Trismus

Trismus
Classification and external resources
ICD-10	R25.2
ICD-9	781.0
DiseasesDB	27801
MeSH	D014313

Trismus, or lockjaw, refers to reduced opening of the jaws caused by spasm of the muscles of mastication, or may generally refer to all causes of limited mouth opening.^[1] It is a common problem with a variety of causes, and may interfere with eating, speech, oral hygiene, and could alter facial appearance. There is an increased risk of aspiration. Temporary trismus is much more common than permanent trismus,^[2] and may be distressing and painful, and limit or prevent medical examination or treatments requiring access to the oral cavity.

Definition

Classically, the definition of trismus is an inability to open the mouth due to muscular spasm, but more generally it refers to limited mouth opening of any cause.^[3] Another definition of trismus is simply a limitation of movement.^[2] Historically and commonly, the term lock jaw was sometimes used as a synonym for both trismus and tetanus. Definitions from popular medical dictionaries vary, e.g.:

"a motor disturbance of the trigeminal nerve, especially spasm of the masticatory muscles, with difficulty in opening the mouth (lockjaw); a characteristic early symptom of tetanus."

"a firm closing of the jaw due to tonic spasm of the muscles of mastication from disease of the motor branch of the trigeminal nerve. It is usually associated with general tetanus. Also called lockjaw."

"a prolonged tonic spasm of the muscles of the jaw."

"spasms of the muscles of mastication resulting in the inability to open the oral cavity; often symptomatic of pericoronitis."^[4]

Normal mouth opening ranges from 35 to 45 mm.^[3] Males usually have slightly greater mouth opening than females. (40-60mm)=(avg-35mm). The Normal Lateral movement is (8-12mm).^[5] Some have distinguished mild trismus as 20–30 mm interincisal opening, moderate as 10–20 mm and severe as less than 10 mm.^[6]

Trismus is derived from the Greek word trismos meaning "a scream; a grinding, rasping or gnashing"^[7]

Differential diagnosis

Traditionally causes of trismus are divided into intra-articular (factors within the temporomandibular joint [TMJ]) and extra-articular (factors outside the joint, see table).^[2]

Commonly listed causes of trismus

Intra-articular: Internal derangement of TMJ / meniscus displacement.[1][3] Fractured mandibular condyle or intracapsular fracture.[1] TMJ dislocation.[2] Traumatic synovitis.[1] Septic arthritis.[3] Osteoarthritis.[1] Inflammatory arthritis (e.g. rheumatoid or psoriatic).[1] Ankylosis.[1] Osteophyte formation.[3] Extra-articular: Trauma not involving the mandibular condyle (e.g. a fracture of another part of the mandible, fractures of the middle third of the facial skeleton, fractures of the zygoma or zygomatic arch).[1] Post surgical edema, e.g. removal of impacted lower wisdom teeth,[1] or other dentoalveolar surgery.[3] Recent prolonged dental treatment (e.g. root canal therapy).[1] Following administration of inferior alveolar nerve block with local anesthetic (medial pterygoid).[3] Hematoma of medial pterygoid.[2] Acute infections of the oral tissues, especially involving the buccal space or muscles of mastication.[1] Odontogenic infection.[1][3] Peritonsillar abscess.[3] Acute parotitis, e.g. mumps.[2] Pericoronitis.[2] Submasseteric abscess.[2] Tetanus.[2][3] Tetany.[2] Local malignancy.[3] Myofascial pain / temporomandibular joint dysfunction.[3] Radiation fibrosis.[3] Fibrosis from burns.[2] Submucous fibrosis.[3] Systemic sclerosis.[8] Myositis ossificans.[8] Coronoid hyperplasia.[3] Malignant hyperpyrexia.[3] Epidermolysis bullosa.[5] Drug associated dyskinesia.[2] Psychotic disturbances, hysteria.[2]

Intra-articular causes

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.

