The complexities of temporomandibular disorder

As hygienists, family and friends often ask us teeth-related questions. What toothbrush should I use? What do you think of this area in my mouth? Who is a good dentist in the area? Recently, a friend told me that her 20-something-year-old daughter was having “jaw pain,” and wanted to know what she should do about it. Should she see a dentist or a medical doctor? This simple question brought back memories of when I first was diagnosed with TMD and the search I undertook to discover more about my condition and subsequent treatment.

Our dental hygiene education teaches us about anatomy and physiology, the structures of the head and neck, and the muscles of mastication. We learn that the temporomandibular joint is composed of the mandibular condyle, situated in the mandibular fossa in the posterior articular eminence and in the middle of the articular disk, where it can be best suited for articulation. Any deviation of the positioning can result in temporomandibular pain and dysfunction known as temporomandibular disorder (TMD). Yet, we may know only the basics about TMD when asked by patients or friends. 

Causes of TMD

TMD is caused by a variety of factors, have a variety of signs and symptoms, and there is no one specific cause or treatment for the disorder. TMD can be caused by problems with the structure of the anatomical joint, the muscles of mastication, or head/neck muscles. Depending on the actual diagnosis, treatments vary considerably. The National Institute of Dental and Craniofacial Research classifies TMD by the following:¹ 

• Myofascial pain. This is the most common form of TMD. It results in discomfort or pain in the fascia and muscles of mastication or that control neck and shoulder function.
• Internal derangement of the joint. This involves a dislocated jaw or displaced disk (meniscus) or injury to the condyle.
• Degenerative joint disease. This includes osteoarthritis or rheumatoid arthritis in the jaw joint.

A TMD patient can exhibit one or several of the classifications at any time.

The actual cause of TMD may not be evident. Bruxism is often a cause but it is not exclusive. Trauma to the jaw, head, or neck, or postural and airway considerations are also factors. Arthritis and other autoimmune disorders have been implicated. A study by the National Institute of Dental and Craniofacial Research identified clinical, psychological, sensory, genetic, and nervous system factors that can put a person at higher risk of developing chronic TMD.¹ In my TMD journey, I will never know what truly caused my disorder.

Approximately 35 million people in the United States have some form of TMD, yet not all should seek treatment for the disorder. The predominant patient population is women in their childbearing years, although many men and older/younger patients exhibit signs and symptoms. Due to the majority of women seen as TMD patients, there are numerous research initiatives focusing on the role female sex hormones, particularly estrogen, play in TMD.² During my experiences, I noticed estrogen playing a role in the pain cycle.

Symptoms of TMD 

Symptoms of TMD vary widely. Pain can be described as dull and achy or sharp and shooting. It can come from in front of the ear or along the muscles. Some patients experience no pain, but have limited range of motion (ROM). Symptoms can include but are not limited to:

• Pain in muscles of mastication or neck and shoulder areas
• Chronic headaches
• Limited movement or locking of jaw
• Ear pain, pressure, fullness, or tinnitus
• Clicking, popping, grating noise during jaw movement
• A bite that feels “off”
• Dizziness and vision problems

For patients who complain of limited ROM or locking, there are several possibilities. An internal derangement (ID) with reduction occurs when the meniscus is out of place when the patient’s jaw is in the closed position; upon opening, the meniscus goes into a natural position and then, upon closing, goes back abnormally. Often a click or popping sound will be heard during movement. An internal derangement without reduction occurs when the meniscus is out of position at closure and remains out of position during jaw movement. Patients exhibiting ID without reduction may have limited range of motion and an inability to open wide. Internal derangements are classified as early to late stage disease depending on a variety of diagnostic criteria including positive radiographic and imaging findings.

Patients may also exhibit limited opening but do not have internal derangements. These patients present with myofascial pain dysfunction (MPD) involving the muscles of mastication and/or head and upper body musculature. Patients with MPD will also have limited ROM, ear pain/tinnitus, pain on jaw movement, but will present with lack of radiographic evidence of bone or disk displacement. Patients can present with either MPD or ID with or without reduction or may exhibit signs and symptoms of both. I had both MPD and internal derangement without reduction.

