Trismus

Trismus, commonly known as lock jaw, is a medical condition characterized by restricted mouth opening due to spasm or contraction of the jaw muscles. It commonly occurs in patients undergoing cancer treatment, especially head and neck cancer, but can also result from dental surgery, infections, and other causes.

Key Facts

Trismus refers to the limited ability to open one’s mouth due to muscle spasm, pain, or mechanical restriction

It’s often colloquially referred to as lockjaw

Trismus can arise from a variety of issues, including dental procedures, trauma, infections, and certain medical conditions

Management and treatment depend on the underlying cause but often involve physical therapy, pain management, and addressing the root cause

Trismus can significantly affect an individual’s ability to speak, eat, and maintain oral hygiene

Some causes of trismus can be prevented by early intervention and regular dental check-ups

What is Trismus?

Trismus, or lockjaw, is a medical condition characterized by a reduced ability or inability to open the mouth. This restriction can be due to several factors, including pain, muscle spasms, or mechanical limitations.
The temporomandibular joint (TMJ) is a hinge and sliding joint that connects the jawbone to the skull. Proper functioning of this joint and the associated muscles is crucial for activities like chewing, speaking, and yawning. When the movement of this joint is restricted or when there’s pain upon movement, it’s often referred to as trismus.
Trismus can be temporary or chronic, depending on its cause. Acute trismus, like what might occur after having a dental procedure, typically resolves as the area heals. Chronic trismus might require more intensive treatment, especially if it’s due to ongoing medical conditions or untreated trauma.
The severity of trismus can vary. Some people might find it slightly challenging to open their mouths wide, while others could struggle to open their mouths at all. Regardless of its cause or severity, it’s essential to address the issue because it can significantly impact one’s quality of life.
Patients with head and neck cancers, including neck cancer patients, often develop trismus secondary to the cancer itself or as a complication of cancer treatment such as radiation therapy. Radiation induced trismus is particularly prevalent in those receiving radiation treatment in the head and neck region.

How Does Trismus Affect My Body?

Trismus primarily impacts the jaw’s function, but its effects can be felt more broadly, both physically and psychologically:

Oral Health Implications: Limited mouth opening can make daily oral hygiene practices, such as brushing and flossing, challenging. This can lead to an increased risk of dental cavities, gum disease, and other oral health issues.
Nutritional Challenges: Trismus can make biting and chewing foods difficult, leading to dietary restrictions. Individuals might find themselves limited to soft or liquid diets, which might not provide all the necessary nutrients, leading to potential malnutrition.
Speech Difficulties: Proper jaw movement is essential for clear speech. Those with trismus might find speaking clearly to be challenging, leading to communication difficulties.
Pain and Discomfort: Trismus itself can be painful, especially if caused by inflammation or muscle spasms. This discomfort can extend to the head and neck, leading to headaches or neck pain.
Psychological Impact: Living with trismus can have significant psychological implications. It can affect one’s self-esteem and can lead to feelings of isolation, depression, or anxiety, especially if it impedes social activities like eating in public or speaking.

Who’s Affected by Trismus?

Various groups of people can be affected by trismus, including:

Post-Dental Procedure Patients: Some dental procedures, especially those that require the mouth to remain open for extended periods or surgeries involving the jaw, can lead to temporary trismus. Tooth extractions, particularly wisdom tooth removal, are a common cause.
Trauma Patients: Individuals who have experienced trauma to the face or jaw, such as fractures or significant blows, can develop trismus.
Infection Sufferers: Infections like mumps, tonsillitis, or dental abscesses can cause inflammation leading to trismus.
Individuals with TMJ Disorders: Temporomandibular joint disorders, which impact the joint connecting the jaw to the skull, can cause trismus as a symptom.
Cancer Patients: Those undergoing radiotherapy for head and neck cancers may experience trismus. Similarly, tumors or growths in the area can restrict jaw movement.
People with Certain Systemic Diseases: Conditions like tetanus or certain forms of arthritis that affect the jaw can lead to trismus.
Medication Side Effects: Rarely, some medications or drugs can cause trismus as a side effect.

Trismus can affect people of all ages and backgrounds, the underlying cause often dictates who might be more susceptible.

What’s the Difference Between Trismus and Tetanus (Lockjaw)?

Trismus and tetanus are two distinct conditions, though both can result in the symptom commonly known as lockjaw. Understanding the difference between them is crucial for proper diagnosis and treatment:

Definition: Trismus is a medical condition where there’s a reduced ability or inability to open the mouth due to muscle spasm, pain, or mechanical restriction. It can have various causes, ranging from dental procedures to trauma.
Origins: Trismus can arise from localized factors like dental treatments, infections, trauma, or broader systemic issues like certain diseases or medications.
Duration: The duration can vary based on the cause. Some instances, such as post-dental procedure trismus, might be temporary. In contrast, trismus from chronic conditions might persist longer.

