A bilateral whitish lesion on the mucosa of the cheek

An 8-year-old girl with no medical history presented with a bilateral whitish lesion on the mucosa of the cheek, evident since early childhood. There was no relevant family history, and her parents had not presented similar lesions. They reported a progressive growth of the lesion in the last months, for which she had been evaluated by maxillofacial surgery, the lesion being oriented as a frictional keratosis. However, the use of occlusal splint was not associated with any improvement. She was otherwise asymptomatic. Physical examination revealed a bilateral, whitish, well-demarcated cheek mucosal plaque, which partially coincided with the dental occlusion line. The lesion did not detach with scratching (Figure 1). No other alterations were observed in the oral cavity or in the systematic physical examination.