The influence of the wearing restorations adjustment on blood flow in the prefrontal area

To eliminate discomfort, prosthetic restorations were adjusted based on the subjective assessments of patients. The purpose of this study was to examine, after setting several restorations, the influence of adjusted occlusal interference during gum chewing on blood flow in the prefrontal area using a Spectra tech OEG-16. The psychological rate was assessed using a visual analogue scale (VAS) questionnaire. We selected 16 subjects who desired prosthetic restorative treatment on the lateral dentition. The subjects were divided into 2 groups. For the individuals of one group, restorations, including inlays and full-cast crowns, were placed on one side of either the maxillary or the mandibular premolar area (PA). In the other group, restorations were placed on one side of either the maxillary or the mandibular molar area (MA). The OEG-16 was fastened to the frontal region of the head after the final restoration had been placed but before it had been adjusted. The pre-adjustment blood flow in the prefrontal cortex was measured during gum-chewing. Blood flow was again measured during gum-chewing after the restoration had been adjusted in accordance with the patient´s subjective assessment while wearing the device. The VAS gave a measure of comfort during gum-chewing before and after adjusting the restoration. For both groups, adjusting restorations significantly decreased discomfort during gum-chewing. Moreover, in the MA group, not only was prefrontal blood flow significantly reduced but also blood flow was correlated with discomfort score. Even though, in the P A group, there was no significant difference of blood flow in the prefrontal area between pre-adjustment and after restorations were adjusted. In the present study, we suggest that activation of the prefrontal area provided an objective criterion for judging the comfortability of the occlusion after prosthetic occlusal reconstruction and/or orthodontics.