Anatomical landmarks for edentulous patients and facial landmarks physiology of muscles muscles of mastication muscles of facial expression physiology of saliva Prosthodontics dentistry

1. Anatomical Landmarks,
Physiology And Myology
Of Facial Expression
Done By: Mohammed Abdulaziz
Supervised By: Dr Faiza M AbdulAmeer

2. Contents…
 Introduction
 Extra-Oral Anatomical Landmarks
 Intra-Oral Anatomical Landmarks
-Classification Of Oral Mucosa
-Landmarks Of Maxillary Edentulous Arch
-Landmarks of Mandibular Edentulous Arch
 Myology Of Face And Oral Cavity
 Physiology Of Oral Cavity
 Conclusion

3. Introduction…
 The good knowledge of anatomy and physiology is
a keystone in getting the best result during the
fabrication of any prosthesis, this best result is
which restores the missing oral parts and
preserves what is remaining.

4. Facial Anatomical Landmarks
 Effects Of Edentulism on face:
1-
2-

5. Eye

6. Ear

7. Nose

8. Lips

9. Folds (Grooves)

10. Naso Labial Angel
 Indication of lip support by upper
anterior teeth.
 Used In jaw-relation clinic to
correct the position of wax rim
anteriorly
 90-110 in average.

11. Interpupillary line + Ala Tragus Line

12. Canthus Tragus Line

14. Oral Mucosa
Epithelial Layer
Connective Tissue layer
Sub-Mucosa

15. Types Of Oral Mucosa
Masticatory Mucosa
Lining Mucosa
Specialized Mucosa

16. Masticatory Mucosa
 Free, attached gingiva and hard
palate comes in primary contact
with food during mastication and is
keratinized.

17. Lining Mucosa
 the lips cheeks, vestibule, floor of
the mouth, ventral surface of the
tongue and soft palate. It does not
function in mastication. It is soft,
pliable and non-keratinized.

18. Specialized Mucosa
 SPECIALIZED MUCOSA: on the
dorsal surface (dorsum) of the
tongue. It is covered with cornified
epithelial papillae.

19. Intra Oral Anatomical Landmarks
 Maxillary Anatomical Landmarks
 Mandibular Anatomical Landmarks

20. Maxillary Anatomical Landmarks
a} Limiting structures
- Labial frenum
- Labial vestibule
- Buccal frenum
- Buccal vestibule
- Hamular notch
- Posterior palatal seal
area
b} Supporting structures
-Hard palate
-Residual ridge
-Palatal rugae
Maxillary Tuberosity
c} Relief areas
- Incisive papilla
- Mid palatine raphe
- Canine Eminence
- Fovea palatine
- Palatal Tori

21. Limiting Structures
Labial Frenum
 It contains no muscle and has no
action on its own.
 It should be properly relieved.

22. Limiting Structures
Labial Vestibule
 The labial vestibule is divided into
a left and right labial vestibule by
the labial frenum and extends upto
the buccal frenum on either side.
 The main muscle of the lip, which
forms the outer surface of the
labial vestibule, is the orbicularis
oris.

23. Limiting Structures
Buccal Frenum
 Consist of one or more bands.
 Influenced by 3 muscles
 Orbicularis oris (forward)
 Buccinator (backward)
 Levator anguli oris (position)

24. Limiting Structures
Buccal Vestibule
 Buccal frenum to hamular notch

25. Limiting Structures
Hamular Notch
 Situated between the tuberosity
and hamulus of the medial
pterygoid plate.
 Distal extension of denture.
 If the denture extends too far into
the hamular notch, the mucous
membrane covering the raphe will
be traumatized.
 Anterior Vs Posterior Vibrating lines

26. Limiting Structures
Posterior Palatal Seal Area
 The soft tissue area at or beyond
the junction of the hard and soft
palates on which pressure,within
physiologic limits, can be applied
by a denture to aid in its
retention”. (GPT-8).
 Posterior palatal seal has several
advantages.

28. Supporting Structures
Hard Palate
 The horizontal part of palate is
considered as primary stress
bearing area.

29. Supporting Structures
Residual Ridge
 “The portion of the alveolar ridge
and its soft tissue covering, which
remains following the removal of
teeth”.(GPT-8).

30. Supporting Structures
Palatal Rugae
 This area contributes to the stress-
bearing role (secondary stress
bearing area) as well as to
retention although in a secondary
capacity.

31. Supporting Structures
Maxillary tuberosity
 It is considered as secondary stress
bearing area, if it is firm it can
withstand more forces.
 Sometimes it is oversized either
with soft tissue or with bone.

32. Combination Syndrome

33. Relief areas
Incisive Papilla
 This covers the incisive foramen
and is located in the midline
immediately behind and between
central incisors.
 Care should be taken that the
denture base does not impinge on
them and hence should be
relieved.

