بسم الله الرحمن الرحيم

1. بسم الله الرحمن الرحيم

2. Oral Mucous Membrane

3. Objectives: At the end of this subject students should know thoroughly: 1- The definition & function of oral mucous membrane. 2- The classification of oral mucous membrane. 3- The histological structure of the mucous membrane. 4- The differences between the two different types of the oral epithelium. 5- Keratinocytes and non keratinocytes. 6- The macro & micro-anatomy of the gingival. 7- The macro & micro-anatomy of the hard palate. 8- The different types of lining mucosa. 9- The specialized mucosa and the different types of the papillae. 10- Dento-gingival junction (Histology and Histogenesis)

4. Oral mucous membrane Hard palate Dorsal surface of the tongue Cheek mucosa Floor of mouth Gingiva Ventral surface of the tongue Vestibular fornix Alveolar mucosa Labial mucosa

5. Masticatory Mucosa

6. Macro-anatomy of the gingiva

7. 1-Free gingiva (Marginal G.) - It Extends along the cervical level facially and lingually. - It is freely movable. -It tapers to knife edge (the gingival margin). -The free gingiva is about 1-1.5 mm. & separated from the attached gingiva by a free gingival groove both labially and lingually.

8. -This groove appears histologically as a v-shaped notch corresponding to a heavy epithelial rete pegs found between the free and attached gingiva. -This V-shape due to functional forces upon the free gingiva, folding the movable free part upon the immovable attached gingiva. free rete pegs attached gingiva

9. Gingival sulcus • - Shallow groove lined by non-k. epith. • - Its depth varies from zero-6 mm, and the average 1.8 mm. • The more shallow the sulcus • no food impaction • More favorable the condition of the gingival Margin. • - Lymphocytes and plasma cells are commonly seen in the C.T. of the sulcus as a defense reaction. مهم

10. 2- Attached gingiva - Immovable, anchored to the underlying cementum or periosteum. - Mucogingival junction separates it from alveolar mucosa. - Its surface shows stippling which is due to functional adaptation to mechanical impacts. - Absence of the stippling denoting inflammation.

11. 3-Interdental papilla and gingival Col - Fills the interproximal spaces below the contact areas of the teeth. -If there is no contact point present, it is reduced. e.g. (diastema).(gap bet. 2 teeth). - Simulates a tent shape. Its apex tapers to the contact area. - The Interdental gingival tissue found in the depression between the two peaks of the inter d. pap. is called (Col) and it is non-Keratinized. Gingival col peak peak NON=KERATINIZED: G.SULCUS….FREE GINIGIVA G. COL….INTERD.PAPILLA

12. Histology of gingiva مهم Stratified squamous keratenized epithelium Tall Epithelial rete peg Numerous C.T papilla Slender Lamina propria Irregular No submucosa

13. TYPES OF KERATINS : 1- Orthokeratinized epith ( 15 %): The nuclei and the other organelles are completely absent. 2- Parakeratinized epith ( 75 % ): The nuclei are retained in the whole surface layer and the Keratohyaline granules disappears (SOME ORGANELLS PRESENT). 3- Non Keratinized epith ( 10 % ): The stratum cornium is absent (located at gingival col and gingival sulcus ).

14. Gingival fibers Circular group Dento-gingival group Alveolo-gingival group Dento-periosteal group

15. Macroanatomy of palate Incisive papilla Palatine gingiva Rugae area Antro-lateral area (fatty zone) Postro-lateral area (glandular zone) Median palatine raphe Soft palate Uvula

16. Histology of hard palate Epithelial rete pegs are short , numerous& BOX SHAPED. Mucosa ANTROLATERAL(Fatty zone). POSTERO LATERAL (Glandular zone) Submucosa

17. FUNCTION: • 1) ANTROLATERAL (FATTY ZONE): • ACT AS CUSION SO PREVENT BONE RESORBTION. • 2) POSTEROLATERAL(GLANDULAR ZONE): • CUSION • + • PRODUCE MUCOUS SECRETION LUBRICATE FOR SWALLOW. • (NB) SUBMUCOSA IS ONLY PRESENT IN 1) ANT. LAT. • 2) POST. LAT

18. DIFFERENTIATE BET.GINGIVA AND HARDPALAT: GINGIVA HARDPALAT PRESENT ABSCENT 1) SUBMUCOSA 2) RETE PEGS NUMEROUS SHORT BOX SHAPED NUMEROUS TALL ARREGULAR SELENDER

19. Lining Mucosa

20. Firmly attached 1- Soft Palate. 2- Lip. 3- Cheek. 4- Inferior (VENTRAL) surface of the tongue Short and few Short and numerous

23. Soft palate Nasal side Oral side

24. - Its epithelium is continuous with that of the hard palate but non-keratinized So between them there is a healthy line

25. Histology of the soft palate Oral side Lamina propria is thin with few and short papillae. - A continuous layer of elastic fibers separating lamina propria from submucosa. - The submucosa contains fat cells and mucous glands.

