Histologic changes associated with experimental partial anterior disc displacement in the rabbit temporomandibular joint.
OBJECTIVE
To correlate histologic changes with the stress developed by various disc interferences via a model of partial anterior disc displacement in the rabbit temporomandibular joint (TMJ).


METHODS
Eighteen male New Zealand rabbits were operated on to expose the temporomandibular disc without severing its attachments. A suture was passed around the lateral part of the disc over the condylar attachments and the 2 strands were fixed in the orbital cavity. In 9 rabbits, a resorbable suture was used to secure the disc displacement. In the other 9, a nonresorbable suture was fixed with a nickel-titanium spring to displace and maintain tension on the disc. Three non-operated animals served as controls. The animals were sacrificed at 12 and 24 weeks after surgery, and the TMJs were prepared for undecalcified histology.


RESULTS
In the first group, the disc remained in a normal position, but its morphology was modified and small histologic changes were observed in the cartilage. In the second group, the disc was displaced in various positions corresponding to the strength delivered by the spring.


CONCLUSIONS
Adaptive changes were observed in joints with a slightly displaced disc, while degenerative changes were associated with larger disc displacements. In each experimental joint, histologic changes increased from the medial to lateral parts. This phenomenon was related to the stress gradient induced by axial disc rotation over the condyle. Any disc displacement always resulted in changes in the cartilage.
Berteretche
M V
MV
Department of Prosthodontics, Faculty of Dentistry, Paris University, 7-Denis Diderot, Paris, France. berteret@ccr.jussieu.fr
Foucart
J M
JM
Meunier
A
A
Carpentier
P
P
D020341:Absorbable Implants; D000497:Alloys; D000818:Animals; D002358:Cartilage, Articular / Q000473:pathology; D002452:Cell Count; D019902:Chondrocytes / Q000473:pathology; D003094:Collagen; D004396:Coloring Agents; D004195:Disease Models, Animal; D004204:Joint Dislocations / Q000473:pathology*; D008297:Male; D008335:Mandibular Condyle / Q000473:pathology; D009532:Nickel; D010003:Osteoarthritis / Q000473:pathology; D011817:Rabbits; D012399:Rotation; D013536:Suture Techniques / Q000295:instrumentation; D013537:Sutures; D013583:Synovial Membrane / Q000473:pathology; D013704:Temporomandibular Joint / Q000473:pathology; D019224:Temporomandibular Joint Disc / Q000473:pathology*; D013997:Time Factors; D014025:Titanium
D000497:Alloys; D004396:Coloring Agents; C040654:titanium nickelide; D009532:Nickel; D003094:Collagen; D014025:Titanium