Frictional Keratoses on the Facial Attached Gingiva Are Rare Clinical Findings and Do Not Belong to the Category of Leukoplakia

Abstract

To investigate the clinical and histologic features of frictional keratoses located exclusively on the facial attached gingiva and establish whether these belong to the category of leukoplakia. Over a period of 15 years, 159 patients presenting with oral keratotic plaques, located exclusively on the facial attached gingival mucosa, excluding the edentulous alveolar ridge and retromolar pad area, were retrospectively selected. Clinical and histologic features and the symptoms and progression of these lesions were carefully assessed. The presence of oral frictional keratosis located exclusively on the facial attached gingival mucosa was clinically and immunohistologically diagnosed in 14 of 159 patients (8.8%). Eleven patients (78.5%) showed unilateral involvement, whereas 3 patients (21.5%) had bilateral involvement. The disappearance of the lesions was accomplished in only 9 of 14 patients, resulting from discontinuation of bad habits. Clinically, these lesions appeared as distinct, sharply demarcated, isolated, asymptomatic, homogeneous whitish-plaques that were neither removable nor painful. The plaques did not create discomfort, change shape, or develop into malignancy. Histologically, these plaques showed features superimposable to those present in benign alveolar ridge keratoses. The results highlighted that frictional keratoses on the facial attached gingival mucosa 1) are rare findings, 2) clinically appear as "true leukoplakia" but histologically have the same features as benign alveolar ridge keratoses, 3) have no propensity for malignant transformation, 4) have a good prognosis, and 5) have a specific cause, and resolution is accomplished if the frictional element is eliminated. Thus, these must be removed from the category of leukoplakia.