Deglutition

Deglutition and its importance in Prosthodontics

1. DEGLUTITION Dr. Shubham Parmar 1 st Year MDS Department Of Prosthodontics 13-02-2022 1

2. Contents Introduction Components of deglutition Theories of deglutition Stages of deglutition Muscles associated with deglutition Gag Reflex 13-02-2022 2

3. Applied physiology Prosthodontic considerations 13-02-2022 3

4. INTRODUCTION Deglutition - Movement of substances from the mouth to the stomach via the oesophagus R eflexive and voluntary actions of nerves and muscles produce this coordinated movement Co-ordinated activity of muscles of oral cavity, pharynx and oesophagus L earned early in development (15 weeks in utero) A verage person swallows from 200 to 2,400 times per day 13-02-2022 Guyton and Hall Textbook Of Medical Physiology 13 th e 4

5. DEFNITION The coordination of voluntary and involuntary muscle contractions at the initiation of digestion; the act of swallowing -GPT 9 13-02-2022 GPT- 9 5

6. Swallowing is a complicated mechanism, principally because the pharynx subserves respiration and swallowing The pharynx is converted to a food tract only for a brief period Respiration is not compromised because of swallowing 13-02-2022 6 Swallowing Oesophageal(Involuntary) Pharyngeal (Involuntary) Initiation (Voluntary)

7. Anatomy Of Deglutition 55 muscles of the oral, pharyngeal and laryngeal region are involved 5 cranial nerves – V, VII, IX, XII are involved 2 cervical nerve roots Brainstem centres 13-02-2022 7

8. Components of deglutition Deglutition has 3 components Passage of bolus from oral cavity to stomach Protection of airway Inhibition of air entry into the stomach 13-02-2022 8

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10. Theories Of Deglutition 13-02-2022 Wildman A, Fletcher S, Cox B. Patterns of Deglutition. Angle Orthod 1964; 34(4):271-291 10

11. Theory of constant proportion Describes passage of bolus through upper git in three phases Oral phase – bolus is formed and transported under voluntary control to pharynx Pharyngeal phase – pharynx is activated to propel bolus to oesophagus Oesophageal phase –passage of bolus to stomach by oesophageal contraction 13-02-2022 Wildman A, Fletcher S, Cox B. Patterns of Deglutition. Angle Orthod 1964; 34(4):271-291 11

12. Theory Of Oral Expulsion The oral expulsion arising from contraction of tongue and mylohyoid throws bolus into the stomach 13-02-2022 Wildman A, Fletcher S, Cox B. Patterns of Deglutition. Angle Orthod 1964; 34(4):271-291 12

13. Theory of negative pressure The tongue is brought forward to create a negative pressure which is accentuated by the descent of the larynx and therefore the food is sucked into the oesophagus 13-02-2022 Wildman A, Fletcher S, Cox B. Patterns of Deglutition. Angle Orthod 1964; 34(4):271-291 13

14. Theory of Integral Function Based on myometric and electromyographic studies and considers the act of swallowing as a total dynamic process Most accepted theory 13-02-2022 Wildman A, Fletcher S, Cox B. Patterns of Deglutition. Angle Orthod 1964; 34(4):271-291 14

15. Stages of deglutition 13-02-2022 Guyton and Hall Textbook Of Medical Physiology 13 th e 15 Oral Pharyngeal Oesophageal

16. Oral Stage - initiates the swallowing process (Voluntary stage) Pharyngeal stage - passage of food through the pharynx into the oesophagus (Involuntary) Oesophageal stage – transportation of food from the pharynx to the stomach (Involuntary) 13-02-2022 16

17. Oral Stage When the food is ready for swallowing, it is “voluntarily” squeezed or rolled posteriorly into the pharynx by pressure of the tongue upward and backward against the palate Elevators of mandible are raised Buccinator contracts to prevent food from going into vestibule It is the only voluntary stage in the deglutition sequence 13-02-2022 17

