Correlation of Bone Mineral Density and Fractal Analysis of the Mandibular Condyle in Women with Temporomandibular Joint Osteoarthritis: A Pilot Study

Temporomandibular joint osteoarthritis (TMJOA) appears to be more common in osteoporotic patients. Fractal analysis is a mathematical method that can be used to assess trabecular bone. The aim of this study was to assess the correlation of bone mineral density (BMD) and fractal dimension (FD) of the condyles in women with TMJOA using cone-beam computed tomography (CBCT).  

In this cross-sectional study, the FD and lacunarity of the condylar head were assessed on CBCT images of 39 women (20 healthy women with no signs/symptoms of TMJOA, and 19 TMJOA patients). The BMD and the T-score of the hip and lumbar vertebrae were determined using dual energy X-ray absorptiometry. Data were analyzed by t-test, chi-square test, and Pearson’s correlation coefficient.

TMJOA patients and healthy controls did not differ significantly in terms of the mean age (P=0.63), BMD and T-score (P>0.05), or FD and lacunarity (P>0.05). A significant correlation was observed, however, between lacunarity in the two condyles (r=0.47, P=0.003) and BMD of the lumbar vertebrae and the hip (r=0.40, P=0.01). 
 Conclusion

The mean BMD of total spine and hip did not differ significantly in the two groups of healthy controls and TMJOA patients. The FD and lacunarity also       showed no significant difference between the groups. FD based on CBCT images of the TMJ is not a reliable indicator for categorization of skeletal status.