Histochemical study of the elastic fibers in pathologic human temporomandibular joint discs.
OBJECTIVE
This study investigated histochemically the elastic fibers in human temporomandibular joint (TMJ) discs with varying degrees of tissue degeneration/regeneration to determine whether there are differences that correlate with the histologic findings.


METHODS
Ten diseased human TMJ discs and 2 control specimens were studied histochemically by staining with Weigert's resorcin-fuchsin after oxidation with peracetic acid. This technique selectively stains elastic, elaunin, (pre-elastic), and oxytalan fibers.


RESULTS
In TMJ discs with an abnormal collagen fiber arrangement, an increased number of oxytalan fibers could be observed, contrary to discs with scar-like tissue transformation in which oxytalan fibers were decreased in number. In discs showing tears and clefts, the oxytalan fibers run perpendicular to the defects, whereas elaunin and elastic fibers were mainly circumferentially arranged. In discs with chondroid metaplasia, elastic, elaunin, and oxytalan fibers were extensively detected.


CONCLUSIONS
It is hypothesized that the elastic, elaunin, and oxytalan fibers found in severely damaged discs appear to ensure biomechanical compliance by reinforcing regions devoid of collagen bundles and thus function as shock absorbers of stretch and compression.
Leonardi
R
R
Cattedra di Ortognatodonzia, Universitá di Catania, Catania, Italy. rleonard@mbox.unict.it
Villari
L
L
Bernasconi
G
G
Caltabiano
M
M
D000328:Adult; D003094:Collagen; D003285:Contractile Proteins; D004547:Elastic Tissue / Q000737:chemistry / Q000473:pathology; D004549:Elastin; D016326:Extracellular Matrix Proteins; D005260:Female; D006651:Histocytochemistry; D006801:Humans; D008297:Male; D020894:Microfibrils / Q000473:pathology; D008875:Middle Aged; D018485:Muscle Fibers, Skeletal / Q000473:pathology*; D019224:Temporomandibular Joint Disc / Q000473:pathology*; D013705:Temporomandibular Joint Disorders / Q000473:pathology*
D003285:Contractile Proteins; D016326:Extracellular Matrix Proteins; C049028:elaunin; C437744:oxytalan; D003094:Collagen; D004549:Elastin