18. Pharyngeal stage B olus of food enters the posterior mouth and pharynx A series of automatic pharyngeal muscle contractions is seen The soft palate is pulled upward to prevent reflux of food into the nasal cavities P alatopharyngeal folds are pulled medially to approximate each o ther – form a slit 13-02-2022 18

19. Vocal cords of the larynx are approximated Larynx is pulled upward and anteriorly by the neck muscles Epiglottis swung backward over the opening of the larynx U pper oesophageal sphincter is relaxed M uscular wall of the pharynx contracts and relaxes to push the food downward (propulsive contraction) E ntire process occurs in less than 2 seconds 13-02-2022 Guyton and Hall Textbook Of Medical Physiology 13 th e 19

20. Bolus can enter into 4 paths Back to mouth Upwards into nasopharynx Forwards into larynx Downwards into oesophagus 13-02-2022 20

21. Entrance Of Bolus Prevented By Back into mouth Position of tongue High intraoral pressure developed by movement tongue Upwards into Nasopharynx Elevation of soft palate along with uvula 13-02-2022 21

22. Forwards into larynx Approximation of vocal cords Forward and upward movement of larynx Backward movement of epiglottis to seal larynx Temporary arrest of breathing 13-02-2022 22

23. Effect Of Swallowing On Respiration The swallowing center specifically inhibits the respiratory center of the medulla during this time, halting respiration at any point in its cycle to allow swallowing to proceed Swallowing occurs during expiratory phase of respiration 13-02-2022 23

24. Oesophageal stage Esophagus exhibits two types of peristaltic 13-02-2022 24 Primary peristalsis is simply continuation of the peristaltic wave that begins in the pharynx and spreads into the oesophagus during the pharyngeal stage of swallowing Secondary peristaltic waves result from distention of the oesophagus itself by the retained food

25. Secondary waves continue until all the food has emptied into the stomach Pharyngeal wall and upper third of the oesophagus have striated muscles 13-02-2022 25

26. Peristaltic waves in these regions are controlled by skeletal nerve impulses from the glossopharyngeal and vagus nerves Lower two thirds of the esophagus has smooth muscle, but this portion of the oesophagus is also strongly controlled by the vagus nerves that act through connections with the oesophageal myenteric nervous system 13-02-2022 26

27. 13-02-2022 27 Muscles Associated With Swallowing Muscle of the Tongue Muscle of Soft Palate Muscle of the Pharynx

28. Muscle of Tongue 28

29. Intrinsic Muscles Superior Longitudinal lies beneath the mucous membrane, shortens the tongue and makes dorsum concave. Inferior Longitudinal muscle is a narrow band lies close to inferior surface of tongue, shortens tongue makes dorsum convex Transverse muscle extends from medium septum to margin, makes the tongue narrow and elongated. Vertical Muscle found at the border of the anterior part of tongue, makes tongue broad and flattened 29

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31. Extrinsic muscles 13-02-2022 31

32. Genioglossus Action Protrusion of tongue Depress the dorsum and make it concave Action – depression of tongue 32 13-02-2022 Gray’s Anatomy – The anatomical basis of clinical practice 41 st e Hyoglossus Styloglossus Action – moves the tongue upwards and backwards Action – elevates root, approximates palatoglossal arch, closes oropharyngeal isthmus Palatoglossus

33. Applied Anatomy Injury to hypoglossal nerve produces paralysis of the muscles of the tongue on the side of lesion. In cases of acute glossitis tongue fills the oral cavity & protrudes out of it causing difficulty in mastication Glossectomy patients require rehabilitation for speech and deglutiton 33

34. M obile flap suspended from the posterior border of the hard palate, sloping down and back between the oral and nasal parts of the pharynx T hick fold of mucosa enclosing an aponeurosis, muscular tissue, vessels, nerves, lymphoid tissue and mucous glands 13-02-2022 34 Soft Palate

35. Classification of soft palate Based on the angle that soft palate makes with the hard palate : By HOUSE CLASS I CLASS II CLASS III 13-02-2022 Winkler Essential's of Complete Denture Prosthodontics . 2 nd edition p 111 35

