Characteristic Magnetic Resonance Imaging Findings in Rheumatoid Arthritis of the Temporomandibular Joint: Focus on Abnormal Bone Marrow Signal of the Mandibular Condyle, Pannus, and Lymph Node Swelling in the Parotid Glands.
OBJECTIVE
The purpose of this study was to determine the characteristic magnetic resonance imaging (MRI) findings indicating bone and soft tissue involvement in patients with rheumatoid arthritis (RA) of the temporomandibular joints (TMJs).


METHODS
Twenty-one patients with RA and TMJ pain who underwent MRI examination of the TMJs at the authors' hospital from August 2006 to December 2014 were included in this study. Twenty-two patients with normal TMJs who underwent MRI examination at the authors' hospital from November to December 2014 were included as controls. MRI findings were compared between the 2 groups.


RESULTS
MRI findings of RA in the TMJ included 1) abnormal disc position (95.2%), 2) abnormal disc morphology (83.3%), 3) joint effusion (30.9%), 4) osseous changes in the mandibular condyle (83.3%), 5) synovial proliferation (pannus; 85.7%), 6) erosion of the articular eminence and glenoid fossa (9.52%), 7) deformity of the articular eminence and glenoid fossa (16.6%), 8) abnormal bone marrow signal in the mandibular condyle (83.3%), and 9) swelling of lymph nodes in the parotid glands (78.5%). The abnormal bone marrow signal and pannus in the mandibular condyle and lymph node swelling in the parotid glands were markedly more common in patients with RA than in controls.


CONCLUSIONS
MRI findings of RA of the TMJs were characterized by bone and soft tissue involvement, including abnormal bone marrow signal of the mandibular condyle, pannus, and swelling of lymph nodes in the parotid glands. These characteristic MRI findings could be useful in detecting RA in the TMJ in a clinical situation.
Graduate Student, Department of Radiology, Nihon University School of Dentistry at Matsudo, Chiba, Japan. Electronic address: mana13014@g.nihon-u.ac.jp.
Naohisa
N
Hirahara
Professor, Department of Radiology, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
Takashi
T
Kaneda
Graduate Student, Department of Radiology, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
Hirotaka
H
Muraoka
Graduate Student, Department of Radiology, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
Taiga
T
Fukuda
Assistant Professor, Department of Radiology, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
Kotaro
K
Ito
Assistant Professor, Department of Radiology, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
Yusuke
Y
Kawashima
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging* / Q000473:pathology; D001853:Bone Marrow / Q000000981:diagnostic imaging* / Q000473:pathology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008209:Lymphedema / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008335:Mandibular Condyle / Q000000981:diagnostic imaging* / Q000473:pathology; D008875:Middle Aged; D010306:Parotid Gland / Q000000981:diagnostic imaging* / Q000473:pathology; D013705:Temporomandibular Joint Disorders / Q000000981:diagnostic imaging* / Q000473:pathology