prognathism

Image:Mandibular prognathism pre-surgery.png, making the prognathism more obvious]]

In humans, non-pathological maxillary and alveolar prognathism can occur due to normal variation among phenotypes.

However, mandibular prognathism is usually anomalous, and it may be a malformation, the result of injury, a disease state, or a hereditary condition.{{MedlinePlusEncyclopedia|003026|Prognathism}}

Prognathism is considered a disorder only if it affects chewing, speech or social function as a byproduct of severely affected aesthetics of the face.{{citation needed|date=September 2018}}

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.{{citation needed|date=September 2018}}

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.{{citation needed|date=September 2018}}

Prognathism should not be confused with micrognathism, although combinations of both are found.

Alveolar prognathism is a protrusion of that portion of the maxilla where the teeth are located, in the dental lining of the upper jaw.{{citation needed|date=September 2018}}

Maxillary prognathism affects the middle third of the face, causing the maxilla to jut out, thereby increasing the facial area.

Mandibular prognathism is a protrusion of the mandible, affecting the lower third of the face.

Prognathism can also be used to describe ways that the maxillary and mandibular dental arches relate to one another, including malocclusion (where the upper and lower teeth do not align). When there is maxillary or alveolar prognathism which causes an alignment of the maxillary incisors significantly anterior to the lower teeth, the condition is called an overjet. When the reverse is the case, and the lower jaw extends forward beyond the upper, the condition is referred to as retrognathia (reverse overjet).{{citation needed|date=September 2018}}

Image:Alveolprog.jpg

Not all alveolar prognathism is anomalous, and significant differences can be observed among different ethnicities.{{Sfn|Vioarsdóttir|O'Higgins|Stringer|2002|pp=211–229}}

Harmful habits such as thumb sucking or tongue thrusting can result in or exaggerate an alveolar prognathism, causing teeth to misalign.{{Cite journal |last1=Singh |first1=Tenali Sushmitha |last2=Sridevi |first2=Enuganti |last3=Sankar |first3=Avula Jogendra Sai |last4=Kakarla |first4=Pranitha |last5=Vallabaneni |first5=Siva Sai Krishna |last6=Sridhar |first6=Mukthineni |date=2020 |title=Cephalometric Assessment of Dentoskeletal Characteristics in Children with Digit-sucking Habit |journal=International Journal of Clinical Pediatric Dentistry |volume=13 |issue=3 |pages=221–224 |doi=10.5005/jp-journals-10005-1761 |issn=0974-7052 |pmc=7450188 |pmid=32904107}} 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 also easily be corrected with fixed orthodontic therapy. However, relapse is quite common, unless the cause is removed or a long-term retention is used.{{Cite journal |last1=Sahil |first1=Sahil |last2=Soni |first2=Sanjeev |last3=Kaur |first3=Gurpreet |date=2021-12-31 |title=Challenging Malocclusion in Orthodontics: the Open Bite |url=https://www.neliti.com/publications/426601/challenging-malocclusion-in-orthodontics-the-open-bite |journal=International Journal of Health Sciences |language=en |pages=125–134 |doi=10.53730/ijhs.v5nS2.5581 |issn=2550-6978|doi-access=free }}

In disease states, maxillary prognathism is associated with Cornelia de Lange syndrome;{{cite web |title=Medical Definition of de Lange syndrome |url=https://www.medicinenet.com/de_lange_syndrome/definition.htm |website=MedicineNet }} however, so-called false maxillary prognathism, or more accurately, retrognathism, where there is a lack of growth of the mandible, is by far a more common condition.{{citation needed|date=September 2018}}

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.{{citation needed|date=September 2018}}

On average, Neanderthals were far more prognathic than modern humans regarding the maxilla. This maxillary prognathism, along with their wide noses, suggests that their faces were not adapted to cold climate.{{Cite web |last1=Rae |first1=Todd C. |last2=Koppe |first2=Thomas |last3=Stringer |first3=Chris B. |date=27 October 2010 |title=The Neanderthal face is not cold adapted |url=https://edisciplinas.usp.br/pluginfile.php/6200375/mod_resource/content/1/The%20neanderthal%20face%20is%20not%20cold%20adapted%20%28Rae%20et%20al%202011%29.pdf |access-date=5 May 2024 |website=Moodle USP: e-Disciplinas}}

