Reliability of Two Methods for Measurement of Alveolar Bone Loss

Background: Different methods have been employed for assessing alveolar bone loss (ABL) in primary teeth, what is probably contributing to the variable prevalence of this pathology in dental literature. Objectives: To evaluate the reliability and the intra- and inter-examiner's variability of two methods for measurement of the cementoenamel junction (CEJ)-alveolar bone crest (ABC) distance on bitewings of children with primary dentition, as well as the capacity of both methods in measuring the sites. Methods: Twenty standardized bitewings from 10 preschool children were analyzed by two methods in order to assess the CEJ-ABC distance: an image analysis program (Image Tool - IT) and a digimatic caliper (DC). Eight different sites were measured on each bitewing, what represented a total of 160 sites. Radiographs were measured three times for each method by three trained examiners. The difference between the methods' ability in measuring all possible sites was analyzed by McNemar χ² and Kappa. Agreement degree's assessment among CEJ-ABC distances for each measured site was performed by calculating intraclass correlation coefficient (ICC), and constructing both the Altman-Bland and survival-agreement plots. Besides, paired t test was also used for methods' comparison. Results: There was a significant tendency for having fewer measured sites by IT (non-measured sites ranged from 25 to 41.9% for IT), and also, a statistically significant bias (ranging from 0.11 to 0.23, in average) indicating higher measurements for this method with regard to all examiners, although the observed difference could be considered clinically irrelevant. The measured distances showed good consistency concerning intra- and inter-examiner agreement, for both methods (all ICC were above 0.85). Conclusion: Both methods could be used interchangeably for diagnosing ABL in primary teeth concerning their very good reliability and intra- and inter-examiner agreement. However, DC would be more advisable as for its capacity of measuring more sites than IT.