Phenytoin and your teeth

Phenytoin is a long-established anticonvulsant used to control seizures, especially generalized tonic-clonic and focal seizures.

Phenytoin is the textbook cause of medication-induced gum overgrowth and was the first medication where this effect was widely recognized. Studies estimate visible overgrowth in roughly half of patients on long-term phenytoin. The mechanism is similar to but distinct from the calcium channel blockers and cyclosporine. Newer anticonvulsants have largely replaced phenytoin in many cases, but it is still used and still causes the same dental issue.