Temporomandibular joint and 3.0 T pseudodynamic magnetic resonance imaging. Part 1: evaluation of condylar and disc dysfunction.
OBJECTIVE
This study describes an improved method for examining and diagnosing temporomandibular joint (TMJ) dynamics by 3.0 T pseudodynamic MRI.


METHODS
Clinical observation and conventional static MRI of volunteers (one without and eight with TMJ arthrosis) were followed by 3.0 T pseudodynamic MRI in positions ranging from the mouth closed to mouth fully opened. Condylar head (Cd), articular disc anterior border (Da) and articular disc posterior border (Dp) were digitized on sagittal images to determine trajectory and velocity patterns.


RESULTS
Patients were divided into three groups based on the presence or absence of dysfunction: Group 1, no dysfunction on the right or left side of the TMJ; Group 2, dysfunction on the right or left side of the TMJ; and Group 3, dysfunction on both the right and left sides of the TMJs. In 75% of patients (12 of 16 joints), pseudodynamic TMJ analysis was useful for determining a functional abnormality. Using a points system based on three trajectory and seven velocity patterns, discs with adhesion and perforation had significantly fewer points than discs with anterior displacement (with and without reduction) and discs with no abnormality (P = 0.019 < 0.05).


CONCLUSIONS
Trajectory and velocity patterns based on 3.0 T pseudodynamic MRI identified the affected side and determined the extent of morbidity in the Cd as well as the Da and Dp. The typical abnormal movement pattern of discs with anterior displacement (with and without reduction) and pathological structural changes of the articular disc (such as adhesion and perforation) could be identified.
Department of Oral and Maxillofacial Radiology, Institute of Health Bioscience (IHBS), The University of Tokushima Graduate School, 18-15 Kuramoto-3-Chome, Tokushima 770-8504, Japan. iwasaki@dent.tokushima-u.as.jp
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Iwasaki
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Kubo
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Harada
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Nishitani
D000328:Adult; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008335:Mandibular Condyle / Q000473:pathology* / Q000503:physiopathology; D010003:Osteoarthritis / Q000473:pathology; D016059:Range of Motion, Articular; D018709:Statistics, Nonparametric; D019224:Temporomandibular Joint Disc / Q000473:pathology* / Q000503:physiopathology; D013705:Temporomandibular Joint Disorders / Q000473:pathology* / Q000503:physiopathology; D055815:Young Adult