Temporomandibular disorders are disorders of the jaw muscles, the temporomandibular joints, and the nerves associated with chronic facial pain. Any problem that prevents the joint function of the complex system of muscles, bones and joints could result in temporomandibular disorder.
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- 1 Introduction
- 2 Causes
- 3 Symptoms
- 4 Treatment
- 1 Personal education
- 2 Pharmacotherapy
- 3 Physical medicine
- 4 Orthopedic treatment
- 5 Cognitive behavioral therapy
- 6 Surgery
- 7 Dental treatment
- 5 Source
The temporomandibular joints (its acronym in English is TMJ, ATM in Spanish) are the two points, one on each side of the face, just in front of the ears, where the temporal skull bone meets the lower jaw (mandible ). The ligaments, tendons and muscles that support the joints are responsible for the movement of the jaws. The temporomandibular joint allows movements of elevation (closing the mouth), depression (opening the mouth), propulsion or protrusion (anterior sliding), retropulsion or retraction (posterior sliding) and lateral deviation or induction.
Disorders of the temporomandibular joint include problems related to the joints and muscles that surround it. Often the cause of the temporomandibular joint disorder is a combination of muscle tension and anatomical problems within the joints. Sometimes a psychological component is also involved. These disorders are more frequent in women between 20 and 50 years old.
Several reviews indicate that 50% of the population suffers from dysfunction of the temporomandibular system and that approximately 7% of the population suffers from an orofacial disorder causing facial and mandibular pain.
The main ligaments that the joint has are :
Temporomandibular ligament: which is located from the zygomatic process of the temporal bone and articular tubercle to the lateral aspect of the mandibular neck. It is in charge of limiting the descent, retropulsion and mandibular induction, in addition to reinforcing the lateral portion of the articular capsule.
Spheno-maxillary ligament: which is located from the spine of the sphenoid bone to the lingula on the lateral aspect of the mandible and is in charge of keeping the condyle, the disc and the temporal bone in intimate contact, also limits excessive propulsion of the jaw.
Stylomaxillary ligament: located from the styloid process of the temporal bone to the angle of the mandible. It is responsible for separating the parotid and submandibular salivary glands, keeping the condyle, disc and temporal bone in contact.
The movements of the temporomandibular joint are controlled by muscles, among which are :
Masseter muscle: originating from the zygomatic arch and inserted into the coronoid process of the mandible, it is innervated by the trigeminal nerve in its mandibular branch. It is responsible for lifting the jaw and clenching the teeth.
Temporal muscle: originating in the temporal fossa and inserted into the coronoid process and anterior branch of the mandible, it is innervated by the mandibular division of the trigeminal nerve. It is responsible for raising and retracting the jaw by moving the jaw to the same side of the food chewing.
Lateral pterygoid muscle: originating from the greater wing of the sphenoid and lateral pterygoid fossa and inserted into the neck of the maxilla and articular cartilage, it is innervated by the mandibular division of the trigeminal nerve; when it contracts bilaterally it protrudes and depresses the jaw, when it contracts unilaterally alternately it produces lateral movements of the jaw.
Medial poterigoid muscle: originating from the medial surface of the lateral pterygoid fossa and tuberosity of the maxilla and inserted into the medial surface of the mandible, near the angle; It is innervated by the mandibular branch of the trigeminal nerve. It helps to raise the jaw, if it contracts bilaterally it helps the protrusion, if it contracts unilaterally it protrudes the same side, if it contracts alternately it produces crushing movements when eating.
The digastric muscle: allows the descent of the jaw with the help of gravity.
The primary cause of this disorder is excessive tension of the muscle group that controls chewing, swallowing, and speech. This tension could be the result of bruxism (persistent clenching of the teeth), or of physical or mental tensions. Such factors could be the cause, in most cases, or aggravate an existing TMD condition.
Many TMJ-related symptoms are caused by effects of physical and emotional stress on the structures around the joint.
These structures include:
* Cartilaginous disc in the joint * Muscles of the jaw, face, and neck * Ligaments, blood vessels, and nearby nerves * Teeth
Many people with disorders of the temporomandibular joint, the cause is unknown. Some causes given for this condition have not been well proven and include:
-A bad bite or orthodontic devices.
-Stress and teeth grinding. Many people with TMJ problems don’t grind their teeth, and many who have been grinding their teeth for a long time have no problem with their temporomandibular joint. For some people, the stress associated with this disorder may be caused by pain rather than the cause of the problem.
Poor posture can also be an important factor in ATM. For example, keeping your head forward all day while looking at a computer tightens the muscles of your face and neck.
Other factors that could worsen TMJ symptoms are stress, poor diet, and lack of sleep.
