How TRISMUS Affects Your Oral Health

2 min

Trismus is a painful condition causing pain and tightening of the muscles of the jaw leading to restriction in opening the mouth. Also known as lockjaw.

The normal opening of the mouth measures 3.5 cm – 4.5 cm i.e. 2 to 3 finger width. This greatly reduces to the width of one finger causing restricted mouth opening and pain.


The eruption of wisdom teeth:

There is a reduction of the human jaw size with the passing years along with reduced space for the eruption of the wisdom teeth in its position.

The outward eruption of the upper wisdom teeth hinders the movement of the jaw causing a deviation while opening and closing the mouth.

Due to various reasons, the wisdom tooth gets entrapped within the bone later getting infected and inflamed causing the difficulty in mouth opening.

Surgery of mouth or jaw:

Surgical intervention for the excision of the cancerous growth or impacted wisdom tooth ends in post-operative swelling of the gums and surrounding tissues subsequently causing stiffness of the muscles.

This causes a temporary restriction of the mouth opening until the surgical wound heals.

Trauma or fracture of the jaw bone:

Indeed a trauma or fracture of the jaw bone causes the dislocation of the jaw with pain and swelling at the site of fracture resulting in the reduced mouth opening.

Once the fracture is treated with plates then the patient is advised for restricting the movements for 3 to 4 weeks.

They face difficulty in movement after the 3 weeks of rest then slowly recovers with frequent massages and exercises.

Temporomandibular joint dysfunction:

Trismus is one of the characteristic features of temporomandibular joint disorder. It causes tension in the muscles attached to the jaw, friction due to the loss of the disk, pain, and inflammation surrounding the jaw joint.

Head and neck cancer & Radiation therapy:

Tightening or stiffness of the cheek or vertical fibrous banding of the cheek muscle is a sign of oral cancer.

Cancer of mouth or association conditions often present with Trismus. Radiation therapy reduces the ability of the tissues to heal on their own causing the stiffness of the muscle and prolonged Trismus.


The characteristic feature of trismus at first is a reduced mouth opening it often presents with the following signs & symptoms:

  • Pain
  • Hindrances in mouth opening.
  • Difficulty in chewing.
  • Difficulty in swallowing food.
  • Speech impairment.
  • Inflammation of the check muscle.
  • Stiffness of the muscles involved in chewing.
  • Compromised oral hygiene.


Firstly, massaging at intervals for 30 seconds with subsequent slow movements of the jaw from right to left followed by stretches should be practiced after the advice of a dentist.

Stretching of the jaw with jaw expanding devices held between the upper and the lower jaw. The expansion of the jaw done at intervals to increase the mouth opening.

In the case of surgical removal of wisdom tooth, prophylactic anti-inflammatory medication is given pre-operatively. Anti-inflammatory medications and muscle relaxants are given after the surgery.

Advised to follow a soft diet in particular and avoid clenching of the teeth.

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Dr Arun

Dr. Arun is a practicing dentist with more than 11 years of experience. Loves to blog and in constant search of new knowledge in dentistry and health niche.


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