What are the tests for lockjaw?

Tetanus or TMJ? The diagnosis is made by history and physical examination. No specific lab test is available to diagnose tetanus. For TMJ lockjaw history past and present, physical examination, review of systems, neurologic exam, musculoskeletal exam and imaging.
Good Clinical Exam. A thorough evaluation including a history of the symptoms, clinical examination, and any additional diagnostic tests are needed. Depending on the clinical findings, a panoramic radiograph allowing visualization of the temporomandibular joints would be the first diagnostic test ordered. A MRI may also be indicated in some cases to help diagnose the problem.