Muscle hypertrophy refers to an increase in the size of a muscle due to enlargement of its component fibers, typically in response to increased workload or certain pathological processes WikipediaMedical News Today.
Superior longitudinal muscle hypertrophy of the tongue is a condition in which the intrinsic superior longitudinal fibers—normally a thin layer beneath the dorsal mucosa—undergo abnormal enlargement. This can lead to tongue thickening, altered shape, and functional impairment during speech, swallowing, and breathing WikipediaWikipedia.
Anatomy
Structure & Location
The superior longitudinal muscle is one of four intrinsic tongue muscles. It is a thin stratum of oblique and longitudinal fibers directly beneath the mucous membrane on the dorsum of the tongue WikipediaWikipedia.
Origin
Fibers arise from the submucous fibrous layer close to the epiglottis and from the median fibrous septum of the tongue WikipediaWikipedia.
Insertion
They run anteriorly to insert into the edges of the tongue and overlying mucosa, allowing them to influence the shape of the entire dorsal surface WikipediaWikipedia.
Blood Supply
Arterial perfusion is provided principally by branches of the lingual artery, ensuring adequate oxygenation for rapid shape changes during speech and swallowing www.elsevier.com.
Nerve Supply
Motor innervation is via the hypoglossal nerve (cranial nerve XII), which drives contraction of all intrinsic tongue muscles WikipediaWikipedia.
Functions
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Shortening the tongue—contracts to make the tongue shorter in length NCBI.
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Widening the tongue—as it shortens, the tongue also broadens mediolaterally NCBI.
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Dorsiflexion (curling upward)—curls the apex and sides upward to aid in articulation Radiopaedia.
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Retraction—contributes to pulling the tongue back into the mouth in concert with the inferior longitudinal muscle Wikipedia.
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Speech articulation—fine-tunes tongue shape for consonant and vowel production, especially “t,” “d,” and “l” sounds Wikipedia.
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Swallowing—helps form and propel the food bolus toward the pharynx during the oral phase Home.
Types of Hypertrophy
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Myofibrillar hypertrophy: Increase in contractile proteins (actin, myosin) enhancing strength Wikipedia.
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Sarcoplasmic hypertrophy: Enlargement of the muscle cell’s fluid and non-contractile elements, increasing volume but less strength WikipediaMedical News Today.
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Transient hypertrophy: Short‑lived swelling (“pump”) due to increased blood flow and fluid shifts after activity Wikipedia.
Causes
True hypertrophy of the superior longitudinal muscle may arise from:
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Chronic resistance exercise (e.g., tongue‐strengthening programs) PMC
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Oral myofunctional therapy overload Wikipedia
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Obstructive sleep apnea (compensatory hypertrophy) Wikipedia
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Beckwith–Wiedemann syndrome (muscular overgrowth) Wikipedia
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Acromegaly (growth hormone excess) Wikipedia
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Amyloidosis (amyloid deposition) Wikipedia
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Hypothyroidism (myxedema) Wikipedia
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Mucopolysaccharidoses (storage diseases) Wikipedia
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Neurofibromatosis (nerve sheath tumors) Wikipedia
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Vascular malformations (e.g., lymphangioma, hemangioma) Wikipedia
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Lingual thyroid Wikipedia
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Certain medications (e.g., phenytoin‐induced gingival and tongue enlargement) MedlinePlus
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Angioedema Wikipedia
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Trauma with chronic inflammation MedlinePlus
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Idiopathic (no identifiable cause) Wikipedia
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Congenital true macroglossia Cleveland Clinic
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Down syndrome (relative macroglossia) Wikipedia
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Glycogen storage diseases (e.g., Pompe) Wikipedia
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Simpson–Golabi–Behmel syndrome Wikipedia
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Post‑radiation fibrosis MedlinePlus
Symptoms
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Tongue enlargement or thickening Wikipedia
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Speech difficulties (lisping, dysarthria) Wikipedia
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Difficulty swallowing (dysphagia) Wikipedia
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Noisy breathing or snoring Wikipedia
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Obstructive sleep apnea Wikipedia
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Drooling (sialorrhea) Wikipedia
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Crenated (tooth‑imprinted) tongue edges Wikipedia
