Tongue Inferior Longitudinal Muscle Hypertrophy

Tongue inferior longitudinal muscle hypertrophy refers to an abnormal enlargement of the inferior longitudinal intrinsic muscle of the tongue. This muscle, located on the underside of the tongue, normally helps shorten and thicken the tongue, but when it becomes excessively large, it can lead to functional issues such as difficulty speaking, chewing, swallowing, and breathing . Hypertrophy of this muscle is a form of macroglossia, and understanding its anatomy, causes, and management is crucial for both patients and clinicians.

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Anatomy

Structure & Location

The inferior longitudinal muscle is one of the four intrinsic muscles of the tongue. It lies just beneath the mucosa on the underside of the tongue, between the genioglossus (front) and the hyoglossus (side) muscles .

Origin

Fibers of this muscle originate from the root of the tongue, near the hyoid bone. Posterior fibers may attach to the body of the hyoid bone itself .

Insertion

Anteriorly, fibers blend into the apex (tip) of the tongue, intermingling with fibers of the styloglossus and genioglossus muscles to form the ventral (underside) tip .

Blood Supply

The lingual artery, a branch of the external carotid artery, provides blood to the tongue’s intrinsic muscles, including the inferior longitudinal muscle. Its branches form an anastomotic network beneath the muscle tissue Medscape Reference.

Nerve Supply

Motor innervation is via the hypoglossal nerve (cranial nerve XII), which supplies all intrinsic tongue muscles .

Functions

1. Shortening: Contracts to shorten the tongue length

2. Thickening: Increases tongue bulk by co-contracting fibers

3. Curling Downward: Curls the apex downward, aiding in lateral movement

4. Retraction: Works with the superior longitudinal muscle to pull the tongue back

5. Articulation Support: Helps shape the tongue for speech sounds

6. Swallowing Assistance: Contributes to bolus manipulation during swallowing .

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Types of Hypertrophy

Hypertrophy of the inferior longitudinal muscle can be classified by origin and histology:

• True vs. Relative

  • True hypertrophy involves actual histologic enlargement of muscle fibers.

  • Relative hypertrophy (pseudo-macroglossia) occurs when surrounding structures are small, making the tongue appear large .

• Congenital vs. Acquired

  • Congenital: Present at birth (e.g., Beckwith–Wiedemann syndrome).

  • Acquired: Develops later due to systemic or local conditions (e.g., hypothyroidism) .

• Physiological vs. Pathological

  • Physiological hypertrophy results from increased use or exercise (rare in intrinsic tongue muscles).

  • Pathological hypertrophy arises from disease processes such as infiltration or endocrine disorders .

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Causes

1. Beckwith–Wiedemann syndrome

2. Down syndrome

3. Idiopathic muscular hypertrophy

4. Hemangioma

5. Lymphangioma

6. Lingual thyroid

7. Mucopolysaccharidoses (e.g., Hunter, Hurler)

8. Hamartoma

9. Hypothyroidism

10. Amyloidosis

11. Acromegaly

12. Myxedema

13. Cretinism

14. Ludwig’s angina (deep neck infection)

15. Pemphigus vulgaris

16. Diphtheria

17. Tuberculosis

18. Sarcoidosis

19. Neurofibromatosis

20. Trauma or surgical injury to the tongue .

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Symptoms

1. Difficulty breathing (dyspnea)

2. Noisy breathing or snoring (sleep apnea)

3. Trouble swallowing (dysphagia)

4. Speech problems (dysphonia, lisp)

5. Excessive drooling (sialorrhea)

6. Sores at mouth corners (angular cheilitis)

7. Indentations on tongue edges (crenation)

8. Open bite malocclusion

9. Enlarged jaw projection (mandibular prognathism)

10. Mouth breathing

11. Orthodontic issues (diastema, crowding)

12. Tongue protrusion at rest

13. Feeding difficulties in infants

14. Choking or gagging

15. Ulceration of the tongue surface

16. Tongue pain or tenderness

17. Altered taste sensation

18. Speech slurring

19. Oral hygiene challenges

20. Reduced tongue mobility .

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Diagnostic Tests

1. Clinical Examination: Inspect tongue size and contour

2. Dental Occlusion Assessment

3. Speech Evaluation

4. Videofluoroscopic Swallow Study

5. Polysomnography (Sleep Study)

6. Lateral Neck Radiograph

7. Ultrasound of Tongue

8. MRI of Tongue

9. CT Scan

10. Dynamic MRI

11. Electromyography (EMG)

12. Muscle Biopsy with Histopathology

13. Biopsy for Amyloid Staining

14. Thyroid Function Tests (TSH, T4)

15. Metabolic Panel (renal, hepatic)

16. Genetic Testing (Beckwith–Wiedemann)

17. Enzyme Assays (MPS)

18. Fine-Needle Aspiration (FNA) of Mass Lesions

19. Endoscopic Evaluation (sleep endoscopy)

20. Abdominal Ultrasound (for BWS workup) Medscape Reference.

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Non-Pharmacological Treatments

