Tongue

Tongue

1. GOOD MORNING

2. SEMINAR ON TONGUE PRESENTED BY: DR. NABEELA BASHA

3. CONTENTS INTRODUCTION FUNCTIONS DEVELOPMENT OF TONGUE EXTERNAL FEATURES STRUCTURES OF TONGUE HISTOLOGY OF TONGUE NERVE, ARTERIAL, VENOUS SUPPLY AND LYMPHATIC DRAINAGE OF TONGUE HOW TO EXAMINE TONGUE DISEASES OF TONGUE APPLIED ANATOMY CONCLUSION REFERENCES PREVIOUS YEAR QUESTIONS

4. INTRODUCTION The word ‘tongue’ is derived from the Latin word ‘lingua’ and Greek word ‘ glossa ’. The tongue is a mobile muscular organ in the oral cavity which bulges upwards from the floor of the mouth and its posterior part forms the anterior wall of the oropharynx . It is essentially a mass of skeletal muscle covered by mucous membrane.

5. Tongue is separated from teeth deep alveolo lingual sulcus . The tongue may be affected as a part of oral disease or as signs of a systemic disease.

6. FUNCTIONS The tongue performs the following functions: Taste Speech Mastication Deglutition Barrier function Jaw development Thermal regulation

7. FUNCTIONS Contd Secretion Defence mechanism Maintenance of oral hygiene Sucking General sensitivity

8. DEVELOPMENT OF TONGUE EPITHELIUM

9. Muscles : develop from the occipital myotomes which are supplied by Hypoglossal nerve Connective tissue : develops from the local mesenchyme .

10. CORRELATION OF NERVE SUPPLY OF TONGUE WITH ITS DEVELOPMENT STRUCTURES MUSCLES MUCOUS MEMBRANE : Anterior two-third Posterior one-third Posterior most SOURCE OF DEVELOPMENT OCCIPITAL MYOTOMES First arch Third arch Fourth arch NERVE SUPPLY HYPOGLOSSAL NERVE Lingual Nerve Chorda Tympani Glossopharyngeal Nerve Internal laryngeal N

11. EXTERNAL FEATURES The tongue exhibits the following external features: A root A tip A body

12. DORSAL SURFACE: Convex on all the sides. Divided by a V-Shaped sulcus into 2 parts: Anterior two-third / Oral part Posterior one-third / Pharyngeal part Apex of sulcus terminalis is marked by Foramen Caecum

13. Features of oral part: A median furrow, representing bilateral origin of the tongue. Large number of papillae Embryological origin – 1 st and 2 nd pharyngeal arches

14. Features of pharyngeal part: A large number of lymphoid follicles, which together constitute the Lingual tonsil Large number of mucous and serous glands Embryological origin: 3 rd and 4 th pharyngeal arches

15. VENTRAL (INFERIOR) SURFACE: The mucous membrane lining this surface is smooth, thin and purplish. It presents the following features: Frenulum Linguae – connecting the floor of the mouth with tongue Deep lingual veins – seen on either side of the lingual frenum

16. 3. Plica fimbriata – It is a fringed fold of mucous membrane lateral to the lingual vein directed forwards towards the tip of the tongue.

17. STRUCTURES OF THE TONGUE MUSCLES; tongue is made up of intrinsic and extrinsic group of muscles. MUCOUS MEMBRANE; it is a layer of connective tissue lined by stratified squamous epithelium. GLANDS; numerous serous and mucous glands lie deep to the mucous membrane

18. MUSCLES OF THE TONGUE Intrinsic Muscles: 1. Superior longitudinal 2. Inferior longitudinal 3. Transverse 4. Vertical Extrinsic Muscles: 1. Genioglossus 2. Hyoglossus 3. Styloglossus 4. Palatoglossus

19. SUPERIOR LONGITUDINAL : Origin : Beneath the mucous membrane of the dorsal surface of tongue Insertion : Into the sides of the tongue Actions : - Shortens the tongue - Makes the dorsum concave

20. INFERIOR LONGITUDINAL : Origin : Close to inferior surface between genioglossus and hyoglossus Insertion: Anterior part of median fibrous septum Actions : - Shortens the tongue - Makes the dorsum convex.