36. Muscles of Soft Palate 36

37. Anterior surface of soft palate is concave and has a median raphe. Posterior surface convex and continuous with the nasal floor. Uvula projects downward from its posterior border 37

38. 13-02-2022 38

39. Arterial supply Levator and Tensor veli Palatini ascending palatine branch of facial artery greater palatine branch of maxillary artery. Palatoglossus ascending palatine branch of facial artery ascending pharyngeal artery. Palatopharyngeus ascending palatine branch of facial artery greater palatine branch of maxillary artery ascending pharyngeal artery 39

40. Pharynx 40

41. 12 to 14 cm long Musculo-membranous tube shaped like an inverted cone Extends from cranial base to lower border of cricoid cartilage where it becomes continuous with oesophagus There are three circular constrictor and three longitudinal elevators 41

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43. Superior Constrictor Q uadrilateral sheet of muscle Thinner than the other two constrictors Attaches to Pterygoid hamulus Posterior border of the pterygomandibular raphe Posterior end of the mylohyoid line of the mandible Side of the tongue 43

44. Middle constrictor Fan-shaped sheet Attached to lesser cornu of the hyoid upper border of the greater cornu of the hyoid lower part of the stylohyoid ligament 44

45. Inferior Constrictor thickest of the three constrictor muscles Divided in two parts thyropharyngeus cricopharyngeus Thyropharyngeus arises from- oblique line of the thyroid lamina, by a small slip from the inferior cornu & some additional fibers arise from a tendinous cord that loops over cricothyroid 13-02-2022 45

46. Cricopharyngeus arises from the side of the cricoid cartilage between the attachment of cricothyroid and the articular facet for the inferior thyroid cornu Cricopharyngeus consists of a superficial upper oblique portion – the pars oblique – and a lower, deeper, transverse portion – the pars fundiformis 13-02-2022 46

47. Insertion of Constrictor of Pharynx Inserted into median raphe on posterior of pharynx. Upper end of raphe reaches base of the skull where it is attached to pharyngeal tubercle on basilar part of occipital bone 13-02-2022 47

48. Longitudinal Muscle of Pharynx 48 Christopher L. B. Lavelle, Applied Oral Physiology 2e

49. Applied Physiology Dysphagia Odynophagia Globus hystericus Phagophobia Vomiting Deglutition apnoea 49

50. Aspiration Cricopharyngeal Dysfunction Choking Antiperistalsis Presbyphagia Gag reflex 13-02-2022 50

51. Dysphagia Lack of coordination or strength of muscles or mechanical obstruction If contractions fail to develop progress, bolus distends the oesophageal lumen and causes discomfort Mechanical narrowing of oesophageal lumen obstructs passage of bolus despite adequate contractions Abnormal sensory perception in oesophagus may cause sensation of dysphagia even after bolus is cleared. 51

52. Vomiting Is highly integrated and complex reflex involving both autonomic and somatic neural pathways Synchronous contraction of diaphragm , intercostal muscles and abdominal muscles raises intra abdominal pressure combined with forcible ejection of gastric contents. 52

53. Deglutition Apnoea Arrest of breathing during deglutition. Occurs reflex during pharyngeal stage. When bolus is pushed into oesophagus from pharynx during pharyngeal stage, there is possibility for the bolus to enter the respiratory passage through trachea which may cause choking. 53

54. Aspiration Defined as the inhalation of oropharyngeal or gastric contents into the larynx & lower respiratory tract. Aspiration Pneumonitis (Mendelson’s Syndrome) chemical injury caused by the inhalation of sterile gastric contents. Aspiration Pneumonia is an infectious process caused by the inhalation of oropharyngeal secretions that are colonized by pathogenic bacteria. 54

55. Risk Factors For Oropharyngeal Aspiration Elderly, neurologic dysphagia, GERD Poor oral hygiene-colonization by respiratory tract pathogens Silent aspiration is common in stroke . Management Upper respiratory suction, Antibiotics, ET intubation for airway 55

