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Frontonasal Dysplasia
Frontonasal dysplasia (FND) is a congenital malformation of the midface. For the diagnosis of FND, a patient should present at least two of the following characteristics: hypertelorism (an increased distance between the eyes), a wide nasal root, vertical midline cleft of the nose and/or upper lip, cleft of the wings of the nose, malformed nasal tip, encephalocele (an opening of the skull with protrusion of the brain) or V-shaped hair pattern on the forehead. The cause of FND remains unknown. FND seems to be sporadic (random) and multiple environmental factors are suggested as possible causes for the syndrome. However, in some families multiple cases of FND were reported, which suggests a genetic cause of FND.Wu E, Vargevik K, Slavotinek AM (2007) Subtypes of frontonasal dysplasia are useful in determining clinical prognosis. Am J Med Genet A. 143A(24):3069-78. Classification There are multiple classification systems for FND. None of these classification systems have unraveled any ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypertelorism
Hypertelorism is an abnormally increased distance between two organs or bodily parts, usually referring to an increased distance between the orbits (eyes), or orbital hypertelorism. In this condition the distance between the inner eye corners as well as the distance between the pupils is greater than normal. Hypertelorism should not be confused with telecanthus, in which the distance between the inner eye corners is increased but the distances between the outer eye corners and the pupils remain unchanged.Michael L. Bentz: ''Pediatric Plastic Surgery''; Chapter 9 Hypertelorism by Renato Ocampo, Jr., MD/ John A. Persing, MD Hypertelorism is a symptom in a variety of syndromes, including Edwards syndrome (trisomy 18), 1q21.1 duplication syndrome, basal cell nevus syndrome, DiGeorge syndrome and Loeys–Dietz syndrome. Hypertelorism can also be seen in Apert syndrome, Autism spectrum disorder, craniofrontonasal dysplasia, Noonan syndrome, neurofibromatosis, LEOPARD syndrome, Crouzon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alveolar Ridge
The alveolar process () or alveolar bone is the thickened ridge of bone that contains the tooth sockets on the jaw bones (in humans, the maxilla and the mandible). The structures are covered by gums as part of the oral cavity. The synonymous terms ''alveolar ridge'' and ''alveolar margin'' are also sometimes used more specifically to refer to the ridges on the inside of the mouth which can be felt with the tongue, either on roof of the mouth between the upper teeth and the hard palate or on the bottom of the mouth behind the lower teeth. Terminology The term ''alveolar'' () ('hollow') refers to the cavities of the tooth sockets, known as dental alveoli. The alveolar process is also called the ''alveolar bone'' or ''alveolar ridge''. The curved portion is referred to as the alveolar arch. The alveolar bone proper, also called bundle bone, directly surrounds the teeth. The term alveolar crest describes the extreme rim of the bone nearest to the crowns of the teeth. The port ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autografts
Autotransplantation is the transplantation of organs, tissues, or even particular proteins from one part of the body to another in the same person ('' auto-'' meaning "self" in Greek). The autologous tissue (also called autogenous, autogeneic, or autogenic tissue) transplanted by such a procedure is called an autograft or autotransplant. It is contrasted with allotransplantation (from other individual of the same species), syngeneic transplantation (grafts transplanted between two genetically identical individuals of the same species) and xenotransplantation (from other species). A common example is the removal of a piece of bone (usually from the hip) and its being ground into a paste for the reconstruction of another portion of bone. Autotransplantation, although most common with blood, bone, or skin, can be used for a wide variety of organs. One of the rare examples is autotransplantation of a kidney from one side of the body to the other. Kidney autotransplantation is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-inactivation
X-inactivation (also called Lyonization, after English geneticist Mary Lyon) is a process by which one of the copies of the X chromosome is inactivated in therian female mammals. The inactive X chromosome is silenced by being packaged into a transcriptionally inactive structure called heterochromatin. As nearly all female mammals have two X chromosomes, X-inactivation prevents them from having twice as many X chromosome gene products as males, who only possess a single copy of the X chromosome (see dosage compensation). The choice of which X chromosome will be inactivated in a particular embryonic cell is random in placental mammals such as humans, but once an X chromosome is inactivated it will remain inactive throughout the lifetime of the cell and its descendants in the organism (its cell line). The result is that the choice of inactivated X chromosome in all the cells of the organism is a random distribution, often with about half the cells having the paternal X chromo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philtrum
The philtrum ( la, philtrum from Ancient Greek ''phíltron,'' lit. "love charm"), or medial cleft, is a vertical indentation in the middle area of the upper lip, common to therian mammals, extending in humans from the nasal septum to the tubercle of the upper lip. Together with a glandular rhinarium and slit-like nostrils, it is believed to constitute the primitive condition for at least therian mammals. Monotremes lack a philtrum, though this could be due to the specialised, beak-like jaws in living species. Function In most mammals, the philtrum is a narrow groove that may carry dissolved odorants from the rhinarium or nose pad to the vomeronasal organ via ducts inside the mouth. For humans and most primates, the philtrum survives only as a vestigial medial depression between the nose and upper lip. The human philtrum, bordered by ridges, is also known as the ''infranasal depression'', but has no apparent function. That may be because most higher primates rely more on v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columella
