Crouzon Syndrome is a genetic disorder known as a branchial arch syndrome. Specifically, this syndrome affects the first branchial (or pharyngeal) arch, which is the precursor of the maxilla and mandible. Since the branchial arches are important developmental features in a growing embryo, disturbances in their development create lasting and widespread effects. The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) is a coding of diseases and signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or diseases, as classified by the World Health Organization (WHO). ... The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ... The Mendelian Inheritance in Man project is a database that catalogues all the known diseases with a genetic component, and - when possible - links them to the relevant genes in the human genome. ... The Disease Bold textDatabase is a free website that provides information about the relationships between medical conditions, symptoms, and medications. ... eMedicine is an online clinical medical knowledge base that was founded in 1996. ... Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ... In the development of vertebrate animals, the branchial arches (or pharyngeal arches) develop during the fourth and fifth week in utero as a series of mesodermal outpouchings on the left and right sides of the developing pharynx. ... It has been suggested that this article or section be merged into branchial arch. ... The maxillae are the largest bones of the face, except for the mandible, and form, by their union, the whole of the upper jaw. ... The mandible (from Latin mandibÅ­la, jawbone) or inferior maxillary bone is, together with the maxilla, the largest and strongest bone of the face. ... For other uses, see Embryo (disambiguation). ...

Overview

Adult with Crouzon Syndrome.

This syndrome is named after Octave Crouzon, a French physician who first described this disorder. He noted the affected patients were a mother and her daughter, implying a genetic basis. First called "craniofacial dysostosis", the disorder was characterized by a number of clinical features; as of 2007, the disorder has no known single, initiating defect to account for all of its characteristics. Image File history File links Metadata No higher resolution available. ... Image File history File links Metadata No higher resolution available. ... Octave Crouzon, full name Louis Edouard Octave Crouzon (1874-1938) was a French neurologist who was born in Paris. ... The Doctor by Luke Fildes This article is about the term physician, one type of doctor; for other uses of the word doctor see Doctor. ...

Breaking down the name, "craniofacial" refers to the skull and face, and "dysostosis" refers to synostosis (a union between adjacent bones or parts of a single bone). Craniofacial (cranio- combining form meaning head or skull + -facial combining form referring to the facial structures grossly) may be used to describe cratain congenital malformations, injuries, surgeons who subspecialize in this area, multi-disiplinary medical-surgical teams that treat and do research on disorders affecting this region, and organizations with... It has been suggested that temporal fenestra be merged into this article or section. ... The face is the front part of the head, in humans from the forehead to chin including the hair, forehead, eyebrow, eyes, nose, cheeks, mouth, lips, philtrum, teeth, skin, and chin. ... Osseous union between the bones forming a joint, an example being the paired frontal bones of the skull which normally fuse along the metopic suture postnatally. ...

Now known as Crouzon Syndrome, the disease can be described by the rudimentary meanings of its former name. What occurs in the disease is that an infant's skull and facial bones, while in development, fuse early or are unable to expand. Thus, normal bone growth cannot occur. Fusion of different sutures lead to different patterns of growth of the skull. Examples include: trigonocephaly (fusion of the metopic suture), brachycephaly (fusion of the coronal suture), dolichocephaly (fusion of the sagittal suture), plagiocephaly (unilateral premature closure of lambdois and coronal sutures), oxycephaly (fusion of coronal and lambdoidal sutures), Kleeblattschaedel ( premature closure of all sutures) The term disease refers to an abnormal condition of an organism that impairs function. ... Trigonocephaly is a type of cephalic disorder. ... Brachycephaly is a type of cephalic disorder. ... A human skull and measurement device from 1902. ... Plagiocephaly is a type of cephalic disorder. ... Oxycephaly is a type of cephalic disorder. ...

Causes

As stated previously, there is evidence for a genetic basis to this disorder, but there is also no known series of events leading to all the manifestations present. Instead, it is more accurate to view the symptoms arising independently from one another.

As in many syndromes, aberrations in chromosomes seem to be responsible in some cases, and in particular there is support that this disorder may propagate in an autosomal dominant mode. Evidence shown is that males and females are affected equally, and affected offspring tend to have an affected parent. Furthermore, some researchers point to the long arm of chromosome 10 as a possible location for a genetic abnormality. It has been suggested that this article or section be merged into Dominance relationship. ...

On the other hand, 20-40% of people with this disorder have no family history of this disorder, meaning that there is little likelihood of a familial inheritance in those cases. Thus, it is believed that a cause may be a fresh mutation, or, alternatively, an environmental disruption of the developing embryo which results in the same physical characteristics as the genetically-derived disorder. In other words, though genetic anomalies may be leading to a disruption of embryogenesis, facts suggest an important role of environmental factors.

Symptoms

As a very complicating result of the changes to the developing embryo, the symptoms are very pronounced features, especially in the facial areas. Low-set ears is a typical characteristic, as in all of the disorders which are called branchial arch syndromes. The reason for this abnormality is that ears on a fetus are much lower than those on an adult. During normal development, the ears "travel" upward on the head; however, in Crouzon patients, this pattern of development is disrupted. Ear canal malformations are extremely common, generally resulting in some hearing loss. In particularly severe cases, Ménière's disease may occur. Ménières disease (or syndrome, since its cause is unknown) is named after the French physician Prosper Ménière, who first reported that vertigo was caused by inner ear disorders in an article published in 1861. ...

