Temporomandibular joint disorder (
TMJD or
TMD), or
TMJ syndrome, is an umbrella term covering acute or
chronicIn medicine, a chronic disease is a disease that is long-lasting or recurrent. The term chronic describes the course of the disease, or its rate of onset and development. A chronic course is distinguished from a recurrent course; recurrent diseases relapse repeatedly, with periods of remission in...
inflammationInflammation is the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli as well as initiate the healing process for the tissue. Inflammation is not a...
of the
temporomandibular jointThe temporomandibular joint is the joint of the jaw and is frequently referred to as TMJ. There are two TMJs, one on either side, working in unison. The name is derived from the two bones which form the joint: the upper temporal bone which is part of the cranium , and the lower jaw bone called the...
, which connects the
mandibleThe mandible or inferior maxillary bone forms the lower jaw and holds the lower teeth in place. It also refers to both the upper and lower sections of the beaks of birds; in this case the "lower mandible" corresponds to the mandible of humans while the "upper mandible" is functionally equivalent...
to the
skullThe skull is a bony structure found in the head of many animals. The skull supports the structures of the face and protects the head against injury....
. The disorder and resultant dysfunction can result in significant
painPhysical Pain is the unpleasant feeling common to a headache and a stubbed toe. It typically consists of negative affect and aversion, and has location, duration, intensity and a distinctive quality...
and impairment. Because the disorder transcends the boundaries between several health-care disciplines — in particular,
dentistryDentistry is the known evaluation, diagnosis, prevention, and treatment of diseases, disorders and conditions of the soft and hard tissues of the jaw , the oral cavity, maxillofacial area and the adjacent and associated structures and their impact on the human body. Dentistry is a part of stomatology...
,
neurologyNeurology is a medical specialty dealing with disorders of the nervous system. Specifically, it deals with the diagnosis and treatment of all categories of disease involving the central, peripheral, and autonomic nervous systems, including their coverings, blood vessels, and all effector tissue,...
,
physical therapyPhysical therapy is a health care profession which provides services to individuals in order to develop, maintain and restore maximum movement and functional ability throughout life...
, and
psychologyPsychology is an academic and applied discipline involving the systematic, and sometimes scientific, study of human or animal mental functions and behavior...
— there are a variety of treatment approaches.
The temporomandibular joint is susceptible to many of the conditions that affect other joints in the body, including
ankylosisAnkylosis, or Anchylosis is a stiffness of a joint, the result of injury or disease. The rigidity may be complete or partial and may be due to inflammation of the tendinous or muscular structures outside the joint or of the tissues of the joint itself...
,
arthritisArthritis is a group of conditions involving damage to the joints of the body....
, trauma,
dislocationJoint dislocation, or luxation , occurs when bones in a joint become displaced or misaligned. It is often caused by a sudden impact to the joint. The ligaments always become damaged as a result of a dislocation...
s, developmental anomalies, and
neoplasiaNeoplasm is an abnormal mass of tissue as a result of neoplasia.Neoplasia is the abnormal proliferation of cells. The growth of this clone of cells exceeds, and is uncoordinated with, that of the normal tissues around it. It usually causes a lump or tumor...
.
Signs and symptoms of temporomandibular joint disorder vary in their presentation and can be very complex.
Temporomandibular joint disorder (
TMJD or
TMD), or
TMJ syndrome, is an umbrella term covering acute or
chronicIn medicine, a chronic disease is a disease that is long-lasting or recurrent. The term chronic describes the course of the disease, or its rate of onset and development. A chronic course is distinguished from a recurrent course; recurrent diseases relapse repeatedly, with periods of remission in...
inflammationInflammation is the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli as well as initiate the healing process for the tissue. Inflammation is not a...
of the
temporomandibular jointThe temporomandibular joint is the joint of the jaw and is frequently referred to as TMJ. There are two TMJs, one on either side, working in unison. The name is derived from the two bones which form the joint: the upper temporal bone which is part of the cranium , and the lower jaw bone called the...
, which connects the
mandibleThe mandible or inferior maxillary bone forms the lower jaw and holds the lower teeth in place. It also refers to both the upper and lower sections of the beaks of birds; in this case the "lower mandible" corresponds to the mandible of humans while the "upper mandible" is functionally equivalent...
to the
skullThe skull is a bony structure found in the head of many animals. The skull supports the structures of the face and protects the head against injury....
