The purpose of this study was to investigate the effects of stress on prefrontal cortex (PFC), emotion (using visual analogue scale, VAS, and State-Trait Anxiety Inventory, STAI), and the autonomic nervous system (ANS). Two types of stress were applied: (1) malocclusion-induced physical stress and (2) mental stress induced by an arithmetic task. Malocclusion was induced using an experimentally deviated mandibular device (EDMD) to obtain an experimentally deviated mandibular position (EDMP). A total of 11 healthy volunteers participated in the study. On day 1 they performed a pretrial arithmetic task followed by a 10-min rest, after which they performed a posttrial EDMD + arithmetic task or rest device + arithmetic task. These two tasks were selected at random and assigned at the rate of one per day. Activity in the PFC tended to show an increase in the pretrial arithmetic tasks and rest device + arithmetic task, but a decrease in the EDMD + arithmetic task compared with the rest device + arithmetic task. Heart rate significantly increased during the rest device + arithmetic task, whereas no significant difference was observed during the EDMD + arithmetic task. The EDMD + arithmetic task significantly increased STAI scores (p = 0.0047), and the significant decrease in VAS indicated “unpleasant” (p = 0.035). These findings suggest that EDMP-induced reduction in the level of PFC activity was a response to discomfort, indicating that EDMP affects systemic function such as that of the ANS as an unpleasant stressor.
This is a preview of subscription content, log in to check access.
The authors would like to thank Associate Professor Jeremy Williams, Tokyo Dental College, for his assistance with the English of the manuscript. This research was partly supported by the Japan Science and Technology Agency under the Strategic Promotion of Innovative Research and Development Program and a Grant-in-Aid from the Ministry of Education, Culture, Sports, Sciences and Technology of Japan (B23300247).
Iwayama K, Ono Y, Komasa Y (2007) Influence of occlusal interference on the autonomic nervous system. Shika Igaku 70:81–90Google Scholar
Kubo KY, Yamada Y, Iinuma M, Iwaku F, Tamura Y, Watanabe K, Nakamura H, Onozuka M (2007) Occlusal disharmony induces spatial memory impairment and hippocampal neuron degeneration via stress in SAMP8 mice. Neurosci Lett 414:188–191CrossRefGoogle Scholar
Lind L, Johansson K, Hall J (2002) The effects of mental stress and the cold pressure test on flow-mediated vasodilation. Blood Press 11:22–27CrossRefGoogle Scholar
Liu X, Iwanaga K, Koda S (2011) Circulatory and central nervous system responses to different types of mental stress. Ind Health 49:265–273CrossRefGoogle Scholar
Muneta Y, Yoshikawa T, Minagawa Y, Shibahara T, Maeda R, Omata Y (2010) Salivary IgA as a useful non-invasive marker for restraint stress in pigs. J Vet Med Sci 72:1295–1300CrossRefGoogle Scholar
Otsuka T, Watanabe K, Hirano Y, Kubo K, Miyake S, Sato S, Sasaguri K (2009) Effects of andibular deviation on brain activation during clenching: an fMRI preliminary study. Cranio 27:88–93CrossRefGoogle Scholar
Takayama K (1993) Study on the relation between stomatognathic system and the systemic condition-influence of load time at change of mandibular position on upright posture. J Jpn Prosthodont Soc 37:582–596CrossRefGoogle Scholar
Tan Z, Nagata S (2002) Superimposed cold stress-induced hypothalamic-pituitary-adrenal response during long-duration restraint stress. J UOEH 24:361–373CrossRefGoogle Scholar
Tanida M, Katsuyama M, Sakatani K (2007) Relation between mental stress-induced prefrontal cortex activity and skin conditions: a near-infrared spectroscopy study. Brain Res 1184:210–216CrossRefGoogle Scholar
Tanida M, Sakatani K, Takano R, Tagai K (2004) Relation between asymmetry of prefrontal cortex activities and the autonomic nervous system during a mental arithmetic task: near infrared spectroscopy study. Neurosci Lett 369:69–74CrossRefGoogle Scholar
Wang J, Rao H, Wetmore GS, Furlan PM, Korczykowski M, Dinges DF, Detre JA (2005) Perfusion functional MRI reveals cerebral blood flow pattern under psychological stress. Proc Natl Acad Sci U S A 102:17804–17809CrossRefGoogle Scholar
Yoshihara T, Taneichi R, Yawaka Y (2009) Occlusal disharmony increases stress response in rats. Neurosci Lett 452:181–184CrossRefGoogle Scholar