Diagnosing TMD

There are various diagnostic tools used to evaluate TMD. Evaluating a patient’s ROM both in straight line opening and in lateral excursive movements while palpating the joint and muscles during an intra-/extraoral evaluation is critical. Note any popping or clicking during palpation along with any tightness or trigger point in the muscles. An adult should have a normal opening of 40-60 mm or three fingers’ width of opening with a lateral excursive movement of 10-15 mm. Observing any deviations on opening is also important. My maximum opening is 25 mm with a deviation to the right and lateral movement of 5 mm following all of my treatments.

Beyond clinical observations there are radiographic and imaging modalities that can be utilized. Panoramic, cephalometric, conventional tomography (CT), cone beam computed tomography (CBCT), or magnetic resonance imaging (MRI) can provide valuable information depending on the area imaged and the information requested. MRI, with or without contrast, is considered the gold standard of TMJ imaging.³ Imaging can be useful in determining disk position and function in both open and closed positions. Panoramic, cephalometric, and CT imaging are best for hard tissue examination, while MRI and arthrography can be used for both hard and soft tissue evaluation.⁴ I had panoramic, tomography, and MRI images of my joints and the diagnosis was inconclusive.

Beyond clinical observations and imaging diagnostic tools, products designed to measure bite analysis, TMJ Doppler auscultation, electromyography, TENS (transcutaneous nerve stimulation), joint or muscle injections, Botox treatments, laboratory testing, and behavioral assessments can be used for either diagnostic or treatment modalities. As diagnostic tools, any of these can assist in determining if an internal derangement or MPD exists, while a few can be used to alleviate pain and limited ROM. I have experienced all of these with the exception of Botox either as treatments or diagnostic tools during my TMD journey.

Treating TMD 

The goal of any TMD treatment is to provide good function and a relatively pain-free existence with friction-free movement. There are myriad treatments available for TMD depending on whether the involvement is structural or muscular. Approximately 90% of patients can be treated successfully with nonsurgical interventions, while 10% will eventually need surgery. I am one of the 10 percenters.

Nonsurgical treatments should commence for a minimum of two to three months with a maximum of one year of treatment unless there are definitive osseous changes noted during the treatment. Due to the nature of TMD, treatments less than two to three months of treatment are often not sufficient in length to provide long-term relief. Treatment goals center around restoring normal joint mobility and restoring normal body balance, and two to three months are required to obtain these goals.

Initially, a soft diet is recommended with heat or ice treatments to either the joint or muscles as appropriate. Physical therapy treatment and exercises may be recommended. Analgesics such as NSAIDS or muscle relaxants may also be prescribed. There is controversy regarding the use of opioid medications due to the potential for addiction, and these should be used only in consultation with the patient’s physician.⁵

Many patients find relief by using balanced oral appliances. TMD appliances range from maxillary only, mandibular only, both maxillary and mandibular combined, or a nociceptive trigeminal inhibition device (NTI). An NTI device is an anterior bite stop that is indicated for the prevention of bruxism, TMD, tension-type headaches, and migraines.⁶ The specific TMD diagnosis and the practitioner’s philosophy of treatment will determine the type of appliance the patient receives. No one type of appliance has been proven to be more effective than others for all patients. I have experienced maxillary, mandibular, NTI, and combination appliances.

Since there is an emergent body of evidence that suggests correlation of obstructive sleep apnea with chronic pain disorders, including TMD,⁷ it is recommended to evaluate all TMD patients for OSA and treat appropriately with noninvasive therapies.

When conservative treatments are not successful, more invasive options must be considered. Although considered conservative, the use of low-level laser therapy has shown mixed results in a variety of studies.⁸ Muscle and joint injections with Botox, anesthetics, or steroids can be utilized as part of increasingly invasive treatment protocols.