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Malocclusion or open bite Wikipedia
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Mandibular prognathism Wikipedia
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Tongue protrusion at rest Wikipedia
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Oral ulceration MedlinePlus
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Infection risk (dryness, trauma) MedlinePlus
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Impaired mastication Wikipedia
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Altered taste sensation Wikipedia
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Buccal mucosa trauma Wikipedia
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Speech fatigue Wikipedia
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Jaw pain from muscle strain MedlinePlus
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Difficulty fitting dentures Wikipedia
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Sleep disturbances Wikipedia
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Anxiety or social embarrassment Wikipedia
Diagnostic Tests
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Clinical oral examination Wikipedia
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Cephalometric radiography MedlinePlus
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CT scan of head and neck Wikipedia
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MRI of the tongue Wikipedia
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Ultrasound imaging Wikipedia
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Polysomnography (sleep study) Wikipedia
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Sleep endoscopy Wikipedia
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Video fluoroscopic swallow study MedlinePlus
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Electromyography (EMG) of tongue muscles PMC
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Tongue strength measurement (IOPI device) BPB
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Genetic testing (e.g., Beckwith–Wiedemann panel) Wikipedia
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Thyroid function tests Wikipedia
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Serum IGF‑1 and GH levels (acromegaly workup) Wikipedia
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Enzyme assays for storage diseases Wikipedia
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Biopsy and histology (e.g., amyloid Congo red stain) MedlinePlus
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C1‑esterase inhibitor level (hereditary angioedema) Wikipedia
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Cardiac echo (associated systemic disease) Wikipedia
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Liver ultrasound (storage disease assessment) Wikipedia
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Speech pathology evaluation Wikipedia
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Oropharyngeal endoscopy Wikipedia
Non‑Pharmacological Treatments
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Orofacial myofunctional therapy Wikipedia
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Tongue‑strengthening exercises Home
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Speech therapy Wikipedia
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Manual massage of tongue muscles Physiopedia
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Heat and cold therapy Physiopedia
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Neuromuscular electrical stimulation BPB
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Ultrasound phonophoresis Physiopedia
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Acupuncture Physiopedia
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Biofeedback training Physiopedia
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Mandibular advancement device (for OSA) Wikipedia
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Continuous positive airway pressure (CPAP) Wikipedia
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Dental/orthodontic appliances Wikipedia
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Dietary modifications (soft diet) MedlinePlus
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Hydration protocols MedlinePlus
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Positional therapy (sleep posture) Wikipedia
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Tongue taping Wikipedia
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Oxygen therapy (sleep breathing support) Wikipedia
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Yoga and mindfulness (muscle relaxation) Physiopedia
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Myofascial release techniques Physiopedia
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Craniosacral therapy Physiopedia
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Respiratory muscle training Physiopedia
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Tongue stabilization exercises Home
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Transcutaneous electrical nerve stimulation (TENS) Physiopedia
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Photobiomodulation (low‑level laser therapy) Physiopedia
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Surgical orthodontic planning (to relieve denture stress) MedlinePlus
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Behavioral modification (habit reversal) Wikipedia
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Neuro‑muscular facilitation techniques Physiopedia
