What is tongue?
The tongue is a muscular organ in the oral cavity that is responsible for a variety of functions such as taste, speech, mastication, and swallowing. It is mucous membrane-coated and contains taste buds that allow for the perception of various flavors. The tongue’s intricate structure, which includes muscles, nerves, and taste receptors, makes it necessary for both sensory and mechanical functions such as food manipulation and sound articulation. Its health and functionality are critical to daily activities and overall well-being.
Key Insights into Tongue Anatomy
The tongue is a complex and versatile organ that includes muscles, nerves, blood vessels, and taste and sensation-specific structures. It has three parts: the apex (tip), the body, and the base (root).
External Features
- Apex (Tip): The tip of the tongue is the most anterior part and is extremely flexible, which aids in speech and food manipulation.
- Body: The middle portion of the tongue, from the apex to the base, is covered in various types of papillae that contain taste buds.
- Base (Root): The posterior portion of the tongue that attaches to the mouth floor. It includes the lingual tonsils, which are part of the immune system.
Papillae
Different types of papillae, which are small, nipple-like structures that contain taste buds and sensory receptors, cover the surface of the tongue:
- Filiform Papillae: The most numerous, but do not contain taste buds. They give the tongue texture, making it easier to manipulate food.
- Fungiform Papillae: Found among the filiform papillae, particularly on the tip and sides of the tongue. They contain taste buds and contribute to the sensation of taste.
- Circumvallate Papillae are large, dome-shaped papillae that form a V-shaped row at the back of the tongue. A trench surrounds each papilla, which contains numerous taste buds.
- Foliate Papillae: These papillae are located on the sides of the tongue near the back and contain taste buds, which play a role in taste sensation.
Muscles
The tongue’s remarkable range of motion and flexibility are due to the presence of both intrinsic and extrinsic muscles.
- Intrinsic Muscles: These muscles are entirely within the tongue and are in charge of changing its shape. They include:
- Superior Longitudinal Muscle: Lifts the tongue tip and shortens it.
- Inferior Longitudinal Muscle: pulls the tongue tip down and shortens it.
- Transverse Muscle: Narrows and lengthens the tongue.
- Vertical Muscle: Flattens and expands the tongue.
- Extrinsic Muscles: These muscles originate outside and insert into the tongue, allowing it to move in a variety of directions. They include:
- Genioglossus: The tongue protrudes and depresses in the center.
- Hyoglossus depresses and retracts the tongue.
- Styloglossus elevates and retracts the tongue.
- Palatoglossus: Raises the back of the tongue and closes the oropharyngeal isthmus while swallowing.
Nerve Supply
A dense network of nerves, including sensory, motor, and special sensory innervation, supports the tongue’s functionality.
- Motor Innervation: Provided by the hypoglossal nerve (cranial nerve XII), which controls all intrinsic and extrinsic muscles except the palatoglossus (cranial nerve X).
- Sensory Innervation*:
- Anterior Two-Thirds: The lingual nerve, a mandibular nerve branch (cranial nerve V3), provides general sensory innervation.
- The glossopharyngeal nerve (cranial nerve IX) provides general sensory innervation in the posterior one-third.
- Special Sensory (Taste) Innervation
- Anterior Two-Thirds: The chorda tympani, a branch of the facial nerve (cranial nerve VII), controls taste sensation.
- The glossopharyngeal nerve (cranial nerve IX) provides taste sensation in the posterior one-third.
- Base of the Tongue: The internal laryngeal nerve, a branch of the vagus nerve, supplies taste sensation to the area surrounding the epiglottis.
Blood Supply
The tongue’s blood supply comes from the lingual artery, a branch of the external carotid artery. The lingual artery divides into:
- Dorsal Lingual Artery: This artery supplies the tongue’s base and dorsum.
- The Deep Lingual Artery supplies the tongue’s body.
Venous drainage occurs primarily through the lingual veins, which lead to the internal jugular vein.