The final treatments involve surgical options. These include arthrocentesis, arthroscopic surgery, or full open-joint surgery and joint replacement. Arthrocentesis is a minimally invasive surgical procedure that relieves joint stiffness from fluid buildup while reducing inflammation or allows for disk repositioning. For TMJ arthrocentesis, an oral surgeon will administer either IV sedation or general or local anesthetic and inject sterile fluid to flush out any inflammatory buildup in the joint. A second needle-tipped syringe is then inserted to collect synovial fluid and the excess sterile liquid. The surgeon also can try to gently manipulate a displaced meniscus into position.⁹

Arthroscopic surgery is more invasive than arthrocentesis and is performed using two hypodermic needles. The procedure is almost always performed in a hospital outpatient facility under general anesthesia. An arthroscope is used to evaluate the joint and determine accurate diagnosis. It can be used similar to arthrocentesis to flush inflammatory products from the joint, but can also be used to remove scar tissue (adhesions), smooth bone, or reposition the meniscus.¹⁰

TMJ arthroplasty is an open-joint surgery performed on patients who have intolerable and/or intractable TMJ pain. Most patients have failed nonsurgical treatments and/or arthroscopic surgery performed in a hospital setting under general anesthesia. Open-joint procedures include discoplasty (meniscoplasty, repair and/or relocation of the disk), discectomy (meniscectomy, removal of the disk with or without replacement), condylectomy, condylotomy, and total or partial joint replacement. During an arthroplasty, an incision is made over the joint area in front of the ear. The incision usually extends from inside the sideburn area, then in front of the top of the ear, and then extending into the ear itself. The part that extends into the ear is placed there to hide the incision from view. This “skin flap” is then reflected forward to expose the underlying layers and expose the joint proper. Postprocedural care can include heat/ice therapy, pain medication, aggressive physical therapy including motion therapy, and close and frequent patient follow-up.¹¹ Since I am one of the 10-percenters who progressed to TMD surgery, I have experienced arthrocentesis, arthroscopic surgery, and open-joint surgery with meniscectomy and disk replacement. The type of replacement procedure I had done is no longer utilized due to severe complications of the procedure and product used. I am one of the lucky ones who survived the procedure, while many others have suffered years of pain and treatments. In general, complications from TMD surgery include malocclusion, temporary or permanent nerve damage, infection, and implant or surgical failure. I experienced a malocclusion that resulted in having to commence orthodontic treatment and temporary nerve damage.

With the variety of signs, symptoms, and treatments available for TMD, there are a number of health-care providers beyond the dental professional who treat the disorder. These include physical therapists, chiropractors, osteopaths, acupuncturists, nutritionists, and psychologists. I dealt with a general dentist, a periodontist, an oral surgeon, several physical therapists, and a psychologist.

As hygienists, we may find ourselves treating TMD patients or being questioned about it by family and friends. In the clinical setting, performing a thorough intra-/extraoral exam, noting any deviations or limitations is essential. Recommendations include use of mouth props, chin supports, lumbar/cervical supports, and, as applicable, ultrasonic scalers (although in the age of COVID-19, these may be contraindicated) along with three- to four-month recare intervals. Having complete documentation of the patient’s TMD health-care providers for referral and consultation can be beneficial. From the patient’s perspective, using heat/ice and/or medications both pre- and postprocedure can be helpful, along with using stress reduction techniques during hygiene treatment. Some TMD patients prefer shorter appointments; others prefer longer. There is no set protocol for appointment length; it is dependent on the patient’s tolerance level and ability to maintain opening. Home-care instruction can include power toothbrushes or small/pedo brush heads, rubber tips, floss holders, oral irrigators, and oral rinses. Educating the patient regarding their condition and self-help modalities can provide reassurance to TMD patients.

