Fractal Dimensions Analysis of Mandibular Cortical Thickness in Rheumatoid Arthritis Patients – A CBCT Study

Abstract

Introduction

The fractal analysis involves examining the fractal properties of data and utilizes mathematical techniques to measure the complexity inherent in the geometric patterns of various objects. Rheumatoid arthritis (RA) is a chronic autoimmune condition that primarily impacts the joints but can also affect various other bodily systems, including the jaw. Individuals with RA are at an elevated risk for developing secondary osteoporosis due to both the disease itself and the treatments used. In mandibular bone, RA can cause a decrease in bone density, changes in the trabecular structures, and thinning of the cortical bone. Assessing bone structure and morphology, fractal dimensions analysis can provide additional information about the complexity of the bone structure, which can be useful in diagnosing and monitoring bone diseases, various counting algorithms in fractal analysis, including the box-counting method, are employed to examine trabecular patterns.

Materials And Methods

A single-centered prospective imaging study. 50 (25 Rheumatoid arthritis and 25 healthy patients). The patient is diagnosed with rheumatoid arthritis. Age group 30-70. CBCT images were obtained by using CS 9300 select (Carestream) with 85kv, 4.0mA, and 8.01s. The regions of interest (ROI) for CBCT imaging were selected in the mandibular region, specifically before the mental foramen, typically targeting the apical areas of teeth 33 and 43. The images were subsequently transferred to the FIJI (ImageJ) version 1.51 software (National Institutes of Health, Bethesda, MD; available at https://imagej.nih.gov/ij/download.html) for the calculation of fractal dimensions (FDs). SPSS 20.0 (SPSS, Chicago, IL) was used to perform all statistical analyses. This statistical test was chosen to compare the FD values between two groups: healthy individuals and patients with rheumatoid arthritis (RA). The Independent Samples t-test is used to compare the means of two separate groups to determine if there is a statistically significant difference between them. A comparison of variables within the group (left side/right side) was done using a paired t-test. Significance was defined as p≤0.05.

Results

The results demonstrated that RA patients had lower fractal dimension (FD) values than healthy individuals, indicating reduced bone complexity in RA patients. The fractal dimension values of the trabecular bone structure corroborate the hypothesis of the study, that there is a significantly differences in trabecular bone complexity in female RA patients than the healthy females.

Conclusion

The study's findings indicate that fractal dimension (FD) analysis of CBCT images can detect osteoporosis-related reductions in mandibular cortical thickness in patients with rheumatoid arthritis (RA). Further research is needed to validate the use of fractal analysis in clinical practice and to explore the potential clinical implications of this technique for the early detection and management of Rheumatoid arthritis diseases.