Lymph Drainage
The regions of lymphatic drainage from the tongue are as follows:
- Tip: Drains to the submental lymph nodes.
- Lateral Margins: Drain to submandibular lymph nodes.
- Central and Base: Drain to the deep cervical lymph nodes.
Microscopic Anatomy
At the microscopic level, the tongue’s surface epithelium varies by region:
- Dorsal Surface: Covered in keratinized stratified squamous epithelium that protects and houses the taste buds within the papillae.
- Ventral Surface: The non-keratinized stratified squamous epithelium is thinner, allowing for greater mobility and flexibility.
The connective tissue beneath the epithelium contains salivary glands (primarily the lingual glands), which secrete mucus and serous fluid to aid digestion and maintain oral health.
Tongue Physiology and Functions
The tongue serves multiple functions and is required for a variety of physiological processes. Its functions go beyond taste to include speech, chewing, and swallowing.
Taste
The tongue’s primary sensory function is taste, which is facilitated by taste buds on the papillae. Taste buds have gustatory cells that detect five basic tastes: sweet, sour, salty, bitter, and umami. These sensory cells convert chemical signals from food into neural signals that are transmitted to the brain, where they are recognized as distinct flavors. Taste perception is critical for making dietary decisions, monitoring nutritional intake, and detecting potentially harmful substances.
Speech
The tongue is essential for articulating sounds and forming words. It controls the flow of air and shapes the sounds produced by the larynx into separate phonemes. This articulation requires precise and coordinated movement of the tongue’s intrinsic and extrinsic muscles. Different parts of the tongue work with the teeth, hard palate, and soft palate to produce the various sounds required for clear and effective speech.
Mastication
During chewing, the tongue positions food between the teeth and mixes it with saliva, which aids mechanical breakdown and enzymatic digestion. The tongue’s movements ensure thorough mixing, which improves chewing effectiveness and prepares food for swallowing. This process is necessary for proper digestion and nutrient absorption.
Swallowing
The tongue plays an important role in swallowing (deglutition). It aids in the formation of a bolus (a mass of chewed food) and propels it to the back of the mouth, into the pharynx. The tongue’s coordinated action with other muscles ensures that food enters the esophagus rather than the airway. Neural pathways regulate voluntary and involuntary muscle contractions in this complex process.
Additional Functions
- Sensation: The tongue detects temperature, texture, and pain, which contributes to the overall sensory experience of eating and drinking. These sensory functions assist in determining food quality and potential hazards.
- Immune Function: The lingual tonsils at the base of the tongue are part of the body’s immune system and serve as the first line of defense against pathogens that enter the mouth.
Common Conditions
A variety of conditions and disorders can affect the tongue, each with its own set of symptoms and necessitating a unique diagnostic and treatment approach. Understanding these common conditions is critical to maintaining oral health and overall well-being.
Geographic Tongue
Geographic tongue, also known as benign migratory glossitis, is a condition that causes red patches on the tongue’s surface that resemble maps. These patches are usually surrounded by white or light-colored borders. Geographic tongue is not completely understood, but it is thought to be caused by genetics and may be linked to psoriasis and other skin disorders.
Symptoms:
- Red, smooth patches on the tongue.
- White or light-colored borders around the patches.
- Sensitivity to specific foods and beverages
Treatment:
- Usually not necessary since the condition is benign.
- Avoiding irritants like spicy and acidic foods.
- Antihistamines or topical corticosteroids for severe discomfort.
Glossitis
Glossitis is inflammation of the tongue, which can cause swelling, color changes, and pain. Infections, allergic reactions, nutritional deficiencies (for example, vitamin B12 or iron), and irritants such as alcohol or tobacco can all contribute to it.
Symptoms:
- Swollen, red, smooth tongue
- Pain or tenderness.
- Difficulty swallowing and speaking
Treatment:
- Identifying and treating the root cause.
