Criteria for assessment of interproximal bone loss on bite-wing radiographs in adolescents.

The present study was performed to determine radiographically the normal distance between the cemento-enamel junction (CEJ) and the alveolar bone crest (AC) as a background for diagnostic decision on bone loss in adolescents. For this purpose, the normal appearance of the alveolar crest was studied in 30, 18-year-olds reported to have had a clinically healthy gingiva at the age of 16 years. A clinical examination was performed and 4 posterior bite-wing radiographs were taken. Sites with bleeding on probing, loss of probing attachment, defective fillings and calculus were excluded from the analysis. At the remaining 737 sites, the distance CEJ-AC was measured on radiographs. Also, the appearance of the marginal bone (normal, sclerotic, notched and/or irregular image, widening of the periodontal ligament space) was recorded. The mean distances CEJ-AC for the separately-recorded maxillary surfaces amounted to 0.9 or 1.0 mm. In the mandible, the distances amounted to 0.7 or 0.8 mm except for the mesial surface of the mandibular first premolar, where a mean distance of 0.5 mm was noted. At maxillary surfaces, 84-90% of the sites showed a distance of 1 mm or less and 94-100% a distance of 1.5 mm or less. At mandibular surfaces, 93-100% of the sites showed a distance of 1.0 mm or less and 100% a distance of 1.5 mm or less. At 4 sites, located at the mesial surface of the first and second premolars in the maxilla, the CEJ-AC distance was recorded as 2 mm. One site was classified as not having a normal appearance.(ABSTRACT TRUNCATED AT 250 WORDS)