The alveolar bone height of the primary and first permanent molars in healthy 6-to 9-year-old Jordanian children

Aim. To establish a threshold cemantoenamel junction (CEJ)-alveolar bone crest (ABC) distance in healthy 6- to 9-year-old Jordanian children and determine the effect of pathological changes, physiological changes, gender, and age on the CEJ-ABC distance. Design. Bitewing radiographs were made for 539 6- to 9-year-old children. Plaque index (PI), gingival index (GI), calculus index (CI), DMFS score, and pocket depth were all assessed through clinical examination. CEJ-ABC distance was measured from radiographs at the mesial surface of permanent first molars (PFM), and the mesial and distal surfaces of primary molars. Results. The CEJ-ABC distance ranged from 0.00 to 4.49 mm, the mean for all surfaces was 0.84 +/- 0.44 mm, no gender or age group differences were found. The mesial surface of the PFMs had the smallest mean CEJ-ABC distance. The CEJ-ABC distances were greater in the maxilla than in the mandible. No significant effect of PI, GI or CI on CEJ-ABC distance was found. Caries, faulty restorations, exfoliation, and partial eruption adjacent to measured surfaces had significant effect on the CEJ-ABC distance. Conclusion. The mean CEJ-ABC distance was < 1 mm. Threshold CEJ-ABC distances of 1.0 and 1.5 mm for PFMs and primary molars, respectively, are suggested to be used in 6- to 9-year-old children.