21. TRANSVERSUS LINGUAE : Origin : Arise from the median fibrous septum Insertion : Margins of the tongue Actions : - Makes the tongue narrow and elongated.

22. VERTICALUS LINGUAE : Origin : At the border of the anterior part of tongue Insertion : Sides of the tongue Action : - Makes the tongue broad and flattened.

23. GENIOGLOSSUS (fan shaped muscle): Origin : Superior genial tubercle Insertion : - Whole of the tongue (fibers radiate from the tip to the base) - Hyoid bone (lowest fibers) Actions : - Upper fibres : Retract the tip - Middle fibres : Depresses the tongue - Lower fibres : Pulls the posterior part forward Thus protrusion of the tongue

24. HYOGLOSSUS (Flat quadrilateral muscle) : Origin : Greater cornu and adjacent part of the body of hyoid. Insertion : Side of the tongue (posterior half) Actions : - Depresses the sides of the tongue - Makes the dorsal surface convex

25. STYLOGLOSSUS (an elongated slip): Origin : Tip and the anterior surface of styloid process Insertion : Side of the tongue, interdigitating posteriorly with the fibres of hyoglossus. Actions : Pulls the tongue upwards and backwards during swallowing.

26. PALATOGLOSSUS (a slender slip): Origin : Oral surface of palatine aponeurosis Insertion : Side of the tongue (at the junction of its oral & pharyngeal parts) Actions : - Pulls up the root of the tongue - Approximates the palatoglossal arches

27. MOVEMENTS OF THE TONGUE Protrusion (most important movement) Retraction Depression Elevation (of posterior one third) Changes in shape Genioglossus (of both side acting together) Styloglossus (of both sides acting together) Hypoglossus (of both sides acting together) Palatoglossus (of both side acting together) Intrinsic muscles

28. MUCOUS MEMBRANE The mucosa on the oral dorsum part is moist and pink and appears velvety due to presence of numerous papillae. It is thicker than the ventral surface and is adherent to muscular tissue covered by numerous papillae. Papillae are projections of lamina propria (corium) of mucous membrane covered with epithelium.

29. The mucous membrane over the dorsum of pharyngeal part is devoid of papillae. It contain numerous lymphoid follicles in the underlying submucosa. The mucous membrane in this part is continuous with mucous membrane covering the palatine tonsil and the pharynx. The lingual mucosa is thin, smooth and purplish on the inferior surface of the tongue.

30. GLANDS Mucous glands are numerous in the pharyngeal part but are also present at the apex. Serous glands of Von ebner are present near the taste buds and their ducts open mostly into the sulci of vallate papillae and their secretion is watery.

31. Mixed glands lie in the ventral surface of the apex, on either side of the frenulum which are covered by mucous membrane.

32. GLANDS OF BLANDIN AND NUHN: Anterior lingual glands (also called apical glands) are deeply placed seromucous glands that are located near the tip of the tongue on each side of lingual frenum . They are between 12 to 25mm in length & approx. 8mm wide and each opens by 3 to 4 ducts on the inferior surface of the tip.

33. GLANDS OF VON EBNER: They are serous salivary glands. Located adjacent to the circular sulcus (moat) around the vallate papillae. Von Ebner’s glands secrete lingual lipase They are innervated by the glossopharyngeal nerve.

34. GLANDS OF WEBER: They lie along the lateral border of the tongue. These glands are pure mucous secreting glands. These open into the crypts of lingual tonsils on the posterior dorsum of tongue. Abscess formed due to accumulation of pus and fluids in this gland is called Peritonsillar abscess.

35. HISTOLOGY OF TONGUE Inferior surface of the tongue. Dorsal surface of the tongue. Papillae of the tongue. Taste buds.

36. Inferior surface: a. The mucous membrane is thin and loosely attached to the underlying surface for free mobility. b. Made of non-keratinized epithelium. c. Sub mucosa contains adipose tissue. d. Sub lingual glands lie close to the sublingual fold. e. Mucous membrane is smooth and thin.

