Aspects of the validity of buccal loss of attachment ≥ 1 mm in studies of early periodontitis

Abstract The aim of this study was to consider the validity of measurements of loss of attachment on buccal surfaces in studies of early periodontitis and in particular to monitor the development of loss of attachment ≥ 1 mm on buccal surfaces over a 2-year study period in 229 subjects initially aged 14.3 years and to relate this loss of attachment to gingival status and oral cleanliness at baseline. 3 subgroups were considered: the first comprised 83 subjects who developed no loss of attachment over the 2-year study period; subgroup 2 comprised 56 subjects who developed loss of attachment ≥ I mm on buccal surfaces only; subgroup 3 comprised 75 subjects who developed loss of attachment ≥ 1 mm on at least 1 buccal surface and on at least 1 mesio-buccal surface over the study period. The mean number of buccal sites with plaque, subgingival calculus, gingival colour change and gingival bleeding at baseline was lower in subgroup 2 than subgroup 3, the differences being significant for the latter three variables. The data failed to reject the null hypothesis of no differences between subgroups 2 and 1. It was concluded that the buccal loss of attachment ≥ 1 mm found in subgroup 2 at age 16 years was associated with few oral deposits and little gingival inflammation and could probably be related to toothbrushing practices. In contrast, the buccal loss of attachment that developed in subgroup 3 was associated with oral deposits, especially subgingival calculus, and gingival inflammation, and it seemed reasonable to attribute this to early periodontitis. In view of these 2 possible different aetiologies for buccal loss of attachment, it is recommended that in studies of early periodontitis, loss of attachment measurements should be restricted to proximal surfaces.