Stomatognathic System

a system that compromises of a highly coordinated structure comprising the human masticatory apparatus.

1. STOMATOGNATHIC SYSTEM

2. DEFINITION OF TERMS: PHYSIOLOGY – is the science which deals with the study of normal tissue functions of a normal living body.

3. GENERAL PHYSIOLOGY – deals with the study of basic activities of living organisms as a whole, emphasizing on function and dynamic changes occurring within cells, tissues and blood vessels.

4. ORAL PHYSIOLOGY – a branch of Gen. Physiology which focuses on the functions of the different parts in the oral cavity as well as its associated structures. It deals with the Masticatory Apparatus (All structures & organs involved in mastication.)

5. STOMATOGNATHIC SYSTEM – is a system that comprises of a highly coordinated structure comprising the human masticatory apparatus.

6. STOMATOGNATHIC SYSTEM – is a system composed of several parts capable of acting as a single unit for the processes of: 1. mastication 2. deglutition 3. phonation 4. respiration 5. other behavioral characteristics or activities

7. Group of structures that comprises the Stomatognathic System: 1. Dental Group 2. Osseous Group 3. Receptor Group 4. Muscular Group 5. Salivary Glands 6. Organs of the Digestive System 7. Organs of the Respiratory System

8. DEVELOPMENT OF THE ORAL CAVITY: > ORAL STOMODEUM is the primitive oral cavity that begins to develop at 3 ½ weeks of fetal life. > It is lined with an ectoderm and unites with the endoderm to form the buccopharyngeal membrane.

9. ORAL STOMODEUM (3 ½ WEEKS Human Embryo)

10. > At about 27 days this membrane raptures and the stomodeum establishes a connection with the foregut (future digestive tract). > At 6 weeks old, the first sign of tooth development is seen.

11. > The oral ectoderm will give rise to the oral epithelium that runs along the outline of the future dental arches, which is called the DENTAL LAMINA (invagination that forms 2 thicker bands; vestibular lamina & dental lamina).

12. > Simultaneous with the differentiation of the dental lamina, there arises round or ovoid swellings at 10 different points in each jaw, corresponding to the future position of the deciduous dentition ( TOOTH BUDS ) .

13. Dental Lamina Tooth bud Enamel Organ - enamel Dental Papilla - dentin & pulp Dental Sac - cementum, periodontal ligament & alveolar bone

14. ORAL CAVITY – is the first portion of the alimentary canal or digestive tract. Boundaries: 1. Anteriorly – Lips 2. Laterally – Cheeks 3. Superiorly – Hard & Soft Palate 4. Inferiorly – Floor of the Mouth & Tongue

15. Divisions of the Oral Cavity: A. Vestibule – smaller, outer portion Boundaries: 1. Antero-laterally – lips & cheeks 2. Postero -medially – gums & teeth 3. Superior & Inferiorly – mucous membrane from the lips & cheeks to the gums

16. B. Oral Cavity Proper – larger, inner portion Boundaries: 1. Antero-laterally – alveolar arches with their teeth 2. Superiorly – hard & soft palate 3. Inferiorly – tongue & mucous membrane from the side of the tongue to the gums

17. PARTS OF THE ORAL CAVITY: A. Lips B. Cheeks C. Palate D. Floor of the mouth E. Tongue

18. A. LIPS > Two mobile folds that encircle the rima oris . * Rima / Orbicularis oris - sphincter muscle of the mouth. > Covered by skin on its external surface & mucous membrane on its internal surface.

19. > Parts: 1. Angle of the mouth – points where the upper & lower lips meet at the sides. 2. Naso -labial groove – from the side of the nose to the angle of the mouth.

20. 3. Mento -labial groove – between the chin & lower lip. 4. Philtrum – from the inferior border of the nose to the upper lip.

21. 5. Frenulum of the upper & lower lips – vertical mucous folds found on the internal surface of the lips connecting them to the gums.

22. > Composed of the following layers: 1. Skin 2. Superficial Fascia 3. Orbicularis oris Muscle 4. Submucous Layer 5. Mucous Membrane

23. > Supplied by the following: Nerve: 1. Infra-orbital Nerve – from the maxillary nerve & supplies the upper lip 2. Mental Nerve – from the mandibular nerve & supplies the lower lip

24. Blood: 1. Superior Labial Artery 2. Inferior Labial Artery

25. B. CHEEKS > Forms the lateral boundary of the vestibule of the mouth. > Buccinator muscle is the major muscle that makes up the cheeks.

26. > Composed of the following: 1. Skin 2. Superficial Fascia 3. Buccopharyngeal Fascia 4. Buccinator Muscle 5. Submucous Layer 6. Mucous Membrane

27. C. PALATE > Forms the roof of the mouth separating the nasal cavity & the nasopharynx from the buccal cavity.

28. > Divided into 2 parts: 1. Hard palate – larger, anterior 2/3 2. Soft Palate – smaller, posterior 1/3

29. 1. HARD PALATE > Formed by the palatine processes of the maxilla & the horizontal plates of the palatine bones.