. The disorder and resultant dysfunction can result in significant
painPhysical Pain is the unpleasant feeling common to a headache and a stubbed toe. It typically consists of negative affect and aversion, and has location, duration, intensity and a distinctive quality...
and impairment. Because the disorder transcends the boundaries between several health-care disciplines — in particular,
dentistryDentistry is the known evaluation, diagnosis, prevention, and treatment of diseases, disorders and conditions of the soft and hard tissues of the jaw , the oral cavity, maxillofacial area and the adjacent and associated structures and their impact on the human body. Dentistry is a part of stomatology...
,
neurologyNeurology is a medical specialty dealing with disorders of the nervous system. Specifically, it deals with the diagnosis and treatment of all categories of disease involving the central, peripheral, and autonomic nervous systems, including their coverings, blood vessels, and all effector tissue,...
,
physical therapyPhysical therapy is a health care profession which provides services to individuals in order to develop, maintain and restore maximum movement and functional ability throughout life...
, and
psychologyPsychology is an academic and applied discipline involving the systematic, and sometimes scientific, study of human or animal mental functions and behavior...
— there are a variety of treatment approaches.
The temporomandibular joint is susceptible to many of the conditions that affect other joints in the body, including
ankylosisAnkylosis, or Anchylosis is a stiffness of a joint, the result of injury or disease. The rigidity may be complete or partial and may be due to inflammation of the tendinous or muscular structures outside the joint or of the tissues of the joint itself...
,
arthritisArthritis is a group of conditions involving damage to the joints of the body....
, trauma,
dislocationJoint dislocation, or luxation , occurs when bones in a joint become displaced or misaligned. It is often caused by a sudden impact to the joint. The ligaments always become damaged as a result of a dislocation...
s, developmental anomalies, and
neoplasiaNeoplasm is an abnormal mass of tissue as a result of neoplasia.Neoplasia is the abnormal proliferation of cells. The growth of this clone of cells exceeds, and is uncoordinated with, that of the normal tissues around it. It usually causes a lump or tumor...
.
Signs and symptoms
Signs and symptoms of temporomandibular joint disorder vary in their presentation and can be very complex. Often the symptoms will involve more than one of the numerous TMJ components:
muscleMuscle is the contractile tissue of the body and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
s, nerves, tendons, ligaments,
boneBones are rigid organs that form part of the endoskeleton of vertebrates. They function to move, support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...
s,
connective tissueConnective tissue is a form of fibrous tissue.. It is one of the four types of tissue in traditional classifications ....
, and the teeth.
Ear pain associated with the swelling of proximal tissue is a symptom of temporomandibular joint disorder.
Muscles
Disorders of the muscles of the temporomandibular joint are the most common complaints by TMD patients. The two major observations concerning the muscles are pain and dysfunction. The dysfunction can present as
trismusTrismus is the inability to normally open the mouth due to one of many causes. It involves the trigeminal nerve.-Common causes:*Pericoronitis is the most common cause of trismus....
or limitation of jaw movement ranging from minor to severe. In milder cases, the only representation may be joint sound such as clicking or popping. These symptoms of TMD are often caused by overusage of the muscles of mastication. Common causes include chewing gum continuously, biting habits (fingernails and pencils), grinding habits, and clenching habits.
Most cases of TMJ, however, are not so simple. Deep-space infections with resulting
trismusTrismus is the inability to normally open the mouth due to one of many causes. It involves the trigeminal nerve.-Common causes:*Pericoronitis is the most common cause of trismus....
or neoplasm about the joint may mimic TMJ dysfunction. Muscle pain can sometimes be associated with
trigger pointTrigger points or trigger sites are described as hyperirritable spots in skeletal muscle that are associated with palpable nodules in taut bands of muscle fibers. Trigger point researchers believe that palpable nodules are small contraction knots and a common cause of pain. Compression of a...
s in muscle tissue. These trigger points can be localized by digital
palpationPalpation is used as part of a physical examination in which an object is felt to determine its size, shape, firmness, or location...
, both intraorally and extraorally. This is known as
Myofascial pain syndromeMyofascial Pain Syndrome is a term used to describe one of the conditions characterized by chronic, and in some cases, severe, pain. It is associated with and caused by "trigger points" , which are localized and sometimes extremely painful contractures found in any skeletal muscle of the body...
