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Mandibles
In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone is the skull's only movable, posable bone, sharing joints with the cranium's temporal bones. The mandible hosts the lower teeth (their depth delineated by the alveolar process). Many muscles attach to the bone, which also hosts nerves (some connecting to the teeth) and blood vessels. Amongst other functions, the jawbone is essential for chewing food. Owing to the Neolithic advent of agriculture (), human jaws evolved to be smaller. Although it is the strongest bone of the facial skeleton, the mandible tends to deform in old age; it is also subject to fracturing. Surgery allows for the removal of jawbone fragments (or its entirety) as well as regenerative methods. Additionally, the bone is of great forensic significance. Structure In h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mouth
A mouth also referred to as the oral is the body orifice through which many animals ingest food and animal communication#Auditory, vocalize. The body cavity immediately behind the mouth opening, known as the oral cavity (or in Latin), is also the first part of the alimentary canal, which leads to the pharynx and the gullet. In tetrapod vertebrates, the mouth is bounded on the outside by the lips and cheeks — thus the oral cavity is also known as the buccal cavity (from Latin ', meaning "cheek") — and contains the tongue on the inside. Except for some groups like birds and lissamphibians, vertebrates usually have teeth in their mouths, although some fish species have pharyngeal teeth instead of oral teeth. Most bilaterian phylum, phyla, including arthropods, molluscs and chordates, have a two-opening gut tube with a mouth at one end and an anus at the other. Which end forms first in ontogeny is a criterion used to classify bilaterian animals into protostomes and deuterostomes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skull
The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent parts: the neurocranium and the facial skeleton, which evolved from the first pharyngeal arch. The skull forms the frontmost portion of the axial skeleton and is a product of cephalization and vesicular enlargement of the brain, with several special senses structures such as the eyes, ears, nose, tongue and, in fish, specialized tactile organs such as barbels near the mouth. The skull is composed of three types of bone: cranial bones, facial bones and ossicles, which is made up of a number of fused flat and irregular bones. The cranial bones are joined at firm fibrous junctions called sutures and contains many foramina, fossae, processes, and sinuses. In zoology, the openings in the skull are called fenestrae, the most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Skull
The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent parts: the neurocranium and the facial skeleton, which evolved from the first pharyngeal arch. The skull forms the frontmost portion of the axial skeleton and is a product of cephalization and vesicular enlargement of the brain, with several special senses structures such as the eyes, ears, nose, tongue and, in fish, specialized tactile organs such as barbels near the mouth. The skull is composed of three types of bone: cranial bones, facial bones and ossicles, which is made up of a number of fused flat and irregular bones. The cranial bones are joined at firm fibrous junctions called sutures and contains many foramina, fossae, processes, and sinuses. In zoology, the openings in the skull are called fenestrae, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Jaw Shrinkage
Human jaw shrinkage is the phenomenon of continued size reduction of the human mandible and maxilla over the past 12,000 to 15,000 years. Modern human lifestyles and diets are vastly different now from what they were for most of human evolutionary history. Human jaws, as well as oral cavities, have been shrinking ever since the spread of agriculture during the Neolithic Revolution ( years ago). This has been confirmed by bone remains dated to this time period.Pinhasi, R., Eshed, V., & von Cramon-Taubadel, N. (2015). Incongruity between affinity patterns based on mandibular and lower dental dimensions following the transition to agriculture in the Near East, Anatolia, and Europe. PLOS ONE, 10(2), e0117301.Lieberman, D. E., Krovitz, G. E., Yates, F. W., Devlin, M., & Claire, M. S. (2004). Effects of food processing on masticatory strain and craniofacial growth in a retrognathic face. Journal of human evolution, 46(6), 655-677. Researchers are able to infer the basic lifestyle practi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mandibular Fracture
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. Mandibular fractures are typically the result of trauma. This can include a fall onto the chin or a hit from the side. Rarely they may be due to osteonecrosis or tumors in the bone. The most common area of fracture is at the condyle (36%), body (21%), angle (20%) and symphysis (14%). Rarely the fracture may occur at the ramus (3%) or coronoid process (2%). While a diagnosis can occasionally be made with plain X-ray, modern CT scans are more accurate. Immediate surgery is not necessarily required. Occasionally people may go home and follow up for surgery in the next few days. A number of surgical techniques may b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Jawbone Front
Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing#Evolution of hairlessness, hairlessness, bipedality, bipedalism, and high Human intelligence, intelligence. Humans have large Human brain, brains, enabling more advanced cognitive skills that facilitate successful adaptation to varied environments, development of sophisticated tools, and formation of complex social structures and civilizations. Humans are Sociality, highly social, with individual humans tending to belong to a Level of analysis, multi-layered network of distinct social groups — from families and peer groups to corporations and State (polity), political states. As such, social interactions between humans have established a wide variety of Value theory, values, norm (sociology), social norms, languages, and traditions (co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertebral Column
