Mastication Muscle Sprain

A mastication muscle sprain—often termed a jaw muscle strain—occurs when the fibers of one of the muscles you use to chew (the masticatory muscles) are overstretched or torn. This injury can cause sudden, localized pain, swelling, tenderness, and difficulty moving the jaw normally HomeMayo Clinic. While any of the four main chewing muscles (masseter, temporalis, medial pterygoid, lateral pterygoid) can be affected, the masseter is most commonly involved due to its superficial position and heavy workload during chewing.

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Anatomy of the Masticatory Muscles

Structure and Location

The masticatory muscles lie on the side and inside of your jaw. The masseter is a thick, quadrangular muscle on the side of the lower jaw, easily felt when you clench your teeth WikipediaNCBI. The temporalis fans out over the temple and inserts into the coronoid process of the mandible. The medial and lateral pterygoids lie deeper, beneath the cheekbone, helping with side-to-side and forward movements of the jaw.

Origin and Insertion

• Masseter

  • Origin: Zygomatic arch and maxillary process of the zygomatic bone

  • Insertion: Lateral surface and angle of the mandibular ramus WikipediaNCBI

• Temporalis

  • Origin: Temporal fossa of the skull

  • Insertion: Coronoid process of the mandible

• Medial Pterygoid

  • Origin: Medial surface of the lateral pterygoid plate and maxilla

  • Insertion: Medial surface of the mandibular ramus

• Lateral Pterygoid

  • Origin: Greater wing of sphenoid and lateral pterygoid plate

  • Insertion: Neck of the mandible and articular disc of the TMJ

Blood Supply

Each muscle receives arteries from branches of the maxillary artery:

• Masseter → masseteric artery

• Temporalis → deep temporal arteries

• Pterygoids → pterygoid branches
  These vessels bring oxygen and nutrients to muscle fibers NCBI.

Nerve Supply

All four muscles are innervated by the mandibular division (V₃) of the trigeminal nerve:

• Motor fibers travel via the masseteric, deep temporal, and pterygoid branches to reach each muscle NCBI.

Functions (Key Actions)

1. Elevation of the Mandible (closing the mouth) WikipediaPhysiopedia

2. Protrusion (pushing the lower jaw forward)

3. Retraction (pulling the jaw backward)

4. Lateral Excursion (side-to-side grinding of food)

5. Stabilization of the TMJ during chewing and speaking

6. Maintenance of Dental Occlusion, ensuring teeth align properly when closed

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Types of Jaw Muscle Sprain

Muscle strains (tears) and ligament sprains around the jaw are graded by severity Pivotal Motion PhysiotherapyVerywell Health:

• Grade I (Mild): A few muscle fibers overstretched or slightly torn. Mild pain, minimal loss of strength.

• Grade II (Moderate): More extensive fiber tearing but the muscle is not completely ruptured. Noticeable pain, swelling, reduced movement.

• Grade III (Severe): Full-thickness tear or complete rupture of the muscle or ligament. Severe pain, major functional loss, possible gap in muscle on palpation.