Some people end up with “trigger points”: muscle contraction in the jaw, head, and neck. These trigger points can remit pain to other areas causing headache, ear or tooth pain.
Other possible causes of symptoms related to TMJ are, among others: arthritis, fractures, dislocations and structural problems present at birth.
The most common TMD symptoms are listed below. However, each individual may experience symptoms in a different way. Symptoms may include the following:
* Discomfort and pain of the jaw (it prevails more in the morning or in the late afternoon). * Headaches. * Pain that radiates behind the eyes, on the face, shoulders, neck, and / or back. * Earaches or chime sound (sounds caused by an infection of the internal ear canal). * Cracking or snapping of the jaw. * Stiffness of the jaw. * Limited mouth movements. * Teeth clenched or teeth grinding. * Dizziness. * Sensitivity of the teeth without the presence of an oral disease. * Numbness or tingling sensation in the fingers.
There are several different types of chewing muscle pain:
– Myofascial painIt is the most common muscle injury, it is characterized by being a regional pain whose main characteristic is the association with sensitive areas (trigger points). Reproduction of pain on palpation of the trigger point is considered diagnostic of this type of pain. Although pain typically occurs over the trigger point, it can be referred to distant areas, for example, pain in the temporal area is reported in the frontal region and the masseter in the ear. Myofascial pain is the most common cause of muscle pain of masticatory origin, accounting for 60% of cases of temporomandibular joint pain. Although the etiology of myofascial pain is confusing, there are hypotheses about macro or microtrauma produced on a normal or weakened muscle, either by a wound or by the sustained contraction of the same.bruxism .
– Myositis is the least common and acute injury that involves inflammation of the muscle and connective tissue, causing pain and swelling of the area. It can be septic or aseptic. There is no trigger point or increased electromyographic activity. The pain is characterized in that it becomes apparent or intensifies with movement. The inflammation usually occurs from a local cause such as infection of a tooth, pericoronitis, trauma, or cellulite.
– Muscle spasm is another acute disorder characterized by the involuntary and tonic transient contraction of a muscle. This can happen after the overstretch of a muscle that was weakened by different causes such as excessive acute use. A spasm produces a shortened, painful muscle that will limit movements of the jaw, and is identified by increased electromyographic activity of the resting muscle.
-Muscle contract is a chronic injury characterized by persistent muscle weakness. This can occur after trauma, infection, or prolonged hypomobility. If the muscle is kept in a shortened state, fibrosis and contracture can last for several months. Pain is often decreased with muscle rest.
Several joint pathologies can be associated with arthralgia:
-The displacement of the disc accompanied by joint reduction is characterized by the click that produces the movement of the jaw opening and closing. The articular disc is placed on the opposite side to its usual situation. This displacement only occurs with the mouth closed, when the mouth opens and the jaw slides forward, the disc snaps back into place while clicking. As the mouth closes, the disc slides forward again, often making another noise. Momentary disc dysfunction can be caused by irregularities in the articular surface, degradation of the synovial fluid, uncoordination of the disc-condyle junction, increased muscle activity, or disc deformation. As the album becomes increasingly dysfunctional, it begins to interfere with the normal movement of the condyle and may be the cause of permanent jaw closure. Sometimes patients have excessive opening due to laxity in the ligaments, which may cause mandibular subluxation.
-Unreduced disc displacement is characterized by a limitation in mouth opening by interfering with normal sliding of the condyle over the disc due to disc adhesion, deformation, or dystrophy. In this situation, the opening is usually decreased 20-30 mm with a deviation of the jaw to the affected side during the opening that is usually accompanied by pain. After the disc is permanently displaced, there is a remodeling of the disc and a ligamentous alteration. When there is a permanent mandibular closure, a muscular and ligamentous accommodation occurs that allows the normal mandibular opening and the reduction of pain. This joint adaptation includes the remodeling of the surfaces of the condyle, fossa, and the joint eminence, with the corresponding radiographic changes and a joint crepitus during mandibular opening and closing. A good remodel allows patients to regain normal opening with minimal pain, but joint crepitus often persists. Sometimes, however, there is a progression in bone degeneration leading to severe erosion, loss of vertical dimension, changes in occlusion, muscle pain, and greatly compromised jaw function. The origin of disc pathologies and joint arthralgia have been attributed at least partially to biomechanical alterations on the condyle. Other causes are jaw trauma and excessive chewing. A good remodel allows patients to regain normal opening with minimal pain, but joint crepitus often persists. Sometimes, however, there is a progression in bone degeneration resulting in severe erosion, loss of vertical dimension, changes in occlusion, muscle pain, and greatly compromised jaw function. The origin of disc pathologies and joint arthralgia have been attributed at least partially to biomechanical alterations on the condyle. Other causes are jaw trauma and excessive chewing. A good remodel allows patients to regain normal opening with minimal pain, but joint crepitus often persists. Sometimes, however, there is a progression in bone degeneration resulting in severe erosion, loss of vertical dimension, changes in occlusion, muscle pain, and greatly compromised jaw function. The origin of disc pathologies and joint arthralgia have been attributed at least partially to biomechanical alterations on the condyle. Other causes are jaw trauma and excessive chewing. and an enormously compromised mandibular function. The origin of disc pathologies and joint arthralgia have been attributed at least partially to biomechanical alterations on the condyle. Other causes are jaw trauma and excessive chewing. and an enormously compromised mandibular function. The origin of disc pathologies and joint arthralgia have been attributed at least partially to biomechanical alterations on the condyle. Other causes are jaw trauma and excessive chewing.
