The effect of hyaluronic acid on experimental temporomandibular joint osteoarthrosis in the sheep.
OBJECTIVE
The purpose of this study was to test the effect of repeated injections of hyaluronic acid (HA) on the sheep model of osteoarthrotic temporomandibular joint (TMJ) disease.


METHODS
Bilateral osteoarthrosis (OA) was induced in the TMJs of six sheep. HA was injected into one joint on 7, 10, 14, 17, and 21 days postoperatively. Normal saline was injected into the contralateral joint. Three sheep were killed at 1 month and 3 at 3 months. The joints were removed and examined macroscopically and histologically. A special scoring system was applied following the modified Mankin's score to evaluate the histologic changes.


RESULTS
The control group showed severe osteoarthrotic changes in the condyle, deviation in form from normal morphology, and marked marrow fibrosis. The HA-treated group showed less deviation from normal condylar morphology. The histologic scores at 1 month were HA 12.6, control 24.2 (P < .001), and at 3 months were HA 6.9, control 18.9 (P < .001). There was a significant difference in osteoarthrotic changes between HA-treated and control TMJs, with the HA-treated TMJs having less severe changes.


CONCLUSIONS
Repeated intraarticular injections of HA into a sheep TMJ with experimentally induced OA minimizes the extent of osteoarthrotic change when compared with the control joint. Thus, HA may have a role in preventing the progression of TMJ OA.
Neo
H
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Oral and Maxillofacial Surgery Unit, The University of Adelaide, South Australia.
Ishimaru
J I
JI
Kurita
K
K
Goss
A N
AN
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D002358:Cartilage, Articular / Q000473:pathology; D004195:Disease Models, Animal; D018450:Disease Progression; D006820:Hyaluronic Acid / Q000008:administration & dosage / Q000627:therapeutic use*; D007270:Injections, Intra-Articular; D008297:Male; D008335:Mandibular Condyle / Q000473:pathology; D010003:Osteoarthritis / Q000188:drug therapy* / Q000473:pathology; D055728:Primary Myelofibrosis / Q000473:pathology; D012756:Sheep; D013701:Temporal Bone / Q000473:pathology; D019224:Temporomandibular Joint Disc / Q000473:pathology; D013705:Temporomandibular Joint Disorders / Q000188:drug therapy* / Q000473:pathology
D000893:Anti-Inflammatory Agents; D006820:Hyaluronic Acid