- Nutritional supplements to treat deficiencies
- Avoiding irritants.
- Anti-inflammatory medications or antibiotics to treat infections
Thrush (oral Candidiasis)
Thrush is a fungal infection caused by an overgrowth of Candida species, most commonly Candida albicans. It is more common in people who have a weakened immune system, have diabetes, or use inhaled corticosteroids or antibiotics.
Symptoms:
- White, creamy lesions on the tongue and inner cheeks.
Redness and soreness - Difficulty swallowing and a cottony sensation in the mouth
Treatment:
- Antifungal treatments (oral or topical)
- Good oral hygiene practices.
- Managing underlying conditions that contribute to fungal infections.
Tongue Tie (Ankyloglossia)
Ankyloglossia, or tongue tie, is a congenital condition in which the lingual frenulum (the tissue that connects the underside of the tongue to the floor of the mouth) is abnormally short or thick, limiting tongue movement. It can impair speech, eating, and oral hygiene.
Symptoms:
- Difficulty sticking out your tongue
- Speech difficulties.
- Issues with infant breastfeeding
Treatment:
Observation in mild cases
- Frenotomy or frenuloplasty (surgical procedures) in more severe cases.
Leukoplakia
Leukoplakia is defined by thick, white patches on the tongue or other areas of the mouth. These patches cannot be scraped away and are frequently caused by chronic irritation from tobacco use, alcohol, or ill-fitting dentures. Leukoplakia is usually benign, but it can occasionally be precancerous.
Symptoms:
- White patches on the tongue that will not scrape off
- Potential discomfort or sensitivity.
Treatment:
- Removing sources of irritation.
- Constant monitoring and biopsy to rule out malignancy.
- The surgical removal of persistent or suspicious patches.
Oral Cancer
Oral cancer can develop on the tongue, gums, mouth floor, or any other part of the oral cavity. Tobacco use, excessive alcohol consumption, HPV infection, and a history of head and neck cancer all increase the risk.
Symptoms:
- Ongoing sores or ulcers on the tongue
- Red or white patches.
- Pain, numbness, or bleeding.
- Difficulties swallowing and moving the tongue.
Treatment:
- Surgery to remove the tumor.
- Radiation Therapy
– Chemotherapy - Targeted therapy or immunotherapy in advanced cases.
Burning Mouth Syndrome
Burning mouth syndrome (BMS) is a chronic condition characterized by a burning sensation on the tongue or other oral areas that has no apparent cause. It is more common in postmenopausal women and may be linked to dry mouth, nutritional deficiencies, or psychological factors.
Symptoms:
- Burning sensation on the tongue, lips, or whole mouth.
- Dry mouth and altered taste.
- Pain that gets worse throughout the day.
Treatment:
- Recognizing and treating underlying conditions.
- Saliva substitutes and hydration
- Nutritional supplements if deficiencies exist.
- Pain-relieving medications, like antidepressants or anticonvulsants.
Black Hairy Tongue
Black hairy tongue is a harmless condition in which the tongue’s papillae become elongated and discolored, usually due to an overgrowth of bacteria or yeast. Poor oral hygiene, smoking, drinking too much coffee or tea, and taking antibiotics are all risk factors for this condition.
Symptoms:
- Tongue discoloration (black or brown)
- Furry or hairy appearance.
- Bad breath and altered taste.
Treatment:
- Better oral hygiene.
- Regular brushing of the tongue.
- Avoiding contributing factors.
Macroglossia
Macroglossia is an abnormally large tongue that can be congenital or acquired through conditions such as hypothyroidism, amyloidosis, or acromegaly. It can cause difficulties with speech, eating, and breathing.
Symptoms:
- An enlarged tongue may protrude from the mouth.
- Difficulty communicating, eating, or breathing
- Drooling and dental problems.
Treatment:
- Addressing the underlying condition.
- Orthodontic or surgical interventions in severe cases.