.
Any dysfunction of the muscles may cause the teeth to occlude (bite) with each other incorrectly; if teeth are traumatized by this, they may become sensitive, demonstrating one of the many interplays between muscle, joint, and tooth.
Temporomandibular joints
This is arguably the most complex set of joints in the human body. Unlike typical finger or vertebral junctions, each TMJ actually has two joints, which allow it to both rotate and to translate (slide). With use, it is common to see wear of both the bone and cartilage components of it. Clicking is common, as are popping motions and deviations in the movements of the joint. It is considered a TMJ disorder when pain is involved.
In a healthy joint, the surfaces in contact with one another (bone and cartilage) do not have any receptors to transmit the feeling of pain. The pain therefore originates from one of the surrounding soft tissues. When receptors from one of these areas are triggered, the pain causes a reflex to limit the mandible's movement. Furthermore, inflammation of the joints can cause constant pain, even without movement of the jaw.
Due to the proximity of the ear to the temporomandibular joint, TMJ pain can often be confused with ear pain. The pain may be
referredReferred pain is a term used to describe the phenomenon of pain perceived at a site adjacent to or at a distance from the site of an injury's origin...
in around half of all patients and experienced as
otalgiaOtalgia is ear pain or an earache. Primary otalgia is from pain that originates inside the ear. Referred otalgia is from pain that originates from outside the ear.Otalgia is not always associated with ear disease...
(earache). Conversely, TMD is an important possible cause of secondary otalgia. Treatment of TMD may then significantly reduce symptoms of otalgia and
tinnitusTinnitus is the perception of sound within the human ear in the absence of corresponding external sound....
, as well as atypical facial pain. Despite some of these findings, some researchers question whether TMD therapy can reduce symptoms in the ear, and there is currently an ongoing debate to settle the controversy.
The dysfunction involved is most often in regards to the relationship between the condyle of the mandible and the disc. The sounds produced by this dysfunction are usually described as a "click" or a "pop" when a single sound is heard and as "crepitation" or "crepitus" when there are multiple, rough sounds
Teeth
Disorders of the teeth can contribute to TMJ dysfunction. Impaired tooth mobility and
tooth lossTooth loss is when one or more teeth come loose and fall out. Tooth loss is normal for deciduous teeth , when they are replaced by a person's adult teeth. Otherwise, losing teeth is undesirable and is the result of injury or disease, such as mouth trauma, tooth injury, tooth decay, and gum disease...
can be caused by destruction of the supporting bone and by heavy forces being placed on teeth. The movement of the teeth affects how they contact one another when the mouth closes, and the overall relationship between the teeth, muscles, and joints can be altered. Pulpitis, inflammation of the dental pulp, is another symptom that may result from excessive surface erosion. Maybe the most important factor is the way the teeth meet together: the equilibration of forces of mastication and therefore the displacements of the condyle.
Precipitating factors
There are many external factors that place undue strain on the TMJ. These include but are not limited to the following:
Over-opening the jaw beyond its range for the individual or unusually aggressive or repetitive sliding of the jaw sideways (
laterallyStandard anatomical terms of location are employed in science which deal with the anatomy of animals to avoid ambiguities which might otherwise arise. They are not language-specific, and thus require no translation...
) or forward (protrusive). These movements may also be due to parafunctional habits or a malalignment of the jaw or dentition. This may be due to:
- Trauma
- Repetitive unconscious jaw movements called bruxing
Bruxism is characterized by the grinding of the teeth and is typically accompanied by the clenching of the jaw. It is an oral parafunctional activity that occurs in most humans at some time in their lives. In most people, bruxism is mild enough not to be a health problem...
.
- Malalignment of the occlusal surfaces of the teeth due to dental defect or neglect.
- Jaw thrusting (causing unusual speech and chewing habits).
- Excessive gum chewing or nail biting.
- Size of foods eaten.
- Degenerative joint disease, such as osteoarthritis or organic degeneration of the articular surfaces, recurrent fibrous and/or bony ankylosis, developmental abnormality, or pathologic lesions within the TMJ
- Myofascial pain dysfunction syndrome
- Lack of Overbite
Restoration of the occlusal surfaces of the teeth
If the occlusal surfaces of the teeth or the supporting structures have been damaged due to dental neglect, periodontal diseases or trauma, the proper occlusion should be restored.