{{Anchor|Mandibular prognathism}}

File:Berlín DHM Leopoldo I 02.JPG, showing progenism]]

Mandibular prognathism is a potentially disfiguring genetic disorder where the lower jaw outgrows the upper, resulting in an extended chin and a crossbite. In both humans and animals, it can be the result of inbreeding.{{Sfn|Vilas|Ceballos|Al-Soufi|González-García|2019|pp=563-571}}

Unlike alveolar or maxillary prognathism, which are common traits in some populations, mandibular prognathism is typically pathological. However, it is more common among East Asian populations but overall, the condition is polygenic.{{Cite journal |last1=Kulkarni |first1=Shilpa Devdatt |last2=Bhad |first2=Wasundhara A. |last3=Doshi |first3=Umal H. |date=2020 |title=Association Between Mandibular Prognathism and MATRILIN-1 Gene in Central India Population: A Cross-sectional Study |journal=Journal of Indian Orthodontic Society |volume=55 |issue=1 |pages=28–32 |doi=10.1177/0301574220956421 |doi-access=free }}

In brachycephalic or flat-faced dogs, like shih tzus and boxers, it can lead to problems such as underbite.{{Sfn|Beuchat|2015}}

In humans, it results in a condition sometimes called lantern jaw, reportedly derived from 15th century horn lanterns, which had convex sides.{{OMIM|176700|PROGNATHISM, MANDIBULAR}}{{Efn|The OED uses a slightly different definition: "long thin jaws, giving a hollow appearance to the cheek".{{OED|lantern jaw|id=105665}}}} Traits such as these were often exaggerated by inbreeding, and can be traced within specific families.{{Sfn|Vilas|Ceballos|Al-Soufi|González-García|2019|pp=563-571}}

Although more common than appreciated, the best known historical example is Habsburg jaw, or Habsburg or Austrian lip, due to its prevalence in members of the House of Habsburg, which can be traced in their portraits.{{Sfn|Vilas|Ceballos|Al-Soufi|González-García|2019}} The process of portrait-mapping has provided tools for geneticists and pedigree analysis; most instances are considered polygenic,{{Sfn|Wolff|Wienker|Sander|1993|pp=112–116}} but a number of researchers believe that this trait is transmitted through an autosomal recessive type of inheritance.{{cite web |last1=Безуглый |first1=Т. А. |title=Влияние На Человека Признаков, Передаваемых По Аутосомно-Рецессивному Типу (на Примере Династии Габсбургов) |trans-title=Influence on the Human Traits Transmitted According to the Autosomal-Recessive Type (on the Example of the Habsburg Dynasty) |date=2020 |url=https://www.elibrary.ru/item.asp?id=44270977 |language=ru }}{{Sfn|Vilas|Ceballos|Al-Soufi|González-García|2019}}

Allegedly introduced into the family by a member of the Piast dynasty, it is clearly visible on family tomb sculptures in St. John's Cathedral, Warsaw. A high propensity for politically motivated intermarriage among Habsburgs meant the dynasty was virtually unparalleled in the degree of its inbreeding. Charles II of Spain, who lived 1661 to 1700, is said to have had the most pronounced case of the Habsburg jaw on record,{{Sfn|Mitchell|2013|pp=303-308}} due to the high number of consanguineous marriages in the dynasty preceding his birth.{{Sfn|Vilas|Ceballos|Al-Soufi|González-García|2019}}

{{multiple image

| align = center

| image1 = Charles II.jpg

| width1 = 150

| caption1 = Charles II of Spain showing Habsburg jaw, a severe type of mandibular prognathism

| image2 = Vlad Ţepeş, the Impaler, Prince of Wallachia (1456-1462) (died 1477).jpg

| width2 = 150

| caption2 = Vlad III of Wallachia, showing progenism

| image3 = Arveprins Frederik (Juel).JPG

| width3 = 150

| caption3 = Frederick, regent of Denmark-Norway, showing progenism

| image4 = Pedro II of Brazil 1851 edit.png

| width4 = 150

| caption4 = Pedro II of Brazil, showing progenism. His mother was Archduchess Maria Leopoldina of Austria, a member of the House of Habsburg-Lorraine by birth.

