Trismus is a condition of restricted opening of the mouth. The term was initially used in the setting of

tetanus Tetanus (), also known as lockjaw, is a bacterial infection caused by ''Clostridium tetani'' and characterized by muscle spasms. In the most common type, the spasms begin in the jaw and then progress to the rest of the body. Each spasm usually l ...

. Trismus may be caused by

spasm A spasm is a sudden involuntary contraction of a muscle, a group of muscles, or a hollow organ, such as the bladder. A spasmodic muscle contraction may be caused by many medical conditions, including dystonia. Most commonly, it is a musc ...

of the

muscles of mastication The four classical muscles of mastication elevate the mandible (closing the jaw) and move it forward/backward and laterally, facilitating biting and chewing. Other muscles are responsible for opening the jaw, namely the geniohyoid, mylohyoid, an ...

or a variety of other causes. Temporary trismus occurs much more frequently than permanent trismus. It is known to interfere with eating, speaking, and maintaining proper oral hygiene. This interference, specifically with an inability to swallow properly, results in an increased risk of aspiration. In some instances, trismus presents with altered facial appearance. The condition may be distressing and painful. Examination and treatments requiring access to the oral cavity can be limited, or in some cases impossible, due to the nature of the condition itself.

Definition

Trismus is defined as painful restriction in opening the mouth due to a muscle spasm, however it can also refer to limited mouth opening of any cause. Another definition of trismus is simply a limitation of movement. Historically and commonly, the term ''lockjaw'' was sometimes used as a synonym for both trismus and

. Normal mouth-opening ranges from 35 to 45 mm. Males usually have slightly greater mouth opening than females. (40–60 mm, average of 50 mm). The normal lateral movement is 8–12 mm, and normal protrusive movement is approximately 10 mm. Some have distinguished mild trismus as 20–30 mm interincisal opening, moderate as 10–20 mm and severe as less than 10 mm. Trismus is derived from the Greek word ''trigmos/trismos'' meaning "a scream; a grinding, rasping or gnashing".

Differential diagnosis

Traditionally causes of trismus are divided into intra-articular (factors within the

temporomandibular joint In anatomy, the temporomandibular joints (TMJ) are the two joints connecting the jawbone to the skull. It is a bilateral Synovial joint, synovial articulation between the temporal bone of the skull above and the condylar process of mandible be ...

MJ and extra-articular (factors outside the joint, see table).

Joint problems

Ankylosis

* True bony ankylosis: can result from trauma to chin, infections and from prolonged immobilization following condylar fracture ** Treatment – several surgical procedures are used to treat bony ankylosis, e.g.: Gap arthroplasty using interpositional materials between the cut segments. * Fibrous ankylosis: usually results due to trauma and infection ** Treatment – trismus appliances in conjunction with physical therapy.

Arthritis synovitis

Meniscus pathology

Extra-articular causes

Infection

* Odontogenic- Pulpal ** Periodontal ** Pericoronal * Non-odontogenic- Peritonsillar abscess ** Tetanus ** Meningitis ** Brain abscess ** Parotid abscess * The hallmark of a masticatory space infection is trismus or infection in anterior compartment of lateral pharyngeal space results in trismus. If these infections are unchecked, can spread to various facial spaces of the head and neck and lead to serious complications such as cervical cellulitis or mediastinitis. ** Treatment: Elimination of etiologic agent along with antibiotic coverage * Trismus or lock jaw due to masseter muscle spasm, can be a primary presenting symptom in tetanus, Caused by ''Clostridium tetani'', where tetanospasmin (toxin) is responsible for muscle spasms. ** Prevention: primary immunization (DPT)

Dental treatment

* Dental trismus is defined by difficulty in opening the jaw. It is a temporary condition that usually lasts no more than two weeks. Dental trismus is caused by an injury to the masticatory muscles, such as opening the jaw for an extended period of time or having a needle pass through a muscle. Typical dental anesthesia for the lower jaw involves inserting a needle into or through a muscle. In these cases it is usually the medial pterygoid or the

buccinator muscle The bucinator () is a thin quadrilateral muscle occupying the interval between the maxilla and the Human mandible, mandible at the side of the face. It forms the anterior part of the cheek or the lateral wall of the oral cavity.Illustrated Anatom ...

