Bilateral traumatic temporomandibular joint luxation in a rat

Bilateral temporomandibular joint (TMJ) luxation was diagnosed postmortem in a female, 6-mo-old CD rat (Rattus norvegicus) after probable head entrapment and subsequent disentanglement from a protective jacket. Clinical antemortem signs included inability to close her mouth, prehend food and drink water, anxiety, and linear skin erosions extending down the right and left commissures of the mouth. Radiography revealed rostral displacement of the mandible with concomitant malocclusion. The combination of clinical signs, acute nature of the presentation, and torn appearance of the protective jacket were strongly indicative of a traumatic etiology. To our knowledge, this is the first reported case of TMJ luxation in a rat.