Three epidemiological surveys have been carried out in Malaysia since 1971. All showed a high level of caries prevalence. Ninety per cent of school children between the ages of 6 and 18 suffered from dental caries, with a DMFT of approximately 3 and a dft of approximately 2. Ninety-five per cent of the adult population had caries experience, with the mean DMFT being 13.2. Approximately 55 per cent of children showed the presence of gingivitis with the mean number of inflamed gingival units per child ranging from 1.9 to 2.8, while 72.4 per cent of adults had some form of periodontal disease with 29 per cent having pockets deeper than 3 mm. The OHI-S score for adults was 2.2 and 81 per cent used toothbrushes to clean their teeth. A further 5.1 per cent used twigs and fingers with powdered charcoal or salt. One-third of the child population needed orthodontic treatment, with 0.3 per cent examined in peninsular Malaysia having cleft lip or palate or both. In the adult population 10.4 per cent of those examined required some form of orthodontic treatment. Twenty per cent of the children in the survey were in need of dentures; 54.7 per cent of the adults were either in need of dentures or were wearing dentures. Of these 25 per cent had complete dentures. The smoking habit was most commonly associated with pre-cancerous/cancerous lesions with alcohol consumption a close competitor; 114 adults, that is 1.3 per cent of those examined, suffer from leukoplakia but only one case of oral cancer was detected.(ABSTRACT TRUNCATED AT 250 WORDS)