Abstract
Background
To examine the regional alterations of mandibular trabecular bone microarchitecture in RA patients using the analysis of panoramic radiographs based on the fractal dimension (FD)' and to assess the effect of the duration of glucocorticoid (GC) treatment․ METHODS: In this retrospective study' 96 RA patients and 96 controls were recruited․ The FD of four standardized regions of interest (ROIs) was measured using ImageJ: the condyle' the mandibular angle' the two trabecular areas of the corpus (including the area anterior to the mental foramen)․ Group comparisons were performed using non-parametric tests and multivariable logistic regression' adjusted for age and sex․ A subgroup analysis based on age (≥ 40 years' respectively) was used to rule out residual confounding by age․ RESULTS: FD was considerably lower in the RA group compared to the control group in all regions of interest (p 0․05) with GC duration of use․ CONCLUSION: RA is associated with site-specific deterioration of mandibular trabecular microarchitecture' particularly in the condylar region and the trabecular region anterior to the mental foramen․ FD analysis of panoramic radiographs may be a useful imaging biomarker for detecting skeletal involvement in the RA population․.