title: Relationship between pain and effusion on magnetic resonance imaging in temporomandibular disorder patients.
abstract: OBJECTIVE
  This study was performed to find the relationship between pain and joint effusion using magnetic resonance imaging (MRI) in temporomandibular disorder (TMD) patients.
  
  
  METHODS
  The study subjects included 232 TMD patients. The inclusion criteria in this study were the presence of spontaneous pain or provoked pain on one or both temporomandibular joints (TMJs). The provoked pain was divided into three groups: pain on palpation (G1), pain on mouth opening (G2), and pain on mastication (G3). MRI examinations were performed using a 1.5-T MRI scanner. T1- and T2-weighted images with para-sagittal and para-coronal images were obtained. According to the T2-weighted image findings, the cases of effusions were divided into four groups: normal, mild (E1), moderate (E2), and marked effusion (E3). A statistical analysis was carried out using the χ(2) test with SPSS (version 12.0, SPSS Inc., Chicago, IL, USA).
  
  
  RESULTS
  Spontaneous pain, provoked pain, and both spontaneous and provoked pain were significantly related to joint effusion in TMD patients (p<0.05). However, among the various types of provoked pain, pain on palpation of the masticatory muscles and TMJ (G1) was not related to joint effusion in TMD patients (p>0.05).
  
  
  CONCLUSIONS
  Spontaneous pain was related to the MRI findings of joint effusion; however, among the various types of provoked pain, pain on palpation of the masticatory muscles and TMJ was not related to the MRI findings of joint effusion. These results suggest that joint effusion has a significant influence on the prediction of TMJ pain.
authors.affiliation: Department of Oral and Maxillofacial Radiology, School of Dentistry and Institute of Oral Bioscience, Chonbuk National University, Jeonju, Korea.
authors.forename: Ha-Na
authors.initials: HN
authors.lastname: Park
authors.affiliation: Department of Oral and Maxillofacial Radiology, School of Dentistry and Institute of Oral Bioscience, Chonbuk National University, Jeonju, Korea.
authors.forename: Kyoung-A
authors.initials: KA
authors.lastname: Kim
authors.affiliation: Department of Oral and Maxillofacial Radiology, School of Dentistry and Institute of Oral Bioscience, Chonbuk National University, Jeonju, Korea.
authors.forename: Kwang-Joon
authors.initials: KJ
authors.lastname: Koh
keywords: Effusion; Magnetic Resonance Imaging; Pain; Temporomandibular Joint