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
