Department of Diagnostic and Biological Sciences, University of Minnesota School of Dentistry, Minneapolis, Minnesota, United States of America.
Division of Biostatistics, University of Minnesota School of Public Health, Minneapolis, Minnesota, United States of America.
PLoS One. 2022 Oct 14;17(10):e0266349. doi: 10.1371/journal.pone.0266349. eCollection 2022.
High-impact temporomandibular disorder (TMD) pain may involve brain mechanisms related to maladaptive central pain modulation. We investigated brain responses to stimulation of trigeminal sites not typically associated with TMD pain by applying noxious dentoalveolar pressure to high- and low-impact TMD pain cases and pain-free controls during functional magnetic resonance imaging (fMRI). Fifty female participants were recruited and assigned to one of three groups based on the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and Graded Chronic Pain Scale: controls (n = 17), low-impact (n = 17) and high-impact TMD (n = 16). Multimodal whole-brain MRI was acquired following the Human Connectome Project Lifespan protocol, including stimulus-evoked fMRI scans during which painful dentoalveolar pressure was applied to the buccal gingiva of participants. Group analyses were performed using non-parametric permutation tests for parcellated cortical and subcortical neuroimaging data. There were no significant between-group differences for brain activations/deactivations evoked by the noxious dentoalveolar pressure. For individual group mean activations/deactivations, a gradient in the number of parcels surviving thresholding was found according to the TMD pain grade, with the highest number seen in the high-impact group. Among the brain regions activated in chronic TMD pain groups were those previously implicated in sensory-discriminative and motivational-affective pain processing. These results suggest that dentoalveolar pressure pain evokes abnormal brain responses to sensory processing of noxious stimuli in high-impact TMD pain participants, which supports the presence of maladaptive brain plasticity in chronic TMD pain.
高影响力的颞下颌关节紊乱（TMD）疼痛可能涉及与适应性中枢疼痛调节相关的大脑机制。我们通过在功能磁共振成像（fMRI）期间向高影响力和低影响力 TMD 疼痛病例和无疼痛对照施加有害的牙牙槽压力，研究了对通常与 TMD 疼痛无关的三叉神经部位刺激的大脑反应。招募了 50 名女性参与者，并根据颞下颌关节紊乱诊断标准（DC/TMD）和分级慢性疼痛量表将其分配到三个组之一：对照组（n = 17），低影响力组（n = 17）和高影响力 TMD 组（n = 16）。在人类连接组计划生命周期协议之后，采集了多模态全脑 MRI，包括在刺激诱发 fMRI 扫描期间向参与者的颊牙龈施加疼痛的牙牙槽压力。使用针对分割皮质和皮质下神经影像学数据的非参数置换检验进行组分析。有害的牙牙槽压力引起的大脑激活/失活在组间没有显着差异。对于个体组平均激活/失活，根据 TMD 疼痛等级发现了幸存阈值的包裹数量的梯度，在高影响力组中观察到的数量最高。在慢性 TMD 疼痛组中激活的大脑区域包括以前涉及感觉辨别和动机情感疼痛处理的那些。这些结果表明，牙牙槽压力疼痛在高影响力 TMD 疼痛参与者中引起了对有害刺激的感觉处理的异常大脑反应，这支持慢性 TMD 疼痛中存在适应性大脑可塑性。
