragments of the skull and mandible, and was recovered from the Sabbie d'Asti Formation of Piedmont, Italy.

Dicondylia is a taxonomic group (taxon) that includes all insects except the jumping bristletails (Archaeognatha). Dicondylia species have a mandible attached with two hinges to the head capsule (dicondyl), in contrast to a hypothetical ancestral mandible with a single ball joint (monocondyl); the members of Archaeognatha do in fact have dicondylic mandibles, though they are not identical to the structure seen in "true" dicondylic insects.

Totenkopf (German: [ˈtoːtn̩ˌkɔpf], literally "dead person's head") is a German compound word for death's head. The word is often used to denote a figurative, graphic or sculptural symbol, common in Western culture, consisting of the representation of a human skull – usually frontal, more rarely in profile with or without the mandible. In some cases, other human skeletal parts may be added, often including two crossed long bones (femurs) depicted below or behind the skull (when it may be referred to in English as a "skull and crossbones"). The human skull is an internationally used symbol for death, the defiance of death, danger, or the dead, as well as piracy or toxicity.

In English, the term Totenkopf is commonly associated with 19th- and 20th-century German militarism, particularly in Nazi Germany.