A total of 404 maxillary lateral and central incisors were examined in a group of 101 individuals comprising 64 males and 37 females for the presence of palato-radicular groove (PRG). The methods used to document the presence of PRG situated at or apical to the cemento-enamel junction (CEJ) included clinical probing, flap operation and inspection with the aid of an enlarging oral mirror. PRGs were classified by location in the mesial, distal and midpalatal areas of affected teeth. The plaque index (P1I), gingival index (GI) and probing pocket depth (PPD) were recorded on the lingual aspect of the teeth examined. Those PRG with initial PPDs of > or = 4 mm and located at or apical to the CEJ were counted as PRG with PPD. The difference in the PRG location for teeth with and without PPDs was analyzed via the chi 2 test. The relationship between the presence of a PRG and the patients periodontal health and plaque accumulation were analyzed using the t-test.(ABSTRACT TRUNCATED AT 250 WORDS)