Metastasis-induced dislocation of the temporomandibular joint (TMJ) is rare. The present study describes a case of TMJ dislocation caused by metastasis from pancreatic cancer, and discusses this in the context of literature on occlusal abnormality and/or dislocation due to metastasis. In the present case, unilateral TMJ dislocation was suspected when the patient first presented; destructive bone changes were not observed on conventional radiographs, and magnetic resonance imaging (MRI) revealed a tumorous lesion. The present case suggests that healthcare professionals should consider whether a malignant disease is present in cases of occlusal abnormality and/or dislocation of the TMJ, and that, in patients with TMJ dislocation that cannot easily be repositioned, additional imaging examinations, including MRI, should be performed as soon as possible, regardless of whether destructive bone changes are present. Metastasis to the TMJ is typically associated with generalized skeletal metastasis in the final stage of malignancy. Therefore, it is crucial to consider the possibility of cervical spine metastasis in order to decrease the risk of cervical fracture when attempting reduction of a TMJ dislocation, particularly in patients with a history of cancer.
Keywords: metastasis; occlusal abnormality; pancreatic cancer; temporomandibular dislocation; tumor marker.