Temporomandibular joint disorder (TMJD) features a breakdown of the synovial joint, meniscus and related structures of the temporomandibular joint (TMJ). This joint is a diarthrotic synovial joint with unique features. The glenoid fossa of the temporal bone articulates with the mandibular condyle to create a hinge apparatus.
According to the National Institute of Dental & Craniofacial Research, surveys’ research indicates the prevalence of TMJD is between 5% and 12% of the general population, more witnessed in women ages 20 to 39. With men, bruxism and tinnitus were more commonly witnessed. All other classic signs and symptoms were more prevalent in women.
There are three distinctive categories of TMJD classically defined by physicians. A proper diagnosis needs to include one of these categorizations:
Anterior displacement with reduction
The articular meniscus slides forward longer than expected and/or is delayed upon sliding back into proper place. A client may state they experience clicking and popping sensations, unusual pressure, intermittent or constant pain and shooting sensations frequently within their TMJ region.
Anterior displacement without reduction
Often referred to as lockjaw, the articular meniscus cannot slide back into proper place. Severe pain may be experienced as the jaw is fixed in an open (depressed) position. Trismus is the clinical term used if this condition is caused by muscle spasms of the masseter or internal facial oral musculature. More rarely, lockjaw could be caused by hypocalcemia or result as a complication from thyroid surgeries.
Lockjaw is a clinically significant condition. If not treated immediately, oral health can be harmed due to the inability to swallow saliva. This deficit can result in dry mouth (xerostomia) or mucositis (sore, inflamed oral cavity). Digestion can be impacted as saliva is necessary to initially catabolize carbohydrates consumed within the oral cavity.
Inflammatory
An infectious agent is harming the inner ear environment. Clostridium tetani infection, the bacteria causing tetanus, may be a cause of lockjaw. There are several other bacteria that reside within the middle and external auricular environment that can potentially enter the inner ear, then toward the TMJ via the petrous ridge pathway. These bacteria include Staphylococcus (S.) auricularis, S. capitis, S. epidermidis, S. warnen, Escherichia (E.) coli, Turicella otitdis and Micrococcus luteus.
What Causes TMJD?
There are numerous causes associated with TMJD. Trauma to the jaw by external force is quite common. Whether by external force or internal cause, trauma can damage bone and joint structures, creating misalignments to exacerbate this condition.
Other factors include ergonomic (work-related) factors, dental procedures that force the jaw open for long periods of time, bruxism (grinding of teeth) and infectious causes. Myofascial tension may develop spasms of the masseter muscle known as trismus.
Signs, symptoms and complications of TMJD include pain felt either acutely or chronically. The pain may originate within the jaw or TMJ itself. Pain may radiate around the temple region toward the orbital region and/or extend inferior toward the lateral neck. Additionally:
• Clicking or popping sounds that indicate the meniscus disc is sliding within the cavity within the TMJ. This could result in a fixed depressed (open) jaw position known as lockjaw.
• Inner or outer ear pain that may extend anterior to the tragus or posterior along the pinna and lobe. Pain may mimic that of tension headaches or ear infections.
• Headaches on lateral skull which may be confused with cluster headaches. Remember that cluster headaches tend to have predictable patterns due to stress or hormonal fluctuations (i.e., feeling the headache the same time each day). Headaches caused by TMJD usually present with tension, spasms and achy pain in the temporalis, scalene and upper trapezius muscles.
• Tinnitus is a consistent ringing or similar sensation felt and heard audibly within the ears. Aside from ringing, a patient may use words such as buzzing, roaring, clicking, pounding, drumming, hissing and/or humming to describe what they perceive.
• Bruxism describes grinding of the teeth. Gnashing or clenching the teeth can also be observed. This may or may not be related to “sleep bruxism,” a condition more likely associated with sleep disorders; however, the same emotional factors contributing to TMJD could also contribute to snoring, sleep apnea or other sleep disorders. This can lead to greater sensitivity of the teeth and uneven tooth wear, especially when viewing left side to right.
• Fatigue upon chewing may be witnessed with TMJD patients as the pain and discomfort caused by TMJD weakens jaw structures and musculature. Mastication, commonly known as chewing, becomes laborious.
• Oral cavity soreness can be a common complaint as the fatigue, pain and tension creates an overall sensation of soreness which can range from mild to severe.
• Neck pain may result from muscle fatigue and weakness within the TMJ and surrounding structures. The neck may compensate for said weakness, causing the scalene, levator scapula, trapezius, platysma and sternocleidomastoid muscles to hold more tension than usual.
Aching facial pain is another manifestation of pain common to TMJD patients as the muscle fatigue and weakness spreads anterior toward the facial muscles.
Anatomy of the TMJ Region
The major nerve supply for this region stems from the auriculotemporal and masseteric branches of the third division of cranial nerve V, trigeminal nerve. The major blood supply for this region stems from the superficial temporal, middle meningeal and branches of the maxillary artery.
