Multifactorial analysis of factors influencing premolar mobility in stage III/IV grade C periodontitis patients ≤35 years of age: A cross-sectional study

Abstract

Background: Previous studies has revealed a potential association between crown-root ratio and root morphology in patients with mild chronic periodontitis, suggesting a possible link to tooth mobility. However, further comprehensive analytical investigations were not pursued. Our previous study observed that 76% of aggressive periodontitis patients exhibit abnormal root morphology, especially in premolars, associated with severe alveolar bone loss and mobility, leading to poor clinical outcomes. This study aims to investigate the specific correlations between factors such as alveolar bone resorption, root morphology, crown-root ratio, and periodontal clinical indicators with tooth mobility of premolars in stage III/IV grade C periodontitis patients ≤35 years of age. Materials and methods: A total of 1064 premolars from 151 stage III/IV grade C periodontitis patients ≤35 years of age were recruited. Clinical periodontal parameters and radiographic parameters were recorded. Logistic regression analysis was employed to investigate the relationships between these indicators and tooth mobility. Results: The difference in the length of the premolar roots wassignificant, ranging from 6.80 mm-20.96 mm. Teeth with shorter roots (mean root length of 10.22 mm) exhibitedgrade I mobility with only 28% alveolar bone resorption, while the percentages ofmedium-length roots (mean root length of 12.67 mm) and longer roots(average of 14.91 mm) exhibiting alveolar bone resorptionwere 34% and 37%, respectively. In terms of classifying the degree of mobility, multiple regression models incorporating the crown-root ratio at the bone level, average probing depth and root length demonstrated optimal performance (P<0.001, AIC=1700.574). Conclusion: Premolar mobility is associated with variations in root length, alveolar bone resorption, and probing depth. The crown-root ratio at the bone level can effectively serve as a predictor for assessing tooth mobility when there are discrepancies in root length and extent of alveolar bone resorption.