Mastication Muscle Strain

Anatomy? of the Masticatory Muscles

The muscles of mastication form a specialized group that elevates, depresses, protrudes, retracts, and moves the jaw side-to-side. Understanding their anatomy helps explain why they are prone to strain.

Structure & Location

• Masseter: A thick, rectangular muscle on the lateral surface of the mandible?.

• Temporalis: A fan-shaped muscle above the ear, spanning from the temporal fossa to the coronoid process of the mandible.

• Medial Pterygoid: A quadrangular muscle on the inner aspect of the mandible’s ramus.

• Lateral Pterygoid: A bi-headed muscle on the infratemporal surface of the sphenoid bone attaching to the condyle of the mandible Physiopedia.

Origin & Insertion

• Masseter originates from the zygomatic arch and inserts on the lateral surface of the mandibular ramus.

• Temporalis originates on the temporal fossa and inserts on the coronoid process of the mandible.

• Medial Pterygoid originates from the medial surface of the lateral pterygoid plate and inserts on the medial mandibular ramus.

• Lateral Pterygoid has two heads: the superior head from the greater wing of the sphenoid, the inferior head from the lateral pterygoid plate; both insert on the neck of the mandible and articular disc of the TMJ Physiopedia.

Blood Supply
All four muscles receive arterial blood chiefly from branches of the maxillary artery?:

• Masseteric branch to the masseter.

• Deep temporal arteries? to the temporalis.

• Pterygoid branches to the pterygoids.

Nerve Supply
All are innervated by the mandibular division (V₃) of the trigeminal nerve:

• Masseteric nerve to the masseter.

• Deep temporal nerves to the temporalis.

• Medial and lateral pterygoid branches to the pterygoids.

Functions of the Masticatory Muscles

1. Elevation (closing the jaw)

2. Depression (opening the jaw via relaxation and gravity)

3. Protrusion (pushing jaw forward)

4. Retraction (pulling jaw back)

5. Lateral excursion (side-to-side chewing motions)

6. Stabilization (holding the jaw steady during speech and swallowing) Physiopedia.

Types of Mastication Muscle Strain

1. Grade I (Mild?): Microtears in muscle fibers with minimal loss of function.

2. Grade II (Moderate?): Partial tearing leading to visible swelling?, moderate pain, and reduced jaw movement.

3. Grade III (Severe?): Complete tear of the muscle or tendon? with significant functional loss, often requiring surgical repair Lippincott Journals.

