Final answer:
TMJ refers to the temporomandibular joint itself, not the disorder, so the most appropriate term for a disorder of the jaw joint is 'temporomandibular joint disorder' or TMD, not just 'TMJ'.
Step-by-step explanation:
The term "TMJ" stands for temporomandibular joint, which is the articulation between the condyle of the mandible and the mandibular fossa and articular tubercle of the temporal bone of the skull.
However, when referring to disorders of this joint, it is more accurate to use the term temporomandibular joint disorder (often abbreviated as TMD), not just TMJ.
Disorders of the TMJ occur due to various causes such as arthritis, injury, or continuous wear and tear and can result in pain, dislocation, difficulty chewing, headaches, and jaw locking.