The effect of facial growth, attrition, and age on the distance from the cementoenamel junction to the alveolar bone crest in the deciduous dentition.

The aim of this study was to describe the distances from the cementoenamel junction to the alveolar bone crest (CEJ-ABC) in the deciduous dentition and to relate them to age, facial, and tooth structure in 72 dry human skulls. Age correlated significantly with anterior face height (AntFH), the distance from condyle to gnathion (Co-Gn), lateral face height (LatFH), molar anatomic crown (MAC), and molar space (MS). The CEJ-ABC per skull and for the molars correlated with age, LatFH, AntFH, Co-Gn, MS, and MAC. The CEJ-ABC for the canines and the incisors correlated with age, LatFH, AntFH, and Co-GN. Multiple regression analysis on the effect of age, AntFH, LatFH, Co-Gn, and MAC on the CEJ-ABC distances indicated that they account for 36.3% of the CEJ-ABC distance per skull, 68.8% for the molars, 34.3% for the canines, and 44.2% for the incisors. The effect of each variable while controlling for the others indicated that age, LatFH, and MAC had a significant effect on the CEJ-ABC of the molars, whereas only age had a significant effect on the CEJ-ABC of the canines and incisors. These results indicate that there is a site-specific effect of facial growth and attrition on the CEJ-ABC distances in the deciduous dentition.

Root exposure in the primary dentition studied in human skulls.

The aims of the present study were to examine, on the primary dentition of 75 human dried skulls, the distance from the cemento-enamel junction (CEJ) to the alveolar bone crest, and to evaluate its relation to developmental age, bone morphology and attrition. The measurements from the CEJ to the alveolar crest were longer for the maxillary teeth, the second molars showed the shortest measurements, while the cuspids showed the longest. Significant positive partial correlations were found between age and the distance from the CEJ to the alveolar crest when controlling for attrition (r = 0.64), and between age and attrition when controlling for the distance from the CEJ to the alveolar bone crest (r = 0.54). The partial correlation between migration and attrition when controlling for age proved to be not significant (r = 0.13). Significant correlations were found between age and the distances from the mental foramen to: the alveolar crest (r = 0.90), and to the lower border of the mandible (r = 0.97). These findings suggest that root exposure takes place in the primary dentition, as the result of continuous eruption at a faster rate than formation of alveolar bone, presumably to compensate for facial growth.