OBJECTIVETo study the influence of emotional stress on the ultrastructures of temporomandibular joint in rats.

METHODSSixteen male Wistar rats, aged 12 weeks, were divided into 2 groups randomly, experimental group and control group. Animal model of chronic unpredictable stress was established in the experimental group. After 6 weeks, all rats in both groups were killed and their condyles and articular discs were dissected, taken out and observed by scanning electron microscope.

RESULTSUnder scanning electron microscope, the surface gelatum of the condyles in experimental group were cracked, and collagen fibrils in disorder and broke, and deep layer collagen fibrils were exposed. The articular discs' surface gelatum were still integrated, but the gyri dispose were irregular. In control group, there were no such changes in condyles and articular discs.

CONCLUSIONSThe long-term emotional chronic unpredictable stress could induce the injuries of temporomandibular joint in rats in ultrastructure level.