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 characterized by a difficulty in opening the jaw. It is a temporary condition with a duration usually not longer than two weeks. Dental trismus results from some sort of insult to the muscles of mastication, such as opening the jaw for a period of time or having a needle pass through a muscle. Typical dental anesthesia to the lower jaw often involves the needle passing into or through a muscle. In these cases it is usually the medial pterygoid or the buccinator muscles.
• 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 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 and tricyclic antidepressants causes trismus as a secondary effect. Trismus can be seen as an extra-pyramidal side-effect of metaclopromide, 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

• Hysteric patients: Through the mechanisms of conversion, 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.^[9]
• Inflammation of muscles of mastication.^[9] It is a frequent sequel to surgical removal of mandibular third molars (lower wisdom teeth). The condition is usually resolved on its own in 10–14 days, during which time eating and oral hygiene 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,^[9] a complication of tonsillitis which usually presents with sore throat, dysphagia, fever, and change in voice.
• Temporomandibular joint dysfunction (TMD).^[9]
• Trismus is often mistaken as a common temporary side effect of many stimulants of the sympathetic nervous system. Users of amphetamines as well as many other pharmacological agents commonly report bruxism 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.^[9]
• Submucous fibrosis.
• Fracture of the zygomatic arch.

Other causes

• Acute osteomyelitis
• Ankylosis 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
• Infection
• Local anesthesia (dental injections into the infratemporal fossa)
• Needle prick to the medial pterygoid muscle
• Oral submucous fibrosis.
• Radiation therapy to the head and neck.
• Tetanus, also called lockjaw for this reason
• Malignant hyperthermia
• Malaria severa
• Secondary to neuroleptic drug use
• Malignant otitis externa
• Mumps
• Peritonsillar abscess
• Retropharyngeal or parapharyngeal abscess
• Seizure
• Stroke

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, physical therapy, and passive range of motion devices. Additionally, control of symptoms with pain medications (NSAIDs), muscle relaxants, and warm compresses may be used.

Splints have been used.^[10]

History

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

References

Oral and maxillofacial pathology (K00–K06, K11–K14, 520–525, 527–529) Lips Cheilitis Actinic Angular Plasma cell Cleft lip Herpes labialis Macrocheilia Microcheilia Trumpeter's wart Tongue Ankyloglossia Black hairy tongue Caviar tongue Crenated tongue Cunnilingus tongue Fissured tongue Glossitis Geographic tongue Median rhomboid glossitis Transient lingual papillitis Hypoglossia Macroglossia Oral mucosa Amalgam tattoo Angina bullosa haemorrhagica Behçet syndrome Burning mouth syndrome Epulis fissuratum Erythroplakia Focal epithelial hyperplasia Fordyce spots Hairy leukoplakia Herpangina Intraoral dental sinus Leukoedema Leukoplakia Lichen planus Linea alba Melanocytic oral lesion Morsicatio buccarum Oral candidiasis Oral florid papillomatosis Oral melanosis Plasmoacanthoma Stomatitis Aphthous Denture-related Herpetic Nicotinic Ulceration White sponge nevus Teeth (pulp, dentin, enamel) Amelogenesis imperfecta Anodontia Caries Early childhood caries Concrescence Delayed eruption Dens evaginatus Talon cusp Dentin dysplasia Dentin hypersensitivity Dentinogenesis imperfecta Dilaceration Ectopic enamel Enamel hypocalcification Enamel hypoplasia Turner's hypoplasia Enamel pearl Fluorosis Fusion Gemination Hyperdontia Hypodontia Impaction Wisdom tooth impaction Macrodontia Meth mouth Microdontia Odontogenic tumors Keratocystic odontogenic tumour Odontoma Dens in dente Premature eruption Pulp calcification Pulp necrosis Pulp polyp Pulpitis Regional odontodysplasia Resorption Supernumerary root Taurodontism Trauma Cracked tooth syndrome Vertical root fracture Occlusal Tooth wear Abrasion Abfraction Acid erosion Attrition Periodontium (gingiva, Periodontal ligament, cementum, alveolus) Cementoblastoma Gigantiform Cementoma Epulis Pyogenic granuloma Gingival enlargement Gingivitis Desquamative Plasma cell Hypercementosis Hypocementosis Linear gingival erythema Necrotizing periodontal diseases Acute necrotizing ulcerative gingivitis Pericoronitis Periodontal abscess Periodontitis Perio-endo lesion Periapaical, mandibular and maxillary hard tissues Alveolar osteitis Cherubism Mandibular fracture Microgenia Cyst Odontogenic Osteomyelitis Osteonecrosis Bisphosphonate-associated Neuralgia-inducing cavitational osteonecrosis Osteoradionecrosis Paget's disease of bone Periapical abscess Phoenix abscess Periapical periodontitis Stafne defect Torus mandibularis Temporomandibular joints and muscles of mastication Bruxism Mandibular dislocation Temporomandibular joint dysfunction Salivary glands Benign lymphoepithelial lesion Frey's syndrome HIV salivary gland disease Necrotizing sialometaplasia Mucocele Ranula Pneumoparotitis Salivary duct stenosis Salivary duct cyst Salivary fistula Salivary gland aplasia Salivary gland atresia Salivary gland diverticulum Salivary gland heterotopia Salivary gland hyperplasia Salivary gland hypoplasia Salivary gland neoplasms Benign: Basal cell adenoma Canalicular adenoma Ductal papilloma Monomorphic adenoma Myoepithelioma Oncocytoma Papillary cystadenoma lymphomatosum Pleomorphic adenoma Sebaceous adenoma Malignant: Acinic cell carcinoma Adenocarcinoma Adenoid cystic carcinoma Carcinoma ex pleomorphic adenoma Lymphoma Mucoepidermoid carcinoma Sialadenitis Parotitis Chronic sclerosing sialadenitis Sialocele Sialosis Sialolithiasis Sjögren's syndrome Orofacial soft tissues Actinomycosis Cutaneous sinus of dental origin Cystic hygroma Ludwig's angina Macrostomia Melkersson–Rosenthal syndrome Microstomia Noma Oral Crohn's disease Orofacial granulomatosis Perioral dermatitis Pyostomatitis vegetans Palate Cleft palate Torus palatinus High-arched palate Index of the mouth Description Anatomy Development Disease Congenital face and neck cleft digestive system Neoplasms and cancer Other Symptoms and signs Treatment Procedures periodontology Drugs