37. Dorsal mucosa : a. It is made up of specialized mucosa. b. It is rough and irregular. c. The dorsal surface of the tongue is a mixture of thin, keratinized, filiform papillae interspersed with pink mushroom-shaped fungiform papillae

38. PAPILLAE OF THE TONGUE There are 4 types of papillae: Filiform Fungiform Vallate Foliate Papillae simplex ( surface projections which can only be seen under microscope

39. FILIFORM PAPILLAE Narrowest and most numerous in number Minute conical projections with sharply pointed tips. Located abundantly on the presulcal dorsal area and are largely responsible for its velvety appearance.

40. FUNGIFORM PAPILLAE They have red rounded head (about 1mm in diameter) & a narrower base Mostly found on the apex and margins of the tongue, while some are scattered over the dorsal surface. They are visible as discrete pink pinheads.

41. FOLIATE PAPILLAE Red leaf-like mucosal ridges Found near the margin in front of sulcus terminalis . More prominent in tongues of rabbits. They are rudimentary in humans.

42. VALLATE PAPILLAE Formerly known as circumvallate papillae. Largest (1-2mm in diameter) Vary in number from 8-12 Arranged in a V-shaped row in front of sulcus terminalis . Von ebner's glands open through these papillae by a duct to wash out the soluble elements of food.

43. TASTE BUDS Taste buds are numerous on the inner wall of the vallate papillae, on folds of foliate papillae and on posterior surface of epiglottis. Small ovoid or barrel shaped intraepithelial organs about 80 um height and 40 um thickness.

44. Outer surface has flat epithelial cells, surrounded by a small opening called taste pore. Taste pore leads to narrow space lined by supporting cells( sustentacular cells). The other group of cells present in the taste buds are the gustatory receptor cells which end with microvilli .

45. The afferent nerves from the gustatory receptor cells begin as minute fibers which join to form 2 or 3 large fibers and each large fiber connects with 1 or more taste cells . Each taste bud has approx. 50 nerve fibers, and each nerve fiber in turn receives input from about 5 taste buds.

46. TASTE SENSATION The taste receptor cells in the taste buds opens through the pores to detect the various tastes. The taste receptors are chemoreceptors (located on the edges, dorsum of the tongue, epiglottis, soft palate and pharynx) stimulated by substances dissolved in the oral fluids.

47. Four primary tastes are: Salty- tip & lateral border. Sour- sides of the tongue. Sweet- tip of the tongue. Bitter- palate and posterior 1/3rd.

48. PHYSIOLOGY OF TASTE: Receptor stimulation: taste producing substance gets dissolved in the oral fluids and acts by forming a weak attachment to receptors on microvilli of gustatory cells which evokes generator potentials in the sensory nerves. Sourness directly proportional to degree of dissociation of H+ from acids, salt from NaCl , bitter from chemical substances ( quinine,sulphate ) and cations and sweet due to organic compounds (sucrose).

49. NERVE SUPPLY Bitter and sour taste- Glossopharyngeal nerve. Sweet and salt- Chorda tympani nerve.

50. Motor nerve: Intrinsic and extrinsic muscles except palatoglossus muscles are supplied by hypoglossal nerve. Palatoglossus muscles are supplied by cranial part of accessory nerve through the pharyngeal plexus.

51. Sensory nerve : Anterior two third - General sensation is supplied by lingual nerve. - Taste buds are supplied by Chorda tympani nerve. Posterior one third - General sensation and taste buds are supplied by glossopharyngeal nerve. Small myelinated taste fibers of all the three nerves run into the nucleus of tractus solitarius (NTS) in medulla.

52. ARTERIAL SUPPLY Lingual artery is a branch of external carotid artery supplies the major part of the tongue. Root of the tongue is also supplied by the tonsillar and ascending pharyngeal arteries

53. LYMPHATIC DRAINAGE Tip of the tongue drains into the submental lymph nodes. The right and the left halves of the anterior 2/3 rd tongue drains into the submandibular lymph nodes on either side. The posterior 1/3 rd of the tongue drains into the jugulo-omohyoid group of deep cervical lymph nodes.

54. VENOUS DRAINAGE

55. Deep lingual vein is the largest and main vein, which supplies the tongue. The vein is visible in the inferior surface of the tongue. It runs backwards and crosses the genioglossus and hyoglossus muscle.

