Association between condylar morphology and changes in bony microstructure and sub-synovial inflammation in experimental temporomandibular joint arthritis.
BACKGROUND
In juvenile idiopathic arthritis involvement of the temporomandibular joints (TMJs) is often associated with mandibular growth deviations. The relation between the growth deviations and severity of the inflammation, condylar shape, the micro-architecture, and the quality of the bone has not previously been investigated. This paper studies the effect on the bony structures in mandibular condylar development in rabbits with antigen-induced arthritis.


METHODS
Included were 42 juvenile rabbits with ovalbumin-induced arthritis of the TMJs treated with intraarticular saline, intraarticular etanercept or subcutaneous etanercept. A TMJ from each animal was scanned using micro-computed tomography and structural parameters were calculated. Three-dimensional reconstructions of the mandibular condyle were scored blindly as normal or abnormal. TMJs were stratified for condylar morphology and were evaluated against data on trabecular structural parameters, inflammation, degree of mineralization, overall mandibular growth, and mineral apposition rate.


RESULTS
Abnormal morphology were seen in 15/32 animals available for data analysis. Erosions were an uncommon finding. Abnormal morphology was strongly related to the degree of inflammation. The trabecular separation was larger in group with abnormal morphology than in the group with normal morphology. Abnormal condylar morphology was not associated with overall mandibular growth. No differences were observed in mineral apposition rate. No differences in structural parameters were seen according to treatment modality.


CONCLUSIONS
We showed that severe inflammation in the TMJs during mandibular development was associated with morphological changes in the mandibular condyle. These changes were predominantly seen at the macro-morphological level and only very few differences were structural.
Kristensen
Kasper D
KD
Department of Orthodontics, Faculty of Health Sciences, University of Aarhus, Vennelyst Boulevard 9, DK-8000 Aarhus C, Denmark. kdahl@odont.au.dk
Hauge
Ellen-M
EM
Dalstra
Michel
M
Stoustrup
Peter
P
Küseler
Annelise
A
Pedersen
Thomas K
TK
Herlin
Troels
T
D000818:Animals; D001169:Arthritis, Experimental / Q000276:immunology / Q000473:pathology*; D001171:Arthritis, Juvenile / Q000276:immunology / Q000473:pathology*; D015519:Bone Density / Q000276:immunology; D005260:Female; D008335:Mandibular Condyle / Q000254:growth & development / Q000473:pathology*; D016555:Matched-Pair Analysis; D011817:Rabbits; D013705:Temporomandibular Joint Disorders / Q000276:immunology / Q000473:pathology*; D055114:X-Ray Microtomography