Trismus (Lockjaw): Causes, Symptoms & Treatment
Trismus, commonly referred to as lockjaw, is a condition where a person experiences restricted mouth opening due to muscle spasm, inflammation, or joint-related issues. While it may seem temporary or minor, untreated trismus can interfere with eating, speaking, oral hygiene, and dental treatments.
Trismus Meaning
Trismus is a condition characterized by limited jaw movement, usually caused by stiffness or spasm of the jaw muscles. Clinically, it is diagnosed when mouth opening is significantly reduced, often less than 35 mm.
Although often temporary, trismus can become chronic if the underlying cause is not addressed.
What causes trismus?
Trismus can develop due to several dental, medical, and lifestyle-related factors.
Common Causes of Trismus
- Dental infections or abscesses
- Inflammation of jaw muscles
- Temporomandibular joint (TMJ) disorders
- Oral trauma or injury
- Radiation therapy to the head and neck
- Neurological conditions
Trismus after tooth extraction
One of the most common dental causes is trismus after extraction, especially after wisdom tooth removal.
Causes of trismus after extraction
- Prolonged mouth opening during surgery
- Trauma to jaw muscles
- Post-operative inflammation
- Infection around the extraction site
This usually appears within 2–3 days after extraction and is often temporary.
Symptoms of Trismus
Common signs include:
- Difficulty opening the mouth
- Jaw pain or stiffness
- Pain while chewing or speaking
- Headache or ear pain
- Facial muscle tightness
In severe cases, maintaining oral hygiene becomes difficult.
How long does trismus last?
- Mild trismus: 3–7 days
- Post-extraction trismus: 1–2 weeks
- Chronic or untreated cases: Several weeks or longer
Recovery time depends on the cause, severity, and early intervention.
Trismus Treatment
Treatment focuses on reducing inflammation, relieving muscle spasm, and restoring jaw mobility.
- Anti-inflammatory medications
- Muscle relaxants (prescribed by a doctor)
- Warm compress therapy
- Treatment of underlying dental infection
- Physiotherapy or guided jaw exercises
The best muscle relaxant for trismus varies by individual and should only be prescribed by a healthcare professional.
Trismus Treatment at Home
For mild cases, conservative home care can be effective.
Home Management Tips
- Apply warm compresses to the jaw 3–4 times daily
- Avoid hard or chewy foods
- Stick to a soft diet
- Maintain gentle jaw movements
- Avoid excessive talking or yawning
Exercises for Trismus
Jaw exercises play a crucial role in recovery and prevention of recurrence.
Jaw Exercises for Trismus
Perform these exercises gently, 2–3 times daily:
Jaw Opening Stretch: Slowly open your mouth as wide as comfortable, hold for 5 seconds, and relax.
Side-to-Side Jaw Movement: Move the lower jaw gently left and right.
Resistance Opening: Place fingers under the chin and gently resist while opening the mouth.
Tongue-to-Roof Stretch: Keep the tongue on the roof of the mouth while opening slowly.
Consistency is key and exercises should never cause sharp pain.
Trismus Management and Prevention
Effective management includes:
- Early dental evaluation
- Completing prescribed medications
- Regular jaw exercises
- Stress management
- Quick treatment of dental infections
Patients undergoing dental surgery should follow post-operative instructions carefully to reduce risk.
When to see a dentist?
Consult a dentist if:
- Jaw opening is severely limited
- Pain worsens or persists beyond a week
- Swelling or fever develops
- Trismus interferes with eating or oral hygiene
Early treatment prevents long-term jaw stiffness and complications.
Conclusion
Trismus is a manageable condition when identified early. Whether caused by dental procedures, infections, or muscle strain, proper treatment, home care, and jaw exercises can restore normal jaw movement effectively.
If you experience persistent jaw stiffness or difficulty opening your mouth, professional dental evaluation is essential for accurate diagnosis and long-term relief.