56. HOW TO EXAMINE TONGUE…? On physical examination, there are several characteristics of the tongue that should be noted: Color Pink-red on dorsal and ventral surfaces. The ventral surface may have some visible vasculature.

57. Texture Rough dorsal surface owing to papillae. There should be no hairs, furrows, or ulceration. Size Should fit comfortably in mouth, tip against lower incisors. Sublingual glands should not be displaced.

58. The tongue can be checked for swelling or abnormal color or texture as the tongue is extended out. If the tongue deviates to one side or the other, a possible sign that something is affecting the nerves which control its movement.

59. Then a small piece of gauze is used to gently pull the tongue to one side, then the other to fully visualize its edges (a common location for lesions to occur). The borders of the tongue will be felt for (for hard spots) at the same time.

60. In general, the examination of the tongue should occur in the following steps: Have the patient touch the tip of the tongue to the roof of their mouth and inspect the ventral surface. 2. Have the patient protrude the tongue straight out and inspect for deviation, color, texture, and masses

61. 3. With gloved hands, hold the tongue with gauze in one hand while palpating the tongue between the thumb and index finger of the other, noting masses and areas of tenderness

62. A common site for oral cancer to occur is the base of the tongue where it begins to curve down the throat. This area cannot be visualized well unless the tongue is pulled forward, and the gauze is necessary to do this. The underside of your tongue should be examined.

63. DISEASES OF THE TONGUE Inherited, Congenital & Developmental anomalies Disorders of the lingual mucosa Diseases affecting the body of the tongue Malignant tumors of the tongue

64. Inherited, Congenital & Developmental anomalies: Variations in morphology: Ankyloglossia Fissured Tongue Macroglossia Microglossia Lingual thyroid nodule

65. ANKYLOGLOSSIA Also called ‘Tongue- tie’. Short or tight lingual frenum . Etiology : Genetic in most cases. Occasionally due to factors like cocaine addicted mothers. Incidence : 1.7% of population. Male = female ratio of occurence .

66. Clinical Feature : Frenum is short. Difficulty in cleansing food away from teeth and vestibule. Breast-feeding will be a problem. Speech defects Management :- Surgery if needed

67. FISSURED TONGUE (scrotal or plicated tongue) Grooves and fissures on the dorsum of the tongue. Etiology: Genetic Psychological Nutritional deficiency Chronic trauma

68. Rarely it may be associated with erythema migrans , Melkersson -Rosenthal syndrome, Down syndrome and psoriasis. Incidence : 5% of the population. Clinical Feature : Multiple fissures on the dorsum of the tongue. Mostly asymptomatic. Management: Maintenance of tongue hygiene

69. MACROGLOSSIA Enlargement of tongue. Etiology: Congenital: Hemangioma , down syndrome, lymphangioma etc Inflammatory: Dental infections, Syphilitic gumma etc Traumatic Neoplastic

70. Incidence : Most common in children, mild to severe in infants. Clinical Features: Enlarged, diffuse, smooth and drooling tongue. Difficulty in eating and speech. Noisy breathing and open bite.

71. Management : Depends on the severity and etiology. In mild cases speech therapy can be done. In sever cases glossectomy , a surgical removal of excess tongue can be advised.

72. MICROGLOSSIA & AGLOSSIA Definitions: Aglossia - Complete absence of tongue at birth Microglossia – Presence of small rudimentary tongue Etiology: Usually associated with syndromes such as Pierre Robin syndrome etc

73. Also associated with cleft lip and palate. Clinical Features: Difficulty in eating and speaking. High arched palate and narrow constricted mandible. There may be airway obstruction, due to negative pressure generated by deglutition and inspiration.

74. Management: Non surgical techniques such as nasogastric intubation, temporary endotracheal intubation may be carried out to prevent airway obstruction.

75. Disorders of Lingual Mucosa: Geographic Tongue Hairy tongue Non Keratotic & Keratotic white lesions: Candidiasis Leukoplakia

76. Nutritional deficiencies and hematological abnormalities: Vit B12 deficiency Iron deficiency anemia Infections: Tertiary syphilis

77. GEOGRAPHIC TONGUE Also called as Erythema migrans . Geographic tongue Definition: They are the irregularly shaped reddish areas of Depapillation & thinning of dorsal tongue epithelium that is surrounded by a narrow zone of regenerating papillae which are whiter than the surrounding tongue surface.