The most notable characteristic of Crouzon Syndrome is cranial synostosis, as described above, but it usually presents as brachycephaly, which results in the appearance of a short and broad head. Exophthalmos (bulging eyes due to shallow eye sockets after early fusion of surrounding bones), hypertelorism (greater than normal distance between the eyes), and psittichorhina (beak-like nose) are also symptoms. Additionally, a common occurrence is external strabismus, which can be thought of as opposite from the eye position found in Down Syndrome. Lastly, hypoplastic maxilla (insufficient growth of the midface) results in relative mandibular prognathism (chin appears to protrude despite normal growth of mandible) and gives the effect of the patient having a concave face. Exophthalmos (or proptosis) is a bulging of the eye anteriorly out of the orbit. ... A human eye. ... Hypertelorism is an abnormally increased distance between two organs or bodily parts, usually referring to an increased distance between the eyes (orbital hypertelorism), seen in a variety of syndromes, including DiGeorge syndrome and Loeys-Dietz syndrome. ... For the protein Strabismus, see Strabismus (protein) Strabismus, also known as heterotropia, squint, crossed eye, cockeyed, wandering eye,weak eye or wall eyed, is a condition in which the eyes are not properly aligned with each other. ... It has been suggested that this article or section be merged into Prognathism. ...

For reasons that are not entirely clear, most Crouzon patients also have noticeably shorter humerus and femur bones, in proportion to the rest of their bodies, than members of the general population. A small percentage of Crouzon patients also have what is called "Type II" Crouzon Syndrome, distinguished by partial syndactyly. The humerus is a long bone in the arm or fore-legs (animals) that runs from the shoulder to the elbow. ... The femur or thigh bone is the longest, most voluminous, and strongest bone of the mammalian bodies. ... In zoology, dactyly is the arrangement of digits (fingers and toes) on the hands, feet, or sometimes wings of an animal. ...

Diagnosis

Diagnosis of Crouzon Syndrome usually can occur at birth by assessing the signs and symptoms of the baby. Further analysis, including radiographs, magnetic resonance imaging (MRI) scans, and genetic testing, can be used to confirm the diagnosis. Magnetic Resonance Image showing a median sagittal cross section through a human head. ...

Incidence

Incidence of Crouzon Syndrome is currently estimated to occur in 1 out of every 25,000 people out of the general population.Naturally, there is a greater frequency in families with a history of the disorder, but that doesn't mean that everyone in the family is afflicted (as referred to above).

Treatment

A child with Crouzon Syndrome wearing a corrective cranial band.

Surgery is typically used to prevent the closure of sutures of the skull from damaging the brain's development. Without surgery, blindness and mental retardation are typical outcomes. To treat the cosmetic troubles, a combination of orthodontic and orthognathic surgery can be used to relieve some of the midface deficiency. In addition, many patients wear a custom-fitted helmet (or cranial band) for several months after surgery. Image File history File linksMetadata Cranialband. ... Image File history File linksMetadata Cranialband. ... orthodontic treatment of crowded teeth; the canine is being pulled down into proper position with highly flexible co-axial wire After 10 months of fixed orthodontic treatment. ...

Once treated for the cranial vault symptoms, Crouzon patients generally go on to live a normal lifespan.

Dental significance

For dentists, this disorder is very important to understand since most of the physical abnormalities are presented in the head, and particularly the oral cavity. Common features are a narrow/high-arched palate, posterior bilateral crossbite, hypodontia (missing some teeth), and increased spacing between teeth. Due to maxillary hypoplasia, Crouzon patients generally have a considerable permanent underbite and subsequently cannot chew using their incisors. For this reason, Crouzon patients sometimes eat in an unusual way--eating fried chicken with a fork, for example, or breaking off pieces of a sandwich rather than taking a bite out of it. X-rays can reveal if a person has cavities Dentistry is the practical application of knowledge of dental science (the science of placement, arrangement, function of teeth) to human beings. ... In dentistry, hypodontia is the condition of naturally having fewer than the regular number of teeth. ... A smiling humans visible teeth. ... This article or section is in need of attention from an expert on the subject. ...

See also

• Apert syndrome
• Hearing loss with craniofacial syndromes

This article does not cite any references or sources. ... Hearing loss with craniofacial syndromes is a common occurrence. ...

External links

• Crouzon Syndrome: Frequently Asked Questions - AboutFace
• Crouzon Syndrome - About.com
• Crouzon Syndrome - Seattle Children's Hospital Craniofacial Center
• cleftAdvocate - Non-profit support organization for all craniofacial conditions; on-line and in-person family support, insurance and advocacy assistance, and more.
• Crouzon Support Network - Information, on-line and in-person family support and more.
• General Information at hopkinsmedicine.org
• Diagnosis Information
• Features and Treatment