Diagnosis of occlusal dysesthesia utilizing prefrontal hemodynamic activity with slight occlusal interference.

Clinical diagnosis of occlusal dysesthesia (OD), also referred to as phantom bite syndrome, is currently based on the absence of objective occlusal discrepancy despite the persistent complaint of uncomfortable bite sensation. We previously demonstrated that the subjective feeling of occlusal discomfort generated by artificial occlusal interference can be objectively evaluated using prefrontal hemodynamic activity in young healthy individuals. The aim of this study was to investigate whether dental patients with and without OD show distinct prefrontal activity during grinding behavior with an occlusal interference. Six dental patients with OD (OD group) and eight patients without OD (control group) grinded piled occlusal strips placed between their first molars and reported their perception and discomfort thresholds during continuous monitoring of prefrontal hemodynamic activity with a portable functional near-infrared spectroscopy. Although patients without OD showed the typical hemodynamic pattern of increased oxyhemoglobin and reduced deoxyhemoglobin (HHb) concentration, those with OD showed persistent incremental increases of HHb concentration that began at the loading of occlusal strips on their molars before they executed grinding. The intensities of the task-related HHb activities showed statistically significant differences between OD and control groups, particularly at channel 3, arranged over the left frontal pole cortex. When the discrimination criterion was set using the intensity values of channel 3 from both groups, the overall accuracy of the OD discrimination was 92.9%. Although physiological interpretation has yet to be elucidated, the task-related response of an increase in HHb may be a useful neuronal signature to characterize dental patients with OD.

Detecting mental disorders in dental patients with occlusion-related problems.

Dentists often treat patients who may be suffering from comorbid mental disorders without paying attention to their symptoms. This leads to a delay in starting the treatment of mental disorders and to inappropriate dental treatments for physical symptoms originating from mental disorders. In the present study, the ways in which dentists can easily detect mental disorders in dental patients with occlusion-related problems were examined. Fifty-three patients who visited the Occlusion Clinic of Kanagawa Dental College were interviewed by a psychiatrist and a dentist specialized in psychosomatic medicine. Thirty-five patients (66.0%) were diagnosed as having DSM-IV Axis I disorders. The demographic and psychological factors that correlate with the presence of mental disorders are duration of chief complaint, number of clinics and hospitals visited for the current symptom, total score of the General Health Questionnaire (GHQ), the scores of the anxiety and insomnia and social dysfunction subscales in the GHQ and the scores of the confusion-bewilderment and fatigue-inertia subscales in the Profile of Mood States (POMS). A logistic regression analysis indicated that number of clinics and hospitals visited markedly correlated with cormobidity of a mental disorder. This information may be useful for screening mental disorder patients. Dental patients having comorbid mental disorders should be treated both odontologically and psychologically.