Disc displacement is a frequent pathology suffered by up to 20% of the population, but in most cases it does not require treatment. When joint noise is the only symptomatology, observation, education, and self-care are sufficient, however pain, intermittent closure, and difficulty in using the jaw do require closer observation and possibly intervention.
-Temporo-mandibular joint subluxation or dislocation with or without disc displacement is characterized by hypermobility of the joint due to laxity and weakness of the ligaments. This can be caused during excessive and sustained mouth openings over time in patients predisposed to it (eg dentist). The condyle is dislocated occupying a previous situation with respect to the disc and the articular eminence, producing pain and difficulty when closing the mouth due to the inability to return to its position. In most cases, the condyle can be moved down and back by the patient or clinician thus allowing normal mandibular closure.
-Osteoarthrosis of the temporomandibular joint involves degenerative changes of the joint surfaces that cause crepitus, mandibular dysfunction, and radiographic changes. Osteoarthrosis can occur at any stage of a disc displacement as well as after trauma, infection, and other causes that affect the integrity of the joint such as rheumatic pathologies. Osteoarthritis is characterized in that joint degenerative changes are accompanied by pain, inflammation, and weakness.
-Other disorders include ankylosis, traumatic wounds, fractures of the neck, condyle head or external ear canal, benign and malignant primary tumors, metastases, local extensions of tumors, fibrous dysplasias, and developmental abnormalities. Ankylosis or total lack of movement may be due to multiple causes, including accessory bones or fibrosis of the condylar fossa. Extracapsular causes include polyarthritis and muscle contraction that can cause significant limitation of mandibular movements. Traumatic wounds usually cause contusion and bleeding at the joint junction and are accompanied by pain and limitation in movement.
80% of patients with temporomandibular pathology improve without treatment after 6 months. The disorders of the temporomandibular joint that require treatment, of the most common at least, are muscle pain and tension, internal displacement, arthritis, wounds or trauma, excessive or reduced mobility of the joint and abnormalities of the developing. The treatment of all patients with temporo-mandibular pathologies has as objectives a reduction or elimination of pain, a restoration of mandibular function and a reduction in the need for future medical care. A key determinant in therapeutic success is the patient’s education about the disorder he suffers from as well as self-care, which includes mandibular exercises, habit changes,
The most acute temporo-mandibular symptoms are self-limiting and the need for intervention for resolution is generally minimal. Therefore, the initial treatment for myalgia and arthralgia should be self-care, in order to reduce the tension of the masticatory system by achieving relaxation of the muscles and the joint. Sometimes the use of mouth guards is recommended, especially at night to prevent teeth grinding, allowing rest and recovery of the maxillary muscles. Most patients respond well in 4-6 weeks; otherwise the need for other therapeutic interventions would arise.
In general it is recommended:
- Apply wet or cold heat to the joint or sore muscles for 20 minutes several times a day.
- Eat a milder diet. Avoid difficult chewing products and chop food before ingesting them.
- Chew food on both sides at the same time or alternate side to reduce stress on one side.
- Avoid certain foods like coffee , tea , chocolate that can increase jaw tension and trigger pain.
- Avoid bruxism with mouth guards.
- Avoid activities that involve widening the jaw (yawning, long dental treatments, etc.).
Treatment for chronic jaw pain is based on the WHO Analgesic Scale. Among the drugs we use: NSAIDs, corticosteroids, opiates, and adjuvants such as muscle relaxants, hypnotic anxiolytics, and antidepressants.
