Open AccessDifferent Brain Responses to Pain and Its Expectation in the Dental Chair
Author(s) -
Adam Raček,
XiaoSu Hu,
Thiago D. Nascimento,
Moritz Bender,
Leen Khatib,
Daniel J. Chiego,
G. Holland,
Patricia Bauer,
Neville J. McDonald,
Roger P Ellwood,
Alexandre F. DaSilva
Publication year - 2015
Publication title -
journal of dental research
Language(s) - English
Resource type - Journals
eISSN - 1544-0591
pISSN - 0022-0345
DOI - 10.1177/0022034515581642
Subject(s) - somatosensory system , stimulation , prefrontal cortex , haemodynamic response , secondary somatosensory cortex , medicine , stimulus (psychology) , sensory system , perception , hemodynamics , psychology , audiology , cognition , neuroscience , anesthesia , heart rate , blood pressure , psychotherapist
A dental appointment commonly prompts fear of a painful experience, yet we have never fully understood how our brains react to the expectation of imminent tooth pain once in a dental chair. In our study, 21 patients with hypersensitive teeth were tested using nonpainful and painful stimuli in a clinical setting. Subjects were tested in a dental chair using functional near-infrared spectroscopy to measure cortical activity during a stepwise cold stimulation of a hypersensitive tooth, as well as nonpainful control stimulation on the same tooth. Patients' sensory-discriminative and emotional-cognitive cortical regions were studied through the transition of a neutral to a painful stimulation. In the putative somatosensory cortex contralateral to the stimulus, 2 well-defined hemodynamic peaks were detected in the homuncular orofacial region: the first peak during the nonpainful phase and a second peak after the pain threshold was reached. Moreover, in the upper-left and lower-right prefrontal cortices, there was a significant active hemodynamic response in only the first phase, before the pain. Subsequently, the same prefrontal cortical areas deactivated after a painful experience had been reached. Our study indicates for the first time that pain perception and expectation elicit different hemodynamic cortical responses in a dental clinical setting.