Methods to Diagnose Tongue Conditions
Tongue conditions are diagnosed using clinical evaluation, laboratory tests, imaging techniques, and, in some cases, biopsy procedures. These methods aid in determining the root causes and directing appropriate treatment.
Clinical Examination
The first step in diagnosing tongue conditions is a thorough clinical examination that includes:
- Visual Inspection: The healthcare provider looks for any abnormalities on the tongue, such as color changes, lesions, swelling, or unusual textures. This examination can reveal clues to a variety of conditions, including infections, inflammatory diseases, and cancer.
- Palpation: Gently palpate the tongue to check for texture, consistency, and the presence of any masses or nodules. This can help detect conditions such as tumors or cysts.
- Medical History: A detailed medical history is obtained to better understand the patient’s symptoms, the duration of the condition, and any associated factors. This includes questions about oral hygiene habits, tobacco or alcohol use, recent illnesses, and medications.
Lab Tests
Laboratory tests are important for diagnosing infections, nutritional deficiencies, and autoimmune conditions.
- Microbial Cultures: Swabs of tongue lesions can be cultured to detect bacterial, fungal, or viral infections. This is especially useful for diagnosing conditions like thrush and bacterial glossitis.
- Blood Tests: Blood tests can identify nutritional deficiencies (e.g., vitamin B12 or iron deficiency), systemic infections, and autoimmune markers. Common tests include a complete blood count (CBC), serum iron levels, and vitamin B12 levels.
- Serologic Tests: Specific antibody tests can aid in the diagnosis of autoimmune diseases such as lupus and pemphigus, both of which can cause oral lesions.
Imaging Techniques
Imaging tests are useful for evaluating structural abnormalities and tumors.
- Ultrasonography: This non-invasive imaging technique can measure the tongue’s size, shape, and structure. It is especially effective for detecting cysts, abscesses, and tumors.
- Magnetic Resonance Imaging (MRI): MRI produces detailed images of soft tissues, making it useful for assessing tongue tumors and deep tissue involvement. It can distinguish between benign and malignant lesions and determine the severity of the disease.
- Computed Tomography (CT) Scan: CT scans provide detailed cross-sectional images and are used to assess the size of tumors, particularly when planning surgical procedures. They can also detect structural abnormalities, such as macroglossia or congenital defects.
Biopsy/Cytology
Biopsy procedures are critical for diagnosing cancer and other serious conditions.
- Fine-Needle Aspiration (FNA) Biopsy: FNA is the process of extracting cells from a suspicious lesion using a thin needle. The cells are then examined under a microscope to look for signs of cancer or other pathologies.
- Incisional Biopsy: A small piece of tissue is surgically removed from the affected area and histologically analyzed. This is frequently done when a larger or more representative sample is required, especially in suspected cases of oral cancer.
- Exfoliative Cytology involves scraping cells from the tongue’s surface and examining them under a microscope. This technique is less invasive and used to screen for lesions such as leukoplakia or oral thrush.
Functional Tests
Functional tests evaluate the effects of tongue conditions on speech, swallowing, and taste.
- Speech Evaluation: A speech-language pathologist assesses the patient’s speech to detect any abnormalities in tongue function. This is especially important in cases of tongue tie and macroglossia.
- Swallowing Study: Swallowing function is evaluated using techniques such as videofluoroscopy or fiberoptic endoscopic evaluation of swallowing (FEES). These studies aid in diagnosing dysphagia and developing appropriate interventions.
- Taste Tests: Taste perception can be assessed using taste strips or solutions containing various flavors. This aids in the identification of taste disorders and an understanding of how they affect the patient’s quality of life.
Additional Diagnostic Tools
- Salivary Gland Function Tests: Determine the function of the salivary glands, which can be compromised by conditions such as Sjögren’s syndrome, which also affects the tongue.
