Prognathism
2026665
224434040
2008-07-08T20:45:33Z
Father Goose
1920826
/* Other */ All of these need citations. Lists of "people whom I think have a deformity" are not a good idea.
{{Infobox_Disease |
Name = Prognathism |
Image = |
Caption = |
DiseasesDB = 29354 |
ICD10 = {{ICD10|K|07|1|k|00}} |
ICD9 = {{ICD9|524.10}} |
ICDO = |
OMIM = |
MedlinePlus = |
eMedicineSubj = |
eMedicineTopic = |
MeshID = D011378 |
}}
[[Image:Prognathism3.png|thumb|300px|right|]]
'''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 [[Anatomical terms of location|sagittal]] plane of the skull. In dentistry, oral and maxillofacial surgery and orthodontics this is assessed clinically or radiographically ([[cephalometrics]]). The word prognathism derives from Greek ''pro'' (forward) and ''gnathos'' (jaw).
==Presentation==
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.<ref>[http://www.nlm.nih.gov/medlineplus/ency/article/003026.htm MedlinePlus Medical Encyclopedia: Prognathism<!-- Bot generated title -->]</ref> Prognathism is considered a disorder only if it affects [[mastication]], [[Manner of articulation|speech]] or social function as a byproduct of severely affected aesthetics of the face.
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 [[malocclusion|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 is not to be confused with [[micrognathism]], although combinations of both may be found. 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, affecting 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 can also 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 maxillary incisors significantly anterior to the lower teeth, the condition is called an ''overbite''. When the reverse is the case, and the lower jaw extends forward beyond the upper, the condition is referred to as an ''underbite''.
[[Image:Alveolprog.jpg|thumb|175px|right|Alveolar prognathism, caused by thumb sucking and tongue thrusting in a 7 year old girl.]]
==Classification==
===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.
Not all alveolar prognathism is anomalous, and significant differences can be observed among different ethnic groups.<ref name="pmid12363273">{{cite journal |author=Vioarsdóttir US, O'Higgins P, Stringer C |title=A geometric morphometric study of regional differences in the ontogeny of the modern human facial skeleton |journal=J. Anat. |volume=201 |issue=3 |pages=211–29 |year=2002 |pmid=12363273 |doi=10.1046/j.1469-7580.2002.00092.x}}</ref>
[[Image:Class2profile.jpg|thumb|120px|right|10-year-old boy with false maxillary prognathism]]
[[Image:Alfonso XIII de España (1901).jpg|thumb|right|220px|A young [[King Alfonso XIII of Spain]], son of the [[Maria Christina of Austria|Hapsburg Archduchess Maria Christina]], displays the prominent [[Habsburg]] lip and jaw.]]
===Maxillary Prognathism===
In disease states, maxillary prognathism is associated with [[Cornelia de Lange Syndrome]]<ref>[http://www.medterms.com/script/main/art.asp?articlekey=13301 de Lange syndrome definition - Medical Dictionary definitions of popular medical terms easily defined on MedTerms<!-- Bot generated title -->]</ref>; 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 [[Mandible|mandibular]] prognathism is a potentially 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]].<ref>{{cite web |url=http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=176700 |title=OMIM - PROGNATHISM, MANDIBULAR |accessdate=2007-10-31 |format= |work=}}</ref> The trait is easily traceable in portraits of Habsburg family members.<ref name="pmid9831338">{{cite journal |author=Chudley AE |title=Genetic landmarks through philately--the Habsburg jaw |journal=Clin. Genet. |volume=54 |issue=4 |pages=283–4 |year=1998 |pmid=9831338 |doi=10.1034/j.1399-0004.1998.5440404.x}}</ref> This has provided tools for people interested in studying [[genetics]] and [[pedigree]] analysis. Most instances are considered polygenetic.<ref name="pmid8445614">{{cite journal |author=Wolff G, Wienker TF, Sander H |title=On the genetics of mandibular prognathism: analysis of large European noble families |journal=J. Med. Genet. |volume=30 |issue=2 |pages=112–6 |year=1993 |pmid=8445614 |doi=}}</ref>
It is alleged to have been derived through a female from the princely [[Poland|Polish]] family of [[Piast]]s, its [[Masovia]]n branch. The deformation of lips is clearly visible on tomb sculptures of Mazovian Piasts in the [[St. John's Cathedral, Warsaw|St. John's Cathedral]] in [[Warsaw]]. However this may be, there exists evidence that the trait is longstanding. It is perhaps first observed in [[Maximilian I, Holy Roman Emperor|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. This may be due, as in the case of [[bulldogs]], to a slower growing maxilla in relation to the mandible.
==Treatment==
The most common treatment for mandibular prognathism is a combination of [[orthodontics]] and surgery ([[Orthognathic surgery]]). The orthodontics can involve [[Dental braces|braces]], removal of teeth, or a [[bite splint]].
==Notable people with abnormal prognathism==
===European royalty===
*[[Cymburgis of Masovia]], [[Piast]] princess through whom (supposedly) the condition was brought into the [[Habsburg]] family
*[[Maximilian I, Holy Roman Emperor]]
*[[Charles V, Holy Roman Emperor]] (Charles I of Spain)
*[[Philip II of Spain]]
*[[Philip IV of Spain]]
*[[Leopold I, Holy Roman Emperor]]
*[[Charles II of Spain]] suffered from the condition and was unable to chew as a result.
*[[Marie Antoinette]]
===Other===
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*[[Jay Leno]]<ref name="pmid9831338">{{cite journal |author=Chudley AE |title=Genetic landmarks through philately--the Habsburg jaw |journal=Clin. Genet. |volume=54 |issue=4 |pages=283–4 |year=1998 |pmid=9831338 |doi= 10.1034/j.1399-0004.1998.5440404.x|url=http://www.blackwell-synergy.com/openurl?genre=article&sid=nlm:pubmed&issn=0009-9163&date=1998&volume=54&issue=4&spage=283}}</ref>
==See also==
For prognathism as a metric in forensics and ethnic anthropology see
*[[Craniofacial anthropometry]]
*[[Forensics]]
==References==
{{reflist}}
{{Oral pathology}}
[[Category:Dentistry]]
[[Category:House of Habsburg]]
[[Category:Physical anthropology]]
[[Category:Oral and maxillofacial surgery]]
[[de:Habsburger Unterlippe]]
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