Dental appointments are necessary in ensuring optimal oral health. At the same time, most of us do not look forward to visiting the dentist or hygenist. In some cases, going to the dentist and having your mouth open for prolonged periods can also cause post-dental visit jaw / temporomandibular joint (TMJ) pain and dysfunction. Sometimes this can present with difficulty opening your jaw. If you experience post-dental visit pain and or difficulty opening your mouth, don't worry, REP Physio in Edmonton can help!

Can dental procedures cause jaw locking?

During a dental procedure, it is common to have your jaw open for prolonged periods. Sometimes, your jaw may even be open wider than what you are typically used to. This may cause the muscles of mouth closing (pterygoid muscle, temporalis and masseter) to spasm and tighten up following the procedure, as a reaction to being overstretched. This is sometimes referred to as myofascial pain syndrome. When the muscles that close your jaw become tight, they can lack the capacity to stretch sufficiently when opening.  Prolonged time in the dental chair, such as getting your wisdom teeth removed (or actually any procedure were the mouth is held open longer than typical) may further increase your risk of post-dental procedure pain, muscle tightness in the jaw, and limited opening.  In other cases, having your jaw open for prolonged periods can also irritate the capsule of the temporomandibular joint.  This is known as a capsulitis and/or post-dental capsulitis. The joint capsule is a collection of fibrous tissue that along with ligaments surrounding the jaw help stabilize the joint and prevent excessive range of motion (stops you from opening your mouth too wide).The jaw joint also contains an intraarticular disc, but more on this later.  Joint capsules also contain synovial fluid to help lubricate the joint. When the capsule is inflammed, it is called "capsulitis", when the inner lining of the capsule is inflammed it is known as synovitis. Both a capsulitis and synovitis typically present with pain localized to the jaw joint and limited opening. Isolated jaw joint pain tends to be more localized to the jaw joint itself, whereas muscular pain can radiate into the cheek, temple and around the eyes.  Whether it is the joint or the muscles that are not allowing you to open the jaw, it can feel like the jaw is "locked".  For more information on other causes of jaw locking, check out our other TMJ blog here.

Fortunately, it is rare for lengthy dental procedures to result in you being unable to open your mouth wide, or at all. Moreover it should not be permanent. With a little help from the experienced physios at REP Physio in Edmonton, we can relieve jaw pain and restore function.

Jaw locking vs. trismus vs. orofacial pain

Trismus refers to restricted opening of the jaw. Originally it was associated with tetany (constant jaw spasm), but now trismus and lock jaw or jaw locking can be used interchangeably. Orofacial pain refers to pain generated by either the face of the mouth. Indeed both the face and mouth have a complicated innervation and anatomical relationship, but for the purposes of this blog, it is important to know that pain from a lock jaw can refer to other parts of the face, and facial pain that is not related to the jaw can refer to the jaw. If in doubt, best see your physiotherapist.

If your jaw locks or gets stuck, preventing you from fully opening or closing your mouth, it is typically due to a change in the relationship between the intraarticular disc and the mandible. Medically, we refer to this as a disc displacement with/without reduction. When the jaw locks, the disc sits too far forward of the jaw bone, causing it to act as a structural block to the forward displacement of the jaw bone that allows for full opening. Fortunately, a locked jaw is rarely permanent. A disc that reduces “with reduction” suggests that the disc can return to its normal resting position. Without reduction means the disc is permanently stuck forward, alterning joint mechanics. In some cases the disc may be stuck forward for a period of time, and then return to its normal resting position (intermittent reduction).

In very rare instances, the jaw can open too far making it difficult/impossible to close the mouth. This is known as an open lock. This happens because the mandible has moved too far forward on one or both sides of the jaw. If this occurs, it can be quite concerning for the individual, as it can be nearly impossible for them to close their mouth on their own. They won’t be able to chew food and are stuck with a wide open gaping mouth, which also puts excessive strain on the jaw muscles as they get stretched beyond a comfortable range of motion. If your physiotherapist is unable to “unlock”/put your jaw back in place with manual therapy, then typically clients are sent to the emergency room, where they are placed under a general anesthetic and the jaw is manipulated back into place.