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Elevation of head during sleep Wikipedia
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Tongue protrusion control drills Home
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Early intervention in congenital cases Cleveland Clinic
Drugs
Therapy is tailored to cause:
1–4. Somatostatin analogues: octreotide, lanreotide, pasireotide, controlled GH secretion in acromegaly PMCWikipedia
5. Growth hormone receptor antagonist: pegvisomant ScienceDirect
6. Dopamine agonists: cabergoline, bromocriptine ScienceDirectWikipedia
7. Levothyroxine: for hypothyroidism-induced macroglossia Wikipedia
8–9. Enzyme replacement therapies: alglucosidase alfa (Pompe), laronidase (Hurler) Wikipedia
10. Idursulfase: Hunter syndrome Wikipedia
11. Bortezomib: for AL amyloidosis Wikipedia
12. Daratumumab: for amyloid light-chain Wikipedia
13. C1-esterase inhibitor concentrate: hereditary angioedema Wikipedia
14. Icatibant: bradykinin receptor antagonist in angioedema Wikipedia
15. Corticosteroids: reduce inflammatory swelling MedlinePlus
16. Antihistamines: for allergic angioedema MedlinePlus
17. Radiotherapy adjunct: in infiltrative tumors MedlinePlus
18. Glucocorticoids: decrease lymphangioma size Wikipedia
19. mTOR inhibitors (e.g., sirolimus): vascular malformations Wikipedia
20. Interferon‑α: for hemangioma involution Wikipedia
Surgeries
All involve reduction glossectomy, chosen based on tongue shape and severity Wikipedia:
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Anterior wedge glossectomy
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Lateral glossectomy
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Midline elliptical resection
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Keyhole (star-shaped) glossectomy
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Z-plasty technique
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Marginal glossectomy
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Submucosal resection
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Laser-assisted reduction
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Radiofrequency ablation
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Microsurgical reconstructive procedures
Prevention Strategies
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Early treatment of underlying endocrine disorders Wikipedia
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Avoidance of medications known to cause tissue overgrowth MedlinePlus
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Routine oral–motor exercises Home
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Regular dental check‑ups and appliance adjustments MedlinePlus
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Genetic counseling for congenital syndromes Cleveland Clinic
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Maintaining optimal thyroid function Wikipedia
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Control of systemic amyloidosis Wikipedia
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Nighttime CPAP/end‑expiratory pressure optimization Wikipedia
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Early myofunctional therapy in infants with macroglossia Cleveland Clinic
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Monitoring tongue size during growth hormone therapy Wikipedia
When to See a Doctor
Seek evaluation if you experience:
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Persistent tongue thickening or protrusion
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Speech changes or difficulty articulating sounds
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Swallowing difficulty or choking episodes
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Noisy breathing, snoring, or daytime sleepiness
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Unexplained drooling or tongue ulceration
Frequently Asked Questions
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What exactly is superior longitudinal muscle hypertrophy?
It’s abnormal enlargement of the tongue’s top‑surface muscle, affecting shape and function. -
Is it painful?
Often it’s painless, but chronic irritation can lead to soreness or ulcers. -
Can tongue exercises cause hypertrophy?
Intensive, prolonged exercises (e.g., dysphagia therapy) can induce physiological hypertrophy. -
How is it diagnosed?
Through clinical exam, imaging (MRI/CT), sleep study, and sometimes muscle biopsy. -
Is treatment always surgical?
No—many cases respond to therapies like CPAP, myofunctional exercises, or medication for underlying disease. -
Can speech therapy help?
Yes—retraining muscle patterns can improve function and comfort. -
Will it recur after surgery?
Recurrence depends on cause; congenital and systemic disorders may require ongoing management. -
Are there medical treatments?
Yes—targeting the underlying cause (e.g., octreotide for acromegaly, levothyroxine for hypothyroidism). -
Is it genetic?
Some forms (e.g., Beckwith–Wiedemann, storage diseases) are inherited. -
Can it cause sleep apnea?
Enlarged tongue muscles may obstruct the airway during sleep. -
Is it dangerous?
If it impairs breathing or swallowing, it can be life‑threatening without treatment. -
Can it affect taste?
Rarely—severe enlargement can alter taste bud exposure. -
How long does non‑surgical therapy take?
Improvements may be seen within weeks to months of consistent exercises. -
Should children be evaluated differently?
Yes—growth patterns and congenital causes require pediatric assessment. -
Can dietary changes help?
Soft diets can reduce discomfort, but they do 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 22, 2025.