s. * Oral surgery procedures, as in the extraction of lower molar teeth, may cause trismus as a result either of inflammation to the muscles of mastication or direct trauma to the TMJ. * Barbing of needles at the time of injection followed by tissue damage on withdrawal of the barbed needle causes post-injection persistent paresthesia, trismus and paresis. ** Treatment: in acute phase: *** Heat therapy *** Analgesics *** A soft diet *** Muscle relaxants (if necessary) *** Note: When acute phase is over the patient should be advised to initiate physiotherapy for opening and closing mouth.

Trauma

Fractures, particularly those of the mandible and fractures of

zygomatic arch In anatomy, the zygomatic arch (colloquially known as the cheek bone), is a part of the skull formed by the zygomatic process of temporal bone, zygomatic process of the temporal bone (a bone extending forward from the side of the skull, over the ...

and zygomatic arch complex, accidental incorporation of foreign bodies due to external traumatic injury. Treatment: fracture reduction, removal of foreign bodies with antibiotic coverage

TMJ disorders

* Extra-capsular disorders – Myofascial pain dysfunction syndrome * Intra-capsular problems – Disc displacement, arthritis, fibrosis, etc. * Acute closed locked conditions – displaced meniscus

Tumors and oral care

Rarely, trismus is a symptom of nasopharyngeal or infratemporal tumors/ fibrosis of temporalis tendon, when patient has limited mouth opening, always premalignant conditions like oral submucous fibrosis (OSMF) should also be considered in differential diagnosis.

Drug therapy

Succinyl choline,

phenothiazines Phenothiazine, abbreviated PTZ, is an organic compound that has the formula S(C6H4)2NH and is related to the thiazine-class of heterocyclic compounds. Derivatives of phenothiazine are highly bioactive and have widespread use and rich history. ...

and tricyclic antidepressants causes trismus as a secondary effect. Trismus can be seen as an extra-pyramidal side-effect of metoclopromide, phenothiazines and other medications.

Radiotherapy and chemotherapy

* Complications of radiotherapy: ** Osteoradionecrosis may result in pain, trismus, suppuration and occasionally a foul smelling wound. ** When muscles of mastication are within the field of radiation, it leads to fibrosis and result in decreased mouth opening. * Complications of Chemotherapy: ** Oral mucosal cells have high growth rate and are susceptible to the toxic effects of chemotherapy, which lead to stomatitis.

Congenital and developmental causes

* Hypertrophy of coronoid process causes interference of coronoid against the anteromedial margin of the zygomatic arch. ** Treatment: Coronoidectomy * Trismus-pseudo-camtodactyly syndrome is a rare combination of hand, foot and mouth abnormalities and trismus.

Miscellaneous disorders

* Functional disorders ( neuro-psychiatric), the emotional conflict are converted into a physical symptom. E.g.: trismus * Scleroderma: A condition marked by edema and induration of the skin involving facial region can cause trismus

Common causes

* Pericoronitis (inflammation of soft tissue around impacted third molar) is the most common cause of trismus. * Inflammation of

. It is a frequent sequel to surgical removal of mandibular third molars (lower

wisdom teeth The third molar, commonly called wisdom tooth, is the most posterior of the three molars in each quadrant of the human dentition. The age at which wisdom teeth come through ( erupt) is variable, but this generally occurs between late teens a ...

