Assessing the causal role of the structural connectome in temporomandibular disorders: A Mendelian randomization study

Objective: We examined the relationships between the structural connectome and temporomandibular disorders (TMDs).

Methods: Bidirectional Mendelian randomization analyses were conducted using Genome-wide association studies data on the structural connectome and TMDs.

Results: Positive associations with TMD risk were found for white matter structural connectivity from the left hemisphere limbic network to putamen, left hemisphere salience_ventral attention network to caudate, right hemisphere visual network to thalamus, and right hemisphere salience_ventral attention network to right hemisphere control network, while negative associations were observed for connectivity from the left hemisphere control and somatomotor networks to pallidum, left hemisphere somatomotor network to right hemisphere dorsal attention network, and right hemisphere somatomotor network to hippocampus (p< 0.05). In TMD patients, connectivity from the Left-hemisphere visual network to putamen was reduced, whereas connectivity from the Left-hemisphere limbic network to left-hemisphere control network was increased (p< 0.05).

Conclusion: Our findings provide insights into the TMD pathogenesis.