This fact is from TMJ Disorders in Oral & Maxillofacial Surgery. It is a commonly tested concept in NEET MDS examinations. Understanding this fact is crucial for answering MCQs correctly.
Internal derangement = disc displacement
With reduction = click on opening
Without reduction = lock = limited opening
Arthrocentesis = simplest surgical treatment lavage
Arthroscopy = minimally invasive diagnostic and therapeutic
Crepitus = osteoarthritis degenerative changes
Condylectomy = ankylosis treatment.