). The condition is usually resolved on its own in 10–14 days, during which time eating and

oral hygiene Oral hygiene is the practice of keeping one's oral cavity clean and free of disease and other problems (e.g. bad breath) by regular brushing of the teeth (dental hygiene) and adopting good hygiene habits. It is important that oral hygiene be carr ...

are compromised. The application of heat (e.g. heat bag extraorally, and warm salt water intraorally) may help, reducing the severity and duration of the condition. * Peritonsillar abscess, a complication of

tonsillitis Tonsillitis is inflammation of the tonsils in the upper part of the throat. It can be acute or chronic. Acute tonsillitis typically has a rapid onset. Symptoms may include sore throat, fever, enlargement of the tonsils, trouble swallowing, and en ...

which usually presents with sore throat,

dysphagia Dysphagia is difficulty in swallowing. Although classified under " symptoms and signs" in ICD-10, in some contexts it is classified as a condition in its own right. It may be a sensation that suggests difficulty in the passage of solids or l ...

fever Fever or pyrexia in humans is a symptom of an anti-infection defense mechanism that appears with Human body temperature, body temperature exceeding the normal range caused by an increase in the body's temperature Human body temperature#Fever, s ...

, and change in voice. *

Temporomandibular joint dysfunction Temporomandibular joint dysfunction (TMD, TMJD) is an umbrella term covering pain and dysfunction of the muscles of mastication (the muscles that move the jaw) and the temporomandibular joints (the joints which connect the Human mandible, mand ...

(TMD). * Trismus is often mistaken as a common temporary side effect of many

stimulants Stimulants (also known as central nervous system stimulants, or psychostimulants, or colloquially as uppers) are a class of drugs that increase alertness. They are used for various purposes, such as enhancing attention, motivation, cognitio ...

of the sympathetic nervous system. Users of

amphetamines Substituted amphetamines, or simply amphetamines, are a chemical class, class of compounds based upon the amphetamine structure; it includes all derivative (chemistry), derivative compounds which are formed by replacing, or substitution reacti ...

as well as many other pharmacological agents commonly report

bruxism Bruxism is excessive teeth grinding or jaw clenching. It is an oral Parafunctional habit, parafunctional activity; i.e., it is unrelated to normal function such as eating or talking. Bruxism is a common behavior; the global prevalence of brux ...

as a side-effect; however, it is sometimes mis-referred to as trismus. Users' jaws do not lock, but rather the muscles become tight and the jaw clenched. It is still perfectly possible to open the mouth. * Submucous fibrosis. * Fracture of the

. * Oral sex

Other causes

* Acute

osteomyelitis Osteomyelitis (OM) is the infectious inflammation of bone marrow. Symptoms may include pain in a specific bone with overlying redness, fever, and weakness. The feet, spine, and hips are the most commonly involved bones in adults. The cause is ...

Ankylosis Ankylosis () is a stiffness of a joint due to abnormal adhesion and rigidity of the bones of the joint, which may be the result of injury or disease. The rigidity may be complete or partial and may be due to inflammation of the Tendon, tendinous ...

of the TMJ (fibrous or bony) * Condylar fracture or other trauma. * Gaucher disease which is caused by deficiency of the enzyme glucocerebrosidase. *

Giant cell arteritis Giant cell arteritis (GCA), also called temporal arteritis, is an inflammatory autoimmune disease of large blood vessels. Symptoms may include headache, pain over the temples, flu-like symptoms, double vision, and difficulty opening the mout ...

* Sympathomimetic drugs, such as

amphetamine Amphetamine (contracted from Alpha and beta carbon, alpha-methylphenethylamine, methylphenethylamine) is a central nervous system (CNS) stimulant that is used in the treatment of attention deficit hyperactivity disorder (ADHD), narcolepsy, an ...

methamphetamine Methamphetamine (contracted from ) is a potent central nervous system (CNS) stimulant that is mainly used as a recreational drug use, recreational or Performance-enhancing substance, performance-enhancing drug and less commonly as a secon ...

, MDA,

MDMA 3,4-Methylenedioxymethamphetamine (MDMA), commonly known as ecstasy (tablet form), and molly (crystal form), is an empathogen–entactogenic drug with stimulant and minor Psychedelic drug, psychedelic properties. In studies, it has been used ...

, MDEA,

methylphenidate Methylphenidate, sold under the brand names Ritalin ( ) and Concerta ( ) among others, is a central nervous system (CNS) stimulant used in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. It may be taken Oral adm ...

