Moebius Syndrome

Moebius syndrome is a rare disorder that causes weakness or paralysis of certain cranial nerves. It’s present at birth but does not get worse over time. Signs and symptoms vary widely but often involve problems with the face, especially the mouth and eyes. Several specialists and procedures, such as “smile surgery,” can help.


What is Moebius syndrome?

Moebius syndrome is a rare, congenital (present at birth) neurological disorder. It causes weakness or paralysis of certain cranial nerves, which connect the brain to the head, neck and trunk. The condition usually affects the sixth cranial nerve (which controls the eyes) and the seventh (which controls facial expression). Other nerves are sometimes affected.

Children with Moebius syndrome often have trouble moving their faces. For example, they may not be able to smile, frown, raise their eyebrows or close their eyelids. The face might droop or appear “mask-like.” They may also have trouble feeding. Some children with Moebius syndrome also have abnormal development in the limbs or chest muscles.

Moebius syndrome is not progressive, meaning it does not get worse over time.


Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

Who might get Moebius syndrome?

Scientists have not identified any specific factors that increase a person’s chances of having Moebius syndrome. It occurs in both girls and boys of all ethnicities.

How common is Moebius syndrome?

Moebius syndrome is very rare. The exact incidence is unknown, but some estimates are 2 to 20 cases per million births.


Symptoms and Causes

What causes Moebius syndrome?

Scientists are still researching the causes of Moebius syndrome. Sometimes it’s linked to mutations in specific genes, but it usually happens sporadically (no known reason or family link).

What are the symptoms of Moebius syndrome?

The signs and symptoms of Moebius syndrome vary widely, depending on which cranial nerves are affected.

Physical signs may include:

  • Cleft palate (abnormal opening in the roof of the mouth).
  • Crossed eyes (strabismus).
  • Defects in the hands and feet (clubfoot, webbed fingers, missing fingers or toes).
  • Facial paralysis (facial palsy).
  • Small chin (micrognathia).
  • Small mouth (microstomia).
  • Tongue that is short or shaped differently.
  • Underdeveloped pectoral (chest) muscles.
  • Weak muscle tone (hypotonia).

Mobius syndrome can cause problems with:

  • Breathing.
  • Closing the eyelids (such as blinking or even sleeping).
  • Dry eyes.
  • Eating (trouble sucking or swallowing).
  • Hearing.
  • Looking in the same direction with both eyes.
  • Making and keeping eye contact.
  • Moving the eyes back and forth (side to side, especially outward).
  • Puckering the lips.
  • Raising the eyebrows.
  • Smiling or frowning.
  • Speaking.
  • Tooth development (missing or crooked teeth).

Some children with Moebius syndrome may have developmental delays (such as sitting, crawling or walking later than expected), but most eventually catch up. A few studies have suggested that children with Moebius syndrome may be more likely to have autism spectrum disorder. But that has not been proven.


Diagnosis and Tests

How is Moebius syndrome diagnosed?

A healthcare provider diagnoses Moebius syndrome based on clinical criteria. That means there are no specific tests for the disorder. Diagnosis is based on a healthcare provider observing specific symptoms during an examination.

To diagnose Mobius syndrome, a child must have:

  • Facial weakness or paralysis that has been present since birth but does not get worse over time.
  • Inability to move one or both eyes outward or side to side (but can move the eyes up and down).

A healthcare provider may conduct tests to rule out other causes of facial weakness or paralysis.

Management and Treatment

How is Moebius syndrome treated?

There’s no cure for Moebius syndrome, but treatments can correct or lessen some signs and symptoms. Depending on your child’s condition, your pediatrician may refer you to medical specialists, such as:

  • Audiologists, who specialize in hearing.
  • Dentists.
  • Occupational therapists, who can help your child perform everyday tasks, such as holding a spoon.
  • Ophthalmologists, who specialize in the eyes.
  • Otolaryngologists, who specialize in the ear, nose and throat.
  • Physical therapists, who can help your child move better.
  • Speech therapists, who can help with problems speaking.
  • Surgeons, including general surgeons, plastic surgeons and orthopedic surgeons.

Treatment may involve:

  • Contact lenses to protect and correct the eyes.
  • Eye drops for lubrication.
  • Ponseti method for clubfoot, which involves a series of casts.
  • Splints, braces and prostheses (artificial body parts) for the limbs.
  • Various surgeries.

Surgical procedures can:

  • Correct strabismus.
  • Fix tooth spacing or other dental issues.
  • Make the eyelids close.
  • Move nerve or muscle tissue from one area of the body to another (known as a nerve or muscle graft) to promote movement.
  • Open and support the airway (called a tracheotomy) to improve breathing.
  • Separate webbed fingers.

Recently, children with Mobius syndrome have benefitted from “smile surgery,” also called a “smile operation.” During this procedure, a surgeon takes a muscle from the thigh, implants it in the face and connects it to other facial muscles and nerves. It’s helped children achieve:

  • Facial movement, including smiling and eating.
  • Speech.
  • Self-esteem.
  • Symmetrical smile.


How can I prevent Moebius syndrome?

There is no way to prevent Moebius syndrome. Scientists are still working to understand what causes it and possible risk factors.

Outlook / Prognosis

What is the outlook for people with Moebius syndrome?

With proper medical care, people with Moebius syndrome usually have a normal life expectancy. This is especially true if they don’t have life-threatening complications in the first year of life.

Although symptoms can make life more challenging, many people with the condition live productive and meaningful lives.

Living With

What can I ask my child’s doctor about Moebius syndrome?

Consider asking your healthcare team the following questions:

  • Which cranial nerves are affected?
  • What specialists can help with the signs and symptoms?
  • Should I consider surgery for my child?
  • Are there any reasons I should seek immediate medical attention for my child?
  • Should my family get genetic testing or counseling?

How can my child best learn to cope with Moebius mouth?

People with Moebius syndrome often live full lives, especially after treatment to correct or lessen the signs and symptoms. However, they may have various problems with self-esteem or the emotional aspects of the condition. It may help to:

  • Attend support groups to connect with other people with Moebius syndrome.
  • Get involved in the Moebius syndrome community through advocacy, fundraising, etc.
  • Talk to a therapist (such as a counselor or psychologist).

A note from Cleveland Clinic

Moebius syndrome is a rare congenital disorder that causes weakness or paralysis of certain cranial nerves. The signs and symptoms vary but often involve facial paralysis. Medical specialists and procedures can correct or lessen some effects so your child can live a more productive, meaningful life.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 05/04/2021.

Learn more about our editorial process.

Appointments 216.444.8500