30. > The surface is covered by the mucous membrane & periosteum. > The inferior surface is thicker & its posterior part contain the blood vessels, nerves & mucous glands.

31. > Presents the following: 1. Median Raphe – longitudinal ridge extending from the uvula to the incisive papilla.

32. 2 . Incisive Papilla – small projection of the mucous membrane which lies behind the central incisor indicating the location of the opening of the incisive foramen.

33. - It forms the anterior limit of the median raphe. (Clinical significance: site of puncture for nasopalatine block injection)

34. 3. Transverse Palatine Ridges or Rugae – is about 3 to 4 distinct elevations crossing the anterior part of the palate.

35. 4. Fovea Palatinae – constant pits found on the posterior end of the palate, near the midline, that are formed by a coalescence of several mucous gland ducts.

36. (Clinical significance: These pits are close to the vibrating line which makes them an ideal guide for the location of the posterior border of the denture.)

37. 2. SOFT PALATE > A soft, flexible mass attached to the posterior end of the hard palate. > Composed of folds of mucous membrane.

38. > Presents the following: 1. Uvula – a conical process on the midline of the posterior border of the soft palate.

39. 2. Palatine Arches or Velum – free margin of the soft palate extending laterally from the uvula that splits as they approach the lateral walls. The split portion forms the pillars of the soft palate.

40. 3 . Palatoglossal Arch – anterior pillar of the fauces or anterior palatine arch, encloses the palatoglossal muscle

41. 4. Palatopharyngeal Arch – larger, posterior pillar of the fauces or posterior palatine arch, encloses the palato -pharyngeal muscle.

42. 5. Isthmus of the Fauces or Tonsillar Sinus – an interval between the anterior & posterior pillars. It is triangular in shape & encloses the palatine tonsils.

43. 6. Isthmus of the Pharynx – interval between the free margin of the soft palate & the posterior pharyngeal wall separating the nasopharynx from the lower pharynx.

44. > Consists of the following: 1. Palatal Aponeurosis 2. Mucous glands 3. Muscles A. Levator Palati Muscle B. Tensor Palati Muscle C. Palatoglossus Muscle D. Palatopharyngeal Muscle E. Uvulae Muscle

45. > Supplied by the following: Nerve: 1. Vagus Nerve 2. Accessory Nerve 3. Mandibular Nerve 4. Glossopharyngeal Nerve Blood: 1. Greater Palatine Artery 2. Lesser Palatine Artery

46. D. FLOOR OF THE MOUTH > Formed chiefly by the mylohyoid muscle & other structures which lie beneath the 2 halves of the body of the mandible.

47. > Presents the following: 1. Frenulum Linguae or Lingual Frenum – median fold of mucous membrane extending from the floor of the mouth to the inferior surface or the tongue.

48. 2. Sublingual Fold – seen on the side of the tongue where the ducts of the sublingual salivary gland is located.

49. 3. Sublingual Papilla – slight elevation on the anterior end of the sublingual fold indicating the opening of the submandibular ducts.

50. 4. Fimbriated Fold – fold of mucous membrane lying lateral to the frenulum.

51. E. TONGUE > A movable mass of muscle covered with mucous membrane lying on the floor of the mouth & associated with the functions of taste, chewing, swallowing & speaking.

52. > Parts: 1. Root – lower, posterior portion through which the extrinsic muscles, blood vessels & nerves are connected with the organ.

53. 2. Body – anterior, larger portion made up of interlacing skeletal muscles.

54. 3. Margins – lateral sides of the organ, free & blunt in relation to the gums & teeth.

55. 4. Tip/Apex – pointed & free anterior end, directed anteriorly against the incisor teeth. It is blunt & rounded when the tongue is at rest.

56. 5. Dorsum Linguae – slightly convex anteroposteriorly . It is divided by a V-shaped groove called Sulcus Terminalis into; A. Anterior 2/3 – where lingual papilla are found. B. Posterior 1/3 – where lingual tonsils are located.

57. > Lingual papillae – consists of 3 kinds: A. Vallate /Circumvallate papilla – 10 to 12 per human tongue B. Fungiform papilla – scattered in between filiform papilla C. Filiform papilla – most numerous & distributed in rows

58. > Muscles of the tongue: A. Extrinsic Muscles – originate from the outside of the tongue. These functions to change the position as well as the shape of the tongue. 1. Genioglossus 2. Hyoglossus 3. Styloglossus 4. Palatoglossus 5. Chondroglossus

59. Nerve supply: 1. Hypoglossal Nerve 2. Spinal Accessory Nerve

60. B. Intrinsic Muscles – are confined within the substance of the tongue & capable only of changing the shape. 1. Inferior Longitudinal 2. Superior Longitudinal 3. Transverse 4. Vertical

61. Nerve supply: 1. Hypoglossal Nerve 2. Lingual Nerve 3. Glossopharyngeal 4. Chorda Tympani Blood supply: 1. Lingual Artery 2. Tonsillar Artery