TMJ Jaw Dislocation / “Open Lock” from Yawning (Case Study #11)

TMJ Jaw Dislocation / “Open Lock” from Yawning (Case Study #11)

A Distressed Patient Who Dislocated Her Jaw After Yawning Widely

Miss T, 28, came to our clinic in a panic. After yawning widely, she had heard a loud ‘crack’ sound coming from her jaw. She could no longer close her mouth or speak coherently, and her jaw was swollen and painful. She was in obvious pain and distress.

After we calmed her down, we carried out the requisite clinical examination and scans, and discovered that she had a TMJ jaw dislocation, where her TMJ (temporomandibular joint) had been displaced out of its socket. This is what is known as a “Luxation of the TMJ”, or “Open Lock”, which is quite the opposite of a “Closed Lock”. (You can read about how we treated another patient with Closed Lock in this case study.) An Open Lock is considerably less common than a Closed Lock, and Miss T’s case was even more unusual, as such a condition is more common in the elderly.

*Disclaimer: The term ‘Orofacial Pain Specialist‘ is made within the context of the USA and not Singapore. Please refer to our Disclaimers page and read our FAQs for more information.

What is TMJ Jaw Dislocation, or Open Lock?

Dislocations can happen to any joint in your body, and are classified into subluxations and luxations. The former is a partial dislocation, whilst the latter is a complete dislocation. Joint dislocations are more common in the knee, elbow, shoulder, hip and finger joints. TMJ jaw dislocations or Open Locks are rare, with about only 3% reported of all joint dislocations in the body (Agbara et al., 2014).

Patients may be able to self-manipulate their jaw back into position if it is a subluxation, but will need help from a trained orofacial specialist in the case of a luxation. Either way, it can be dangerous to attempt manual manipulation on your own, as this can cause even more pain as well as permanent damage.

TMJ jaw dislocation happens when the disk of the TMJ is displaced and the jaw is at a maximal mouth opening position, hence the term, “Open Lock”. The cause is usually due to a neuromuscular issue (Kai et al., 1992) in the orofacial region, or a structural deficit in the TMJ.

Contributing Factors for TMJ Jaw Dislocation

Age is a contributing factor for TMJ jaw dislocation, due to the natural loss of flexibility in ligaments around joints, and/or the degradation of neuromuscular coordination as we age (Pai et al., 2017).

Some antipsychotic medications can also contribute to TMJ jaw dislocation (Steinpreis et al., 1997), due to their interaction with neuromuscular mechanisms.

People with systemic conditions such as Multiple Sclerosis and Parkinson’s Disease may have a higher disposition for TMJ jaw dislocation (Agbara et al., 2014), as well as those with hypermobility disorders (Dijkstra et al., 2002) such as Ehlers Danlos Syndrome, and muscle disorders like Dystonia. More research is needed to ascertain the actual link between TMJ  jaw dislocation and these conditions, however.

Acute vs Chronic TMJ Jaw Dislocation

TMJ jaw dislocation, or TMJ luxation, can be acute or chronic in nature. The causes can be from trauma or whilst undergoing a long dental procedure, or even from simple, mundane things such as laughing, yawning, or taking a large bite of food, where one opens their mouth wide all of a sudden.

Acute TMJ jaw dislocation (Sharma et al., 2015) can be a frightening experience, as the person is unable to close their mouth or talk properly. They may also drool and be unable to control their lips. There is usually pain around the ears and orofacial region as well, and the jaw may be slanted out of position.

There may not be as much pain in chronic TMJ jaw dislocation, but it can be more problematic as long-term management and treatment can be trickier.

Treatments for TMJ Jaw Dislocation / Open Lock

If you suffer from a TMJ jaw dislocation, it is vital that you seek help from a trained orofacial pain specialist or medical professional immediately, as it is considered a dental emergency. The longer you wait, the more difficult it is to manipulate the jaw back into its original position, and increases the chances for complications.

Non-surgical methods are often the first choice for treating TMJ jaw dislocations, especially in acute cases. Whilst there are several types of surgical treatments to treat chronic TMJ jaw dislocation cases, it is better to attempt conservative treatments first (Szkutnik et al., 2018).