56. Cricopharyngeal Dysfunction Failure of the tonically contracted upper oesophageal sphincter to relax and open when one swallows Symptoms - pills or solid food begin to lodge at the level of the lower part of the larynx. Treatment - Resolved through surgical procedure - Cricopharyngeal Myotomy 56

57. Choking Mechanical obstruction of the flow of air from the environment into the lungs that prevents breathing. Causes - Foreign body, respiratory disease, compression of laryngopharynx 57

58. Signs & symptoms Person cannot speak or cry, violent cough, difficult in breathing produce wheezing sounds, clutches throat, if respiration not restored ,then cyanosis Treatment BLS Heimlich maneuver 58

59. Antiperistalsis 59 Wave of contraction in digestive tract that moves toward the oral end of tract -regurgitation

60. Presbyphagia Characteristic changes in the swallowing mechanism of otherwise healthy older adults. AGE ASSOCIATED CHANGES Demonstrate delay in onset of specific pharyngeal events Swallowing is slow Larger duration Upper Oesophageal Sphincter opening is delayed Chance of Aspiration-more 13-02-2022 60

61. Odynophagia - Painful swallowing Globus Hystericus - Sensation of lump lodged in throat Phagophobia - Fear of swallowing as in rabies, tetanus, pharyngeal paralysis due to fear of aspiration. 61

62. Gag Reflex Stimulation of sensitive areas of pharynx, soft palate, uvula, tongue 62 Stimulation of Trigeminal & Glossopharyngeal & Vagus nerves Uncoordinated & spasmodic movements of swallowing muscles Gagging

63. Gag reflex – a normal defence mechanism that prevents foreign bodies from entering trachea , pharynx , larynx. 5 trigger zones for gagging – Palatoglossal fold & Palatopharyngeal fold Palate Base of Tongue Uvula Posterior pharyngeal wall 13-02-2022 63

64. Treatment - Removal of factors Local anaesthetic may be used while working Drugs like atropine along with a sedative may be prescribed Acupressure 64

65. 65 Prosthodontic Consideration

66. Classification of soft palate Based on the angle that soft palate makes with the hard palate : By HOUSE CLASS I CLASS II CLASS III 13-02-2022 Winkler Essential's of Complete Denture Prosthodontics . 2 nd edition p 111 66

67. Defects of soft palate 13-02-2022 Taylor Clinical Maxillofacial Prosthesis .3 rd Edition p 121-132 67

68. 13-02-2022 Taylor Clinical Maxillofacial Prosthesis .3 rd Edition p 121-132 68

69. Veau’ s classification 13-02-2022 Tandon S . Textbook Of Pedodontics .2 nd Edition 69

70. Management of soft palate defects Obturator prosthesis : Pharyngeal obturator. Meatus prosthesis. Feeding obturators. Palatal lift prosthesis. 13-02-2022 Taylor Clinical Maxillofacial Prosthesis .3 rd Edition p121-132 70

71. Pharyngeal obturator A pharyngeal obturator prosthesis, which may also be called speech aid or speech bulb prosthesis , extends beyond the residual soft palate to create separation between the oropharynx and nasopharynx. It provides a fixed structure against which the pharyngeal muscles can function to effect palatopharyngeal closure. 13-02-2022 Taylor Clinical Maxillofacial Prosthesis .3 rd Edition p121-132 71

72. MEATUS OBTURATOR A meatus obturator is designed to close the posterior nasal choncae through a vertical extension form the distal aspect of the maxillary prosthesis. Indication : The entire soft palate has been lost in an edentulous patient. Such a design will reduce leverage factors on the pharyngeal muscles against it. The meatus obturator is often thought to be mechanical, whereas the fixed horizontal pharyngeal obturator is thought to be more physiologic 13-02-2022 Taylor Clinical Maxillofacial Prosthesis .3 rd Edition p121-132 72

73. FEEDING OBTURATORs Prosthetic aid that is designed to close the cleft & provide the separation between oral & nasal cavities & is used in infancy period. Helps in following : Feeding Reduces nasal regurgitation. Prevents tongue from entering the defect. Allows spontaneous growth of palatal shelves Speech development 13-02-2022 Sowmya S , Sadakshari S , Ravi Mb, Gujjari A.Prosthodontic Care Of Patients With Cleft .J Orofac Res 2013; 3(1):22-27 73

