Deeceevoice (talk | contribs) →Racial or ethnic anthropology: rev2 earlier, more accurate text.It IS used widely outside the U.S. -- & not about "judicially enforced 'racial' categories" |
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Humankind historically has been grouped into [[race|racial]] categories based on sets of phenotypical characteristics. While the concept of race has fallen into disfavor, certain clusters of phenotypical characteristics historically assigned to closely related human populations remain useful today in various archaeological and forensic disciplines. The degree to which prognathism is, or is not, present commonly is used today to help establish the relatedness of human populations, living and dead; their likely geographic origins; and, still, to assign racial classification. It is also one of many commonly utilized metrics in the identification of human remains, including in the field of forensic reconstruction. |
Humankind historically has been grouped into [[race|racial]] categories based on sets of phenotypical characteristics. While the concept of race has fallen into disfavor, certain clusters of phenotypical characteristics historically assigned to closely related human populations remain useful today in various archaeological and forensic disciplines. The degree to which prognathism is, or is not, present commonly is used today to help establish the relatedness of human populations, living and dead; their likely geographic origins; and, still, to assign racial classification. It is also one of many commonly utilized metrics in the identification of human remains, including in the field of forensic reconstruction. |
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Maxillary prognathism was also one of the major criteria used by [[Carleton Coon]], 20th-century America's most influential craniofacial anthropometrist, in his now-obsolete studies distinguishing Sub-Saharan "Caucasoids" (the people of Senegal, Gambia, Chad, Niger, Sudan, Ethiopia and Somalia) from what he called "Congoids." |
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Broadly speaking, prognathism is most common among virtually all [[black people]]s indigenous to [[Africa]], the [[Australoid]] peoples of [[Australia]] and [[New Guinea]], various [[sundadont]] and usually darker-skinned [[Southeast Asia]]n populations, and the [[Sudroid]] (sometimes called [[Veddoid]]) and [[Australoid]] peoples of the [[India]]n subcontinent. It also occurs frequently in [[indigenous peoples of the Americas]], thought by some to be traceable to a very early Australoid presence in the Americas{{fact}}. Alveolar, maxillary and mandibular prognathism are most common in these populations. [[Caucasoid]] peoples, generally considered indigenous to [[Europe]] and nearby regions, commonly have an [[orthognathous]], or flat profile. [[East Asians]], generally of the [[Mongoloid]] phenotype, are [[sinodont]] populations and typically are without prognathism. There are, however, frequent exceptions to these broad categories, which defy narrow racial and/or ethnic classifications. |
Broadly speaking, prognathism is most common among virtually all [[black people]]s indigenous to [[Africa]], the [[Australoid]] peoples of [[Australia]] and [[New Guinea]], various [[sundadont]] and usually darker-skinned [[Southeast Asia]]n populations, and the [[Sudroid]] (sometimes called [[Veddoid]]) and [[Australoid]] peoples of the [[India]]n subcontinent. It also occurs frequently in [[indigenous peoples of the Americas]], thought by some to be traceable to a very early Australoid presence in the Americas{{fact}}. Alveolar, maxillary and mandibular prognathism are most common in these populations. [[Caucasoid]] peoples, generally considered indigenous to [[Europe]] and nearby regions, commonly have an [[orthognathous]], or flat profile. [[East Asians]], generally of the [[Mongoloid]] phenotype, are [[sinodont]] populations and typically are without prognathism. There are, however, frequent exceptions to these broad categories, which defy narrow racial and/or ethnic classifications. |
Revision as of 19:23, 30 January 2007
Prognathism | |
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Specialty | Orthodontics |
The word prognathism derives from Greek pro (forward) and ganathos (jaw). The word refers to a craniofacial structure where the either the maxilla (upper jaw), or the mandible ( lower jaw), protrudes beyond the plane of the forehead.
Prognathism is a term used to describe the positional relationship of the mandible and/or maxilla to the skeletal base where either of the jaws protrudes beyond a predetermined imaginary line in the sagittal plane of the skull. In dentistry, oral and maxillofacial surgery and orthodontics this is assessed clinically or radiographically (cephalometrics).
Clinical determinants include soft tissue analysis where the clinician assesses nasolabial angle the relationship of the soft tissue portion of the chin to the nose and the relationship between the upper and lower lips; also used is dental arch relationship assessment such as Angle's classification.
Cephalometric analysis is the most accurate way of determining all types of prognathism as it includes assessments of skeletal base, occlusal plane angulation, facial height, soft tissue assessment and anterior dental angulation. Various calculations and assessments of the information in a cephalometric radiograph allow the clinician to objectively determine dental and skeletal relationships and determine a treatment plan.
Maxillary prognathism is a protrusion of the maxilla, and is also a common feature of many populations. It affects the middle third of the face, causing it to jut out, thereby increasing the facial area. Mandibular prognathism is a protrusion of the mandible. It affects the lower third of the face. Alveolar prognathism is a protrusion of that portion of the maxilla where the teeth are located, in the dental lining of the upper jaw. Prognathism also can be used to describe ways that the maxillary and mandibular dental arches can relate to one another. When there is maxillary and/or alveolar prognathism which causes an alignment of the incisors significantly beyond the lower teeth, the condition is called an overbite. When the reverse is the case and the lower jaw extends beyond the upper, the condition commonly is called an underbite.
The vast majority of prognathism in humans is due to normal variation among phenotypes. In human populations where prognathism is not the norm, it may be a malformation, the result of injury, a disease state or a hereditary condition.[1] Prognathism is only a disease if it affects mastication, speech or social function as a byproduct of severely affected aesthetics of the face.