Lucius Junius Moderatus Columella (; Arabic: , 4 – ) was a prominent writer on agriculture in the Roman Empire. His ' in twelve volumes has been completely preserved and forms an important source on Roman agriculture, together with the works of Cato the Elder and Marcus Terentius Varro, both of which he occasionally cites. A smaller book on trees, ', is usually attributed to him. In 1794 the Spanish botanists José Antonio Pavón Jiménez and Hipólito Ruiz López named a genus of Peruvian asterid ''Columellia'' in his honour. Personal life Little is known of Columella's life. He was probably born in Gades, Hispania Baetica (modern Cádiz), possibly to Roman parents. After a career in the army (he was tribune in Syria in 35), he turned to farming his estates at Ardea, Carseoli, and Alba in Latium. ''De re rustica'' In ancient times, Columella's work "appears to have been but little read", cited only by Pliny the Elder, Servius, Cassiodorus, and Isidorus, and having ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Preaxial Polydactyly
Polydactyly or polydactylism (), also known as hyperdactyly, is an anomaly in humans and animals resulting in supernumerary fingers and/or toes. Polydactyly is the opposite of oligodactyly (fewer fingers or toes). Signs and symptoms In humans/animals this condition can present itself on one or both hands or feet. The extra digit is usually a small piece of soft tissue that can be removed. Occasionally it contains bone without joints; rarely it may be a complete functioning digit. The extra digit is most common on the ulnar (little finger) side of the hand, less common on the radial ( thumb) side, and very rarely within the middle three digits. These are respectively known as postaxial (little finger), preaxial (thumb), and central (ring, middle, index fingers) polydactyly. The extra digit is most commonly an abnormal fork in an existing digit, or it may rarely originate at the wrist as a normal digit does. The incidence of congenital deformities in newborns is approximately 2% ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clubfoot
Clubfoot is a birth defect where one or both feet are rotated inward and downward. Congenital clubfoot is the most common congenital malformation of the foot with an incidence of 1 per 1000 births. In approximately 50% of cases, clubfoot affects both feet, but it can present unilaterally causing one leg or foot to be shorter than the other. Most of the time, it is not associated with other problems. Without appropriate treatment, the foot deformity will persist and lead to pain and impaired ability to walk, which can have a dramatic impact on the quality of life. The exact cause is usually not identified. Both genetic and environmental factors are believed to be involved. There are two main types of congenital clubfoot: idiopathic (80% of cases) and secondary clubfoot (20% of cases). The idiopathic congenital clubfoot is a multifactorial condition that includes environmental, vascular, positional, and genetic factors. There appears to be hereditary component for this birth d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frenulum Linguae
The frenulum of tongue or tongue web (also lingual frenulum or frenulum linguæ; also fraenulum) is a small fold of mucous membrane extending from the floor of the mouth to the midline of the underside of the tongue. Development The tongue starts to develop at about four weeks. The tongue originates from the first, second, and third pharyngeal arches which induces the migration of muscles from the occipital myotomes. A U-shaped sulcus develops in front of and on both sides of the oral part of the tongue. This allows the tongue to be free and highly mobile, except at the region of the lingual frenulum, where it remains attached. Disturbances during this stage cause tongue tie or ankyloglossia. During the sixth week of gestation, the medial nasal processes approach each other to form a single globular process that in time gives rise to the nasal tip, columella, prolabium, frenulum of the upper lip, and the primary palate. As the tongue continues to develop, frenulum cells underg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conjunctivae
The conjunctiva is a thin mucous membrane that lines the inside of the eyelids and covers the sclera (the white of the eye). It is composed of non-keratinized, stratified squamous epithelium with goblet cells, stratified columnar epithelium and stratified cuboidal epithelium (depending on the zone). The conjunctiva is highly vascularised, with many microvessels easily accessible for imaging studies. Structure The conjunctiva is typically divided into three parts: Blood supply Blood to the bulbar conjunctiva is primarily derived from the ophthalmic artery. The blood supply to the palpebral conjunctiva (the eyelid) is derived from the external carotid artery. However, the circulations of the bulbar conjunctiva and palpebral conjunctiva are linked, so both bulbar conjunctival and palpebral conjunctival vessels are supplied by both the ophthalmic artery and the external carotid artery, to varying extents. Nerve supply Sensory innervation of the conjunctiva is divided into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ALX3 (gene)
The ALX3 gene, also known as aristaless-like homeobox 3, is a protein coding gene that provides instructions to build a protein which is a member of the homeobox protein family. This grouping regulates patterns of anatomical development. The gene encodes a nuclear protein that functions as a transcription regulator involved in cell-type differentiation and development. The ALX3 protein, encoded by the gene, is a transcription factor, meaning that it binds to DNA and obtains control over the action of other genes. The ALX3 protein specifically controls genes that regulate cell growth, proliferation, and migration. This protein is essential for the development of the head and face, specifically the nose. This event begins around the fourth week of development. At least 7 mutations in the ALX3 gene are known to cause frontonasal dysplasia. The mutations eliminate the function of the ALX3 protein, resulting in decreased ability to bind to DNA. The loss of regulatory function re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encephalocele
Encephalocele is a neural tube defect characterized by sac-like protrusions of the brain and the membranes that cover it through openings in the skull. These defects are caused by failure of the neural tube to close completely during fetal development. Encephaloceles cause a groove down the middle of the skull, or between the forehead and nose, or on the back side of the skull. The severity of encephalocele varies, depending on its location. Signs and symptoms Encephaloceles are often accompanied by craniofacial abnormalities or other brain malformations. Symptoms may include neurologic problems, hydrocephalus (cerebrospinal fluid accumulated in the brain), spastic quadriplegia (paralysis of the limbs), microcephaly (an abnormally small head), ataxia (uncoordinated muscle movement), developmental delay, vision problems, mental and growth retardation, and seizures. File:Encephalocele of a newborn.JPG, A neonate with a large encephalocele. File:Encephalocele2.jpg, Encephalocele on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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