78. Etiology: Immunological reaction, allergic, emotional stress & hereditary factors Infections and nutritional deficiencies. Clinical Features: Common in young & middle aged, 5-84 years Usually asymptomatic, can be sometimes associated with burning sensation.

79. Management: Bland diet, elimination of irritants Zinc supplements – recent Topical corticosteroids

80. HAIRY TONGUE (lingua villosa /lingua nigra ) Discoloration of the tongue with marked accumulation of keratin on filliform papillae results in hair like appearance. Etiology: Poor oral hygiene, smokers, alcohol and drug users, Radiation therapy and xerostomia , Fungal and bacterial growth, Antibiotic therapy.

81. Clinical Features: Appears usually in midline just anterior to circumvallate papillae. The papillae are elongated, usually yellow or black in colour result of pigmentation. asymptomatic. Some time patient may complaints of bad taste and breath.

82. Management: Improve oral hygiene. Treatment for the etiology. Scrape or brush the tongue. Sodium bicarbonate and hydrogen peroxide mouthwash.

83. CANDIDAL GLOSSITIS Sore tongue due to candidal infection. Etiology : Opportunistic infection with candida.albicans Xerostomia , Immune defects

84. Clinical Feature: Diffuse erythema , Soreness of the tongue, White patches on the tongue. Management: Elimination of etiology Antifungal drugs

85. DEFICIENCY GLOSSITIS Soreness of tongue due to deficiency of vitamins and minerals. Etiology : Deficiency of iron, folic acid and vitamin B12. Clinical Feature: Linear patchy or red lesion, Depapillated tongue,

86. Oral ulcer and angular stomatitis may be associated Other Investigations : Investigation for anemia and vitamin levels. Management : Replacement therapy.

87. LEUKOPLAKIA It is a whitish patch or plaque that cannot be characterized, clinically or pathologically, as any other disease. The white color results from thick surface keratin layer.

88. Etiology: Classically known as the 6 ‘S’. Smoking, Sharp tooth, Syphilis, Sepsis, Spirit and Spices. Clinical Features : White lesion on both sides of the tongue, vertically corrugated. Appears to be benign and self-limiting

89. Management: Elimination of etiology Conservative treatment Surgical Management

90. ORAL SUBMUCOUS FIBROSIS Chronic and high risk precancerous condition. Overall incidence in India is 0.2 – 0.5%, high in southern parts of India. Etiology: Chillies Tobacco Areca nut Nutritional deficiency

91. Affects the tongue in 37% cases, most common site being buccal mucosa. Stage II – Stage of Fibrosis-: Inability to open mouth completely. Inability to protrude tongue. Tongue movements become restricted. Depapillation usually on the lateral margins, tongue appears smooth.

92. Management: Restriction of habit Vitamin rich diet Steroids Lycopene Surgery, if neoplastic changes seen or when there is marked trismus and dysphagia .

93. SQUAMOUS CELL CARCINOMA OF TONGUE Most common intraoral site. 60% lesions arise from anterior two-thirds of the tongue. Affected side of the tongue is r emoved surgically. All the deep cervical nodes are a lso removed, i.e., block d issection of neck

94. OTHER CLINICAL ASPECTS

95. TONGUE THRUST Positioning of tongue between the anterior teeth during swallowing, speaking or at rest. It is seen in retained infantile swallowing pattern. May be associated with Macroglossia. In these cases, anterior open bite is present.

96. TONGUE PIERCINGS Studs, hoops or barbell shaped ring that are hooked in the tongue. Types : Multiple centre-tongue piercing. Off-center tongue piercing. Centre tongue piercing. Horizontal tongue piercing. Vertical tongue piercing.

