Temporomandibular Disorder (TMD)
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Temporomandibular joint disorder (TMD) is a broad term that includes disorders of the temporomandibular joint and its associated anatomy.
The condition may be intra-articular due to inflammation, internal structural changes (internal disturbances), or degeneration, or it may be extra-articular due to imbalance or overactivity of the jaw muscles (usually the muscles of mastication or neck). have a strong correlation Relationship between cervical postural dysfunction and TMD. There are many other conditions that can cause pain in the TMJ area. It is important to make an accurate diagnosis to ensure that the correct treatment is given and that potentially serious problems are not overlooked.
In an earlier study of postmortem specimens , it was found that in more than half of the specimens, the lateral pterygoid was attached to the meniscus of the joint capsule and medial to the fovea of the condyle. This suggests that muscle may have a specific contribution to TMD.
See the Muscles of Mastication page for more information on their anatomy.
Causes of TMD
1. Inflammation in the joint usually caused by direct trauma, such as a blow to the jaw or jaw Indirect trauma, such as whiplash Severe chewing molars (bruxism) Jaw clenching or decreased tooth height due to worn or missing teeth.
- Synovitis – The synovial membrane or joint capsule may become inflamed. Pain at rest, limited range of motion, or pain at end of range of motion is common.
- Postdiscitis – The retrodiscal tissue (where the joint disc connects to the back of the mandibular fossa) is rich in blood vessels and innervation and can cause severe pain if inflamed. The jaw may deviate from the painful side when resting and opening.
2. Internal disturbance describes a situation where structural changes occur within the joint. This can be caused by direct trauma, such as a blow to the jaw or a fall on the jaw, indirect trauma, such as whiplash, prolonged clenching or grinding of heavy objects or chewing hard or for prolonged periods of time Openings, such as dental surgery or general anesthesia.
- Disc displacement – The disc can be displaced in any direction, but most commonly it is forward. The disc is pushed forward and bunched up during opening. At some point within the range, the disc will reposition or shrink itself causing an audible or Obvious click. The jaw usually deviates to the affected side.
- Displaced disc without reduction – In this more severe version, the disc will not reset, causing pain and loss of range. This is called latch-up. The jaw usually deviates to the affected side. There will be no clicking, but patients may report that there is a clicking sound at the time When their jaws lock.
- Degenerative Arthritis can occur in the TMJ. Typically can be seen on plain x-ray or Orthopantomagram (OPG) general flattening of the condylar head and some osteophytic formation MRI for many observations done in open and closed positions. This shows the position of the joint and disc at the beginning and end of the range. Crepitus is usually palpable or audible. It can be an age-related tumor usually seen in over 50s or secondary to childhood dementia.
- Inflammatory joint diseases can affect the TMJ, including rheumatoid arthritis, ankylosing spondylitis, infectious arthritis, Reiter’s syndrome, and gout .
4. Hyper mobility
- It causes excessive forward movement of the jaw and joint disc. This will cause the jaw to deviate from the affected side. There is usually some clicking in the TMJ, which may or may not be painful. Hyperactivity may be associated with connective tissue disorders such as Conditions such as Marfan syndrome or Down syndrome and cerebral palsy. Chronic hypermobility can cause the joint disc to elongate and degenerate. The discs then fail to reduce when closed, causing the TMJ to become stuck in the open position (open lock). This usually happens when Opening your mouth to an extreme position, such as singing or yawning or after a long dental procedure.
1. Muscle spasms cause significant pain and limited jaw movement. This is called trismus. It usually affects one or more muscles, usually the muscles of mastication, especially the masseter and pterygium. Causes include prolonged dental surgery or Anesthetics with the mouth open for prolonged periods of time can cause bruxism and postural dysfunction.
2. Cervical Postural Disorders can cause jaw pain. The anterior belly of the digastric muscle extends from the tip of the nose to the hyoid bone. This attachment means that when the head is pulled forward, digastric will exert a posterior force on the mandible. The longer the uterus expands how occurs with poor posture or stress-induced posture, the mandibular condyle is pushed back posteriorly towards the posterior root causing eventually painful swelling and progressive degeneration of the disc.
3. Temporal tendinopathy is caused by excessive contraction of the temporalis muscle due to bruxism. There was palpable tenderness and swelling anterior to the temporalis tendon above the zygomatic arch. The temporal tendon may also be tender, where When the jaw is slightly open, it inserts onto the coronoid process palpable below the zygomatic arch.