74. Palatal lift prosthesis (PLP) The concept of a PLP was described by Gibbons and Bloomer, Beder et al, and Gonzalez and Aronson to improve soft palate dysfunction. The PLP places the soft palate in contact with the lateral and posterior pharyngeal walls to prevent nasal air escape during speech and prevent regurgitation of food and liquid during swallowing. Indications – Speech disorders Neurologic disorders   13-02-2022 Taylor Clinical Maxillofacial Prosthesis .3 rd Edition p 121-132 74

75. Fabrication of palatal lift appliance 13-02-2022 Premkumar S. Clinical application of palatal lift appliance in velopharyngeal incompetence. J Indian Soc Pedod Prev Dent 2011;29, Suppl S1:70-3 75

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79. 13-02-2022 Nanda A, Koli D, Sharma S, Suryavanshi S, Verma M. Alleviating speech and deglutition: Role of a prosthodontist in multidisciplinary management of velopharyngeal insufficiency. J Indian Prosthodont Soc 2015;15:281-3. 79

80. Tongue prosthesis A total glossectomy or laryngectomy results in loss of basic vital function In these patients fabrication of a mandibular tongue prosthesis can be done Tongue prosthesis can be made for Swallowing Speech 13-02-2022 80 Balasubramaniam MK, Chidambaranathan AS, Shanmugam G, Tah R. Rehabilitation of Glossectomy Cases with Tongue Prosthesis: A Literature Review. J Clin Diagn Res. 2016 Feb;10(2):ZE01-4

81. Balasubramaniam MK, Chidambaranathan AS, Shanmugam G, Tah R. Rehabilitation of Glossectomy Cases with Tongue Prosthesis: A Literature Review. J Clin Diagn Res. 2016 Feb;10(2):ZE01-4 81

82. 13-02-2022 Balasubramaniam MK, Chidambaranathan AS, Shanmugam G, Tah R. Rehabilitation of Glossectomy Cases with Tongue Prosthesis: A Literature Review. J Clin Diagn Res. 2016 Feb;10(2):ZE01-4 82

83. The Use Of Swallowing In Making Complete Denture Lower Impressions The neuro musculature of the oral cavity provides a physiologic adjunct for molding the lingual and buccal flanges and the posterior borders of impressions for lower dentures The most extreme movements of the posterior part of the floor of the mouth occur during swallowing. 13-02-2022 Marmor D, Herbertson JE. The used of swallowing in making complete denture impressions. J Prosthet Dent. 1968 Mar; 19(3):208-18. 83

84. Buccal and labial borders of the impression are established by manipulation of the lips and cheeks Shape of the buccinator muscle is recorded in a nonfunctional displaced position Anterior part of the lingual border is recorded by asking the patient to lick the upper lip with the tip of the tongue by gently moving the tip from side to side 13-02-2022 Marmor D, Herbertson JE. The used of swallowing in making complete denture impressions. J Prosthet Dent. 1968 Mar; 19(3):208-18. 84

85. The most posterior lingual region, the hyoglossus muscle presses against the passive lateral wall of the retro mylohyoid space The posterior part of the mylohyoid muscle raises medially and upward, thereby molding the lingual flange anterior to the retro mylohyoid space anterior part of the mylohyoid muscle molds the anterior part of the border of the lingual flange resulting in classical S-shaped curve 13-02-2022 Marmor D, Herbertson JE. The used of swallowing in making complete denture impressions. J Prosthet Dent. 1968 Mar; 19(3):208-18. 85

86. Review Articles 13-02-2022 86

87. Palatal augmentation prosthesis (PAP) can improve swallowing function for the patients in rehabilitation hospital Aim - To clarify the effects of fitting palatal augmentation prosthesis (PAP) on the swallowing function for the patients in rehabilitation hospital 13-02-2022 M. Yoshida, et al. Palatal augmentation prosthesis (PAP) can improve swallowing function for the patients in rehabilitation hospital. J Prosthodont Res 2018 87