Tetanus (Lockjaw)

Definition: Tetanus is a serious bacterial infection caused by Clostridium tetani. The bacteria produce a toxin that affects the nervous system, leading to muscle stiffness and spasms.
Origins: The tetanus bacteria typically enter the body through cuts, scratches, or wounds, especially if they’re contaminated with soil, dust, or animal feces where the bacteria are commonly found.
Duration: Tetanus is a life-threatening condition if not treated promptly. The muscle stiffness starts in the jaw, which is why it’s often called lockjaw, and then progresses to other parts of the body.
Vaccination: Tetanus is preventable through vaccination. Regular booster shots are recommended every ten years.

In summary, while both trismus and tetanus can lead to a limited ability to open the mouth (lockjaw), their origins, implications, and treatments are distinct.

What are Trismus Symptoms?

The primary symptom of trismus is the limited ability to open the mouth. Patients may only be able to open their mouths to a width of two fingers or less. Other symptoms include jaw spasms, difficulty eating, and difficulty opening the mouth wide. However, other symptoms might accompany this condition:

Pain or discomfort in the jaw or temporomandibular joint (TMJ)
Difficulty chewing or swallowing
Speech difficulties
Headache or earache
Muscle spasms in the jaw
Swelling or inflammation in the jaw area
A feeling of tightness in the facial muscles

What Causes Trismus?

Trismus can be caused by a variety of factors:

Dental Causes
- Dental procedures, especially those requiring prolonged mouth opening or involving the jaw, particularly after wisdom tooth extraction, third molar extraction, or oral surgery involving the lower jaw, such as the removal of mandibular third molars
- Oral surgeries or interventions
- Dental infections or abscesses
Traumatic Causes
Any trauma or surgical intervention to the jaw joint, masseter muscle, or surrounding soft tissue may trigger trismus.
- Jaw fractures or dislocations
- Facial injuries
- Scar tissue formation following trauma or surgery
Infections and Inflammation
Oral infections and dental caries can lead to trismus.
- Mumps, tonsillitis, or other oral infections
- Tetanus infection, which can cause severe muscle spasms including in the jaw
Medical and Systemic Causes
- Temporomandibular joint disorders (TMD)
- Radiotherapy to the head and neck for cancer treatment
- Certain medications or drugs
- Arthritis affecting the jaw
- Tumors or growths in the jaw or mouth area
Disorders affecting the trigeminal nerve or pterygoid muscles may result in trismus
Other Causes
- Prolonged mouth opening, like during specific dental procedures or intubations
- Muscle hyperactivity or spasms
- Psychological factors

Determining the exact cause of trismus is essential for its proper management and treatment.

Diagnosis: What Tests Do Healthcare Providers Do to Diagnose This Condition?

A systematic review of the patient’s medical history, along with a physical examination, is essential for differential diagnosis. In cases following radiation therapy or oral surgery, the onset of trismus may be gradual. Diagnosis of trismus involves a combination of clinical examination and additional tests:

Clinical Examination – This is the most crucial step. The dentist or healthcare provider will:
- Measure the maximum mouth opening, typically using a ruler or specialized tool, noting any discrepancies from the standard range.
- Check for pain, tenderness, or swelling in the jaw area.
- Assess the functioning of the temporomandibular joint (TMJ) and facial muscles.
Medical History – A thorough history will help determine any potential cause, like recent dental procedures, trauma, infections, or other relevant conditions.
Imaging Studies
- X-rays: To visualize bone structures, dental issues, or identify any fractures.
- Magnetic Resonance Imaging (MRI): Especially useful if a TMJ disorder is suspected. It can show the soft tissues, including the disk within the joint.
- Computed Tomography (CT) Scan: Provides detailed images and can help in cases of trauma, tumors, or infections.
Blood Tests

Treatment: How Do Healthcare Providers Treat Trismus?

Treatment of trismus depends on its cause:

Physical Therapy: Physical therapy, including the use of jaw stretching devices, is a primary treatment method. Regular exercises can prevent complications and improve mouth opening.
- Therapeutic Exercises: Aimed at improving jaw mobility and reducing muscle stiffness. These exercises may be passive (done by the therapist) or active (done by the patient).
- Heat or Cold Therapy: Applying heat to the affected area can help relax the jaw muscles and reduce discomfort.
Medications
- Pain Relievers: Over-the-counter pain medications like ibuprofen or acetaminophen.
- Muscle Relaxants: In cases of severe muscle spasm.
Dental Treatments:
- Address any dental or oral causes. This could involve tooth extraction, drainage of an abscess, or other necessary interventions.
- Oral appliances: Trismus appliances like mouthguards can aid in gradually increasing the jaw opening.
Surgerical interventions: In severe trismus or cases where trismus resolves inadequately with conservative measures, surgical removal of the affected tissues or surgical intervention in the jaw joint may be necessary.
Behavioral and Other Therapies:
- Avoidance of factors that exacerbate the condition.
- Relaxation techniques or biofeedback for those whose trismus might have a stress-related component.