- Allergy Testing: Identifying potential allergens can aid in the diagnosis of allergic reactions that appear as tongue inflammation or swelling.
Treatment Approaches for Tongue Conditions
Treating tongue conditions necessitates a multifaceted approach that is dependent on the specific disorder, severity, and underlying cause. Here are detailed descriptions of existing and innovative treatments for various tongue conditions:
Geographic Tongue
Treatment:
- Because the condition is benign and frequently symptomless, no treatment is usually required.
- Avoid eating spicy, acidic, or hot foods that may cause discomfort.
- Using topical corticosteroids or antihistamines to treat severe symptoms.
Glossitis
Treatment:
- Addressing the root cause, such as infections, nutritional deficiencies, or irritants.
- Antibiotics for bacterial infections; antifungals for fungal infections; and antiviral medications for viral infections.
- To treat nutritional deficiencies, take B12, iron, and other essential nutrient supplements.
- Avoiding irritating substances such as tobacco, alcohol, and spicy foods.
- Using anti-inflammatory drugs or topical anesthetics to alleviate pain and inflammation.
Thrush (oral Candidiasis)
Treatment:
- Antifungal medications: Nystatin, clotrimazole, or fluconazole, topical or systemic, depending on severity.
- Practice good oral hygiene, such as brushing your tongue and using antifungal mouth rinses.
- Treating underlying conditions like diabetes or immunosuppressive therapy to avoid recurrence.
Tongue Tie (Ankyloglossia)
Treatment:
- For mild cases, monitor and, if necessary, provide speech therapy.
- Severe cases may require surgical procedures such as frenotomy (simple frenulum snipping) or frenuloplasty (more complex surgery involving tissue repositioning and suturing) to release the tongue and improve mobility.
Leukoplakia
Treatment:
- Eliminating irritants like tobacco and alcohol.
- Regular monitoring and biopsies to rule out or detect early cancers.
- Surgical removal of persistent or suspicious patches with methods such as laser therapy, cryotherapy, or traditional surgery.
Oral Cancer
Treatment:
- Surgery: The primary treatment for removing the tumor, which may include a partial or total glossectomy (removal of part or all of the tongue).
- Radiation therapy: Used postoperatively to kill remaining cancer cells or as the primary treatment in inoperable cases.
- Chemotherapy: Used in conjunction with radiation therapy to treat advanced or metastatic cancers.
- Targeted therapy and immunotherapy: New treatments that target specific molecular pathways involved in cancer progression and immune response modulation.
Burning Mouth Syndrome(BMS)
Treatment:
- Recognizing and treating underlying conditions, such as nutritional deficiencies, dry mouth, or psychological issues.
- Medications for pain and discomfort include antidepressants (e.g., amitriptyline), anticonvulsants (e.g., gabapentin), and topical capsaicin.
- Saliva substitutes and adequate hydration can help with dry mouth symptoms.
- Cognitive behavioral therapy (CBT) or other psychological support for patients with comorbid conditions.
Black Hairy Tongue
Treatment:
- Improving oral hygiene by regularly brushing the tongue with a soft toothbrush or tongue scraper.
- Eliminating risk factors such as smoking, excessive coffee or tea consumption, and specific medications.
- If there is a suspicion of bacterial or fungal overgrowth, use antibacterial or antifungal mouthwash.
Macroglossia
Treatment:
- Treating underlying conditions like hypothyroidism and amyloidosis.
- To address functional issues, consider orthodontic treatment or speech therapy.
- In severe cases, surgical tongue reduction may be required to improve breathing, speech, and eating.
Enhancing Tongue Health with Supplements
Several supplements have been shown to benefit tongue and overall oral health. Here are important nutrients, vitamins, and herbal supplements with proven benefits:
Nutrition and Vitamins
- Vitamin B12 is required to maintain healthy nerve cells and prevent glossitis. B12 supplements can help treat and prevent deficiencies that are common among vegetarians and the elderly.