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Causes

1. Bruxism (teeth grinding) Home

2. Overwide Yawning Home

3. Hard/Bulky Bites (e.g., biting into a large sandwich) Home

4. Lengthy Dental Procedures requiring prolonged mouth opening Oral Health Group

5. Direct Trauma (blow to the jaw) Home

6. Intubation for Surgery > risk of overextension Pivotal Motion Physiotherapy

7. Sports Injuries (e.g., contact sports)

8. Poor Posture (forward head posture strains jaw muscles)

9. Stress-Related Muscle Tension

10. Rapid Jaw Movements (e.g., playing wind instruments) Today’s RDH

11. Temporomandibular Disorder (TMD) causing imbalance Mayo Clinic

12. Malocclusion (misaligned bite) Cleveland Clinic

13. Arthritis of TMJ with compensatory muscle overuse

14. Infections (e.g., masticatory myositis)

15. Electrolyte Imbalance (muscle cramping risk)

16. Autoimmune Disorders (e.g., polymyositis)

17. Tumors impacting muscle function

18. Prior Jaw Surgery leading to scar tissue

19. Drug-Induced Myopathies (e.g., statins causing muscle weakness)

20. Dehydration reducing muscle resilience

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Symptoms

1. Acute Jaw Pain localized to one side Mayo Clinic

2. Tenderness on palpating the muscle

3. Swelling over the jaw area

4. Limited Mouth Opening (trismus) Mayo Clinic

5. Muscle Spasm with involuntary contractions

6. Difficulty Chewing or biting

7. Radiating Earache Mayo Clinic

8. Headache from referred pain

9. Jaw Deviation toward the injured side

10. Clicking or Popping sounds

11. Locking of the joint on opening/closing

12. Muscle Weakness when chewing

13. Facial Asymmetry due to swelling

14. Bruising in severe tears

15. Warmth or Redness

16. Difficulty Swallowing if severe

17. Neck Pain from compensatory tension

18. Fatigue of jaw muscles

19. Tooth Pain secondary to muscle pressure

20. Sleep Disturbances from night-time pain

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Diagnostic Tests

1. Clinical Examination: history and palpation of tender spots Distance Learning and Telehealth

2. Range of Motion Measurement (mouth opening distance)

3. Visual Analog Scale (VAS) for pain intensity

4. Electromyography (EMG) to assess muscle function

5. Ultrasound Imaging for fiber tears

6. MRI to visualize soft-tissue damage

7. CT Scan for bony involvement

8. X-ray of TMJ to rule out fractures

9. Blood Tests: CPK levels if systemic myositis suspected

10. Jaw Tracking Devices measuring movement patterns

11. Diagnostic Anesthetic Block to isolate muscle pain

12. Surface Electrode Mapping of muscle activation

13. Thermography for inflammation detection

14. Ultrasound Elastography for muscle stiffness

15. Occlusal Analysis to check bite alignment

16. Proprioception Tests for neuromuscular control

17. Jaw Opening Force Measurement

18. Postural Assessment (head/neck posture)

19. Dental Impressions to fabricate splints if needed

20. Psychosocial Questionnaires (stress, bruxism habits) Frontiers

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Non-Pharmacological Treatments