Between the mandibular condyles of the mandible and the articular tubercle of the temporal bone lies an articular disc known as a meniscus, also called an articular disc. This disc is primarily made of fibrous cartilage, providing it great compressive and tensile strength.
A fibrous joint capsule covers the TMJ region, providing protection and stability to the region. The thicker portions along either side of this capsule are termed the medial and lateral collateral ligaments. The capsule is thinner along the anterior and posterior planes, allowing for movement of the meniscus disc within the joint.
Upon depression (opening of the jaw), the meniscus slides slightly anterior along the mandibular condyle. Upon elevation (closing of the jaw), the meniscus ideally slides posterior back into anatomical position.
Joint Functions
We will first look at joint functions facilitated at this joint as well as muscles assisting each function:
• Depression: Opening jaw, an axial movement along a mediolateral axis along a sagittal plane that pulls both rows of teeth apart.
Muscles involved: lateral pterygoid (inferior belly), digastricus
• Elevation: Closing jaw, an axial movement along a mediolateral axis along a sagittal plane that brings both rows of teeth together.
Muscles involved: temporalis, masseter, medial pterygoid
• Protrusion: Jaw forward, an anterior nonaxial gliding movement.
Muscles involved: masseter, lateral pterygoid (superior and inferior belly), medial pterygoid
• Retraction: Jaw backward, a posterior nonaxial gliding movement.
Muscles involved: platysma, medial pterygoid
• Laterotrusion/lateral deviation: side-to-side movement, which includes a rotational movement of the mandibular condyle on the side the movement is moving toward as well as gliding condylar motion upon the alternate side.
Muscles involved: masseter, lateral pterygoid (superior and inferior bellies)
Ligaments’ Roles
There are numerous ligaments that bind and support the TMJ region. All play key roles in stabilization, ensuring proper joint movement.
• The temporomandibular ligament, also known as the lateral ligament of the TMJ, stabilizes the lateral side of this joint while also limiting depression.
• The stylomandibular ligament, located upon the medial side of the TMJ, binds the temporal to the mandible from the posterior aspect and limits protraction movement.
• The sphenomandibular ligament, also located upon the medial side of the TMJ, binds the sphenoid to the mandible and limits protraction movement.
Activities to Assess TMJ for Possible Dysfunction
Activity 1: Have your client speak to you for about two minutes about a recent life event. Observe their jaw movements and musculature of head, neck and jaw. Inform your client what you observe in terms of muscular movements and bone movements.
Activity 2: Have your client perform all jaw movements, first at normal speed, then at slower speed. Observe any deviations in jaw movement. Inform your client what you observe in terms of muscular movements and jaw movements.
Activity 3: Locate trigger points within masseter and temporalis muscles. Hold these spots while your client performs all jaw movements. Observe any deviations in jaw movement. Inform your client what you observe in terms of muscular movements and jaw movements.
Medical Approaches to TMJD
• Pain relief measures such as topical agents and non-steroidal anti-inflammatory drugs to temporarily relieve pain.
• Stabilization splints to reposition the jaw, relieving pain and restoring joint function. These splints can be as simple as sports mouth guards and occlusal splints purchased in stores or be specially fitted by an oral specialist to reposition the jaw in an intended direction and prevent tooth damage.
• Devices such as the JawFlex Exerciser and neck toning balls to tonify neighboring muscles.
• Botox to block nerve supply creating pain signals and sensations.
• Surgery to correct the TMJ dysfunctions may be necessary. An arthrocentesis will drain fluid and inflammatory debris from the joint capsule. A modified condylotomy will remove a portion of the mandibular condyle to decrease the tendency of lockjaw. An arthroscopy will involve correcting joint misalignments and lesions using instruments and a camera through a small incision.
• Implants made of plastics, Teflon, silicone or titanium may be used to replace the joint structures either partially or entirely.
• Jaw movement exercises such as smile stretches, neck stretches, chin tucks, jaw side-to-side wiggles and contract-relax sequences.
Work TMJ Wonders
A combination of treatments, including massage therapy, to relieve pain and aid in improving jaw alignment will work wonders to alleviate TMJD. A massage therapist can use the above-listed assessment activities to help ascertain muscles of focus during the session.
Be sure to reassess the client after the session with the same activities chosen to determine the effectiveness of session.
About the Author
Jimmy Gialelis, LMT, BCTMB, is owner of Advanced Massage Arts & Education in Tempe, Arizona. He is a National Certification Board for Therapeutic Massage & Bodywork-approved provider of continuing education, and teaches “Professional Ethics for LMTs” and many other CE classes. He is a regular contributor to MASSAGE Magazine, and his articles include “Massage for Trauma: 3 Ways of Responding to an Emotional Release” and “Chair Massage Success in the New Normal: This is How Coronavirus Has Changed Things (And What Will Stay the Same).”