Pain relief
While conventional
analgesicAn analgesic is any member of the diverse group of drugs used to relieve pain . The word analgesic derives from Greek an- and algos...
pain killers such as
paracetamolParacetamol or acetaminophen is a widely used over-the-counter analgesic and antipyretic . It is commonly used for the relief of fever, headaches, and other minor aches and pains, and is a major ingredient in numerous cold and flu remedies...
(acetaminophen) or NSAIDs provide initial relief for some sufferers, the pain is often more
neuralgicNeuralgia is pain in one or more nerves. When equated to neuropathic pain can be defined as non-nociceptive pain, or in other words, pain that is not related to activation of pain receptor cells in any part of the body. Neuralgia is pain produced by a change in neurological structure or function....
in nature, which often does not respond well to these drugs.
An alternative approach is for pain modification, for which
off-label useOff-label use is the practice of prescribing pharmaceuticals for an unapproved indication.. In the United States, the Food and Drug Administration Center for Drug Evaluation and Research reviews a company's New Drug Application for data from clinical trials to see if the results support the drug...
of low-doses of
Tricyclic antidepressantTricyclic antidepressants are a class of psychoactive drugs used primarily as antidepressants, which were first discovered in the early 1950s, and subsequently introduced later in the decade...
that have anti-muscarinic properties (e.g.
AmitriptylineAmitriptyline is a psychoactive drug and pharmaceutical of the tricyclic antidepressant chemical class which is used primarily as an antidepressant and anxiolytic agent. It is the most widely prescribed TCA and perhaps also the most efficient against depressive symptoms.- Approved :Amitriptyline...
or the less sedative
NortriptylineNortriptyline is a second-generation tricyclic antidepressant marketed as the hydrochloride under the trade names Sensoval, Aventyl, Pamelor, Norpress, Allegron and Nortrilen. It is used in the treatment of major depression and childhood nocturnal enuresis...
) generally prove more effective.
Long-term approach
It is suggested that before the attending dentist commences any plan or approach utilizing medications or surgery, a thorough search for inciting para-functional jaw habits must be performed. Correction of any discrepancies from normal can then be the primary goal.
An approach to eliminating para-functional habits involves the taking of a detailed history and careful physical examination. The medical history should be designed to reveal duration of illness and symptoms, previous treatment and effects, contributing medical findings, history of facial trauma, and a search for habits that may have produced or enhanced symptoms. Particular attention should be directed in identifying perverse jaw habits, such as clenching or teeth grinding, lip or cheek biting, or positioning of the lower jaw in an edge-to-edge bite. All of the above strain the muscles of mastication (chewing) and results in jaw pain. Palpation of these muscles will cause a painful response.
Treatment is oriented to eliminating oral habits, physical therapy to the masticatory muscles, and alleviating bad posture of the head and neck. A flat-plane full-coverage
oral applianceOral appliances are devices that a patient will wear for a certain period of time to treat various orofacial disorders. They are commonly used to treat sleep apnea and TMJ disorders.-MORA:...
, e.g. a non-repositioning stabilization splint, often is helpful to control
bruxismBruxism is characterized by the grinding of the teeth and is typically accompanied by the clenching of the jaw. It is an oral parafunctional activity that occurs in most humans at some time in their lives. In most people, bruxism is mild enough not to be a health problem...
and take stress off the temporomandibular joint, although some individuals may bite harder on it, resulting in a worsening of their conditions. The anterior splint, with contact at the front teeth only, may then prove helpful. This method of treatment is often referred to as "splint therapy."
According to the National Institute of Dental and Craniofacial Research (NIDCR) of the National Institutes of Health (NIH), TMJ treatments should be reversible whenever possible. That means that the treatment should not cause permanent changes to the jaw or teeth.
Examples of reversible treatments are:
- Over-the-counter pain medications, used according to manufacturers’ instructions.
- Prescription medications prescribed by a healthcare provider.
- Gentle jaw stretching and relaxation exercises you can do at home. Your healthcare provider can recommend exercises for your particular condition, if appropriate.
