RESUMEN
Background: The aim of this study was to investigate the frequency of oral lesions in the floor of the mouth fromrepresentative oral pathology centres in Latin America.Material and Methods: This study was conducted on biopsies obtained from January of 1978 to December of 2018at nine Latin America oral and maxillofacial pathology centres. Gender, age and histopathological diagnosis wereevaluated. Data were analysed using descriptive methods. Chi-square test was used for pairwise comparisons.Results: From 114,893 samples, 4,016 lesions (3.49%) occurred in the floor of the mouth. Brazil showed 3,777 cases(94%), Mexico 182 cases (4.5%) and Argentina 57 cases (1.4%). Benign lesions represented 65.1% (2,617 cases),followed by 34.9% (1,404 cases) of malignant disorders. Lesions of epithelial origin were more frequent (1,964) cases; 48.9%), followed by salivary glands (1,245 cases; 31%) and soft tissue lesions (475 cases; 11.7%). The mostcommon histological subtypes were oral squamous cell carcinoma (1,347 cases; 33.5%), ranula (724 cases; 18%), oralleukoplakia (476 cases; 11.8%) and inflammatory fibrous hyperplasia (239 cases; 5.9%). The lesion affected males in2,129 cases and females in 1,897 cases.Conclusions: In the current study, lesions in the floor of the mouth represented 3.49% of biopsies submitted to oralpathology services and oral squamous cell carcinoma, ranula and leukoplakia were the most common lesions.(AU)