The bottom line about jaw popping and clicking is this: it isn’t a cause for concern unless the clicking sound is painful. Painful clicking typically is a result of severe joint damage, and imaging (Xray, MRI etc.) should be considered. Again, it is highly unlikely that non painful popping or clicking is causing damage. Again, as noted above, it is difficult to stop jaw popping and clicking that has bee there for a long time. Lastly, if you experience episodes of jaw locking, jaw and facial pain, or a new onset of jaw popping or clicking, some see any of  the experienced physiotherapists at REP Physio in Edmonton.

Orofacial pain refers to jaw and/or facail pain caused by structures of the jaw or face. Common causes of orofacial pain outside of dental visits include: injury to the muscles of the jaw and neck (jaw dislocation for example), headaches, if you clench your jaw a lot, putting pressure on the jaw from awkward side sleeping positions and/or night time grinding. Orofacial pain varies from mild to severe. If you are experiencing jaw pain that is severe, and is associated with clicking or clunking, see your dentist of physio asap, as they may indicate more concerning damage (also rare) to the jaw joint itsefl.

As mentioned before, the prognosis for decreased jaw opening following a dental procedure is generally good, and chronic pain in the jaw following a dental procedure is rare. Also, limited opening of the mouth following a dental visit does not mean that you have sustained a permanent jaw injury, but rather that your tissues are more likely sensitized and infalmmed. To minimize the risk ahead of time consider trying the following

Preventing locked jaw prior and during a dentist visit

• Ask the dentist or hygenists for frequent, periodic breaks from prolonged mouth opening
• If you experience sudden jaw pain while in the dental chair, ask for a break to close your mouth
• Let your dentist know if you have a history of jaw issues before any procedure, as people with tempormandibular joint dysfunction are likely a higher risk for jaw pain with dental work
• Open your mouth fully in the days leading up to your dental procedure. Can you open it fully without pain?  If not, let your dental professional (and physio!) know.
• Consider a softer food diet, avoid gum chewing in the days prior to your appointment to avoid unnecessary stress on the jaw
• Be mindful of any stress you are under, as it may be causing you to clench your jaw
• If you have difficulty closing the jaw, or your jaw hurt when closing it immediately after your procedure, please tell your dentist so you can be equipped with the best possible management strategies.

Preventing jaw locking after dental visits

If you experience difficulty opening your jaw following a dental visit, the physios at REP Physio in Edmonton can help.  Contact us to book an appointment . In the interim, these points below may help:

• Manage pain in the jaw by trying heat and/or ice.
• If you are getting pain follow up with your dentist, MD or pharmacist about appropriate pain and inflammation management medications
• Decreased the demands placed on the muscles of the jaw by sticking to a soft food diet. Resting the jaw can help!
• Avoid grinding and/or clenching your teeth if possible.
• Choose softer foods, smoothies etc. Take smaller bites.
• Open the mouth as comfortably as you can, don't force it.

What are some jaw exercises to relieve TMJ pain?

Restoring normal function of your jaw is a top priority. Some exercises to help restore normal function and include opening your jaw in front of a mirror to provide visual feedback as to how straight and how wide you can open. Another common exercise that may be appropriate is isometric contractions of the jaw muscles. This means activating the jaw muscles without causing movement of the jaw. Again, talk to your physiotherapist at REP Physio to determine what is most appropriate for you.

How REP Physio can help

REP's treatment of jaw dysfunction post dental procedure begins with a thorough clinical exam. This includes a detailed subjective history of any past jaw and neck issues. A biomechanical exam will then follow to determine what the primary cause of the lack of opening is. In some cases we may apply therapeutic ultrasound (one of the few times we actually ever use ultrasound in the clinic) to the jaw muscles and joints to provide increased blood flow to help heal damaged tissues and relax tight irritated muscles. We may use intramuscular dry needling to cause the muscle fibers of the neck and jaw to relax. This can be complimented with therapeutic massage and self massage techniques as well as various exercises to help open and close your mouth. In our experience, we have been able to restore function with these techniques and more in a only a few visits/weeks.