The spinal column, also known as the vertebral column, spine or backbone, is the core part of the axial skeleton in vertebrates. The vertebral column is the defining and eponymous characteristic of the vertebrate. The spinal column is a segmented column of vertebrae that surrounds and protects the spinal cord. The vertebrae are separated by intervertebral discs in a series of cartilaginous joints. The dorsal portion of the spinal column houses the spinal canal, an elongated body cavity, cavity formed by the alignment of the vertebral neural arches that encloses and protects the spinal cord, with spinal nerves exiting via the intervertebral foramina to innervate each body segment. There are around 50,000 species of animals that have a vertebral column. The human spine is one of the most-studied examples, as the general structure of human vertebrae is fairly homology (biology), typical of that found in other mammals, reptiles, and birds. The shape of the vertebral body does, howev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angle Of The Mandible
__NOTOC__ The angle of the mandible (a.k.a. gonial angle, Masseteric Tuberosity, and Masseteric Insertion) is located at the posterior border at the junction of the lower border of the ramus of the mandible. The angle of the mandible, which may be either inverted or everted, is marked by rough, oblique ridges on each side, for the attachment of the masseter laterally, and the pterygoideus internus ( medial pterygoid muscle) medially; the stylomandibular ligament is attached to the angle between these muscles. The forensic term for the midpoint of the mandibular angle is the gonion. The gonion is a cephalometric landmark located at the lowest, posterior, and lateral point on the angle. This site is at the apex of the maximum curvature of the mandible, where the ascending ramus becomes the body of the mandible. The mandibular angle has been named as a forensic tool for gender determination, but some studies have called into question whether there is any significant sex differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Right Angle
In geometry and trigonometry, a right angle is an angle of exactly 90 Degree (angle), degrees or radians corresponding to a quarter turn (geometry), turn. If a Line (mathematics)#Ray, ray is placed so that its endpoint is on a line and the adjacent angles are equal, then they are right angles. The term is a calque of Latin ''angulus rectus''; here ''rectus'' means "upright", referring to the vertical perpendicular to a horizontal base line. Closely related and important geometrical concepts are perpendicular lines, meaning lines that form right angles at their point of intersection, and orthogonality, which is the property of forming right angles, usually applied to Euclidean vector, vectors. The presence of a right angle in a triangle is the defining factor for right triangles, making the right angle basic to trigonometry. Etymology The meaning of ''right'' in ''right angle'' possibly refers to the Classical Latin, Latin adjective ''rectus'' 'erect, straight, upright, perp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horseshoe
A horseshoe is a product designed to protect a horse hoof from wear. Shoes are attached on the palmar surface (ground side) of the hooves, usually nailed through the insensitive hoof wall that is anatomically akin to the human toenail, although much larger and thicker. However, there are also cases where shoes are glued. Horseshoes are available in a wide variety of materials and styles, developed for different types of horses and for the work they do. The most common materials are steel and aluminium, but specialized shoes may include use of rubber, plastic, magnesium, titanium, or copper.Price, Steven D. (ed.) ''The Whole Horse Catalog: Revised and Updated'' New York:Fireside 1998 , pp. 84–87. Steel tends to be preferred in sports in which a strong, long-wearing shoe is needed, such as polo, eventing, show jumping, and western riding events. Aluminium shoes are lighter, making them common in horse racing where a lighter shoe is desired, and often facilitate certain ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johns Hopkins Medicine
The Johns Hopkins University School of Medicine (JHUSOM) is the medical school of Johns Hopkins University, a private research university in Baltimore, Maryland. Established in 1893 following the construction of the Johns Hopkins Hospital, the school is known for being a center of biomedical research and innovation, and is routinely ranked as one of the top medical schools in the United States. The School of Medicine is located in Baltimore, Maryland, where it shares a campus in East Baltimore with the School of Nursing, Bloomberg School of Public Health, and Johns Hopkins Hospital, the school's primary teaching hospital. As part of the larger Johns Hopkins Medicine health system, the school is also affiliated with numerous regional hospitals and medical centers including the Johns Hopkins Bayview Medical Center, Johns Hopkins Howard County Medical Center, Suburban Hospital in Montgomery County, Sibley Memorial Hospital in Washington, D.C. History Before his death in 1873, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temporomandibular Joint
In anatomy, the temporomandibular joints (TMJ) are the two joints connecting the jawbone to the skull. It is a bilateral Synovial joint, synovial articulation between the temporal bone of the skull above and the condylar process of 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. Structure The main components are the joint capsule, articular disc, mandibular condyles, articular surface of the temporal bone, temporomandibular ligament, stylomandibular ligament, sphenomandibular ligament, and lateral pterygoid muscle. Capsule The articular capsule (capsular ligament) is a thin, loose envelope, attached above to the circumference of the mandibular fossa and the articular tubercle immediately in front; below, to the neck of the condyle of the mandible. Its loose attachment to the neck of the mandible allows for free movement. Articular disc The unique feature of the temporomand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