- Feldenkrais TMJ Program, uses a unique understanding of human neurology to reduce chronic tension in the jaw, face, neck, and upper back, and to reverse long-standing movement habits responsible for the original TMJ symptoms.
- Stabilization splint (biteplate, nightguard) is the most widely used treatment for TMJ and jaw muscle problems; however, the actual effectiveness of these splints is unclear. If an oral splint is recommended, it should be used only for a short time and should not cause permanent changes in the bite. If a splint causes or increases pain, stop using it and tell your healthcare provider. Avoid using over-the-counter mouthguards for TMJ treatment. If a splint is not properly fitted, the teeth may shift and worsen the condition.
- Mandibular Repositioning Devices can be worn for a short time to help alleviate symptoms related to painful clicking when opening the mouth wide, but 24-hour wear for the long term may lead to changes in the position of the teeth that can complicate treatment. A typical long-term permanent treatment (if the device is proven to work especially well for the situation) would be to convert the device to a flat-plane bite plate fully covering either the upper or lower teeth and to be used only at night.
What may be concluded is that there are various treatment modalities which a well-trained experienced dentist may employ to relieve symptoms and improve joint function. They include:
- Manual adjustment of the bite by grinding the teeth
- Mandibular repositioning splints which move the jaw, ligaments and muscles into a new position and myofunctional therapy
- Reconstructive dentistry
- Orthodontics
- Arthrocentesis (joint irrigation)
- Surgical repositoning of jaws to correct congenital jaw malformations such as prognathism and retrognathia
- Replacement of the jaw joint(s) or disc(s) with TMJ implants (This should be considered only as a treatment of last resort.)
Attempts in the last decade to develop
surgical treatmentSurgery is a medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, to help improve bodily function or appearance, or sometimes for some other reason...
s based on MRI and CAT scans now receive less attention. These techniques are reserved for the most recalcitrant cases where other therapeutic modalities have changed. Exercise protocols, habit control, and splinting should be the first line of approach, leaving
oral surgeryOral Surgery is a recognised international specialist training course in dentistry.Oral and maxillofacial surgery is the specialty of dentistry that includes the diagnosis, surgical and related treatment of diseases, injuries and defects involving both the functional and esthetic aspects of the...
as a last resort. Certainly a focus on other possible causes of facial pain and jaw immobility and dysfunction should be the initial consideration of the examining oral-facial pain specialist, oral surgeon or health professional.
One option for oral surgery, is to manipulate the jaw under general anaesthetic and wash out the joint with a saline and anti-inflammatory solution in a procedure known as
arthrocentesisArthrocentesis is the clinical procedure of using a syringe to collect synovial fluid from a joint capsule. It is also known as joint aspiration. Arthrocentesis is used in the diagnosis of gout, arthritis, and synovial infections.- External links :...
. In some cases, this will reduce the inflammatory process.
See also
- Bruxism
Bruxism is characterized by the grinding of the teeth and is typically accompanied by the clenching of the jaw. It is an oral parafunctional activity that occurs in most humans at some time in their lives. In most people, bruxism is mild enough not to be a health problem...
The entry for "syndrome, Costen" in Dorland's Medical Dictionary is an all-encompassing definition of this symptom complex.
External links
- The TMJ Association is a patient based advocacy organization, whose mission is to provide information on temporomandibular joint and the development of universal standards for safe, effective, affordable, research-based diagnostics, treatments, and prevention of Temporomandibular Joint and Muscle Disorders (TMJDs).
- The NIH brochure on TMJ Disorders describes the causes, signs and symptoms, diagnosis and treatment of temporomandibular joint and muscle disorders.
- TMJ/TMJD - Jaw Joints & Allied Musculo-Skeletal Disorders Foundation, Inc.
- The American Association of Oral and Maxillofacial Surgeons (AAOMS) - The Temporomandibular Joint (TMJ)
- TMJ Disorders - National Institute of Dental and Craniofacial Research, National Institutes of Health
- WebMD Information and Resources
- Temporomandibular Joint Disorder - CMD Orthodontics / TMJ-Orthodontics]
- Medical Devices: FDA's Approval of Four Temporomandibular Joint Implants GAO-07-996 September 17, 2007
- The American Academy of Craniofacial Pain
- FDA CDRH Consumer Information Update on TMJ Implants - Center for Devices and Radiological Health Consumer Informational Update on TMJ Implants