Introduction

Painful or restricted mouth opening is not an everyday occurrence. However, when it happens, it can be overwhelming for the person experiencing it. This article explains why trismus occurs and how it can be managed, especially if immediate medical assistance is unavailable.

Normal mouth opening is typically between 50–60 mm, which can be roughly measured by placing three to four fingers vertically between the upper and lower teeth. If the openings less than 35 mm, it is clinically diagnosed as trismus. This condition affects individuals of all ages, significantly impacting their ability to eat, speak, and maintain oral hygiene. If left untreated, trismus can either resolve completely or lead to permanent jaw problems, depending on the underlying cause.

Whatis Trismus?

The term trismus originates from the Greek word trismos or trigmos, meaning"scream."Trismus occurs when the jaw joint(temporomandibular joint or TMJ) and its associated muscles becomeaffected, restricting movement.

Common Symptoms of Trismus 

  • Difficulty opening the mouth Pain or tenderness in the jaw joint.
  • Headaches, particularly on one side Difficulty chewing, speaking, or maintaining oral  hygiene 
  • Clicking or locking sensation in the jaw

 If any of these symptoms persist, medical attention should be sought promptly.

Causes of Trismus

Trismus can be temporary (due to infections or trauma) or permanent (due to congenital deformities or chronic conditions). The most common causes include:

1.Infections 

  • Wisdom tooth infections (especially in the lower jaw) 
  • Gum infections surrounding impacted wisdom teeth 
  • Salivary gland infections.
  • Peritonsillar abscess (infection around the tonsils) 
  • Meningitis (serious brain infection)

2.Inflammatory Disorders 

  • Rheumatoid arthritis Osteoarthritis 
  • Soft tissue fibrosis

3.Neurological and Medication-Related Causes 

  • Tetanus Status epilepticus (prolonged seizures)
  •  Parkinson’s disease 
  • Strychnine or phenothiazine poisoning 
  • Side effects of certain medications (phenothiazines, metoclopramide, tricyclic antidepressants) 
  • Electrolyte imbalances (low calcium or magnesium levels)

4.Trauma and Injury 

  • Fractures of the jaw or TMJ Injuries to the muscles surrounding the jaw.
  • Post-dental extraction complications (particularly after wisdom tooth removal).
  • Severe facial trauma.

5.Pre-Cancerous and Cancerous Conditions 

  • Oral submucous fibrosis (OSMF), a precancerous condition leading to stiffened jaw tissues.
  • Tumors or abnormal growths in the jaw, face, or throat.
  • Partial or total jaw bone resection due to cancer surgery.

6.Radiation Therapy and Medical Procedures 

  • Radiation therapy for head and neck cancers, which may cause tissue fibrosis and reduced jaw mobility
  • Traumatic or improperly administered injections in the jaw region

7.Congenital Conditions (Present from Birth) 

  • Gaucher’s disease 
  • Moebius syndrome

What to Do If You Experience Trismus?

If sudden difficulty in opening the mouth occurs, the following steps can be taken before seeking professional medical help: 

  • Stay calm and avoid panicking.
  • Do not attempt to forcefully open the mouth.
  • Refrain from touching or massaging the tender jaw area 
  • Consume a soft diet to avoid excessive strain on the jaw 
  • Support the jaw while yawning to prevent discomfort.
  •  Maintain oral hygiene by rinsing with an antiseptic mouthwash if brushing is difficult
  •  Consult a doctor or dentist as soon as possible. 

Treatment of Trismus 

The treatment approach depends on the underlying cause and severity of trismus. In most cases, trismus caused by infections, trauma, or inflammation is temporary and reversible with appropriate care.

1.Conservative Management (First-Line Treatment)

  •  Hot and Cold Compress: Alternating heat and ice packs to reduce pain and inflammation 
  • Physiotherapy:   Ultrasound therapy to improve blood circulation and relax stiff muscles.
  • Maitland mobilization, a specialized technique to restore jaw movement 

2.Medications: Based on the diagnosis, the following medications may be prescribed: 

  • Anti-inflammatory drugs Pain relievers (analgesics) 
  • Antibiotics for infection control Muscle relaxants to ease jaw stiffness
  • Antipsychotic medications, if neurological issues are contributing to the condition

3.Mouth Opening Exercises Regular exercises can gradually improve jaw mobility over time: 

  • Mirror Therapy: Open the mouth as wide as possible 10–15 times in one session, repeated three to four times a day
  •  Ice-Cream Stick Method: Place wooden sticks between the teeth and gradually increase the number over time to improve the mouth opening.
  • Jaw Stretching Devices: Some cases may require specialized mechanical devices, which a dentist will prescribe based on the patient’s condition.

Preventive Measures

  •  Regular dental check-ups 
  • Prompt treatment of dental infections 
  • Maintaining good oral hygiene 
  • Avoiding trauma to the jaw area
  •  Individuals experiencing persistent or worsening symptoms should consult a Dentist or Oral and Maxillofacial Specialist without delay.

Conclusion

Trismus is not merely an inconvenience; it can significantly impact daily life. Early diagnosis and treatment are essential to prevent long-term complications and ensure full recovery.