Description
Alveolar prognathism
Harmful habits, such as thumb sucking or tongue thrusting can result in or exaggerate an alveolar prognathism, causing teeth to misalign. Functional appliances can be used in growing children to help modify bad habits and neuro-muscular function, with the aim of correcting this condition.
Alveolar prognathism can be easily corrected also with fixed orthodontic therapy. However, relapse is quite common, unless the cause is removed or a long term retention is used.
Maxillary prognathism
In disease states, maxillary prognathism is associated with de Lange Syndrome[2]; however so-called false maxillary prognathism, where there is a lack of growth of the mandible, is by far a more common condition. Prognathism, if not extremely severe, can be treated in growing patients with orthodontic functional or orthopaedic appliances. In adult patients this condition can be corrected by means of a combined surgical/orthodontic treatment, where most of the time a mandibular advancement is performed. The same can be said for mandibular prognathism.
Mandibular prognathism (progenism)
Pathologic mandibular prognathism is a disfiguring, genetic disorder where the lower jaw outgrows the upper, resulting in an extended chin.
The condition colloquially is known as Habsburg jaw, Habsburg lip or Austrian Lip (see Habsburg) due to its prevalence in that bloodline. The trait is easily traceable in portraits of Habsburg family members. This has provided tools for people interested in studying genetics and pedigree analysis.
It is alleged to have been derived through a female from the princely Polish family of Piasts, its Masovian branch. The deformation of lips is clearly visible on tomb sculptures of Mazovian Piasts in Warsaw. However this may be, there exists evidence that the trait is longstanding. It is perhaps first observed in Maximilian I (1459-1519).
Traits such as these that were common to royal families are believed to have been passed on and exaggerated over time through royal intermarriage which caused acute inbreeding. Due to the large amount of politically motivated intermarriage among Habsburgs, the dynasty was virtually unparalleled in the degree of its inbreeding. Charles II of Spain is said to have had the most pronounced case of the Habsburg jaw on record. His jaw was so deformed that he was unable to chew).
Many dog breeds have underbite, particularly those with short faces. These can get caught in their jowls.
Racial or ethnic anthropology
Most types of prognathism in humans as well as orthognathous profiles are normal variations among phenotypes and occur frequently in various populations with a greater number of intra-group variations (differences between sub-groups within the groups) than inter-group variations (physical differences between groups). Nevertheless, a number of anthropologists of the nineteenth-century believed that a classification in racial categories and their social development could be determined by measuring the facial angle, jaw structure and the shape of the head of humans, and claimed that people with a more orthognathous profile were superior to other cultures because they had "evolved" more than other races.
After Darwin popularized the idea that humans are descended from apes, the prognathous (protruding) jaw became a sign of lower development and of a closer relationship to primitive man. It also became the basis of much racial stereotyping of the Irish, and racial anthropologists argued that working class people were more prognathous than their social superiors- who were- self-flatteringly described as also biologically superior. In his very influential book, The Races of Man (1862), John Beddoe, the future president of the Anthropological Institute, emphasized the vast difference between the prognathous (protruding) and orthognathous (less prominent) jawed people of Britain. These were terms originally The Irish, Welsh, and significantly, the lower class people, were among the prognathous, whereas all men of genius were orthognathous. (Beddoe also developed an Index of Nigressence, from which he argued that the Irish were close to Cro-Magnon man and thus had links with the "Africinoid" races!) These activities were reminiscent of Pieter Camper's theory of a 'facial angle'. One should emphasize, however, that such craniological and anthropometric studies "always represented a minority" of the papers presented at the Anthropological Institute, 1871-1899. These late nineteenth-century anatomical and anthropological descriptions of 'races' and their characteristics, measurements etc. were later the inspiration for the sort of mid twentieth-century racial anthropology as promulgated in Nazi Germany. (Anthony S. Wohl [3])
Humankind historically has been grouped into racial categories based on sets of phenotypical characteristics. While the concept of race has fallen into disfavor, certain clusters of phenotypical characteristics historically assigned to closely related human populations remain useful today in various archaeological and forensic disciplines. The degree to which prognathism is, or is not, present commonly is used today to help establish the relatedness of human populations, living and dead; their likely geographic origins; and, still, to assign racial classification. It is also one of many commonly utilized metrics in the identification of human remains, including in the field of forensic reconstruction.
Broadly speaking, prognathism is most common among virtually all black peoples indigenous to Africa, the Australoid peoples of Australia and New Guinea, various sundadont and usually darker-skinned Southeast Asian populations, and the Sudroid (sometimes called Veddoid) and Australoid peoples of the Indian subcontinent. It also occurs frequently in indigenous peoples of the Americas, thought by some to be traceable to a very early Australoid presence in the Americas[citation needed]. Alveolar, maxillary and mandibular prognathism are most common in these populations. Caucasoid peoples, generally considered indigenous to Europe and nearby regions, commonly have an orthognathous, or flat profile. East Asians, generally of the Mongoloid phenotype, are sinodont populations and typically are without prognathism. There are, however, frequent exceptions to these broad categories, which defy narrow racial and/or ethnic classifications.
Notable people with the condition
- Charles II of Spain suffered from the condition and was unable to chew as a result.
- Charles V, Holy Roman Emperor (Charles I of Spain)
- Bill Cowher
- Cymburgis of Masovia, Piast princess through whom the condition was brought into the Habsburg family
- Bruce Forsyth
- Jimmy Hill
- Jay Leno
- Maximilian I, Holy Roman Emperor
- Philip II of Spain
- Philip IV of Spain
- Michael Schumacher
- Brian Thompson
- Kiera Knightley
- Bruce Springsteen
- H.P. Lovecraft