Estimates of the global prevalence of oral potentially
malignant disorders range from 1–5% (85), although
much higher prevalences are reported from South
East Asia, usually with a male preponderance, e.g. Sri
Lanka (11.3%) (3), Taiwan (12.7%) (15), and some
Pacific countries (Papua New Guinea 11.7%) (128).
Wide geographical variations across countries and
regions are mainly due to differences in sociodemographic
characteristics, the type and pattern of
tobacco use and clinical definitions of disease
(Table 2). In Western countries, the overall prevalence
is low and a decrease over time is observed.