White Matter Diffusion Properties in Chronic Temporomandibular Disorders: An Exploratory Analysis

Area of Science:

• Neuroimaging
• White Matter Integrity
• Diffusion Tensor Imaging

Background:

• Chronic temporomandibular disorders (TMDs) are complex conditions affecting facial pain and jaw function.
• Understanding the underlying neurobiological changes in TMDs is crucial for developing targeted treatments.

Purpose of the Study:

• To investigate differences in white matter (WM) diffusion metrics in key brain tracts between women with chronic TMDs and healthy controls.
• To explore associations between diffusion metrics and clinical variables in women with TMDs.

Main Methods:

• A cross-sectional study compared diffusion metrics (fractional anisotropy [FA], mean diffusivity [MD], radial diffusivity [RD], axial diffusivity [AD]) using tractography.
• Diffusion metrics were analyzed in specific WM tracts including the cingulum (CGC, CGH), fornix, internal capsule (ALIC, PLIC), and uncinate fasciculus (UF).
• Associations between diffusion metrics and clinical measures (pain, central sensitization, somatization, depression, orofacial behavior, jaw function, disability) were examined in TMD subjects.

Main Results:

• Significant differences in diffusion metrics were observed between TMD patients and controls, predominantly in the right hemisphere.
• The right cingulum near the cingulate gyrus (CGC) showed lower FA in TMD patients.
• The right uncinate fasciculus (UF) exhibited lower FA and higher MD and RD in TMD patients compared to controls.

Conclusions:

• The uncinate fasciculus (UF) may exhibit microstructural damage in women with chronic TMDs.
• Current findings suggest potential WM alterations in TMDs, but further research is needed to confirm associations with clinical manifestations.