The thickness of the roof of the glenoid fossa in the temporomandibular joint: relationship to the MRI findings.
OBJECTIVE
The purpose of this study was to clarify the relationship between the thickness of the roof of the glenoid fossa (RGF) and magnetic resonance imaging (MRI) findings of temporomandibular joint (TMJ) disorders (TMDs).


METHODS
Eighty-seven patients with symptoms and indications of TMD in one or both TMJs were referred for MRI. Cone-beam CT (3DX) was used to measure the thickness of the RGF at its thinnest point. Linear measurements were made three times on the monitor by three separate investigators and the mean values obtained were used for the statistical analyses.


RESULTS
The joints were categorised as normal (70 joints), anterior disc displacement with reduction (ADWR; 53 joints) or anterior disc displacement without reduction (ADWOR; 51 joints). The joint disorders were also categorised into the following subgroups: with osteoarthritis (OA) (21 joints), without OA (153 joints), with disc deformation (33 joints), without disc deformation (141 joints), with joint effusion (JE) (61 joints) and without JE (113 joints). The average minimum thickness of the RGF was 0.85 mm for normal joints, 0.90 mm with ADWR, 0.93 mm with ADWOR, 0.99 mm with OA, 0.87 mm without OA, 0.87 mm with disc deformation and 0.89 mm without disc deformation. There was no significant difference between these figures. There was a significant difference in the thickness of the RGF with (0.97 mm) and without (0.84 mm) JE.


CONCLUSIONS
These results suggest that RGF thickness is influenced by JE, but is unaffected by disc position and configuration.
Matsumoto
K
K
Department of Radiology, Nihon University School of Dentistry, Tokyo, Japan.
Honda
K
K
Sawada
K
K
Tomita
T
T
Araki
M
M
Kakehashi
Y
Y
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000473:pathology; D013582:Synovial Fluid; D013701:Temporal Bone / Q000000981:diagnostic imaging / Q000473:pathology*; D013704:Temporomandibular Joint / Q000473:pathology*; D019224:Temporomandibular Joint Disc / Q000473:pathology; D013705:Temporomandibular Joint Disorders / Q000473:pathology*; D014057:Tomography, X-Ray Computed / Q000379:methods