88. Material and Methods The subjects included18 elderly hospitalized patients whose BMI was<18.5 kg/m2 All subjects wore maxillary complete denture During a video fluoroscopic examination the patients were asked to swallow, post-swallowing pyriform sinus residue was detected The subjects’ maxillary dentures were then modified into PAPs by recording tongue movement in the palatal region The resulting swallowing dynamics were evaluated qualitatively and quantitatively before and after fitting the PAP 13-02-2022 M. Yoshida, et al. Palatal augmentation prosthesis (PAP) can improve swallowing function for the patients in rehabilitation hospital. J Prosthodont Res 2018 88

89. 13-02-2022 M. Yoshida, et al. Palatal augmentation prosthesis (PAP) can improve swallowing function for the patients in rehabilitation hospital. J Prosthodont Res 2018 89

90. Results of this study showed that PAPs could be beneficial as treatment devices for reducing post-swallowing pyriform sinus residue formation due to decreased muscle strength PAP fittings resulted in the resolution of aspiration of yogurt in two patients and elimination of pharyngeal residue in three PDT and PTT were significantly shortened with PAP 13-02-2022 M. Yoshida, et al. Palatal augmentation prosthesis (PAP) can improve swallowing function for the patients in rehabilitation hospital. J Prosthodont Res 2018 90

91. 13-02-2022 M. Yoshida, et al. Palatal augmentation prosthesis (PAP) can improve swallowing function for the patients in rehabilitation hospital. J Prosthodont Res 2018 91

92. Conclusion Tongue plays a key role in bolus formation and transfer to the pharynx because tongue pressure generates the pharyngeal squeezing pressure This study suggested that PAP fitting causes more intense contact between the tongue and palatal region, thus reducing PTT. These results demonstrated that PAPs could be beneficial treatment devices that may reduce post-swallowing pharyngeal residue formation due to decreased muscle strength. 13-02-2022 M. Yoshida, et al. Palatal augmentation prosthesis (PAP) can improve swallowing function for the patients in rehabilitation hospital. J Prosthodont Res 2018 92

93. Learning Outcome Deglutition is an important physiological process for proper growth and development of an individual The inter-relationship between mastication, deglutition, respiration and speech are complex A thorough knowledge about this process can help us in, diagnosing, treating and in rehabilitation of patients with deglutition difficulty 13-02-2022 93

94. References Guyton and Hall Textbook Of Medical Physiology 13 th e Wildman A, Fletcher S, Cox B. Patterns of Deglutition. Angle Orthod 1964; 34(4):271-291 Winkler S. Essentials of Complete Denture Prosthodontics . 2 nd edition Taylor Clinical Maxillofacial Prosthesis .3 rd Edition 13-02-2022 94

95. Tandon S . Textbook Of Pedodontics .2 nd Edition Sowmya S , Sadakshari S , Ravi Mb, Gujjari A.Prosthodontic Care Of Patients With Cleft .J Orofac Res 2013; 3(1):22-27 Premkumar S. Clinical application of palatal lift appliance in velopharyngeal incompetence. J Indian Soc Pedod Prev Dent 2011;29, Suppl S1:70-3 Nanda A, Koli D, Sharma S, Suryavanshi S, Verma M. Alleviating speech and deglutition: Role of a prosthodontist in multidisciplinary management of velopharyngeal insufficiency. J Indian Prosthodont Soc 2015;15:281-3 13-02-2022 95

96. Balasubramaniam MK, Chidambaranathan AS, Shanmugam G, Tah R. Rehabilitation of Glossectomy Cases with Tongue Prosthesis: A Literature Review. J Clin Diagn Res. 2016 Feb;10(2):ZE01-4 Marmor D, Herbertson JE. The used of swallowing in making complete denture impressions. J Prosthet Dent. 1968 Mar; 19(3):208-18. Christopher L. B. Lavelle, Applied Oral Physiology 2e 13-02-2022 96