Sex-specific associations between grey matter volume and phobic symptoms in dental phobia

The knowledge about brain structure and function in men and women suffering from dental phobia is still limited. We compared grey matter volume (GMV) data from 36 patients suffering from dental phobia and 36 non-phobic controls via voxel-based morphometry. Half of the subjects were male, the other half female. Scores on different dental anxiety and pain questionnaires were correlated with GMV. Relative to controls, the patients had a smaller volume of the dorsomedial and dorsolateral prefrontal cortex (DMPFC/DLPFC). Within the phobic group, personal pain experience during dental treatment was negatively correlated with DLPFC volume. Sex-specific correlations were found for the amygdala and the hippocampus. Whereas in female patients GMV of both structures was positively correlated with self-reported dental anxiety, for male patients experienced dental pain was negatively associated with hippocampus volume. Our findings show that memory as well as anticipation of dental pain is associated with amygdala-hippocampal structure in men and women afflicted by dental phobia.