- Iron: Required for red blood cell production and to avoid anemia-related glossitis. Iron supplements can alleviate symptoms associated with iron deficiency.
- Vitamin C: Promotes collagen production and protects the mucous membranes. Vitamin C supplements can help prevent and treat scurvy, a condition that causes tongue inflammation and bleeding.
- Zinc helps with immune function and wound healing. Zinc supplements can improve oral health and the immune response to infections.
Herbal Supplements
- Aloe Vera is known for its anti-inflammatory and soothing properties. Aloe vera gel or juice can help relieve the symptoms of glossitis and other tongue-related inflammations.
- Licorice Root contains anti-inflammatory and antimicrobial properties. Licorice root supplements and mouthwashes can help treat oral infections and reduce inflammation.
- Turmeric contains curcumin, which has powerful anti-inflammatory and antioxidant properties. Turmeric supplements can help improve overall oral health and reduce inflammation.
Enzymes and Hormones
- Papain is a papaya-derived enzyme with digestive and anti-inflammatory properties. Papain supplements can improve oral health by lowering inflammation.
- Melatonin is a hormone that regulates sleep and has antioxidant properties. Melatonin supplements can help maintain oral health by lowering oxidative stress and inflammation.
Best Practices for Improving and Maintaining Tongue Health
- Maintain Good Oral Hygiene: Brush your teeth and tongue twice a day and floss frequently to remove plaque and prevent infections.
- Stay Hydrated: Drink plenty of water to keep saliva flowing and prevent dry mouth.
- Avoid Tobacco and Excessive Alcohol: These substances irritate the tongue and raise the risk of oral cancer.
- Eat a Balanced Diet: A diet high in fruits, vegetables, lean proteins, and whole grains will provide essential nutrients for tongue health.
- Use a Tongue Scraper: Scrape the surface of your tongue on a regular basis to remove debris and bacteria.
- Avoid Irritating Foods: Limit your consumption of spicy, acidic, or hot foods that can irritate the tongue.
- Visit the Dentist on a Regular Basis: Schedule regular dental check-ups to monitor oral health and detect problems early.
- Manage Stress: Use stress-reduction techniques like meditation, yoga, and deep breathing exercises to avoid conditions like BMS.
- Address Nutritional Deficiencies: Make sure you’re getting enough vitamins and minerals, and consider taking supplements if needed.
- Practise Safe Oral Habits: Avoid biting your tongue and wear a mouthguard if you grind your teeth at night.
Trusted Resources
Books
- “The Tongue: A Creative Force” by Charles Capps
- Explores the power of words and how the tongue can influence one’s life, with a focus on spiritual and motivational aspects.
- “Oral Pathology: Clinical Pathologic Correlations” by Joseph A. Regezi, James J. Sciubba, and Richard C. K. Jordan
- Provides comprehensive coverage of oral pathology, including diseases and conditions affecting the tongue, with clinical correlations and case studies.
- “Burket’s Oral Medicine” by Michael Glick
- A detailed reference book covering various aspects of oral medicine, including diagnosis and treatment of tongue disorders and other oral conditions.
Academic Journals
- “Journal of Oral Pathology & Medicine”
- Focuses on research and advancements in the field of oral pathology, including studies on tongue conditions, diagnostics, and treatments.
- “Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology”
- Publishes research articles, reviews, and case studies related to oral health, with a strong emphasis on diseases and conditions affecting the tongue and other oral structures.
Mobile Apps
- “Oral-B”
- Provides tools for maintaining oral hygiene, including brushing timers, tips for oral care, and tracking features to monitor oral health habits.
- “MyDentalCare”
- Offers comprehensive information on dental and oral health, including sections on tongue health, common conditions, and preventive care tips.
- “SmartMouth”
- Aimed at promoting better oral hygiene practices, this app includes features for tracking dental care routines, setting reminders, and accessing educational resources on tongue and oral health.