4. By Muscle Group: Strains localized to individual muscles (e.g., masseteric strain vs. temporalis strain).

Causes of Mastication Muscle Strain

1. Bruxism (teeth grinding)

2. Trauma (direct blow to the jaw)

3. Repetitive Overuse (chewing gum excessively)

4. Poor Posture (forward head posture)

5. Malocclusion (misaligned bite)

6. Stress-induced Clenching

7. Whiplash Injuries

8. Heavy Lifting with Clenched Jaw

9. Dental Procedures (prolonged mouth opening)

10. Orthodontic Adjustments

11. Rheumatoid Arthritis? (TMJ involvement)

12. Infection? (e.g., masticatory myositis)

13. Myofascial Trigger Points

14. Dehydration? (electrolyte imbalance)

15. Vitamin D Deficiency (muscle weakness?)

16. Fibromyalgia?

17. autoimmune? Myositis

18. Idiopathic? Muscle Fatigue?

19. Chemotherapy?-induced Myopathy?

20. Excessive Yawning, Laughing, or Crying

Symptoms of Mastication Muscle Strain

1. Localized Jaw Pain

2. Tenderness on Touch

3. Swelling

4. Bruising? (in severe tears)

5. Reduced Mouth Opening (Trismus)

6. Jaw Locking or Clicking

7. Muscle Spasm?

8. Radiating Ear Pain

9. Headaches (Temporal region)

10. Toothache-like Pain

11. Neck Pain

12. Difficulty Chewing

13. Muscle Weakness?

14. Jaw Deviation on Opening

15. Fatigue of Jaw Muscles

16. Pain Worsens with Use

17. Muscle Crepitus (grating sensation)

18. Sensitivity to Cold/Heat

19. Sleep Disturbances

20. Voice Change (when speaking)

Diagnostic Tests for Mastication Muscle Strain

1. Physical Examination & Palpation (tenderness assessment) Distance Learning and Telehealth

2. Range-of-Motion Measurement (interincisal distance)

3. Pain Pressure Threshold Testing (algometry)

4. Provocation Tests (pain on resisted jaw opening/closing)

5. Dental Occlusal Analysis

6. Electromyography (EMG)

7. Ultrasound Imaging (muscle tears)

8. Magnetic Resonance Imaging (MRI) (soft tissue detail)

9. Computed Tomography (CT) (bony involvement)

10. Cone-Beam CT (CBCT)

11. Arthroscopy (intra-articular inspection)

12. Infrared Thermography (inflammation mapping)

13. Blood Tests (creatine kinase, inflammatory markers)

14. Trigger Point Examination

15. Dry Needling Response

16. Sleep Bruxism Monitoring (EMG during sleep)

17. Stress Questionnaires (psychosocial factors)

18. Diagnostic Nerve Blocks

19. Bite Force Measurement

20. Ultrasound Elastography (muscle stiffness assessment)

Non-Pharmacological Treatments

1. Jaw Rest (avoid hard foods)

2. Soft Diet

3. Cold Packs (first 48 hours)

4. Warm Compresses (after acute phase)

5. Gentle Jaw Stretching Exercises

6. Isometric Exercises

7. Progressive Resistance Training

8. Manual Massage

9. Transcutaneous Electrical Nerve Stimulation (TENS)

10. Low-Level Laser Therapy

11. Therapeutic Ultrasound

12. Acupuncture

13. Dry Needling

14. Biofeedback for Relaxation

15. Cognitive Behavioral Therapy

16. Stress Management Techniques

17. Postural Correction Exercises

18. Ergonomic Workstation Setup

19. Nightguards/Mouthguards

20. TMJ Splint Therapy

21. Jaw Opening/Closing Education

22. Mind-Body Practices (Yoga, Tai Chi)

23. Deep Breathing and Relaxation

24. Heat-Moist Applications

25. Cryotherapy

26. Magnet Therapy

27. Ultrasound-Guided Trigger Point Injections (dry needling)

28. Phonophoresis

29. Myofascial Release Techniques

30. Patient Education on Jaw Mechanics

Drugs Used in Mastication Muscle Strain

1. Ibuprofen (NSAID)

2. Naproxen (NSAID)

3. Diclofenac (NSAID)

4. Celecoxib (COX-2 inhibitor)

5. Acetaminophen (analgesic)

6. Cyclobenzaprine (muscle relaxant)

7. Tizanidine (muscle relaxant)

8. Diazepam (benzodiazepine muscle relaxant)

9. Amitriptyline (tricyclic antidepressant for chronic pain)

10. Duloxetine (SNRI for pain modulation)

11. Gabapentin (neuropathic pain adjunct)

12. Pregabalin (neuropathic pain adjunct)

13. Topical Diclofenac Gel

14. Lidocaine Patches

15. Capsaicin Cream

16. Ketorolac (short-term NSAID)

17. Prednisone (short course corticosteroid for severe inflammation)

18. Botulinum Toxin Injections (for refractory spasm)

19. Opioids (e.g., tramadol, reserved for acute severe pain)

20. Muscle Depolarizing Agents (e.g., methocarbamol)

Surgical Interventions

Reserved for cases where conservative and pharmacological therapies fail or in severe Grade III tears.