As an Open Lock is an extremely rare condition, there are few studies to give a definitive conclusion as to what type of surgery works best, and their long-term effects on the patient. Even with surgery, TMJ jaw dislocation can still recur as well. The small area around the TMJ also contains many intricate muscles, nerves, ligaments, blood vessels, bones and glands, which makes it tricky to operate on. If absolutely necessary, it should be done by a trained orofacial pain specialist with intricate knowledge of the TMJ area.

In the case of Miss T, Dr. Eric at our clinic did a manual manipulation of her lower jaw to return the dislocated joint back into its socket. Appropriate regional and local anaesthetic nerve blocks for pain control and muscle relaxation were administered, before the lower jaw was manually adjusted back into position (i.e. “reduction”). The relief on Miss T’s face was immediate.

Manual manipulation for TMJ jaw dislocation can be difficult to execute, especially in inexperienced hands. In some cases where repeated attempts fail, reduction has to be done under General Anaesthesia.

How Nourish Dental Sleep & TMJ Care Can Help with TMJ Jaw Dislocation, or “Open Lock”

Nourish Dental Sleep & TMJ Care has seen and managed its fair share of TMJ jaw dislocations. Dr. Eric Chionh runs the practice together with a committed team, and has over 20 years of hands-on experience in the treatment of Orofacial Pain and TMD / TMJ Disorders. This includes manual manipulation and surgery for cases such as TMJ jaw dislocation / Open Lock, and also other types of pain and TMJ disorders.

We use the necessary technologies combined with in-depth physical examinations to assess and diagnose our patients. We want our patients to achieve the best possible quality of life, and believe in working together as a team.

Dr. Chionh is formally trained in Oral Medicine and Orofacial Pain, and holds a Singapore Dental Council approved qualification in these areas. You can learn more about Dr. Eric Chionh on our About page, and view all services provided by Nourish Dental Sleep & TMJ Care here.


  • Agbara, R., Fomete, B., Obiadazie, A. C., Idehen, K., & Okeke, U. (2014). Temporomandibular joint dislocation: experiences from Zaria, Nigeria. Journal of the Korean Association of Oral and Maxillofacial Surgeons, 40(3), 111.
  • Dijkstra, P. U., Kropmans, T. J. B., & Stegenga, B. (2002). The association between generalized joint hypermobility and temporomandibular joint disorders: a systematic review. Journal of dental research, 81(3), 158-163.
  • Kai, S., Kai, H., Nakayama, E., Tabata, O., Tashiro, H., Miyajima, T., & Sasaguri, M. (1992). Clinical symptoms of open lock position of the condyle: Relation to anterior dislocation of the temporomandibular joint. Oral surgery, oral medicine, oral pathology, 74(2), 143-148.
  • Pai, D., Kamath, A. T., Menon, G., Urala, A. S., Kumar, S., Nayak, S., & Kudva, A. (2017). Recurrent temporomandibular joint dislocations in geriatric patient on antipsychotic drugs and its conservative management. Asian Journal of Pharmaceutical and Clinical Research, 10(11), 8-10.
  • Sharma, N. K., Singh, A. K., Pandey, A., Verma, V., & Singh, S. (2015). Temporomandibular joint dislocation. National journal of maxillofacial surgery, 6(1), 16-20.
  • Steinpreis, R. E., Parret, F., Summ, R. M., & Panos, J. J. (1997). Effects of clozapine and haloperidol on baseline levels of vacuous jaw movements in aged rats. Behavioural brain research, 86(2), 165-169.
  • Szkutnik, Jacek, Marcin Wójcicki, Marcin Berger, Magdalena Bakalczuk, Monika Litko, Michał Łobacz, and Mansur Rahnama-Hezavah. “Treatment of habitual luxation of temporomandibular joint–.” EJMT 2 (2018); 2(19): 17-21

One Comment

May 7, 2024 2:10 pm

I have chronic open lock, on both sides now. Are any test subjects needed to help improve the research for this?

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