, ethylphenidate, and related substances. * Infection *

Local anesthesia Local anesthesia is any technique to induce the absence of sense, sensation in a specific part of the body, generally for the aim of inducing local analgesia, i.e. local insensitivity to pain, although other local senses may be affected as well. ...

(dental injections into the infratemporal fossa) * Needle prick to the

medial pterygoid muscle The medial pterygoid muscle (or internal pterygoid muscle) is a thick, quadrilateral muscle of the face. It is supplied by the mandibular branch of the trigeminal nerve (V). It is important in mastication (chewing). Structure The medial pter ...

* Oral submucous fibrosis. *

Radiation therapy Radiation therapy or radiotherapy (RT, RTx, or XRT) is a therapy, treatment using ionizing radiation, generally provided as part of treatment of cancer, cancer therapy to either kill or control the growth of malignancy, malignant cell (biology), ...

to the head and neck. *

Tetanus Tetanus (), also known as lockjaw, is a bacterial infection caused by ''Clostridium tetani'' and characterized by muscle spasms. In the most common type, the spasms begin in the jaw and then progress to the rest of the body. Each spasm usually l ...

, also called ''lockjaw'' for this reason *

Malignant hyperthermia Malignant hyperthermia (MH) is a type of severe reaction that occurs in response to particular medications used during general anesthesia, among those who are susceptible. Symptoms include muscle rigidity, fever, and a fast heart rate. Complica ...

* Malaria severa * Secondary to neuroleptic drug use * Malignant otitis externa *

Mumps MUMPS ("Massachusetts General Hospital Utility Multi-Programming System"), or M, is an imperative, high-level programming language with an integrated transaction processing key–value database. It was originally developed at Massachusetts Gen ...

* Peritonsillar abscess * Retropharyngeal or parapharyngeal abscess *

Seizure A seizure is a sudden, brief disruption of brain activity caused by abnormal, excessive, or synchronous neuronal firing. Depending on the regions of the brain involved, seizures can lead to changes in movement, sensation, behavior, awareness, o ...

Stroke Stroke is a medical condition in which poor cerebral circulation, blood flow to a part of the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemor ...

Toothache Toothaches, also known as dental pain or tooth pain,Segen JC. (2002). ''McGraw-Hill Concise Dictionary of Modern Medicine''. The McGraw-Hill Companies. is pain in the teeth or their supporting structures, caused by dental diseases or referred ...

Diagnostic approach

X-ray/CT scan taken from the TMJ to see if there is any damage to the TMJ and surrounding structures.

Treatment

Treatment requires treating the underlying condition with dental treatments, speech therapy for swallowing difficulty and mouth opening restrictions,

physical therapy Physical therapy (PT), also known as physiotherapy, is a healthcare profession, as well as the care provided by physical therapists who promote, maintain, or restore health through patient education, physical intervention, disease preventio ...

, and passive

range of motion Range of motion (or ROM) is the linear or angular distance that a moving object may normally travel while properly attached to another. In biomechanics and strength training, ROM refers to the angular distance and direction a joint can move be ...

devices. Additionally, control of symptoms with pain medications (

NSAID Non-steroidal anti-inflammatory drugs (NSAID) are members of a therapeutic drug class which reduces pain, decreases inflammation, decreases fever, and prevents blood clots. Side effects depend on the specific drug, its dose and duration of ...

s),

muscle relaxants A muscle relaxant is a drug that affects skeletal muscle function and decreases the muscle tone. It may be used to alleviate symptoms such as muscle spasms, pain, and hyperreflexia. The term "muscle relaxant" is used to refer to two major therapeu ...

, and warm compresses may be used. Splints have been used.

History

Historically, the term trismus was used to describe the early effects of tetany, also called "lockjaw".

References

External links

{{Nervous and musculoskeletal system symptoms and signs Symptoms and signs: musculoskeletal system Pathology of temporomandibular joints, muscles of mastication and associated structures