I Have Trismus. What Can I Do to Help Myself?

If you’ve been diagnosed with trismus, there are several self-help strategies to consider:

Perform Regular Jaw Exercises: As directed by a physical therapist or healthcare provider.
Apply Heat or Cold: Warm compresses can help relax muscles, while cold compresses can reduce inflammation and pain.
Maintain Oral Hygiene: This helps prevent additional complications.
Dietary Adjustments: Opt for soft foods and avoid wide-mouthed yawning or biting into large foods.
Avoid Stressors: Stress can exacerbate muscle tension. Find relaxation techniques that work for you, such as deep breathing, meditation, or progressive muscle relaxation.
Follow Medication Directives: If prescribed muscle relaxants or pain relievers, take them as directed and be aware of potential side effects.
Stay Informed: Understanding your condition and staying proactive in your care can improve outcomes.
Regular Follow-up: Schedule and attend regular check-ups with your healthcare provider to monitor your progress and adjust treatments as necessary.

How Long Does It Last? How Soon Will I Feel Better?

The duration it takes for relief from trismus depends on its underlying cause. In cases where trismus is due to a dental procedure or minor trauma, improvement might be seen within a few days to a couple of weeks with appropriate treatment. However, if the trismus results from more severe causes like infections, tumors, or chronic conditions, it might take longer, and in some instances, complete resolution may not be possible. Chronic conditions or permanent damage could lead to persistent trismus that requires ongoing management. Following prescribed treatments, maintaining regular check-ups, and performing recommended exercises can hasten recovery.

Trismus Exercises

Exercises are commonly recommended for managing and treating trismus. They help in increasing jaw mobility and reducing stiffness. Here are some commonly recommended exercises:

Passive Stretching: Use your fingers or a suitable object like a mouth prop to gently stretch your mouth open. Hold for a few seconds and then release.
Jaw Pendulum Movement: Allow your jaw to swing gently from side to side like a pendulum.
Maximal Mouth Opening: Open your mouth as wide as comfortably possible. Hold for several seconds and then close.
Tongue Stretch: Stick your tongue out as far as it can go, then try to touch the tip of your nose and then your chin.
Resistance Exercises: Open your mouth against gentle resistance provided by your hand or a soft object.

Always consult with a physical therapist or dentist before starting these exercises to ensure they’re safe and appropriate for your individual situation.

Home Remedies

Several home remedies can help alleviate the discomfort associated with trismus:

Warm Compresses: Applying a warm cloth to the jaw area can help in reducing muscle stiffness.
Cold Packs: Using ice packs can help reduce inflammation and numb the area, providing relief.
Soft Diet: Eating soft foods can reduce the strain on the jaw.
Over-the-counter pain relievers: Medications like ibuprofen or acetaminophen can help in reducing pain.
Massage: Gently massaging the jaw muscles can promote relaxation and relieve tension.
Avoid Extreme Jaw Movements: Avoid activities that require wide mouth opening, like yawning or taking big bites.

Always consult with a healthcare provider before starting any home remedies to ensure they’re suitable for your situation.

Can I Avoid Developing Trismus?

Prevention of trismus primarily revolves around addressing its potential causes:

Dental Care: Regular dental check-ups can help detect and treat oral issues early.
Oral Hygiene: Maintaining proper oral hygiene can prevent infections which might lead to trismus.
Avoid Trauma: Being cautious and using protective gear when participating in activities where facial trauma is possible.
Follow Post-Procedure Instructions: If you have dental or surgical procedures, particularly in the oral region, always follow post-care instructions.
Early Intervention: If you feel initial symptoms of jaw pain or stiffness, seek medical advice promptly.

What Can I Expect If I Have Trismus?

Your experience with trismus will largely depend on its cause and severity:

Symptoms: You might experience pain, difficulty opening your mouth fully, difficulty speaking, eating, or even breathing in extreme cases.
Treatments: This can range from physical therapy and medications to, rarely, surgical interventions.
Prognosis: While many cases of trismus improve with treatment, some causes, particularly chronic ones, might mean long-term management rather than complete resolution.
Lifestyle Adjustments: Adapting to a softer diet, practicing regular jaw exercises, and possibly making modifications to speech or singing techniques.

Bottom Line

Trismus, or restricted jaw movement, can significantly impact one’s quality of life, affecting eating, speaking, and overall well-being. The cause of the condition dictates its treatment and prognosis. Early detection, prompt treatment, and proactive self-care can greatly improve outcomes and mitigate symptoms. If you experience signs of trismus, seeking medical attention promptly can lead to quicker relief and better overall outcomes.

This article is complete and was published on October 21, 2023, and last updated on December 19, 2023.

Key Facts