The causes of pain symptoms in the temporomandibular joint (TMJ) and masticatory muscle (MM) regions may not be determined by clinical examination alone. In this review, we document that pain symptoms of the TMJ and MM regions in patients with temporomandibular disorders (TMDs) are associated with computed tomography and magnetic resonance (MR) findings of internal derangement, joint effusion, osteoarthritis, and bone marrow edema. However, it is emphasized that these imaging findings must not be regarded as the unique and dominant factors in defining TMJ pain. High signal intensity and prominent enhancement of the posterior disk attachment on fat saturation T2-weighted imaging and dynamic MR imaging with contrast material are closely correlated with the severity of TMJ pain. Magnetic transfer contrast, MR spectroscopy, diffusion tensor imaging, and ultrasonography findings have helped identify intramuscular edema and contracture as one of the causes of MM pain and fatigue. Recently, changes in brain as detected by functional MR neuroimaging have been associated with changes in the TMJ and MM regions. The thalamus, the primary somatosensory cortex, the insula, and the anterior and mid-cinglate cortices are most frequently associated with TMD pain.
Temporomandibular disorders; Joint pain; Masticatory muscle pain; Diagnostic imaging; Magnetic resonance imaging; Cone beam computed tomography
Citation: Shigeaki Suenaga, Kunihiro Nagayama, Taisuke Nagasawa, Hiroko Indo, Hideyuki J. Majima The Usefulness Of Diagnostic Imaging For The Assessment Of Pain Symptoms In Temporomandibular Disorders http://dx.doi.org/10.1016/j.jdsr.2016.04.004
Received: 25 May 2015, Revised: 14 April 2016, Accepted: 26 April 2016, Available online: 5 September 2016
Copyright: © 2016 The Authors. Published by Elsevier Ltd on behalf of Japanese Association for Dental Science.
This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
A rating of the usefulness of each imaging modality related to TMJ pain, MM pain and fatigue is summarized in Table 1. This paper reviews the relationship between pain symptoms in the TMJ and MM regions and MR imaging findings for ID, joint effusion, and bone marrow edema. Nonetheless, several reports have denied the relationship between pain symptoms and imaging findings for several different conditions. Fat-saturated T2-weighted and dynamic fat-suppressed MR imaging with contrast material methods have provided a better understanding of the sources of TMJ pain, but not masticatory muscle pain. These imaging techniques are able to detect the presence of synovial inflammatory process in the TMJ, and high signal intensity and strong contrast enhancement of the posterior disk attachment are closely related to the severity of TMJ pain. MM pain is associated with MM pathological changes such as edema, fibrosis, and contracture on MTC, MRS, diffusion tensor imaging, and US images. Recently, changes in brain neuroimaging have been investigated in an attempt to identify the causes of pain symptoms. The thalamus, the primary somatosensory cortex, the insula, and the anterior and mid-cingulate cortices are most frequently associated with TMD pain. In the future, the development of alternative imaging techniques is expected to better diagnose the bony and soft-tissue abnormalities in the TMJ and MM regions.
Conflict of interest statement
The authors declare no conflicts of interest.
We would like to thank our colleagues at the Departments of Oral and Maxillofacial Radiology (Dr. Yoshihiro Kawabata and Dr. Kazunori Kawano), Maxillofacial Diagnostic and Surgical Sciences, Oral and Maxillofacial Surgery, and Orthodontics and Dentofacial Orthopedics.