Micrognathism is a condition where the
jaw
The jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term ''jaws'' is also broadly applied to the whole of the structures constituting the vault of the mouth and serv ...
is undersized. It is also sometimes called
mandibular
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...
hypoplasia. It is common in infants, but is usually self-corrected during growth, due to the jaws' increasing in size. It may be a cause of abnormal tooth alignment and in severe cases can hamper feeding.
It can also, both in adults and children, make
intubation
Intubation (sometimes entubation) is a medical procedure involving the insertion of a tube into the body. Patients are generally anesthetized beforehand. Examples include tracheal intubation, and the balloon tamponade with a Sengstaken-Blakemo ...
difficult, either during anesthesia or in emergency situations.
Causes
While not always pathological, it can present as a birth defect in multiple syndromes including:
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Catel–Manzke syndrome
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Bloom syndrome
Bloom syndrome (often abbreviated as BS in literature) is a rare autosomal recessive genetic disorder characterized by short stature, predisposition to the development of cancer, and genomic instability. BS is caused by mutations in the ''BLM'' gen ...
*
Coffin–Lowry syndrome
Coffin–Lowry syndrome is a genetic disorder that is X-linked dominant and which causes severe mental problems sometimes associated with abnormalities of growth, cardiac abnormalities, kyphoscoliosis, as well as auditory and visual abnormalities.
...
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Congenital rubella syndrome
Congenital rubella syndrome (CRS) can occur in a developing fetus of a pregnant woman who has contracted rubella, usually in the first trimester. If infection occurs 0–28 days before conception, the infant has a 43% risk of being affected. If ...
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Cri du chat syndrome
Cri du chat syndrome is a rare genetic disorder due to a partial chromosome deletion on chromosome 5. Its name is a French term ("cat-cry" or " call of the cat") referring to the characteristic cat-like cry of affected children. It was first de ...
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DiGeorge syndrome
DiGeorge syndrome, also known as 22q11.2 deletion syndrome, is a syndrome caused by a microdeletion on the long arm of chromosome 22. While the symptoms can vary, they often include congenital heart problems, specific facial features, frequent in ...
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Ehlers–Danlos syndrome
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Fetal alcohol syndrome
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Hallermann–Streiff syndrome
Hallermann–Streiff syndrome is a congenital disorder that affects growth, cranial development, hair-growth, and dental development. There are fewer than 200 people with the syndrome worldwide. One notable organization that is supporting peopl ...
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Hemifacial microsomia
Hemifacial microsomia (HFM) is a congenital disorder that affects the development of the lower half of the face, most commonly the ears, the mouth and the mandible. It usually occurs on one side of the face, but both sides are sometimes affected. ...
(as part of
Goldenhar syndrome
Goldenhar syndrome is a rare congenital defect characterized by incomplete development of the ear, nose, soft palate, lip and mandible on usually one side of the body. Common clinical manifestations include limbal dermoids, preauricular skin tags ...
)
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Incontinentia pigmenti
Incontinentia pigmenti (IP) is a rare X-linked dominant genetic disorder that affects the skin, hair, teeth, nails and central nervous system. It is named from its appearance under a microscope.
The disease is characterized by skin abnormalitie ...
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Juvenile idiopathic arthritis
Juvenile idiopathic arthritis (JIA) is the most common, chronic rheumatic disease of childhood, affecting approximately one per 1,000 children. ''Juvenile'', in this context, refers to disease onset before 16 years of age, while ''idiopathic'' r ...
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Marfan syndrome
Marfan syndrome (MFS) is a multi-systemic genetic disorder that affects the connective tissue. Those with the condition tend to be tall and thin, with long arms, legs, fingers, and toes. They also typically have exceptionally flexible joints a ...
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Möbius syndrome
Möbius syndrome is a rare congenital neurological disorder which is characterized by facial paralysis and the inability to move the eyes from side to side. Most people with Möbius syndrome are born with complete facial paralysis and cannot clos ...
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Noonan syndrome
Noonan syndrome (NS) is a genetic disorder that may present with mildly unusual facial features, short height, congenital heart disease, bleeding problems, and skeletal malformations. Facial features include widely spaced eyes, light-colored ...
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Pierre Robin syndrome
Pierre Robin sequence (; abbreviated PRS) is a congenital defect observed in humans which is characterized by facial abnormalities. The three main features are micrognathia (abnormally small mandible), which causes glossoptosis (downwardly displac ...
