Psychological stress induces alterations in temporomandibular joint ultrastructure in a rat model of temporomandibular disorder.

OBJECTIVE

The objective of this study was to investigate the effects of psychological stress on temporomandibular disorder (TMD).

STUDY DESIGN

A communication box was used to induce psychological stress (PS) in rats. Then, the ultrastructure of temporomandibular was observed using scanning electron microscopy. Interleukin-1 (IL-1) and IL-6 were measured with reverse transcription polymerase chain reaction.

RESULTS

The PS group showed evidence of ultrastructural changes in the condyle and articular disk after stimulation, i.e., incomplete gelatinlike material was observed on the condyle after 1 week of PS, wider waves on the articular disk and exposed condylar collagen were observed after 3 weeks of PS, and cracks were apparent on the surface of the condyle. The expression of IL-1 and IL-6 in the condyle cartilage significantly increased after exposure to psychological stress.

CONCLUSIONS

These results indicate that psychological stress induces ultrastructure alterations in the temporomandibular joint and plays an important role in TMD.