Gums that slowly thicken and creep over the teeth can be a side effect of some seizure medicines, phenytoin above all. Not everyone taking these medicines is affected, and for those who are, the amount of plaque and inflammation at the gum line has a large say in how far the change goes. That makes it one of the few medicine side effects where daily cleaning can genuinely help.
What the change looks like
Dentists call it drug-induced gingival overgrowth. The gum tissue gains bulk, starting in the little triangles of gum between the teeth. Early on it can pass for puffy or inflamed gums. Over months it may thicken, firm up and spread across the front surfaces of the teeth.
It is rarely painful, so many people do not notice it until a family member, carer or dentist points it out. The problems it causes are practical ones. Thick gum folds trap food and plaque, which makes cleaning harder and raises the risk of decay and gum disease underneath. It can change the look of a smile. In children it can delay the arrival of adult teeth, a complication noted in a 2005 review of gum overgrowth in children by Doufexi and colleagues in the Journal of Periodontology.
Phenytoin is the best known cause, but not the only one
Three groups of medicines are classically linked with gum overgrowth: the anti-seizure medicine phenytoin, some calcium channel blockers used for blood pressure and heart conditions (nifedipine is the usual example), and the transplant medicine ciclosporin. A 2015 review by Trackman and Kantarci in the Journal of Dental Research estimated that roughly half of people taking these medicines develop some overgrowth, although individual studies vary a great deal because dose, time on treatment, age and the way overgrowth is measured all differ.
Newer anti-seizure medicines are not automatically free of this effect. An Italian study of 162 adults and children with epilepsy (Gallo and colleagues, Journal of Periodontal Research, 2021) found overgrowth in people taking several different seizure medicines, not only phenytoin. It was a single cross-sectional study, so it cannot prove cause, but it is a good reason to tell your dentist about every medicine you take rather than assuming yours is low risk.
Why plaque control makes such a difference
The medicine seems to create the tendency, and inflammation from plaque appears to drive how much tissue builds up. In a Barcelona study comparing people taking anti-seizure medicines with people who were not (Brunet and colleagues, European Journal of Clinical Investigation, 2001), gum inflammation was the risk factor most clearly tied to overgrowth.
In everyday terms that means:
- brushing twice a day with fluoride toothpaste, angling the bristles into the gum line rather than only scrubbing the tooth surfaces
- cleaning between the teeth every day with floss or small interdental brushes, since overgrowth starts there
- a powered toothbrush if manual brushing is tiring or awkward; a Cochrane review (Yaacob and colleagues, 2014) found powered brushes reduced plaque and gum inflammation modestly compared with manual ones
- help from a family member or carer where seizures, coordination or fatigue make thorough cleaning difficult
A dentist may also suggest an antiseptic mouthrinse for a limited period while inflamed gums settle.
Treatment, from cleaning to gum surgery
Most people start with professional cleaning by a dentist or OHT to remove hardened calculus at and under the gum line, followed by reviews at shorter intervals than usual while the gums are being brought under control. Many mild cases improve noticeably with this alone.
Where the overgrowth is significant, your dentist may write to your neurologist or GP. In some situations a different medicine is possible, and overgrowth can partly settle after a change, though established fibrous tissue often does not fully shrink back. Seizure control always takes priority, so this is a medical decision. Never stop, skip or alter a seizure medicine because of your gums.
If thick tissue remains, the extra gum can be trimmed back under local anaesthetic in a procedure called a gingivectomy, which restores a shape that can be cleaned. Our article on gingivectomy and gum reshaping explains what is involved. Overgrowth can return if the medicine continues and plaque builds up again, so home care and regular maintenance stay important afterwards.
Other dental points for people with epilepsy
A seizure can chip a tooth or injure the lips and tongue, and any such injury is worth having checked even if it feels minor. Some medicines reduce saliva, and a dry mouth makes decay more likely, so sipping water and using fluoride toothpaste matter more. Bleeding when you brush is an early sign of inflamed gums and is covered in our guide to bleeding gums when brushing.
Before any appointment it helps to tell the dental team about your seizure type, usual triggers, timing of medicines and what to do if a seizure happens. Then the visit can be planned around you. Families caring for someone with other long-term conditions may find our guides to multiple sclerosis and oral health and cerebral palsy and dental care useful too.
Questions we are often asked
Does everyone on phenytoin get gum overgrowth?
No. A substantial share of people taking it do not, and good plaque control appears to lower both the chance and the severity.
Is it more of a problem in children?
It can be more marked in children and teenagers, and it may affect how adult teeth come through. Regular dental reviews and supervised brushing are especially helpful at these ages.
What does treatment cost?
Cleaning alone costs less than cleaning followed by gum surgery, so the total depends on what your gums need. We do not publish fees in blog articles; you can see our current offers or ask for a written treatment plan with fees at a check-up.
Getting your gums checked
If your gums look puffy, bleed or seem to be growing while you take a seizure medicine, book a dental review. Changes are easier to manage when they are found early. The dentists and OHTs at Lumi Dental can assess your gums, plan cleaning and, with your permission, keep your doctor informed. You can arrange a visit through our contact page.
This article is general information and is not a substitute for individual advice. Do not change any prescribed medicine without speaking to your doctor.
