Trismus

Trismus is the inability to normally open the mouth due to one of many causes.

Common causes

• Pericoronitis (inflammation of soft tissue around impacted third molar) is the most common cause of trismus.
• Inflammation of muscles of mastication. 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, a complication of tonsillitis which usually presents with sore throat, dysphagia, fever, and change in voice.
• Temporomandibular joint disorder (TMD)
• 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. User's jaws do not lock, but rather the muscles become tight and the jaw clenched. It is still perfectly possible to open the mouth.
• Submucousfibrosis.

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
• Malignant hyperthermia
• Malaria severa
• Secondary to neuroleptic drug use
• Malignant otitis externa
• Retropharyngeal or parapharyngeal abscess
• Seizure
• spasam

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.^[1]

References