Understanding Mandibulofacial Dysostosis: Symptoms, Types, Causes, and Treatment

Mandibulofacial dysostosis is an inherited developmental disorder. It is also known as Teacher Collins Syndrome Its prevalence is estimated to be 1 in 25,000 and 50,000 live births. ⁽¹⁾ 

It is a rare genetic disorder and affects the development of one and other tissues in the face, cheekbones, jaw, and ears. A mutation in the TCOF1 gene is the cause of mandibulofacial dysostosis in 95% of people. ⁽²⁾

Mandibulofacial dysostosis can lead to facial abnormalities that may vary from person to person even in those with the same genetic mutations.

The conditions occur due to mutations in the genes that provide instructions for making protein treacle. This protein is crucial for the development of the face and skull.

This condition can impact individuals physically and emotionally. It can affect appearance and lead to social stigma, low self-esteem, and depression. Hearing loss is a common complication of the condition and may impact language development, communication, and academic performance.

There are several reasons that make understanding mandibulofacial dysostosis important.

1. The first reason is that knowing about the condition can help people seek medical help to obtain a proper diagnosis and receive proper emotional and psychological support
2. Understanding mandibulofacial dysostosis can help the healthcare professional to provide an accurate diagnosis, effective treatment, and appropriate support.
3. Knowing about the disease is also helpful for the family and the caregivers of the affected individual. It gives a better understanding of how to support their loved ones. The family members can connect with the family members of the other affected individual and find emotional support.
4. Understanding mandibulofacial dysostosis can be important for advanced research as well. More understanding of the condition can be helpful in developing new treatments and interventions for the affected individuals.

The signs and symptoms of mandibulofacial dysostosis range from not being noticed to some severe symptoms.

Some people may experience very mild symptoms while others may have extremely severe symptoms, which sometimes may have serious consequences as well. The serious consequences may include life-threatening airway problems.

The signs and symptoms of Mandibulofacial Dysostosis may include abnormal or incomplete development of some body parts which include:

• Lazy eye, making it difficult to focus and causing vision problems.
• Absence or sparse eyelashes in the lower eyelid
• Abnormally developed or underdeveloped cheekbones give a sunken appearance to the cheeks
• The jaw is small and underdeveloped causing a receded chin
• Absent, small, malformed, or rotated ears
• There may be a growth of hair in the front of the ears and lateral cheekbones
• There may be an opening at the roof of the mouth, which is known as a cleft palate, with or without a cleft lip
• The small size of the jaw may lead to difficulty in breathing especially during sleep.
• There may be missing teeth or misshaped teeth
• The speech may be affected due to the abnormal development of the palate and the jaw.

The symptoms may vary in severity. A person with mandibulofacial dysostosis may not experience all the symptoms.

Mandibulofacial dysostosis is usually diagnosed by a physical examination and by reviewing a person’s medical history.

However, it can be confirmed by a variety of other tests which may confirm the diagnosis or rule out a condition with similar symptoms.

• Genetic testing can be performed to detect mutations and confirm the diagnosis. It can also be helpful for further family planning,
• Imaging studies including CT scans, x-rays, and MRI scans can help visualize bones of the face and head and detect abnormalities. It can also help detect severe conditions and plan for any necessary surgical interventions.
• Speech evaluation can help identify any speech difficulty and develop a plan for speech therapy.
• Hearing tests assess the extent of hearing and determine which intervention including hearing aids or cochlear implants can be useful.
• Vision tests detect eye abnormalities that may affect vision and help in developing a plan for treatment.

Not all diagnostic tests may be needed for a person. What doctor orders may depend on the signs and symptoms presented by the patient.

It is important to seek medical advice if a child is experiencing symptoms of mandibulofacial dysostosis. Early diagnosis and treatment lead to a better outcome and help in improving the quality of life. Medical attention may be important due to the following reasons:

• Proper Diagnosis: A healthcare professional may help provide a definitive diagnosis and rule out other conditions with similar symptoms and ensure proper treatment.
• Early Intervention: Early intervention may be provided to the individual which may include speech therapy, orthodontic treatment, and surgical intervention. These may reduce the impact of the condition of an individual’s life.
• Improved Outcome: Early diagnosis and treatment may improve the outcome for an individual with mandibulofacial dysostosis.
• Support and Resources: Seeking medical attention may be helpful for an individual to connect to support groups and resources to help manage the condition.

Mandibulofacial dysostosis is also known as Teacher Collins syndrome. The types may vary depending on the severity and specific feature of an individual.

Different types of mandibulofacial dysostosis include: ⁽²⁾

• Teacher Collins syndrome type 1: This is the most common type of mandibulofacial dysostosis and is characterized by underdeveloped cheekbones, downward-slanting eyes, and a small jaw. It occurs due to a mutation in the TCOF1 gene.
• Teacher Colin syndrome type 2: It occurs due to a mutation in the POLR1C gene. It is similar to type 1 but may be more severe and may have additional abnormalities such as the absence of limbs and heart.
• Teacher Collins syndrome type 3: It is a rare type of mandibulofacial dysostosis and is caused by a mutation in the POLR1D gene. It is similar to types 1 and 2 but may additionally have severe hearing loss and other abnormalities.
• Nager syndrome: It is characterized by abnormalities of the hand and arm along with underdeveloped cheekbones and a small jaw.
• Miller syndrome: This is a rare type of mandibulofacial dysostosis and is characterized by underdeveloped cheekbones and abnormalities of fingers and toes.