1. Rest: avoid hard or long chewing sessions

2. Cold Packs for 15–20 min to reduce swelling

3. Warm Compresses to relax muscles

4. Gentle Jaw Stretches (e.g., controlled opening)

5. Isometric Exercises (pushing jaw against resistance)

6. Massage: self-massage or by a professional

7. Physical Therapy: guided exercises, manual therapy PMC

8. TENS (Transcutaneous Electrical Nerve Stimulation)

9. Ultrasound Therapy for deep heating

10. Low-Level Laser Therapy to promote healing

11. Dry Needling/Trigger-Point Therapy PMC

12. Biofeedback for stress-related tension

13. Acupuncture to relieve muscle spasm

14. Jaw Splints/Night Guards to prevent bruxism

15. Occlusal Adjustment by dentist

16. Stress Management Techniques (mindfulness, CBT)

17. Posture Correction (ergonomic work setup)

18. Diet Modification: soft diet (soups, smoothies)

19. Hydration: adequate water intake

20. Avoid Gum Chewing or hard foods

21. Jaw Movement Retraining (slow, controlled)

22. Warm Oral Rinses (saltwater)

23. Neck and Shoulder Stretching for overall relaxation

24. Cold Laser therapy (LLLT)

25. Cervical Traction in physiotherapy setting

26. Chiropractic Mobilization of TMJ

27. Myofascial Release techniques

28. Mind-Body Practices (yoga, Pilates)

29. Ergonomic Mouth Props during dental work

30. Education on proper chewing habits Pivotal Motion Physiotherapy

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Drugs

1. Ibuprofen (NSAID) for pain and inflammation

2. Naproxen (NSAID)

3. Diclofenac (NSAID)

4. Acetaminophen (analgesic)

5. Celecoxib (COX-2 inhibitor)

6. Ketoprofen gel (topical NSAID)

7. Cyclobenzaprine (muscle relaxant)

8. Methocarbamol (muscle relaxant)

9. Tizanidine (muscle relaxant)

10. Baclofen (antispastic agent)

11. Diazepam (benzodiazepine muscle relaxant)

12. Lidocaine Patches/Injections (local anesthetic)

13. Tramadol (opioid analgesic)

14. Oxycodone (opioid, short-term)

15. Corticosteroid Injection into TMJ area Mayo Clinic

16. Botulinum Toxin (Botox) injections to reduce spasm

17. Amitriptyline (tricyclic antidepressant for chronic pain)

18. Gabapentin (anticonvulsant for neuropathic pain)

19. Clonazepam (for night-time bruxism)

20. Capsaicin Cream (topical counterirritant)

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Surgical Options

1. Arthrocentesis: flushing the TMJ space

2. Arthroscopy: minimally invasive joint surgery

3. Open-Joint Surgery (arthroplasty) for advanced TMD

4. Discectomy: removal of damaged disc

5. Coronoidectomy: release tight coronoid muscle attachment

6. Condylectomy/Condylar Reshaping

7. Joint Replacement (TMJ prosthesis)

8. Osteotomy: surgical repositioning of jaw bones Cleveland Clinic

9. Myotomy: cutting part of a muscle to relieve spasm

10. Neurectomy: severing nerve to reduce pain (rare)

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Prevention Strategies

1. Warm-up Stretches before prolonged chewing

2. Use of Night Guard if you grind teeth

3. Limit Hard Foods (nuts, tough meats)

4. Avoid Wide Yawning (e.g., pre-yawn bite)

5. Maintain Good Posture (head and neck alignment)

6. Stress Reduction (meditation, therapy)

7. Regular Jaw Exercises to maintain flexibility

8. Proper Ergonomics at desk (screen at eye level)

9. Hydration to keep muscles pliable

10. Scheduled Breaks during lengthy dental or musical performances Home

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When to See a Doctor

• Severe Pain or Swelling that doesn’t improve after 1 week of home care

• Inability to Open or Close Mouth fully

• Signs of Infection: fever, redness, warmth

• Neurological Symptoms: numbness, tingling

• Persistent Headache or Earache linked to jaw movement

• History of Trauma with suspected fracture

• Progressive Worsening despite conservative treatment
  If any of these occur, prompt medical or dental evaluation is essential to prevent chronic issues Mayo Clinic.

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Frequently Asked Questions

1. What’s the difference between a jaw sprain and a strain?

   • A sprain involves ligaments; a strain involves muscle or tendon fibers Verywell Health.

2. How long does a muscle strain take to heal?

   • Mild (Grade I): 1–2 weeks; Moderate (Grade II): 3–6 weeks; Severe (Grade III): several months.

3. Can bruxism cause a muscle sprain?

   • Yes—night-time clenching can overstretch and tear muscle fibers Home.

4. Are there at-home remedies I can try?

   • Rest, ice/heat, gentle stretches, soft diet, and over-the-counter NSAIDs often help.

5. When should I use ice versus heat?

   • Use ice for the first 48 hours to reduce swelling, then heat to relax muscles.

6. Will a mouth guard help?

   • Yes—night guards prevent grinding and reduce muscle overload.

7. Is physical therapy effective?

   • Absolutely—targeted exercises, TENS, and manual therapy can speed recovery PMC.

8. Can surgery fix a muscle sprain?

   • Surgery is rare for muscle sprain alone but may be needed if joint structures are damaged.

9. Are injections (steroids or Botox) safe?

   • When administered by a specialist, they can reduce inflammation and spasm with minimal risk.

10. How do dentists diagnose this condition?

    • Through exam, palpation, imaging (MRI/ultrasound), and possibly diagnostic blocks Distance Learning and Telehealth.

11. Can stress management help?

    • Yes—reducing psychological tension lowers muscle clenching and pain.

12. Is massage beneficial?

    • Gentle massage or myofascial release can relieve trigger-point discomfort.

13. Should I avoid eating altogether?

    • No—switch to a soft diet but maintain nutrition.

14. Can posture influence jaw pain?

    • Forward head posture increases strain on masticatory muscles.

15. When does a strain become chronic?

    • If untreated within a few weeks, inflammation can lead to persistent myalgia and TMD PMC.

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.

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