1. Myotomy (release of severely contracted muscle)

2. Coronoidectomy (removal of coronoid process to relieve impingement)

3. Arthrocentesis (TMJ lavage plus joint decompression)

4. Arthroscopy (minimally invasive joint inspection and treatment)

5. Condylectomy (removal of part of mandibular condyle)

6. TMJ Disc Repositioning or Repair

7. Total Joint Replacement (alloplastic prosthesis)

8. Orthognathic Surgery (realignment of jaws in malocclusion-induced strain)

9. Muscle Tendon Transfer (in severe muscle loss)

10. Botulinum Toxin Guided Surgical Release

Prevention Strategies

1. Regular Jaw Warm-Up Exercises

2. Avoid Overchewing (gum, tough foods)

3. Use of Nightguards for Bruxism

4. Maintain Good Posture

5. Ergonomic Workplace Adjustments

6. Stress Reduction Techniques

7. Routine Dental Check-Ups

8. Balanced Diet & Hydration

9. Adequate Sleep Hygiene

10. Jaw Position Awareness (avoid clenching)

When to See a Doctor

• Severe or Worsening Pain interfering with eating or speaking

• Inability to Open Mouth > 1–2 Weeks

• Visible Swelling or Bruising around jaw

• Fever suggesting infection

• Neurological Signs (numbness, facial weakness)

• Persistent Headaches or Ear Pain not relieved by OTC measures

• Failed Response to a week of conservative care

Frequently Asked Questions (FAQs)

1. What exactly is a mastication muscle strain?
   A strain is when muscle fibers in your chewing muscles get overstretched or torn, causing pain and difficulty moving your jaw easily.

2. How long does a mild jaw muscle strain take to heal?
   Mild (Grade I) strains often heal in 1–2 weeks with rest, ice, and gentle stretching.

3. Can stress really cause jaw muscle strain?
   Yes. Stress-induced clenching or grinding (bruxism) repeatedly overworks the muscles, leading to strain.

4. Are there exercises I can do at home?
   Yes. Gentle jaw opening/closing and side-to-side stretches help improve flexibility and reduce pain.

5. Is heat or ice better for relief?
   Use ice packs for the first 48 hours to reduce swelling, then switch to warm compresses to relax tight muscles.

6. Should I eat soft foods?
   A soft diet reduces strain on sore muscles while they heal.

7. Can a dentist fix this?
   A dentist can fit you with a nightguard if bruxism is the cause and assess bite alignment issues.

8. When is surgery necessary?
   Surgery is only for severe tears (Grade III) or structural problems not responding to all other treatments.

9. Will physical therapy help?
   Yes. A physical therapist can guide specialized jaw exercises, manual therapy, and modalities like TENS.

10. Are muscle relaxants safe?
    Short-term use of approved muscle relaxants (e.g., cyclobenzaprine) is generally safe under medical supervision.

11. Can this condition become chronic?
    Without proper management, repeated strain may lead to chronic masticatory myalgia or temporomandibular disorder.

12. Is massage beneficial?
    Yes. Therapeutic massage improves circulation, reduces tightness, and breaks up trigger points.

13. Does dehydration play a role?
    Mild dehydration and electrolyte imbalance can make muscles more prone to fatigue and injury.

14. Can I prevent future strains?
    Absolutely—through stress management, proper posture, ergonomic adjustments, and jaw awareness.

15. How do I know if it’s more than a simple strain?
    See your doctor if pain persists beyond 1–2 weeks, you have fever, swelling, or difficulty opening your mouth fully.

Disclaimer: Each person’s journey is unique, treatment plan, life style, food habit, hormonal condition, immune system, chronic disease condition, geological location, weather and previous medical  history is also unique. So always seek the best advice from a qualified medical professional or health care provider before trying any treatments to ensure to find out the best plan for you. This guide is for general information and educational purposes only. Regular check-ups and awareness can help to manage and prevent complications associated with these diseases conditions. If you or someone are suffering from this disease condition bookmark this website or share with someone who might find it useful! Boost your knowledge and stay ahead in your health journey. We always try to ensure that the content is regularly updated to reflect the latest medical research and treatment options. Thank you for giving your valuable time to read the article.

The article is written by Team Rxharun and reviewed by the Rx Editorial Board Members

Last Updated: April 24, 2025.