26. Nasal side The nasal side is covered with pseudo-stratified columnar ciliated epithelium with goblet cells.

27. Lip

28. Lip Mucous side Vermilion border Skin side

29. Vermilion border Covered by stratified squamous epithelium with thin layer of keratin. C.T. papillae are numerous and long these deep papillae carry large cappillary loops, so the thin layer of epithelium permits the red color of blood.

30. Skin A)Stratum luciduim WITH ELIDIN OIL The cells permeated with elaidin (oil) which arise from the liquefaction of keratohyaline granules.

31. B)Skin appendages Hair follicle Sebaceous gland . Sweat glands

32. Cheek mucosa Mixed salivarygland Nonkeratenizedepithelium

33. 1- Inferior surface of the tongue. - Covered by thin non-keratinized epithelium with short & numerous C.T. papillae. - The submucosa can not be differentiated as a separate layer where it connects the mucous membrane to the C.T. surrounding tongue muscles.

34. Loosely attached 1- Alveolar mucosa. 2- Vestibular fornix. 3- Floor of the mouth.

35. ثاني

36. Specialized mucosa Posterior 1/3 Anterior 2/3

37. Posterior 1/3 Lymphatic portion (pharyngeal part) Sulcus terminalis Anterior 2/3 Papillary portion

38. Tongue papillae 1- Filliform pap. 2- Fungiform pap. Taste bud 3- Circumvallate pap. 4- Folliate pap.

39. TASTE BUDSمهم SITE:1)ALL TONGUE PAPILLAE EXCEPT FILLIFORM.2)SOFT PALAT.3)POSTERIOR PART EPIGLOTTIS.

40. A. The Filiform Papillae - Found over the entire dorsal surface. - High narrow, conical structures arranged in rows. - Composed of central C. T. core covered by keratinized epithelium. - The primary papilla (C.T. core) send much smaller 1-2 secondary papillae of C.T. toward the surface. -The epithelium gives projections (threads like) of keratin. - No taste buds.

41. B. The fungiform papillae • - Project like little mushroom, 0.5-1.5 mm in height. • -Narrow base and smooth rounded tops. Red colour. • - Scattered between filiform • More numerous at the tip of • the tongue than elsewhere. • Each has a central core of primary • C.T. papilla which is covered by thin non-keratinized epithelium.

42. -The secondary papillae of lamina propria bring capillaries very close to the surface epithelium which is also relatively translucent, permitting the blood red colour to appear. • - Contain taste buds, usually one at the top corner. • - The fungiform papillae which is present at the tip of the tongue are responsible for sweet sensation while those on the lateral borders are responsible for salty sensation. • Sweet and salty taste are mediated by • the chorda tympani. Secondary papillae

43. C. Circumvallate papilla Trough (FURROW)

44. - 7-12 in front of the sulcus terminals. - 2.0-3.5 mm in width and height. - Embedded in the tongue and surrounded by deep trough, so that its upper surface are not much higher than the general level of the M. M. of the tongue. - Each has central primary papilla of lamina propria, sending secondary papillae to the st. non-k. epith which covers the whole papilla. - It has a narrow base wide top surface. - Numerous taste buds are present in the lateral aspects of the papilla facing the trough of the papilla. - Von-Ebner serou S.G. open in this cleft at the bottom for cleaning and dissolving the trapped food. - The papilla is responsible for bitter sensation which is mediated by the glossopharyngeal nerve.

45. D. Foliate Papilla. • - 2 in number present on the lateral border at the boundary of the ant 2/3. • - Composed of several leaves(FOLIATE) of varying length arranged vertically. • - It is surrounded by furrows in which Von-Ebner Glands open in it. • - Numerous taste buds present on the lateral walls. • - Covered by St. non-k, epith. • Responsible for sour sensation • which is also mediated by • glossopharyngeal N.

46. Taste bud Taste pore 1- Outer supporting cell 2- Inner supporting cell 3- Neuroepithelial cell

47. Taste sensation Bitter Sour Salt Sweet

48. Lingual tonsil (lingual follicle) Weber salivary gland The lingual follicle is covered by st. sq. non-kerat. epith. overlying a lymphatic tissue and in many sites extend down into it to from wells or pits called lingual crypts.

49. Dento-gingival junction

50. Histogenesis of Dento-gingival junction 1 2 Desmolytic enzymes Epithelial plug 4 1ry D.G.J (from Reduced E. E.) 3 2nd D.G.J. (from oral E.)