What every dentist should know about facial palsy

March 1, 2020

Dentists have an important role to play in supporting people with facial palsy to manage the health of their teeth. Unfortunately, there is still not enough awareness about facial palsy and not all dentists are aware of the true impact of this condition. With over fifty different causes of facial palsy it is important for dentists to remember that not every person with facial palsy will have the same dental issues. In our 2019 survey of 421 people with facial palsy in the UK, more understanding among dentists was flagged as one way to improve the lives of those living with the condition.

Brushing and flossing

Facial palsy often makes it more difficult to brush and/or floss teeth. Some people with facial palsy have sensation on the affected side(s) and others don’t. Where there is no feeling on the affected side, food can accumulate in the cheek without the affected person knowing which causes decay, so good dental hygiene is extremely important.

Rinsing

It is important to rinse out the mouth after eating to make sure there is no food residue left in the mouth that could cause tooth decay. It can be difficult though for some people with facial palsy to rinse.

“I found using a waterpik has helped greatly in getting food out, especially when you can’t rinse on the affected side!”

“My dentist sees me every three months and he takes great care of my mouth and has shown me how to rinse my palsy side using my hand. I can’t praise him enough.”

“I often end up dripping toothpaste and water down me as I can’t keep the fluid in one side of my mouth where it doesn’t seal properly.”

Question for dentists

What tips do you have to help with keeping the teeth clean when someone has limited movement on one or both sides of their face?

Mouth Opening

When you measure from the edge of the lower front teeth to the edge of the upper front teeth, the normal amount people should be able to open their jaw is 40 – 50 millimetres. When people cannot open their mouth completely this is referred to as trismus. This is caused by damage to the muscles and/or nerves responsible for opening and closing the mouth and chewing. Surgical procedures to the head, neck, jaw or face; radiotherapy for treatment of head and neck cancer; and facial reanimation surgery can all cause trismus. This can be a common problem in facial palsy where there has been surgical input.

In respect of dental health, being unable to open the jaw fully can cause problems with brushing the teeth, eating and chewing, as well as causing jaw pain or stiffness.

There is help for this, GP’s can refer patients to a consultant, Speech and Language Therapist or Physiotherapist. Jaw exercises using a device such as a Therabite are often recommended.

Find out more about Trismus

Saliva and dry mouth

The facial nerve stimulates two of the three pairs of salivary glands in your mouth. When this part of the nerve is damaged less saliva will be produced. This can occasionally result in a dry mouth. The medical term for dry mouth due to lack of saliva is xerostomia.

Saliva plays an important role in dental health, it cleans the mouth and protects teeth from plaque and decay. When less saliva is produced it makes teeth more vulnerable, and people with dry mouth are at higher risk of tooth decay and gum disease. Regular tooth brushing after meals and six-monthly dental checks are essential. People with reduced saliva need good quality information from their dentist about how to look after their teeth and gums.

There are dry mouth products available which can help. There are also tips on our Dry Mouth website page.

Find out more about Dry Mouth

Hearing

Although hearing won’t directly affect a patient’s teeth, it is important for dentists to remember that some people with facial palsy may have singled-sided deafness (SSD) or in some cases have hearing loss in both ears. In this case dentists should be sensitive to the fact the patient may not hear instructions, i.e. where to move their tongue, or even reassuring comments that treatment is nearly finished.

Another problem that some facial palsy patients suffer with is hyperacusis. The small protective muscle in the ear can be affected when the facial nerve is damaged. This makes everyday sounds seem much louder than they really are. It can also be painful. Dentists need to be aware if a patient is suffering with hyperacusis, as the noise from a drill may cause extreme discomfort.

It is important that dentists understand facial palsy can impact people in many different ways.

Breathing

Some people with facial palsy have breathing problems due to nasal obstruction. This is where there is a sensation of reduced air flow through one or both nostrils. The facial nerve supplies the muscles around the nostril which normally contract when breathing in. These muscles make the nostril wall more rigid and make it easier to breathe in. Nasal obstruction in facial palsy can make it feel more difficult to breathe in but seems better on breathing out. It is more likely to be troublesome when someone has a deviated nasal septum. Nasal obstruction as a result of facial palsy is uncommon. Dentists still need to be aware that if someone struggles to open their mouth widely and has problems with nasal obstruction, having dental work carried out can be very traumatic.

Ramsay Hunt syndrome

Dentists should be educated about Ramsay Hunt syndrome, a rare form of shingles affecting the facial nerve. Symptoms may include painful mouth ulcers and/or blistering of the tongue. Treatment is time-critical (within 72 hours) for the best outcome.

Mnemonic – spot the warning signs of Ramsay Hunt syndrome

Psychological impact

After experiencing facial palsy, patients may be scared of having numbing injections. It is extremely rare to have complications from dental injections but dentists should not minimise the patient’s concerns. They should be prepared to listen to the patient and answer their questions.

Being repeatedly asked to open the mouth wider is also traumatic, especially if it causes pain or the patient is simply unable to due to facial palsy.

Gum health

Some people with facial palsy bite the inside of their cheek or the surface of their gums. Sometimes they will have no feeling and in some cases they will. Dentists should be aware of this as it can lead to ulcers and infections.

Facial pain

Often it is easier for someone with facial palsy to chew their food on the unaffected side of their mouth. This overactivity can result in jaw pain and Temporomandibular joint (TMJ) disorder

Synkinesis (pronounced syn-k-eye-nee-sis) means the development of linked or unwanted facial movements. It is common and occurs in the majority of people who are recovering from prolonged facial palsy. Facial muscles can become short and tight because they are overworking all the time. The overworked muscles become short and stiff which makes them difficult to move.

It can be difficult for someone with facial palsy to keep their mouth open for a length of time due to tight muscles in the face and neck. Some dentists provide a mouth brace that allows the patient to rest one side of their face and helps to prop the mouth open.

“Severe synkinesis pulls my jaw out and I have constant ‘toothache’ across the top gums. As a result of the synkinesis I have TMJ disorder – my osteopath massages my face and jaw – that helps as well as Botox . Causes slight chewing weakness but it helps the pain.” Elizabeth Robinson.

Injections

Some people report numbing injections not always working as they should due to the nerve damage and would like dentists to be patient and listen to their feedback. Some of our community members also say the numbness takes longer to wear off on the affected side.

How can dentists help?

By educating themselves about facial palsy.

It would be helpful for people with facial palsy if a standard dental care sheet was created that dentists could give out. People living with the condition have additional needs and cannot always get the amount of dental advice they need from one appointment.