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

Extra-articular causes

Infection

Dental treatment

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

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

Congenital and developmental causes

Miscellaneous disorders

Common causes

Lock-jaw caused due to muscle rigidity.

Other causes

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

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10 1.11 Odell, edited by Edward W. (2010). Clinical problem solving in dentistry (3rd ed.). Edinburgh: Churchill Livingstone. pp. 37–41. ISBN 9780443067846.
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 Soames, J.V.; Southam, J.C. (1998). Oral pathology (3rd ed.). Oxford: Oxford University Press. p. 330. ISBN 019262895X.
  3. 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 Newlands, edited by Cyrus Kerawala, Carrie (2010). Oral and maxillofacial surgery. Oxford: Oxford University Press. ISBN 9780199204830.
  4. "Definitions of "Trismus" on The Free Online Dictionary by Farlex". Farlex, Inc. Retrieved 11 February 2013.
  5. 5.0 5.1 Scully, Crispian (2008). Oral and maxillofacial medicine : the basis of diagnosis and treatment (2nd ed.). Edinburgh: Churchill Livingstone. pp. 101, 353. ISBN 9780443068188.
  6. Hupp JR, Ellis E, Tucker MR (2008). Contemporary oral and maxillofacial surgery (5th ed.). St. Louis, Mo.: Mosby Elsevier. ISBN 9780323049030.
  7. "Etymology of Trismus on Online Etymology Dictionary". Douglas Harper. Retrieved 10 February 2013.
  8. 8.0 8.1 Kalantzis, Crispian Scully, Athanasios (2005). Oxford handbook of dental patient care (2nd ed.). New York: Oxford University Press. ISBN 9780198566236.
  9. 9.0 9.1 9.2 9.3 9.4 Chris. "Dr.". Locked Jaw (Lockjaw and Slack Jaw) Meaning and Causes |. Healthhype.com. Retrieved 13 September 2012.
  10. Shulman DH, Shipman B, Willis FB (2008). "Treating trismus with dynamic splinting: A cohort, case series". Adv Ther 25 (1): 9–16. doi:10.1007/s12325-008-0007-0. PMID 18227979.