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Prader–Willi syndrome
Prader–Willi syndrome (PWS) is a genetic disorder caused by a loss of function of specific genes on chromosome 15. In newborns, symptoms include weak muscles, poor feeding, and slow development. Beginning in childhood, those affected become c ...
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Progeria
Progeria is a specific type of progeroid syndrome, also known as Hutchinson–Gilford syndrome. A single gene mutation is responsible for progeria. The gene, known as lamin A (LMNA), makes a protein necessary for holding the Nucleus of the cell ...
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Silver–Russell syndrome
Silver–Russell syndrome (SRS), also called Silver–Russell dwarfism, is a rare congenital growth disorder. In the United States it is usually referred to as Russell–Silver syndrome (RSS), and Silver–Russell syndrome elsewhere. It is one of ...
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Seckel syndrome
Seckel syndrome, or microcephalic primordial dwarfism (also known as bird-headed dwarfism, Harper's syndrome, Virchow–Seckel dwarfism and bird-headed dwarf of Seckel) is an extremely rare congenital nanosomic disorder. Inheritance is autosomal r ...
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Smith–Lemli–Opitz syndrome
Smith–Lemli–Opitz syndrome is an inborn error of cholesterol synthesis. It is an autosomal recessive, multiple malformation syndrome caused by a mutation in the enzyme 7-Dehydrocholesterol reductase encoded by the DHCR7 gene. It causes a bro ...
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Stickler syndrome
Stickler syndrome (hereditary progressive arthro-ophthalmodystrophy) is a group of rare genetic disorders affecting connective tissue, specifically collagen. Stickler syndrome is a subtype of collagenopathy, types II and XI. Stickler syndrome i ...
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Treacher Collins syndrome
Treacher Collins syndrome (TCS) is a genetic disorder characterized by deformities of the ears, eyes, cheekbones, and chin. The degree to which a person is affected, however, may vary from mild to severe. Complications may include breathing prob ...
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Trisomy 13
A trisomy is a type of polysomy in which there are three instances of a particular chromosome, instead of the normal two. A trisomy is a type of aneuploidy (an abnormal number of chromosomes).
Description and causes
Most organisms that reprodu ...
(Patau syndrome)
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Trisomy 18
A trisomy is a type of polysomy in which there are three instances of a particular chromosome, instead of the normal two. A trisomy is a type of aneuploidy (an abnormal number of chromosomes).
Description and causes
Most organisms that reprodu ...
(Edwards syndrome)
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Trisomy 21
A trisomy is a type of polysomy in which there are three instances of a particular chromosome, instead of the normal two. A trisomy is a type of aneuploidy (an abnormal number of chromosomes).
Description and causes
Most organisms that reprodu ...
(Down syndrome)
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Wolf–Hirschhorn syndrome
Wolf–Hirschhorn syndrome (WHS) is a chromosomal deletion syndrome resulting from a partial deletion on the short arm of chromosome 4 (del(4p16.3)). Features include a distinct craniofacial phenotype and intellectual disability.
Signs and sympto ...
* X0 syndrome (
Turner syndrome
Turner syndrome (TS), also known as 45,X, or 45,X0, is a genetic condition in which a female is partially or completely missing an X chromosome. Signs and symptoms vary among those affected. Often, a short and webbed neck, low-set ears, low hair ...
)
Diagnosis
It can be detected by the naked eye as well as dental or skull
X-Ray testing.
Treatments
Micrognathia can be treated by surgery, orthodontic braces,
and modified eating methods. Early detection of the problem and monitoring as the problems grows can help understand it better and find the most effective treatment procedure.
See also
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Human mandible
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...
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Macrognathism
Macrognathism is an abnormally large or protruding jaw. The opposite condition is called micrognathia.
__TOC__ Causes
* Heredity
* Pituitary gigantism
* Paget's disease of bone
* Acromegaly
* Fetal alcohol syndrome
* Leontiasis ossea
* Cleidocran ...
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Retrognathism
Retrognathia is a type of malocclusion which refers to an abnormal posterior positioning of the maxilla or mandible, particularly the mandible, relative to the facial skeleton and soft tissues.
A retrognathic mandible is commonly referred to as a ...
References
External links
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{{Dentofacial anomalies and jaw disease
Jaw disorders