4. Mandibular fractures mostly occur at the mandibular symphysis or condylar neck. Syndesmotic fractures usually occur with fracture/dislocation of one or both condyles. The mechanism of injury may be a blow to the jaw or a fall onto the jaw. treat It can usually be started within a week or two after surgery to begin early mobilization of the temporomandibular joint and return to function.
There are different clinical protocols used to establish a TMD diagnosis, but the Research Diagnostic Criteria for TMD (RDC/TMD)  could increase the level of agreement between studies  and it may also have utility in clinical use.
Assessment of TMD
As with all areas of physical therapy, a thorough medical history is required. The examination should include assessment of the patient’s posture (jaw, tongue, and neck position); palpation of the TMJs to assess swelling of one or both TMJs for muscle spasms and stiffness or hypermobility; Assess the range and quality of motion of the jaw and neck, particularly noting any misalignment or deviation of the jaw and assessing the patient’s occlusion. Also check for signs of sleep bruxism (grinding or clenching your teeth during sleep). Often patients are told by their sleeping partner They grind their teeth or their dentist may have noticed excessive wear on their teeth or scalloped edges on the sides of their tongue. Other signs include waking up with clenching of the jaw, waking up with muscle aches or temporal headaches, or sunken tongue or cheeks The patient has an OPG x-ray or MRI, these can give more information about the condition of the joint and disc, and if they can provide an open view about the amount of motion in the joint.
Treatment of TMD
TMD is a recurring but self-limiting condition that often does not progress. Non-invasive conservative treatment has been found to be effective . Physical therapy can be very effective in relieving and controlling TMD, even if symptoms are severe for a long time. Cooperate properly Physiotherapy Most patients see significant improvement in symptoms within 3 to 6 weeks. Treatment needs to address the problems identified in the assessment.
- If the patient’s symptoms are acute and inflammatory, then their condition is likely to be irritable and should be done very gently, with the aim of relieving pain, swelling, and muscle spasms first. When the pain begins to subside, then begin to restore jaw movement and alignment. possible treatment Includes soft tissue release to affected muscles and joint mobilization techniques.
- It is also important to treat any associated neck pain and headaches. Postural correction is essential and should address the position of the head, neck, shoulders, and tongue. Patients should be taught exercises to improve coordinated stability and alignment of the mandible.
- Patients with signs of bruxism should discuss with their dentist whether a bite splint is right for them. The bite splint separates the TMJ slightly to prevent compression of the TMJ when the patient bites or grinds their teeth. This can help relax the jaw muscles and reduce swelling and inflammation. There is some evidence to support the use of splinting to reduce long-term degeneration of the TMJ disc and teeth .
- Other dental problems may also need to be addressed, such as cavities that cause pain or uneven chewing, insufficient tooth height, or missing teeth.
- Patients should be taught strategies to help them manage their condition. This may include education on posture Long-term adherence to their home exercise program Good sleep habits, including sleeping positions Stress management and dietary modifications – soft food diet Acute can help reduce pain and swelling more quickly. The patient should also be taught how to reduce pressure on the TMJ by avoiding activities such as chewing on the jaw with the chin on the hand pencil while yawning with the mouth open and biting the nails while awake. They should avoid chewing chewy foods Eating gum requires a wide opening for foods such as large hamburgers and chewing on hard foods such as nuts and apples. A case report  recommends early postoperative exercises following temporomandibular joint (TMJ) ankylosis in pediatric patients and rigorous follow-up to prevent postoperative shrinkage and adhesions.
A systematic review  was published in 2015 summarizing the effectiveness of manual therapy for the signs and symptoms of TMD. It shows that cervical spine mobilization or manipulation on a mixed manual therapy protocol has considerable evidence of TMD symptom control and improvement Maximum mouth opening. Manipulative techniques include intraoral myofascial release and masticatory muscle massage therapy, atlanto-occipital joint manipulation, and upper cervical spine mobilization.
Clinicians should be trained to follow standardized guidelines and procedures in order to perform cervical grafts when indicated.
The results of a recent clinical trial suggest that both techniques of post-isometric muscle relaxation and myofacial release can be used as an effective adjuvant therapy in the prosthetic treatment of pain-related TMD with masticatory muscle tension including increasing.
Other Causes of TMJ and Facial Pain
It is important to recognize that there are other causes of pain and dysfunction in the oro-facial region that should be differentiated from TMD. Below are some of the most common.
