Functional Magnetic Resonance Connectivity in Patients With Temporomadibular Joint Disorders

Abstract

Myofascial pain in the masticatory region, generally referred to as headache, is a common temporomandibular disorder (TMD) characterized by the hypersensitive regions of the contracted skeletal muscle fibers. A correct clinical treatment of myofascial pain has the potential to modify the functional activation of cerebral networks associated with pain and unconscious teeth clenching, specifically the pain network (PN) and default mode network (DMN). In this study, research is presented as a case series of five patients with myofascial pain: three were diagnosed with intra- and extra-articular disorders, and two were diagnosed with only extra-articular disorders. All five patients received gnathological therapy consisting of passive splints and biofeedback exercises for tongue–palatal vault coordination. Before and after treatment, patients underwent pain assessments (through measures of visual analog scales and muscular palpation tests), nuclear magnetic resonance of the temporomandibular joint, and functional nuclear magnetic resonance of the brain. In each patient, temporomandibular joint nuclear magnetic resonance results were similar before and after the gnathological treatment. However, the treatment resulted in a considerable reduction in pain for all patients, according to the visual analog scales and the palpation test. Furthermore, functional nuclear magnetic resonance of the brain clearly showed a homogeneous modification in cerebral networks associated with pain (i.e., PN and DMN), in all patients. In conclusion, gnathological therapy consisting of passive aligners and biofeedback exercises improved myofascial pain in all five patients. Most importantly, this study showed that all five patients had a homogeneous functional modification of pain and default mode networks. Using passive splints in combination with jaw exercises may be an effective treatment option for patients with TMD. This research could be a starting point for future investigations and for clinicians who want to approach similar situations.

Assessments of Prevalence of Ponticulus Posticus, Atlas Posterior Arch Deficiency, Sella Turcica Bridging, Maxillary Canine Impaction, and Associations Among Them in 500 CBCTs of Italian Orthodontic Patients

“…Written informed consent was obtained from patients for publication of this report and any accompanying images. The sample included 500 Italian patients (age range: 6-87 years; average age: 27.08 ± 15.12 years) who presented for orthodontic diagnosis and treatment planning (28). This cohort was composed of 202 males (40.4%) and 298 (59.6%) females.…”

Topology of pain networks in patients with temporomandibular disorder and pain-free controls with and without concurrent experimental pain: A pilot study

“…Additional ROIs for the present study were selected for their association with the trigemino-thalamocortical, or CN V-TC, pathway ( 5 , 6 ), periaqueductal grey-rostral ventromedial medulla, or PAG-RVM, pathway ( 5 , 72 – 75 ), lateral and/or medial, or LPS and MPS, pain systems ( 5 , 7 , 8 , 76 ), the default-mode network, or DMN ( 17 – 22 ), or other components of the “pain neuromatrix” ( 5 , 7 , 9 – 11 , 13 – 16 , 77 ). These ROIs are listed in Supplementary Table S1 .…”

“…They are closely associated with other cortical and subcortical networks which primarily subserve affective, cognitive, motivational, and integrative functions, but are jointly activated with the above nociceptive systems and pathways during pain sensation. For example, a corpus of brain areas, originally described as a “pain neuromatrix,” are involved in the nociceptive (posterior insular, middle cingulate, and medial parietal opercular cortices) or perceptual aspects of pain (middle and anterior insular, prefrontal, posterior parietal, supplementary motor, and anterior cingulate cortices, hippocampus, striatum, and cerebellum) ( 5 , 9 – 16 ); however, it should be noted that most of these areas are not specific to pain processing. Additionally, alterations in grey matter volume, neurochemistry, and connectivity within the default-mode network (DMN), which functions in monitoring and processing internal states ( 17 – 22 ), are correlated with pain sensitivity, severity, duration, catastrophizing, and rumination ( 16 , 23 – 26 ).…”

“…For example, a corpus of brain areas, originally described as a “pain neuromatrix,” are involved in the nociceptive (posterior insular, middle cingulate, and medial parietal opercular cortices) or perceptual aspects of pain (middle and anterior insular, prefrontal, posterior parietal, supplementary motor, and anterior cingulate cortices, hippocampus, striatum, and cerebellum) ( 5 , 9 – 16 ); however, it should be noted that most of these areas are not specific to pain processing. Additionally, alterations in grey matter volume, neurochemistry, and connectivity within the default-mode network (DMN), which functions in monitoring and processing internal states ( 17 – 22 ), are correlated with pain sensitivity, severity, duration, catastrophizing, and rumination ( 16 , 23 – 26 ). Finally, several regions which mediate body perception, learning and motivational functions, and pain anticipation, perception, and empathy, are often omitted from even the broadly-defined pain neuromatrix.…”

“…Previous attempts to characterize the connectivity of regions subserving pain perception and its sequelae have generally been limited to the well-defined CN V-TC and PAG-RVM pathways, LPS and MPS, DMN, and several of the miscellaneous or ancillary regions ( 5 , 16 , 26 , 46 – 51 ). Adhering to the definition of the pain neuromatrix suggested by Melzack ( 9 , 52 ), however, which includes all systems jointly activated by pain sensation and associated with perceptual-attentional, cognitive, affective, motivational, and nociceptive functions, little is known about its global topology.…”