a condition in which a child has a very small lower jaw. A child with
micrognathia has a lower jaw that’s
much shorter or smaller than the rest of their face.
Children may be born with this problem, or it can occur later
on. It mainly occurs in children who are born with certain genetic conditions, such
as trisomy 13 and progeria. It can also be the result of fetal alcohol
In some cases, this problem goes away as the child’s jaw grows with age.
In severe cases, micrognathia can cause feeding or breathing problems. It can
also lead to malocclusion
of the teeth, which means that your child’s teeth don’t
What Causes Micrognathia?
Some cases of micrognathia are due to inherited disorders.
In other cases, it’s
the result of genetic mutations that don’t pass down through families.
Pierre Robin Syndrome
Pierre Robin syndrome causes your baby’s jaw to form slowly
in the womb, which results in a very small lower jaw. It also causes the baby’s tongue to fall
backward into the throat, which can block the airways and make breathing
Trisomy 13 and 18
A trisomy is
a genetic disorder that occurs when a baby has extra genetic material. A
trisomy causes severe mental deficiencies and physical deformities. About one
in every 16,000 babies has trisomy 13, according to the U.S.
National Library of Medicine. Around one in
every 6,000 babies has trisomy 18 with the exception of those who are stillborn,
according to the Trisomy 18 Foundation.
The number, such as 13 or 18, refers to which chromosome the extra material
Achondrogenesis is a rare inherited disorder in which your
make enough growth hormone. This causes severe bone problems, including a small
lower jaw and a narrow chest. It also causes unusually short:
Progeria is a genetic condition that causes your child to age at a rapid
rate. Babies with progeria typically don’t show signs when they’re born, but they start
showing signs of the disorder by the end of their first year. It’s due to a genetic
mutation, but it’s
not passed down through families. In addition to a small jaw, your child may
also have a slow growth rate, hair loss, and a very narrow face.
This is a rare genetic condition that causes developmental
disabilities and physical deformities, including a small jaw and low-set ears.
The name derives from the high-pitched, cat-like cry that babies with this
condition make. It’s
usually not an inherited condition.
Treacher Collins Syndrome
This hereditary condition causes severe facial abnormalities. In addition to
a small jaw, it can also cause a cleft palate, absent cheekbones, and malformed
When Should I See My Doctor?
Call your child’s
doctor if your child’s jaw looks
unusually small or if your baby is having trouble eating. Some of the genetic
conditions that cause a small lower jaw are serious and need a diagnosis as
soon as possible so that treatment can begin.
Let your child’s
doctor or dentist know if your child has trouble chewing, biting, or talking.
Problems like these can be a sign of misaligned teeth, which an orthodontist or
oral surgeon may be able to treat.
What Are the Treatment Options for Micrognathia?
lower jaw may grow long enough on its own, especially during puberty. In this
case, no treatment is necessary.
In general, treatments for micrognathia include modified eating methods and special
equipment if your child is having trouble eating. Your doctor can help you find
a local hospital that offers classes on this subject. Your child may need
corrective surgery performed
by an oral surgeon. The surgeon will add or move pieces of bone to extend your
jaw. Corrective devices, such as braces, to fix misaligned teeth caused by
having a short jaw can also be helpful.
Specific treatments for your child’s
underlying condition depend on what the condition is, which symptoms it’s causing, and how
severe it is. Treatment methods can range from medications and close monitoring
to major surgery and supportive care.
What Is the Long-Term Outlook?
If your child’s
jaw grows longer on its own, feeding problems usually stop.
Corrective surgery is generally successful, but it can take nine to 12
months for your child’s
jaw to heal.
Ultimately, the outlook depends on the condition that caused micrognathia.
Babies with certain conditions, such as achondrogenesis or trisomy 13, only
live for a short time. Children with conditions such as Pierre Robin syndrome
or Treacher Collins syndrome are able to live relatively normal lives with or
without treatment. Your child’s
doctor can let you know what the outlook is based on your child’s specific condition.
direct way to prevent micrognathia, and many of the underlying conditions that
cause it can’t be
prevented either. If you have an inherited disorder, a genetic counselor can
tell you how likely you are to pass it on to your child.