“…Reports of caries prevalence among aboriginal groups such as Veddha children of Sri Lanka, had very small samples that would not yield meaningful results when subdivided by gender (Dasanayake and Caulfield, 2002). In some analyses the research design was focused on the comparative assessment of caries prevalence or DMFT in pooled-gender subgroups, such as slum versus urban versus rural samples (Christiensen et al, 2003;Mandal et al, 2001), social and economic groups (Sri Lanka; Perera and Ekanayake, 2008), or different ecogeographic zones, such as the terai (lowlands), hills, and Himalayas of Nepal (Milsom et al, 1997). Some meta-analyses of caries prevalence and experience focus on epidemiological evidence of temporal trends in pooled-gender samples from Bangladesh (van Palenstein Helderman et al, 1996) and Nepal (van Palenstein Helderman et al, 1998), for example.…”