A case of oral mucosal ulcer caused by the inappropriate use of nicotine gum is reported.
The patient was a 55-year-old man who was a heavy smoker. He had smoked 60 cigarettes a day for 36 years. He had been using nicotine gum as a "stop-smoking aid" for over 8 months. He was referred to our department because of an unhealed undermining ulcer at the mucogingival junction of the lower right anterior teeth. On exfoliative cytology, there were no atypical cells in a specimen of the ulcer. Therefore, we recommended him to stop using nicotine gum, which was inappropriately placed at the buccal vestibule of mouth. The tenderness then gradually improved, and the ulcer healed in the month. Long-term inappropriate use of nicotine gum can cause adverse effects to the oral mucosa.