Prevalence and local factors associated with radiographic bone loss in primary dentition: A retrospective study

Background: This study aimed to evaluate the radiographic bone level in primary molars in a Brazilian population, define the prevalence of bone loss, and identify the local factors associated with early bone alterations. Methods: Radiographs of children who attended Piracicaba Dental School (Brazil) between 2014 and 2020 were evaluated. Two calibrated examiners measured the distance between the cementoenamel junction and the bone crest (CEJ-BC) in bitewing radiographs, and CEJ-BC > 2 mm represented bone loss. Local factors in the measured sites were screened. Multiple linear and logistic regressions were used in the analysis. Results: 828 bitewing radiographs from 527 patients (8.27 ± 1.71 years) were evaluated. The mean CEJ-BC distance was 1.12 ± 0.40 mm (0.0–3.4 mm). 85 sites were positive for bone loss, with a prevalence of 2.62% at site and 13.28% (70 individuals) at patient levels. Male patients, increasing age, maxilla, first primary molars, and local factors were related to a higher CEJ-BC. Pulpectomies, fillings, and adjacent tooth eruption were positively associated with bone loss, and those statistically significant local factors were present in 42.4% of the sites with bone loss. Conclusion: The prevalence of radiographic bone alterations in primary molars was 13.28%. The CEJ-BC distance and bone loss were positively associated with local factors (58.8% of the cases); however, 41.2% of the sites positive for bone loss did not present the local factors evaluated in this study. Clinical Relevance: Scientific rationale for this study: Bone loss can be present in children and adolescents, and radiographic evaluation could help to elucidate its prevalence and the factors associated with its occurrence. Principal findings: A prevalence of 13.28% bone loss was found at the patient level in primary molars in a Brazilian population, and local factors were positively associated with bone alterations. Despite some cases diagnosed with bone loss being related to local factors, 41.2% had no association with the local risk factors evaluated in the study. Practical implications: The findings regarding bone loss prevalence in primary dentition highlight the importance of careful radiographic examination in children and adolescents as an initial tool to diagnose periodontitis at early stages and to prevent severe damage. Plain Language Summary: This study analyzed x-rays of Brazilian children to assess bone loss in primary molars. It aimed to determine how common bone loss is and to identify local factors linked to the associated bone loss. Researchers reviewed 828 x-rays from 527 children (average age 8.27 years) who visited Piracicaba Dental School between 2014 and 2020. Bone loss was identified when the distance between the cementoenamel junction and bone crest (CEJ-BC) was greater than 2 mm. The results showed an average CEJ-BC distance of 1.12 mm, with 85 areas showing bone loss. The bone loss prevalence was 2.62% per site and 13.28% per patient. Factors linked to higher bone loss included being male, older age, having teeth in the maxilla, first primary molars, and specific local factors. Procedures such as pulpectomies, fillings, and nearby tooth eruptions were associated with bone loss; however, 41.2% of cases identified with bone loss did not present the local factors evaluated in the study. The study concluded that 13.28% of children showed bone changes in their primary molars, with bone loss linked to local factors and other conditions.