1. Pain Referral – Noxious impulses from both the trigeminal nerve C1 C2 and C3 nerves are transmitted to the trigeminocervical nucleus in the brain and can cause referred pain. “The trigeminocervical nucleus is a portion of the upper cervical spine containing sensory nerve fibers in the. the descending course of the trigeminal nerve (trigeminal nucleus caudalis) is believed to communicate with sensory fibers from the superior cervical spine. This overlap between the upper cervical and three-nerve sensory pathways allows bidirectional transmission of pain sensation between the neck and trigeminal sensory receptive fields of the face and head.” This means that each part of the head and upper neck can project pain to any other part. A careful examination of the patient’s TMJ and neck is critical to ensure all factors contributing to the condition diagnosed and treated.
2. Neuropathic Pain
- Trigeminal neuralgia (Tic Doloreaux) is characterized by severe shooting pain in the distribution of one or more of the three branches of the trigeminal nerve (cranial nerve V). It may be caused by sensitization of the trigeminal nerve or compression or impingement of the nerve. usually a support.
- Trigeminal neuritis is caused by inflammation of the trigeminal nerve.
- Complex regional pain syndrome is characterized by a constant burning pain, not necessarily on the path of a specific nerve. It is usually secondary to trauma and exacerbated by fear or anxiety. As it gets worse, skin changes and sweating may appear in the painful area. these patients Early referral to a pain specialist is needed to prevent progression of the condition.
- Bell’s palsy is a palsy of the facial nerve (cranial nerve VII). In about 70% of cases, it resolves within 6 to 8 weeks. Early treatment with prednisone can significantly shorten recovery time. If residual weakness is present, physical therapy may be needed.
- Herpes zoster (herpes zoster) usually affects the ophthalmic branch of the trigeminal nerve and presents as pain and blisters along the nerve’s path.
- Atypical toothache presents as toothache with no apparent dental cause.
- Central sensitization is sensitization of the dorsal horn and central structures, resulting in secondary hyperalgesia of uninjured tissue surrounding the injured site.
3. Vestibular dysfunction can cause secondary headache and jaw pain. The vestibular system is a complex system that includes the inner ear and the balance of central nervous system structures. Its main function is to sense the linear acceleration and angular acceleration of the head coordinates Head and eyes move and assist in maintaining balance.  Dysfunction of the vestibular system can cause dizziness, nausea, anxiety, neck pain, and ear and jaw pain. Since these symptoms may resemble those of TMD, the vestibular system must be considered As a possible alternative cause of jaw pain.
4. Parotid Gland Stone blockage can cause pain and swelling in the parotid gland. This condition requires an accurate diagnosis to rule out parotid tumors. Blocked parotid glands can respond to stroking massage and higher intensity ultrasound.
5. Need to exclude benign or malignant tumors. They can cause loss of function and pain in tonic contractures. These secondary problems may require treatment once the tumor’s treatment is resolved.
6. Sinus Pain is caused by inflammation of the maxillary sinus. It is characterized by facial pain headache pain in the upper teeth and a feeling of crowded side. Sinus pain can lead to secondary cervical pain and TMJ.
7. Vascular pain or Headache
- Migraines with or without aura may be accompanied by itchy rashes that are visual or auditory sensations. It can cause secondary pressure or cervical headache. There is early evidence that treating neck dysfunction with exercise can significantly reduce its severity and frequency atrial fibrillation. Dr Ian Devlin states In the author’s experience, the cervical spine plays an important role in causing headaches. Additionally, some migraine sufferers report significant improvements in the frequency and severity of their migraines with better care of their cervical spine poor performance. In clinical practice patients report that physiotherapists for cervical spine insufficiency can reduce the frequency of migraine episodes. (11) In our practice we have found that neck stiffness relief and pain management have not only reduced but reduced the incidence of neck headaches has also helped our patients reduce their migraine headaches.
- Cluster Headaches are usually unilateral and occur in bouts lasting 30-60 minutes with 1-3 attacks per day. It is more common in men and the pain is usually worse. These headaches are usually not responsive to physio but treatment can help any cervical or secondary TMJ symptoms.
- Arterio-Venous Malformations such as temporal arteritis can cause moderate to severe headaches in the temporal region. The pain is usually unilateral and can refer to the face and neck. It is more common in older people especially women and can be associated with polymyalgia rheumatica. These patients need immediate referral to a specialist as vision may be lost.
8. Psychogenic Pain
- Chronic facial pain occurs when pain becomes chronic and psychological factors cause the pain to persist despite complete resolution of the original injury.
- Bipolar Disorder and other mood disorders.
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