Pharmacological treatment must be accompanied by educational therapy. In the first therapeutic stage we have drugs such as NSAIDs, they are a large group with great analgesic, antipyretic and anti-inflammatory activity. However, prolonged treatment with NSAIDs must be cautious due to the side effects that it produces, especially at the gastrointestinal level. For more severe inflammatory symptoms, such as tenosynovitis, and in general in all rheumatic pathologies, coticosteroids are effective in both oral administration and iontophoresis. But repeated corticosteroid injection can induce chondrocyte apoptosis and acceleration of degenerative changes. However, hyaluronic acid injection is as effective as corticosteroids and does not cause bone degenerative changes. Muscle relaxants are administered when pain due to muscle spasticity predominates. In myalgias, especially with limited mandibular opening, they are very effective as adjuvants to analgesic treatment and also promote sleep reconciliation.
Other adjuvants in the treatment of chronic pain are the group of antidepressants. Tricyclic antidepressants like amitriptyline significantly improve pain, insomnia, and anxiety. Selective serotonin reuptake inhibitors should be used with caution in these patients because they can produce a tension increase in the masticatory musculature, thus aggravating muscle pain. These drugs should be used with caution due to the large number of undesirable effects they produce.
Treatment with opiates is indicated in chronic moderate to severe pain that does not subside with conventional pain relievers, including codeine, tramadol, morphine, fentanyl, etc., with the precautions and contraindications derived from its use.
Physical medicine can be effective in patients with pain and limited mobility. Mandibular exercise is often the only necessary treatment. Exercises include relaxation, rotation, stretching, isometric exercises, and postures.
Stretching together with local cold and heat are very effective in reducing pain and improving mobility. These exercises are effective when performed routinely by the patient, combined with postural and relaxation techniques that decrease mandibular contraction.
If the exercises are ineffective or worsen the pain, there are other physical methods that we can use such as: ultrasound, short wave, diathermy, iontophoresis, superficial heat, cryotherapy and massages.
In the short term, these treatments can reduce jaw pain and increase the range of movement, thus allowing the continuation of exercises. When mandibular movement is restricted by unreduced disc displacement, manipulation of the jaw by a physical therapist or by the patient can help improve disc remodeling, jaw translation, and pain.
The two most common splints include the anterior placement splint and the stabilization splint. The anterior placement splint or splint is used in disc displacement to reduce joint snapping that occurs during mandibular opening and closing. Its function is to hold the lower jaw forward. This splint will hold the disc in position, allowing the ligaments to tighten and joint noise to be reduced. After 2-4 months the splint is removed to allow the jaw to return to its normal position, with the expectation that the disc will remain in place. The stabilization splint or splint provides a flat occlusal surface on the teeth to allow passive protection of the jaw and the reduction of bad oral habits. The stabilization splint is the most effective for myalgia and temporomandibular arthralgia. Such splints are designed to provide postural stabilization and protect the TMJ, muscles, and teeth.
Cognitive behavioral therapy
Correcting bad habits and behaviors like jaw clenching and teeth grinding is important in the treatment of jaw pain. Cognitive behavioral therapies are aimed at eliminating these habits and developing relaxation techniques to decrease jaw tension. These therapies can be effective alone or as adjuvants to other treatments.
Behavioral therapies such as habit reversal, biofeedback, and overcorrection are the most common techniques for changing these behaviors. Although many of these habits are abandoned when the patient becomes aware of them, they often require a structured program facilitated by personnel trained in behavioral strategies. Patients should be aware that habits do not change on their own and they are responsible for these behavioral changes.
Correcting a habit can be accomplished by making the patient aware that the habit exists, how it should be corrected, and why it should be done. When this knowledge is combined with a commitment to self-supervision, most of these bad habits will be corrected.
When there is an unconscious or nightly clenching of teeth, correcting it during the day will help reduce it at night. Splints can also increase the awareness of patients with oral habits. If muscle tension is the inciting factor, relaxation techniques may be indicated. For problems like depression and anxiety, psychological therapy can be helpful. And if the problem is a sleep disorder, treatment should be directed in this regard either by psychologists or by referring the patient to a sleep laboratory for a comprehensive study.
Surgical intervention should be considered in the face of persistent localized pain in the joint that is associated with specific structural changes when the rest of the treatments have failed.
In general, less invasive surgeries are as effective as those that are more invasive, so arthrocentesis or arthroscopies should be considered first before other more aggressive interventions such as discectomy. In the postoperative period, therapy includes appropriate medication, physical therapy, splints and psychological treatment when indicated.
There is currently no documented evidence that improving occlusion by dental adjustment produces a benefit in temporomandibular disorders. Therefore, orthodontic treatments are not recommended systematically in the prevention of these disorders. However, these patients may benefit from these procedures as part of the normal care of their teeth.
Occasionally, factors such as depression and fibromyalgia can act, leading the patient to develop chronic pain that is difficult to treat. In these cases, the pain of the temporomandibular joint is more complex, and its treatment may require a multidisciplinary team that includes the dentist, maxillofacial surgeon, physiotherapist, psychologist, or other health professionals.