Abstract Periodontal conditions in adolescents from the north of Sweden have been described in an earlier study. 2 groups were distinguished, one with proximal and the other with buccal/lingual probing attachment loss (AL). The present study analysed the relationship between AL and various background variables: plaque, bleeding, calculus, pocket depth, toothbrushing, experience of fixed orthodontic appliance, general disease, socio-economic level. No significant differences between the total group with AL and that without AL were seen concerning general disease, socio-economic level, experience of orthodontic treatment, or presence of bleeding, plaque or calculus. When groups with AL on proximal surfaces and on buccal/lingual surfaces were analysed separately, it was found that the group with proximal AL more often had plaque, bleeding, calculus and pocket depths /4 mm than the group with absence of AL and the group with buccal/lingual AL. In the latter group, toothbrushing was more frequent. The differences seen between the group with proximal AL and that with buccal/lingual AL may indicate different etiologies of loss of tooth support in these ages.