Periodontal status of secondary crowded mandibular incisors. Long-term results after orthodontic treatment.

The present study was undertaken to examine whether secondary crowded mandibular incisors experience more periodontal breakdown than aligned lower incisors long-term after orthodontic treatment. Patients from 19 to 35 years after active treatment were selected. 2 groups were established: 1 with crowded mandibular incisors and 1 with aligned incisors. The groups were matched according to age, time after treatment, gender and periodontal disease classification. A separate group with crowded and aligned incisors within the same individual was established. Accumulation of plaque, gingival inflammation, probing pocket depth and probing attachment level were registered at 6 locations around each incisor. Among the patients studied, the oral hygiene level was high. In both groups, the loss of connective tissue attachment was largely due to periodontal pocket formation in interproximal areas and gingival retraction in buccal and lingual areas. A small but statistically significant difference in probing attachment level was found between crowded and aligned interproximal areas within the same individual (P less than 0.05). No differences in accumulation of plaque or in gingival inflammation were found. No differences were found for any of the dependent variables between the groups with crowded and aligned incisors.