Mandibulofacial dysostosis is a genetic disorder, caused by mutations in specific genes. However, there are also a few environmental factors that may contribute to its development and severity.

Mutation in the TCOF1 gene is the most common cause of mandibulofacial dysostosis and accounts for 80% of the cases. The TCOF1 gene is important for making the gene treacle that is important for the development of bones and other tissues in the face.

Though less common, mutations in POLR1C and POLR1D gene is also associated with mandibulofacial dysostosis. These genes are involved in the production of complex proteins that are important for the development of ribosomes, an essential protein for the production of protein.

• Nutritional deficiencies: Some evidence suggests nutritional deficiencies particularly folic acid and vitamin B6 increase the risk of developing mandibulofacial dysostosis.
• Exposure to Teratogenic Agents: Teratogens are substances that interfere with fetal development and cause birth defects. Teratogens may include alcohol, tobacco smoke, and certain medications.

The treatment for mandibulofacial dysostosis may involve a team including a geneticist, craniofacial surgeon, audiologist, speech therapist, and orthodontist. The treatment options include:

• Surgery: Surgical intervention involves correcting abnormalities of the face, small jaw, cleft palate, and abnormal ear shape. The surgery may depend on individual needs.
• Speech Therapy: Speech therapy can be given to improve communication skills.
• Hearing Aids: Some people with mandibulofacial dysostosis have hearing loss due to abnormalities of the ear. Hearing aids may help in improving hearing and language development.
• Orthodontic Treatment: Braces and other orthodontic devices can be used to correct dental abnormalities such as misaligned teeth.
• Psychological Support: Due to their appearance, people with mandibulofacial dysostosis may face social and emotional challenges. Psychological support and counseling can be helpful in improving the quality of life.
• Genetic Counseling: Genetic counseling can be helpful for individuals to get information about the condition and the risk of its occurrence in future pregnancies and the available prenatal testing.

The surgical procedures to correct facial abnormalities may include:

• Rhinoplasty: It is a surgical procedure to reshape the nose.
• Orthognathic Surgery: Corrective jaw surgery to correct the abnormalities of the jaw and facial bones.
• Blepharoplasty: A procedure to correct eyelid abnormalities and drooping and sagging eyelids.
• Facelift: Procedure to lift and tighten the skin on the face and neck. It can also correct the deep creases around the mouth and loose skin on the neck.
• Otoplasty: a surgical procedure to correct ear abnormalities
• Cleft Lip and Palate Repair: A surgical procedure to correct lip and palate abnormalities.

There are several non-surgical interventions that can be used for hearing and speech issues:

• Hearing Aids: Small electronic devices can help amplify sound and make it easier for people with hearing loss to hear
• Speech Therapy: This therapy helps people with language disorders to improve their communication skills. It helps correct stuttering, articulation problem, and language delays.
• Assistive Listening Devices: These can help people with hearing loss to hear better in specific situations such as noisy environments.
• Augmentative and Alternative Communication Devices: These devices can be helpful for people with communication disorders. These help them express themselves when they are not able to speak or write.

Early intervention can be helpful in a better outcome. It can help in preventing further issues.

Early interventions can be helpful in people with hearing and speech deformities develop strong communication skills and improve overall well-being.

Ongoing care can help in reassessing a person’s needs and adjusting the treatment plan according to the person’s needs.

It’s important to work with a healthcare professional to determine the best treatment course and regular follow-up care to ensure the treatment plan is working effectively.

There are several support groups and networks that can be helpful for individuals with mandibulofacial dysostosis and their families.

There is the Teachers Collins foundation that provides support to individuals with mandibulofacial dysostosis. ⁽³⁾ A range of programs are offered to individuals.

There is a National Organization for Rare Disorders (NORD). It is a non-profit organization that provides support to individuals and their families with rare disorders. ⁽⁴⁾

Genetic and Rare Disease Information Center (GARD) is a program of the National Institutes of Health that provides information and resources on genetic and rare diseases. ⁽⁵⁾

Craniofacial clinics are clinics that look after individuals with craniofacial diseases. They offer multidisciplinary approaches including surgical interventions, speech therapy, and psychological support.

Local support groups or communities are also there to support the individual and families with Teacher Collins syndrome.

Coping with mandibulofacial dysostosis can be challenging for both individuals and their families. It can be helped by:

• Seeking support
• Building a strong healthcare team
• Having a focus on a person’s strengths and abilities
• Educating others which can reduce the stigma and promote understanding.
• Practicing self-care can help cope with the conditions. It involves exercises, mindfulness, and spending time with loved ones.

Coping with mandibulofacial dysostosis overall requires a multifaceted approach that includes emotional, social, and physical support.

Mandibulofacial dysostosis is a rare genetic disorder that can affect the development of facial bones and tissues. Coping with this condition can be challenging and many resources and support networks can be helpful.

Early intervention and ongoing care are crucial for addressing the physical, emotional, and social impact of the condition.