This paper describes a new method to create an animal model for TMJ internal derangement in the New Zealand white rabbits and the light and electron microscopical changes of posterior attachment of them. Twenty six rabbits(2.5-3.0kg), four normal
and
twenty two experimental, were used. The right disc of experimental animal was displaced anteriorly without sectioning the posterior attachment and tied to the zygomatic arch with nylon not to be reduced to the original position. The left TMJ was
sham-operated to be compared with its right experimental one. Normal animals were sacrificed one day and eight weeks after experiment. Experimental animals were sacrificed one day, ten days, three weeks, five weeks and eight weeks after surgery
respectively. They were fixed intravenously with 2% glutaldehyde under general anesthesia and the samples of them were processed for light and electron microscopic examination.
The purpose of this experiment is to make a suitable animal model of disc displacement without reduction for studying and understaning the cellular and morphologic events in posterior attachment of TMJ including early changes which were
difficulat
to be
observed in human TMJs.
@ES The results of this investigation suggest the following conclusions :
@EN 1. Authors induced anterior disc displacement surgically in rabbits with new method to examine histologic changes of posterior attahment. Tissue reactions of this model seem to be similar to those observed in human disc displacement. We think
this
animal model for anterior disc displacement may be used to explore and evaluate objectively the effects of many treatent modalities in disc displacements.
2. The animal disease model showed inflammation at early stage(one and ten days). At this stage there were mold-to-severe mononuclear inflammatory cell infiltration, numerous newly formed vessels, vessel dilatation and engormement and many
fibroblasts.
3. At middle stage(three weeks), fibrosis occurred, where fibroblasts decreased in number, but their cytoplasm was profuse indicating high activity. Collagen fibers increased in number and the tissue looked more dense.
4. At late stage(five weeks and eight weeks) showed degenerative changes including perforation of posterior attachment, disintegration of collagen fiber bundles, degeneration of fibroblasts, metastatic ossification and dystrophic calcification.
KOREA J. ORTHOD 1993 ; 23(4) : 503-527.
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