| footer =

}}

Prior to the development of modern dentistry, there was no treatment for this condition; those who had it simply endured it. Today, the most common treatment for mandibular prognathism is a combination of orthodontics and orthognathic surgery. The orthodontics can involve braces, removal of teeth, or a mouthguard.{{cite web |url=https://www.colgate.com/en-us/oral-health/developmental-disabilities/treating-prognathism-ways-to-correct-abnormal-jaw-alignment |title = Treating Prognathism: Ways to Correct Abnormal Jaw Alignment}}

In entomology, prognathous means that the mouthparts face forwards, being at the front of the head, rather than facing downwards as in some insects.{{cite web |title=Prognathous |url=https://www.earthlife.net/insects/glossary.html#16 |website=A Glossary of Entomological Terms |access-date=11 September 2019}}

• Dental pathology

{{notelist}}

{{Reflist}}

• {{Cite web |last1=Beuchat |first1=Carol|date=12 March 2015 |title=Why all the fuss about inbreeding? |url=https://www.instituteofcaninebiology.org/blog/why-all-the-fuss-about-inbreeding-or-why-do-we-have-so-many-genetic-disorders-in-dogs |publisher=Institute of Canine Biology |access-date=16 April 2020}}
• {{Cite thesis |last1=Mitchell |first1=Sylvia Z |date=May 2013 |title=Mariana of Austria and Imperial Spain: Court, Dynastic, and International Politics in Seventeenth-Century Europe |url=https://scholarship.miami.edu/permalink/01UOML_INST/1grrnr5/alma991031447870202976 |type=Ph.D. |location=Coral Gables, Florida |publisher=University of Miami}}
• {{Cite journal |last1=Vilas |first1=Román |last2=Ceballos |first2=Francisco C. |last3=Al-Soufi |first3=Laila |last4=González-García |first4=Raúl |last5=Moreno |first5=Carlos |last6=Moreno |first6=Manuel |last7=Villanueva |first7=Laura |last8=Ruiz |first8=Luis |last9=Mateos |first9=Jesús |last10=González |first10=David |last11=Ruiz |first11=Jennifer |last12=Cinza |first12=Aitor |last13=Monje |first13=Florencio |last14=Álvarez |first14=Gonzalo |title=Is the 'Habsburg jaw' related to inbreeding? |journal=Annals of Human Biology |date=17 November 2019 |volume=46 |issue=7–8 |pages=553–561 |doi=10.1080/03014460.2019.1687752 |pmid=31786955 |s2cid=208536371 |url=https://figshare.com/articles/dataset/Is_the_Habsburg_jaw_related_to_inbreeding_/11302394 |url-access=subscription }}
• {{Cite journal |last1=Vioarsdóttir|first1=US|last2=O'Higgins|first2=O|last3=Stringer|first3=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 |year=2002 |pages=211–229|pmid=12363273 |doi=10.1046/j.1469-7580.2002.00092.x |pmc=1570912}}
• {{Cite journal |last1=Wolff |first1=G |last2=Wienker |first2=T F |last3=Sander |first3=H |title=On the genetics of mandibular prognathism: analysis of large European noble families. |journal=Journal of Medical Genetics |date=1 February 1993 |volume=30 |issue=2 |pages=112–116 |doi=10.1136/jmg.30.2.112 |pmid=8445614 |pmc=1016265}}

• {{Wiktionary-inline}}

{{Medical resources

| DiseasesDB = 29354

| ICD10 = {{ICD10|M26.10}}

| ICD9 = {{ICD9|524.10}}

| ICDO =

| OMIM =

| MedlinePlus = 003026

| eMedicineSubj =

| eMedicineTopic =

| MeshID = D011378

}}

{{Dentofacial anomalies and jaw disease}}

Category:Biological anthropology

Category:Facial features

Category:House of Habsburg

Category:Jaw disorders

Category:Paleoanthropology

pt:Prognatismo