97. Complications : Pain Post-placement swelling Prolonged bleeding Gum injury Permanent numbness Loss of taste HIV and hepatitis infection Oral hygiene problems

98. Management: Avoid piercing. If pierced ; Use chlorhexidine mouthwash every half an hour immediately after tongue piercing for 8 hours. Tongue swelling will subside within 7 to 8 days, and complete healing within 2 weeks. Advice not to take hot and spicy foods. Rinse mouth before and after food. Sterilize the jewellery before placing. Improve and maintain oral hygiene. Regular visit to dentist at least once in 3 months.

99. APPLIED ANATOMY Injury to the hypoglossal nerve leads to the paralysis of the muscles of the tongue on the side of the lesion. If the lesion is infranuclear , there is gradual atrophy of the affected half of the tongue. Supranuclear lesions produce paralysis without wasting.

100. The tongue is stiff, small and moves very sluggishly resulting in defective articulation. The tongue becomes bald in anemias due to atrophy of the filiform papillae. The presence of rich network of lymphatics and loose areolar tissue is responsible for enormous swelling of the tongue in acute glossitis .

101. In unconcious patients the tongue may fall back to obstruct the air passages. Carcinoma of the posterior 1/3 rd of the tongue is more dangerous due to bilateral lymphatic spread. In grandmal epilepsy, the tongue is commonly bitten by the front incisors during attack.

102. Sublingual absorption of drugs: For quick absorption, pill or spray is put under the tongue where it dissolves and enters the lingual vein E.g. Nitroglycerine in angina pectoris

103. CONCLUSION Tongue is an important organ which contributes to speech, mastication, deglutition and taste. The examination of the tongue plays a major role during the oral examination of the soft tissues.

104. The knowledge about the development, functions, anatomy and diseases associated with tongue is important to the dental professionals as it helps in identifying or diagnosing many congenital and systemic diseases leading to pathological changes of the tongue at the earliest. The early signs of cancer can be detected through examination of the tongue routinely during screening in masses which is of public health importance.

105. REFERENCES Anatomy of Head, Neck & Brain. Vishram singh Essentials of Human Anatomy Head & Neck. 5 th Edn . A. K. DATTA B. D Chaurasia’s Human Anatomy. 4 th Edn Textbook of Oral Medicine. 2 nd Edn . Anil Govindrao Ghom http://stanfordmedicine25.stanford.edu/the25/tongue.html

106. Oral pathology- By shafer’s ;5thedition ;2003. Human embryology- By Inderbir singh;6 th edition;1996. http://www.livestrong.com/article/182822-how-to-treat-a-fresh-tongue-piercing/ http://bodyjewelryblog.com/2011/08/04/whats-that-called-dictionary-of-oral-piercings/

107. PREVIOUS YEAR QUESTIONS Short essays on (10marks each): Muscles of the tongue. (MDS Degree Examination; 2002) Tongue. ( MDS Degree Examination; 2005) Taste buds. (MDS Degree Examination; 2001) Musculature, Nerve supply & Lymphatic drainage of tongue. (MDS Degree Examination; Apr/May 2007)

108. Development of Tongue. (JSS University, Mysore; April 2012) (7marks)

109. HAWTHORNE EFFECT It is the name of a place where the effect was first encountered . In 1958, the researcher, Henry A. Landsberger , performed a study and analysis of data from experiments performed between 1924 and 1932, by Elton Mayo, at the Hawthorne Works near Chicago.

110. The company had commissioned studies to determine if the level of light within their building affected the productivity of the workers . Ref: https://en.wikipedia.org/wiki/Hawthorne_effect

111. James Lind was a Scottish physician. He was a pioneer of naval  hygiene  in the  Royal Navy. By conducting the first ever clinical trial.  he developed the theory that   citrus fruits   cured scurvy. He divided twelve scorbutic sailors into six groups of two.

112. They all received the same diet but, in addition, group one was given a quart of  cider  daily, group two twenty-five drops of elixir of  vitriol   (sulfuric acid), group three six spoonfuls of vinegar , group four half a pint of seawater , group five received two  oranges  and one   lemon , and the last group a spicy paste plus a drink of  barley water .  

113. The treatment of group five stopped after six days when they ran out of fruit, but by that time one sailor was fit for duty while the other had almost recovered. Apart from that, only group one also showed some effect of its treatment . Ref:https :// en.wikipedia.org /wiki/ James_Lind

114. THANK YOU