Symptoms and signs: nervous and musculoskeletal systems (R25–R29, 781.0, 781.2–9) Primarily nervous system Primarily CNS Movement disorders Dyskinesia: Athetosis Tremor Dyskinesia Gait abnormality Scissor gait Cerebellar ataxia Festinating gait Marche a petit pas Propulsive gait Stomping gait Spastic gait Magnetic gait Lack of coordination Dyskinesia: Ataxia Cerebellar ataxia/Dysmetria Sensory ataxia Dyssynergia Dysdiadochokinesia Asterixis Other Abnormal posturing: Opisthotonus Sensory processing disorder: Hemispatial neglect Facial weakness Hyperreflexia Pronator drift Primarily PNS Gait abnormality Steppage gait Antalgic gait Primarily muscular Movement disorders Spasm Trismus Fasciculation Fibrillation Myokymia Cramp Gait abnormality Myopathic gait Trendelenburg gait Pigeon gait Other Tetany Meningism Primarily skeletal Rachitic rosary Clubbing Primarily joint Joint locking   Further indexes Index of the central nervous system Description Anatomy meninges cortex association fibers commissural fibers lateral ventricles basal ganglia diencephalon mesencephalon pons cerebellum medulla spinal cord tracts Physiology neutrotransmission enzymes intermediates Development Disease Cerebral palsy Meningitis Demyelinating diseases Seizures and epilepsy Headache Stroke Sleep Congenital Injury Neoplasms and cancer Other paralytic syndromes ALS Symptoms and signs head and neck eponymous lesions Tests CSF Treatment Procedures Drugs general anesthetics analgesics addiction epilepsy cholinergics migraine Parkinson's vertigo other Index of the peripheral nervous system Description Anatomy Nerves cranial trigeminal cervical brachial lumbosacral plexus somatosensory spinal autonomic Physiology reflexes proteins neurotransmitters transporters Development neurotrophins Disease Autonomic Congenital Injury Neoplasms and cancer Other Symptoms and signs eponymous Treatment Procedures Local anesthetics Index of muscle Description Anatomy head neck arms chest and back diaphragm abdomen genital area legs Muscle tissue Physiology connective tissue Disease Myopathy Soft tissue Connective tissue Congenital abdomen muscular dystrophy Neoplasms and cancer Injury Symptoms and signs eponymous Treatment Procedures Drugs anti-inflammatory muscle relaxants Index of bones and cartilage Description Anatomy bones skull face neurocranium compound structures foramina upper extremity torso pelvis lower extremity Physiology Development Cells Disease Congenital Neoplasms and cancer Trauma fracture Other Symptoms and signs eponymous Treatment Procedures Drugs Surgery approaches Index of joint Description Anatomy head and neck cranial arms torso and pelvis legs bursae and sheathes Physiology Disease Arthritis acquired back childhood soft tissue Congenital Injury Symptoms and signs eponymous orthopaedic Examination Treatment Procedures Drugs rheumatoid arthritis gout topical analgesics