Unusual White Plaques on the Tongue in a 37-Year-Old Male.

Frictional keratosis is a benign reactive condition of the oral mucosa resulting from chronic mechanical irritation. This case report describes a 37-year-old male presenting with asymptomatic, bilateral, non-removable white plaques on the lateral borders of the tongue. Clinical examination, medical history, and lesion morphology ruled out infectious and neoplastic conditions, leading to a provisional diagnosis of frictional keratosis associated with the use of orthodontic clear aligners. Discontinuation of aligner use resulted in complete lesion resolution within 21 days, confirming the diagnosis without the need for invasive diagnostic procedures. This case highlights the importance of recognizing orthodontic appliances, particularly clear aligners, as potential sources of frictional trauma. Prompt identification and elimination of the irritant are essential to avoid unnecessary interventions. To the best of our knowledge, this is the first reported case of frictional keratosis linked to orthodontic clear aligners.