Conclusion

Support organizations such as the TMJ Association (www.tmj.org) also provide information and education. The TMJ Association is a nonprofit patient advocacy organization whose mission is to improve the quality of health care and the lives of TMD patients. For over 30 years, the association has worked tirelessly to promote research and education about TMD. Forging partnerships with a variety of research and governmental agencies and organizations, the TMJ Association has been instrumental in gaining funding for TMD research from the National Institutes of Health, including the Orofacial Pain: Prospective Evaluation and Risk Assessment (OPPERA) study. The OPPERA study is a multilocation, multiyear study that recruited and examined 3,258 community-based TMD-free adults, assessing genetic and phenotypic measures of biological, psychosocial, clinical, and health status characteristics. During follow-up, 4% of participants per annum developed clinically verified TMD, although that was a “symptom iceberg” when compared with the 19% annual rate of facial pain symptoms.¹² Information is still being reviewed from the study that will eventually lead to better diagnostic and treatment options for TMD patients.

The TMJ is the most complex joint in the body. The variety of signs, symptoms, and treatments can be a frustrating and confusing experience for the patient. As hygienists, we can assist patients by calming fears, explaining treatments, being a listening ear, and educating ourselves about the complexities of the disorder.

Questions to ask patients experiencing TMD:²

1. Do you experience clicking, popping, and/or pain when opening or closing your jaw?
2. Do you experience any limitations with opening and/or closing your jaw?
3. Do you experience constant pain, or are your symptoms intermittent?
4. What triggers seem to make the pain better or worse?
5. When did you first experience signs or symptoms of temporomandibular disorder?
6. Do you have frequent headaches, neck pain, or toothaches?
7. What strategies have you tried to address this problem? Were any successful or unsuccessful?

References

1. Temporomandibular disorder (TMD). Johns Hopkins Medicine. https://www.hopkinsmedicine.org/health/conditions-and-diseases/temporomandibular-disorder-tmd

2. Luu TM, Kabani F, Muzzin KB. Effects of estrogen in temporomandibular disorder. Decis Dent. 2020;2. https://decisionsindentistry.com/article/effects-estrogen-temporomandibular-disorders/

3. Snearly WN. Internal derangement of the temporomandibular joint. Radsource. Dec. 2012. https://radsource.us/internal-derangement-of-the-temporomandibular-joint/

4. Petrikowski CG. Diagnostic imaging of the temporomandibular joint. Oral Health Group. June 1, 2005. https://www.oralhealthgroup.com/features/diagnostic-imaging-of-the-temporomandibular-joint/

5. Ouanounou A, Goldberg M, Haas DA. Pharmacotherapy in temporomandibular disorders: a review. J Can Dent Assoc. 2017;83:h7. https://jcda.ca/h7

6. Stapelmann H, Türp JC. The NTI-tss device for the therapy of bruxism, temporomandibular disorders, and headache—Where do we stand? A qualitative systematic review of the literature. BMC Oral Health. 2008;8:22.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2583977/

7. Sanders AE, Essick GK, Fillingim R, et al. Sleep apnea symptoms and risk of temporomandibular disorder OPPERA cohort. J Dent Res. 2013;92(7 suppl):S70-S77. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3706181/

8. Low-level laser therapy. The TMJ Association, Ltd. Dec. 6, 2019. http://www.tmj.org/site/page?pageId=432

9. Huot RA. TMJ arthrocentesis: Everything about the procedure. Colgate. https://www.colgate.com/en-us/oral-health/conditions/temporomandibular-disorder/tmj-arthrocentesis--everything-about-the-procedure

10. Arthroscopy. The TMJ Association, Ltd. Dec. 6, 2019. http://tmj.org/site/page?pageId=263

11. Jaw TMJ arthroplasty. CranioRehab.com. https://www.craniorehab.com/Jaw-TMJ-Arthroplasty_c_67.html

12. Slade GD, Ohrbach R, Greenspan JD, et al. Painful temporomandibular disorder: decade of discovery from OPPERA studies. J Dent Res. 2016;95(10):1084-1092. https://pubmed.ncbi.nlm.nih.gov/27339423/