What About Injections For TMJ Problems?

Since  TMJ issues are primarily about a "joint" problem (muscles, ligaments, cartilage discs) it makes sense that traditional musculoskeletal approaches to pain would be applied to the TMJ as well.  Injections for muscle and joint problems typically settle on one of three areas:

1. Trigger Points In The Muscles
2. Arthritis and Inflammation in the Joint Proper
3. Nerve Blocks for Local Nerve (In this case the Trigeminal Nerve)

 Injections In Muscle

If the problem from your TMJ is coming from the muscles, you may have been given a recommendation for  trigger point injections for muscles of the jaw.  The primary ones involved are the Temporalis, Masseter and Pterygoid. A trigger point is a small hyper irritable area of muscle that is staying contracted when the rest of the muscle stays relaxed.  This can limit blood flow and thus oxygen to the muscle causing hypoxia (which can be painful in and of itself).  In addition to oxygen not flowing in due to decreased blood flow, the muscle cell waste products are also not moved out, thus causes inflammation and chemical irritation to both muscle cells and nerves. Finally, the short tight muscles can change the normal movement patterns of the TMJ joint, thus, placing additional strain on the Jaw joint itself and causing more inflammation and muscle shortening.  It is a vicious cycle. 

Trigger Point Injection involves locating the trigger point by palpation (feeling for the tight irritated knot) and then using a fine gauge needle to inject an anesthetic, a steroid and sometimes both, and in some cases botox.  This is done by a medical doctor or dentist. Some practitioners (including chiropractors, physical therapists and acupuncturists) may do what is called "Dry Needling" where they insert a fine needle into the muscle but no medication.

Possible Side Effects: Typically low . This may include local sight irritation, some mild pain with the procedure.  Because of the proximity of the muscles around the jaw to nerves, blood vessels and glands there is some risk of striking non target tissue. Some people have reactions to some medications. 

Does it Work ? Overall the literature seems to show that trigger point injections can be helpful and there does not appear to be an advantage to using medication vs dry needling. Most of the studies combine trigger point injections with exercise, splint therapy or both. A large meta-analysis of randomized clinical trials ranked treatment for muscle related TMJ issues in the following hierarchy:

1. Manual Therapy (Physical therapy, Chiropractic etc.)
2. Counseling 
3. Injections
4. Splints

 Injections In The Joint

If the problem from your TMJ is coming from the Joint itself (cartilage, disc, ligaments that hold the mandible and temporal bone together) you may have been given a recommendation for a shooting something into the joint, or draining something out of the joint. Both would involve a needle. Problems within the TMJ proper (as opposed to the muscles as outlined above) are usually divided into two categories:  Internal Derangement which involves slipping of the disc that sits over the mandibular condyle Osteoarthritis which would involve a roughening and breakdown of the cartilage that covers the bony ends of the mandible and temporal bone.  Both of these conditions can result in limited opening of the mouth, clicks, pops and catches and swelling and pressure in the joint itself.

Common procedures:

Arthrocentesis : This is essentially inserting a needle into the TMJ joint in order to break up adhesions and to flush out local inflammatory by products of pain and bad joint mechanics. 

Intraarticular Injection: This is an injection into the TMJ commonly of a corticosteroid, hyaluronic acid or platelet rich plasma. This is done in order to reduce swelling and lubricate the joint and in the case of platelet rich plasma stimulate the joint. 

These procedures are done independently but may also be done together.

Possible Side Effects: Pain in the Injured Area Infection No Improvement in Injured Area Allergic Reaction.  Blood Clot Skin Discoloration

Does it Work?   A 2019 Large Meta Analysis  concluded the following regarding when comparing injection procedures for the joint (as opposed to the muscle) for pain and maximum mouth opening:

"In contrast to traditional concepts mandating exhaustion of conservative treatment options, minimally invasive procedures, therefore, deserve to be implemented as efficient first-line treatments (e.g. IAIs (joint injection) and/or arthrocentesis (joint draining) ) or should be considered rather early, i.e. as soon as patients do not show a clear benefit from an initial conservative treatment."

Injections To The Nerve

The nerve that supplies sensation in and about the jaw area is called the Trigeminal Nerve (CN V) and it comes off the brainstem (you have one on each side). Behind your ear it further splits into three branches and gives you the sensation to the face.  The three branches are:

1. Ophthalmic which goes up and around the eye area
2. Maxillary which goes to your upper jaw , cheeks, nose, lower eyelids and upper lip and gums. 
3. Mandibular which goes to the  lower part of your face, such as the jaws, lower lip and gum. The Trigeminal Nerve also also has a motor function and helps you bite, chew and swallow.

Some people actually have a nerve problem only ( not issue with the muscles, ligaments or joints of the TMJ itself) , called Trigeminal Neuralgia. This can be a very intense pain with feelings of electric shock. While this might be associated with TMJ issues, it really is in a class of it's own. Trigeminal Neuralgia is sometimes treated with a nerve block. While we will talk about this condition in another post, it is not what we are considering in this article.  In this article we are considering using a nerve block to treat pain coming from the TMJ and it's associated issues like limited opening and pain. 

An injection of a nerve with an anesthetic is called a Nerve Block.  This can be done by itself, but is often (in the cases of a TMJ issue) done and then followed up by exercises that are then done with less or no pain.  This allows a larger and more normal opening of the jaw.  Since the anesthesia wears off, it is repeated over time for maximum results. 

Possible Side Effects: Pain in the Injured Area, Infection, No Improvement in Injured Area, Allergic Reaction, Blood Clot.

Does it Work ? When I was doing research for this article, I did not find as much information on this approach, which leads me to believe that it is not done as often as the other two (Injections to the muscles and joints). One article  with a small sample size compared Nerve Blocks alone to Nerve Blocks combined with Physical Therapy to determine effectiveness on pain and the ability to open the mouth.  Both groups improved regarding pain, but not maximum mouth opening. 

Which Door Should I Pick ?

This review was not meant to be exhaustive.  I have worked on patients over the years that have had these procedures done for various joint issues (typically neck, back and shoulders).  One thing they all have in common is that these are very rarely the first recommendations given for their condition. They only end up at these types of procedures when conservative measures have failed them.  This is due in part to the fact that manual methods; adjustments, massage, exercises, stretches, cold laser can be very effective for most muscle and joint conditions, and they don't carry with them the risks involved with introducing a chemical directly into a muscle or joint does. Still, when conservative measures fail, these procedures may hold hope for TMJ pain.

If you have questions on any of these procedures or would just like to run your concerns by somebody, we would be happy to talk with you on the phone, just give us a call.

Yours in Health,

Doug Williams, D.C.
TMJ Relief Center At Care Chiropractic
134 Executive Drive # 3
Lafayette, Indiana
47905
(765) 448-6489