Micrognathia

Definition

Micrognathia is a term that describes an abnormally small lower jaw.

Alternative Names

Considerations

In true micrognathia, the jaw is small enough to interfere with the infant's feeding. Infants with micrognathia may need special nipples in order to feed properly.

Micrognathia often corrects itself during growth, especially at puberty when the jaw grows quite a bit. It can be caused by certain inherited disorders and syndromes.

Micrognathia is one cause of abnormal alignment of the teeth. You can see this in the way the teeth close. Often there will not be enough room for the teeth to grow. Talk to an orthodontist when the child's adult teeth come in. At times, children can outgrow micrognathia. It makes sense to wait to treat the condition until they are older.

Common Causes

Micrognathia may be part of other genetic syndromes, including:

  • Cri du chat syndrome
  • Hallerman-Streiff syndrome
  • Marfan syndrome
  • Pierre Robin syndrome
  • Progeria
  • Russell-Silver syndrome
  • Seckel syndrome
  • Smith-Lemli-Opitz syndrome
  • Treacher-Collins syndrome
  • Trisomy 13
  • Trisomy 18
  • XO syndrome (Turner syndrome)

Home Care

If micrognathia interferes with feeding, you'll need to use special feeding techniques and equipment. You can learn these techniques through special programs that are available at most hospitals.

Call your health care provider if

Contact your health care provider if:

  • Your child seems to have a very small jaw
  • Your child has trouble feeding properly

What to expect at your health care provider's office

The doctor will do a physical examination and may ask questions about the history of the problem, such as:

  • When did you first notice that the jaw was small?
  • How severe is it?
  • Does the child have trouble eating?
  • What other symptoms are present?

The physical examination will include a thorough check of the mouth.

The following tests may be performed:

  • Dental x-rays
  • Skull x-rays

If there are other symptoms of an inherited condition, the child may need to be tested for that condition. The health care provider might recommend surgery or orthodontic devices.

References