noun
definition
An abnormal formation.
definition
An abnormal developmental feature of offspring.
Examples of malformation in a Sentence
This is a malformation of the jaw bone that leads to further scrambling of the teeth.
More convincing evidence of the absence of true regeneration, however, is the argument from malformation and the phenomenon known as " pseudo-scolex.
Telangiectasia is an arterial-venous malformation (AVM) composed of small blood vessels.
The other terms indicate involvement of the spinal cord and nerves in the malformation.
In most cases, spina bifida is obvious at birth because of malformation of the spine.
Jaundice can result from a congenital (present at birth) malformation of the liver, bile ducts, or gall bladder.
Pectus excavatum is a malformation of the chest in which the child's breastbone, or sternum, is sunken inward.
This may occur for many reasons, including Chiari malformation, abnormal cysts within the brain, and infections such as meningitis.
Truncus arteriosus is a complex malformation in which only one artery comes from the heart and forms the aorta and pulmonary artery.
Spina bifida is usually readily apparent at birth because of the malformation of the back and paralysis below the level of the abnormality.
The term meningocele is used when the spine malformation contains only the protective covering (meninges) of the spinal cord.
As an isolated abnormality, spina bifida is caused by the combination of genetic factors and environmental influences that bring about malformation of the spine and spinal column.
In rare instances, the spinal cord malformation may occur internally, sometimes with a connection to the gastrointestinal tract.
In spina bifida, many complications arise, dependent in part on the level and severity of the spine malformation.
As a rule, the nerves below the level of the abnormality develop in a faulty manner and fail to function, resulting in paralysis and loss of sensation below the level of the spine malformation.
At least one of every seven cases develops findings of Chiari II malformation, a condition in which the lower part of the brain is crowded and may be forced into the upper part of the spinal cavity.
If the spine malformation is not skin covered, alpha-fetoprotein from the fetus's circulation may leak into the surrounding amniotic fluid, a small portion of which is absorbed into the mother's blood.
After direct closure of the spine malformation, the fetus is returned to the womb.
Although complications from paralysis, hydrocephaly, Chiari II malformation, and urinary tract deterioration threaten the well-being of the survivors, the outlook for normal intellectual function is good.
Congenital cystic adenomatoid malformation (CCAM) occurs when one or more lobes of the lungs develop into fluid-filled sacs called cysts rather than into normal lung tissue.
Congenital cystic adenomatoid malformation (CCAM)-A condition in which one or more lobes of the fetal lungs develop into fluid-filled sacs called cysts.
Spina bifida-A birth defect (a congenital malformation) in which part of the vertebrae fail to develop completely so that a portion of the spinal cord, which is normally protected within the vertebral column, is exposed.
Cleft palate-A congenital malformation in which there is an abnormal opening in the roof of the mouth that allows the nasal passages and the mouth to be improperly connected.
Glaucoma can be caused by another eye disorder, such as a tumor or congenital malformation, or can appear without obvious cause, but if untreated it generally leads to blindness.
Anencephaly-A genetic defect resulting in the partial to complete absence of the brain and malformation of the brainstem.
In children, cystic fibrosis, aspiration problems, immunodeficiencies, and congenital or acquired lung malformation may increase the risk of pneumonia from S. pneumoniae.
Transposition of the great arteries is a complex congenital malformation; however, open heart surgery is highly effective in correcting it.
Boys are slightly more likely to have this malformation than girls.
Tetralogy of Fallot is a complex congenital malformation; however, open heart surgery is highly effective in correcting it.
Sturge-Weber syndrome (SWS) is a rare, congenital (present at birth), noninherited disorder characterized by the vascular malformation (birthmark) called a port wine stain, usually seen on an infant's face.
In addition, normal brain formation requires proper development of the surrounding skull, and skull defects may lead to brain malformation.
Anencephaly is the most common severe malformation seen in stillborn births.
Some cases of spina bifida are accompanied by another defect at the base of the brain, known as the Arnold-Chiari malformation or Chiari II malformation.
The Dandy-Walker malformation is a brain defect marked by incomplete formation or absence of the central section of the cerebellum and the growth of cysts within the lowest of the brain's ventricles.
Trisomy of chromosome 9 can cause some cases of Dandy-Walker and Chiari II malformation.
Many children with congenital brain anomalies, such as Chiari I malformation and nearly 50 percent of those affected by hydrocephalus, have normal intellectual functioning, and some have unimpaired physical mobility.
Chiari malformation is a congenital anomaly (a condition that is present at birth), in which parts of the brain protrude through the opening in the base of the skull into the spinal column.
In order to explain the various components of Chiari malformation, it is helpful to describe a few parts of the brain and their functions.
In Chiari malformation, one or more of these parts of the brain function improperly or are malformed.
In addition to brain anomalies, Chiari malformation can also involve defects in the base of the skull and in the bony part of the spine.
There are four types of Chiari malformation.
In Type I malformation, the lower portions of the cerebellum, known as the cerebellar tonsils, protrude through the opening in the skull known as the foramen magnum and into the spinal cord canal.
Type II malformation, sometimes called Arnold Chiari malformation, is more severe than Type I and involves herniation of a more significant part of the cerebellum, part of the fourth ventricle, and parts of the brain stem.
Approximately 80-90 percent of children with Chiari malformation Type II also have hydrocephalus, a condition in which one or more of the ventricles becomes enlarged due to an accumulation of CSF.
Type II Chiari malformation may be diagnosed prenatally by ultrasound or shortly after birth during medical evaluation of the accompanying spina bifida.
In Type III malformation, parts of the cerebellum and the brain stem protrude into a spina bifida defect located at the base of the skull, on the neck.
Some neurologists do not consider it a Chiari malformation but rather a specific type of spina bifida called an encephalocervical meningocele.
Type IV malformation consists of an underdevelopment of the cerebrum and involves no herniation of brain tissue into the spinal area.
As with Type III malformation, many neurologists do not consider this a Chiari malformation but rather cerebellar hypoplasia (underdevelopment).
The remainder of this entry only discusses Chiari malformation Types I and II.