TMJ: Your jaw joint
TMJ stands for temporomandibular joint — your jaw joint that allows you to speak, chew, and yawn — though it's sometimes also used to refer to TMD, the conditions that affect how this joint functions.
Date published: 10/04/2025
Key takeaways:
TMJ stands for Temporomandibular Joint — your jaw joint that allows you to speak, chew, and yawn, though it’s often also used to describe TMD.
The TMJ moves like a hinge and glide system, with a small cartilage disc that helps your jaw open and close smoothly.
TMD (Temporomandibular Disorders) includes a range of conditions affecting the jaw joint (TMJ) and muscles, often causing pain, stiffness, or clicking.
Common TMD symptoms include jaw pain, popping or clicking sounds, limited jaw movement, and sometimes headaches or earaches.
In joint-related TMD, the disc within the TMJ can slip out of place (disc displacement), causing clicking, locking, or restricted opening — but this is often managed with non-invasive care.
What is TMJ?
TMJ stands for Temporomandibular Joint, which is the hinge-like joint connecting your lower jaw (mandible) to the temporal bone of your skull, located in front of each ear. Simply put, your jaw joint.
This joint is responsible for the movement of your jaw, enabling you to speak, chew, and yawn. The muscles controlling your jaw joints are attached to your lower jaw and allow your jaw to move up and down, side-to-side, and back and forth. Your TMJ works by hinging like a door and then gliding forward along its socket at the base of the skull to get to your maximum mouth opening. A cartilage disc between the base of the skull and the TMJ helps these two movements occur smoothly.
What is TMD?
Sometimes the abbreviation "TMJ" is also used to refer to Temporomandibular Disorders, or TMD. These are a group of conditions that affect the jaw joint and surrounding muscles. They can cause pain, discomfort, difficulty moving the jaw, clicking or popping sounds when moving the jaw, and in some cases, headaches and earaches..
It's important to consult a dental professional if you suspect you may be experiencing TMD. Whilst TMD don’t normally cause ongoing damage and respond well to early simple treatments such as self-management, self or professional physical/physiotherapy, or splints/mouthguards worn over the teeth.
What about joint or disc-related TMD?
Not all TMD is muscle-related — sometimes the disc inside the jaw joint itself can slip out of place or become stuck. This can lead to:
Clicking or popping when opening or closing your mouth
A feeling of the jaw “catching” or locking
Limited opening or a change in the way your teeth meet together if the disc doesn't return to place
This is called disc displacement — and it’s a joint-based form of TMD. In many cases, it can still be managed with non-invasive treatments like heat/ice therapy, gentle exercises, and professional guidance. Only in rare cases is surgery considered as the research shows that most disc based TMD has a really good outlook without surgery.
JawSpace offers tools and education to help you understand each type of TMD and how to manage it safely.
References:
The TMJ Association. "TMJ Basics." The TMJ Association, 2023, https://tmj.org/living-with-tmj/basics/.
National Academies of Sciences, Engineering, and Medicine. Temporomandibular Disorders: Priorities for Research and Care. The National Academies Press, 2020. https://doi.org/10.17226/25652.
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