1. Speech therapy

2. Orofacial myofunctional exercises

3. Tongue stretching routines

4. Tongue strengthening exercises

5. Manual tongue massage

6. Cold-compression therapy

7. Warm-compression therapy

8. Therapeutic ultrasound

9. Neuromuscular electrical stimulation

10. Acupuncture

11. Orthodontic appliance use

12. Bite guard or night guard

13. Prosthetic intraoral devices

14. Head-tilt/chin-lift positioning

15. Positional therapy for sleep

16. CPAP for associated sleep apnea

17. Texture-modified diets (soft foods)

18. Thickened liquids

19. Hydration optimization

20. Oral hygiene protocols

21. Saliva management (absorbent pads)

22. Low-level laser therapy

23. Cryotherapy for edema

24. Manual lymphatic drainage

25. Postural training exercises

26. Feeding modifications for infants

27. Occupational therapy

28. Behavioral therapy for drooling

29. Relaxation and breathing techniques

30. Nutritional counseling .

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Pharmacological Treatments

1. Levothyroxine (hypothyroidism)

2. Liothyronine (adjunct for thyroid)

3. Prednisone (inflammatory/infiltrative)

4. Dexamethasone (acute swelling)

5. Ibuprofen (NSAID for pain/inflammation)

6. Penicillin (actinomycosis, Ludwig’s angina)

7. Clindamycin (soft tissue infections)

8. Isoniazid/Rifampin (tuberculosis)

9. Nystatin (oral candidiasis)

10. C1-Esterase Inhibitor (hereditary angioedema)

11. Octreotide (acromegaly)

12. Pegvisomant (acromegaly)

13. Cabergoline (acromegaly)

14. Melphalan (amyloidosis)

15. Bortezomib (amyloidosis)

16. Idursulfase (MPS type II)

17. Hormonal therapy (Beckwith–Wiedemann)

18. Antifibrinolytics (bleeding control)

19. Topical steroids (mucosal lesions)

20. Anticholinergics (drooling control) .

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Surgical Treatments

1. Partial Glossectomy

2. Central Wedge Glossectomy

3. Lateral Wedge Glossectomy

4. Peripheral Glossectomy

5. Median Longitudinal Glossectomy

6. Z-Plasty Glossectomy

7. W-Plasty Glossectomy

8. Laser-Assisted Glossectomy

9. Segmental Glossectomy

10. Elective Tracheostomy (pre-op airway) Medscape ReferencePMC.

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Prevention Strategies

1. Genetic Counseling (for hereditary syndromes)

2. Newborn Screening (Beckwith–Wiedemann)

3. Early Thyroid Function Testing

4. Regular Dental Check-ups (detect early tongue indentations)

5. Prompt Treatment of Infections (e.g., Ludwig’s angina)

6. Control of Endocrine Disorders (acromegaly, hypothyroidism)

7. Head-and-Neck Radiation Precautions

8. Oral Hygiene Maintenance

9. Avoidance of Tongue Trauma (sharp foods, habits)

10. Periodic Speech/Swallow Evaluations .

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When to See a Doctor

Seek medical attention if you experience:

• Breathing difficulties (noisy or obstructive breathing)

• Severe swallowing problems (choking, gagging)

• Speech impairment interfering with communication

• Rapid tongue enlargement over days to weeks

• Persistent pain, ulceration, or bleeding

• Signs of infection (fever, spreading redness)

• Excessive drooling causing social or hygiene issues Medscape Reference.

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FAQs

1. What is inferior longitudinal muscle hypertrophy?
It’s an abnormal enlargement of one of the tongue’s intrinsic muscles that shortens and thickens the tongue.

2. How is it different from general macroglossia?
It specifically involves the inferior longitudinal muscle, while macroglossia refers to overall tongue enlargement.

3. Can isolated inferior longitudinal hypertrophy occur alone?
Rarely, it’s usually part of broader macroglossia due to systemic conditions.

4. Is it painful?
It can cause discomfort, ulceration, or tightness, but pain levels vary.

5. How is it diagnosed?
Through physical exam, imaging (MRI/CT), EMG, and sometimes muscle biopsy.

6. Can exercises reduce hypertrophy?
Exercises may improve function but rarely reduce true muscular hypertrophy.

7. Are there medications to reverse it?
Treatment targets underlying causes (e.g., thyroid, amyloid). No direct anti-hypertrophy drugs exist.

8. When is surgery recommended?
For severe functional impairment—speech, swallowing, or airway issues.

9. What risks come with surgery?
Potential risks include bleeding, infection, loss of taste, and speech changes.

10. Can children outgrow it?
If related to congenital syndromes, hypertrophy often persists without intervention.

11. Is it hereditary?
It can be in genetic syndromes (e.g., Beckwith–Wiedemann).

12. Will dental appliances help?
They may manage occlusion changes but won’t reduce muscle size.

13. How common is this condition?
Isolated inferior longitudinal hypertrophy is very rare; overall macroglossia is uncommon.

14. Does it affect sleep?
Yes—enlargement can obstruct the airway, leading to sleep apnea.

15. Can physical therapy help?
Orofacial therapy can improve mobility and function but not reverse hypertrophy.

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 23, 2025.

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