Concavity of the posterior surface of the temporomandibular condyle: clinical cases and autopsy correlation.
OBJECTIVE
To elucidate the significance of the radiographic finding of a concavity of the posterior surface of the temporomandibular condyle.


METHODS
Three clinical cases with a concavity were followed up clinically and radiographically. A total of 39 temporomandibular joint (TMJ) autopsy specimens were examined by corrected sagittal tomography and seven condyles with a concavity of the posterior surface found. They were analysed microscopically together with three joints with a normal, rounded condyle.


RESULTS
At follow-up tomography, two of the clinical cases revealed no change while the third patient had erosive changes after 7 months. The microscopic findings of the autopsy specimens varied. The articular cartilage in three of the seven joints with a concavity was similar to that in the normal condyles. The outer surface of the articular cartilage was sometimes uneven and the cartilage thickened, with an irregular junction between the articular cartilage and subchondral bone. In three joints the cartilage in the concavity had been replaced by granulation tissue. All seven joints had increased cellular activity in the concavity.


CONCLUSIONS
The radiographic finding of a concavity in the posterior surface of the condyle is not specific. When small and well-defined it is indicative of remodelling and of osteoarthrosis when larger and with a diffuse outline.
Hosoki
H
H
Department of Oral Radiology, University of Tokushima, Japan.
Uemura
S
S
Petersson
A
A
Rohlin
M
M
Akerman
S
S
D000328:Adult; D016723:Bone Remodeling; D005260:Female; D006801:Humans; D008297:Male; D008335:Mandibular Condyle / Q000000981:diagnostic imaging* / Q000473:pathology*; D008875:Middle Aged; D019224:Temporomandibular Joint Disc / Q000000981:diagnostic imaging / Q000473:pathology*; D013705:Temporomandibular Joint Disorders / Q000000981:diagnostic imaging* / Q000628:therapy; D014056:Tomography, X-Ray