34. Relief areas
Mid Palatine Raphe
 Adequate relief should be provided
in this area as, mucosa covering
the raphe is extremely thin and is
traumatized easily.

35. Relief areas
Canine Eminence

36. Relief areas
Fovea Palatine

37. Relief areas
Palatal Tori

38. Mandibular Anatomical Landmarks
Limiting structures
- Labial frenum
-Labial vestibule
-Buccal frenum
-Buccal vestibule
-Lingual frenum
-Alveololingual sulcus
-Retromolar pad
Supporting
structures
-buccal shelf area.
-residual alveolar
ridge.
Relief areas
-mental
foramen.
-genial tubercle.
-Mylohyoid
ridge.
-Torus
mandibularis.

39. Limiting Structures
Labial Frenum

40. Limiting Structures
Labial Vestibule

41. Limiting Structures
Buccal Frenum

42. Limiting Structures
Buccal Vestibule

43. Limiting Structures
Lingual Frenum

44. Limiting Structures
Alveololingual sulcus

45. Limiting Structures
Retromolar Pad

46. Supporting Structures
Buccal Shelf Area
 It is considered as primary stress
bearing area.
 It is horizontal and made up of
dense cortical bone.

47. Supporting Structures
Residual Alveolar Ridge
 It is considered as secondary stress
bearing area (lateral slopes).
 The crest of the ridge should be
relieved.

48. Relief Areas
Mental Foramen

49. Relief Areas
Genial Tubercle

50. Relief Areas
Mylohyoid Ridge
 Soft tissue usually hides the
sharpness of mylohyoid ridge.
 The mucous membrane overlying
the sharp or irregular mylohyoid
ridge needs to be relieved.

51. Relief Areas
Torus Mandibularis

52. Is it time for rest
Any energy remained

53. Myology Of Face And Oral Cavity
 -Physiology Of Muscles
 -Muscles Of Facial Expression
 -Sopra-Hyoid Muscles
 -Infra-Hyoid Muscles
 -Muscles Of Mastication
 -Muscles Of The Tongue
 -Muscles O Soft-Palate

54. Muscles Of Facial Expression

55. Modiolus

56. Modiolus

57. Muscles Of Facial Expression
Buccinator
 Is a thin quadrilateral muscle,
occupying the interval between the
maxilla and the mandible at the
side of the face. It forms the
anterior part of the cheek or the
lateral wall of the oral cavity.

58. Muscles Of Facial Expression
Buccinator

59. Muscles Of Facial Expression
Orbicularis Oris
 “The orbicularis oris muscle is a
complex of muscles in the lips that
encircles the mouth. Until
recently, it was misinterpreted as a
sphincter, or circular muscle, but it
is actually composed of four
independent quadrants that
interlace and give only an
appearance of circularity.”
 Saladin, "Anatomy & Physiology: The Unity of Form
and Function". 5th edition. McGraw Hill. Page 330

60. Muscles Of Facial Expression
Mentalis Muscle
 When contracts it can dislodge the
denture.
 It dictates the level of extension of
the labial flange of mandibular
denture.
 Reduce the lower labial vestibule
when it contracts.

61. Supra-Hyoid Muscles
 Act in elevating the hyoid bone and
larynx and depression of the
mandible.

62.  The mylohyiod and geniohyiod may
influence border of mandibular
denture.
 The mylohyoid constitutes the
floor of the mouth.

63. Infra-Hyoid Muscles
 actions of these muscles are
important to the prosthodontist,
for they are a part of the kinetic
chain of the mandibular
movement.

64. Muscles Of Mastication
 These muscles have masticatory
and non-masticatory movements,
but in concern of complete
denture, the non-masticatory
movements have more influence
on denture borders. Also these
muscles especially the temporalis
aid in obtaining centric relation.

65. Muscles Of Mastication
Temporalis Muscle
 ACTIONS OF TEMPORALIS
 - Elevates the mandible, this
movement requires both the
upward pull of anterior fibers and
backward pull of the posterior
fibers.
 - Posterior fibers draw the
mandible backwards after it has
been protruded.

66. Muscles Of Mastication
Masseter Muscle

67.  ACTIONS OF MASSETER:
 Elevates the mandible to close the
mouth and to occlude the teeth in
mastication.
 It has a small effect in side-to- side
movement, protraction and
retraction.

68. Muscles Of Mastication
Medial And Lateral Pterygoids
 The fibers of the lateral pterygoid,
pull the mandible forwards
(protrusion) and medially.
 The fibers of the medial pterygoid
also perform the same actions in
addition elevate the mandible.

69. Muscles Of The Tongue
 Intrinsic muscles
 Extrinsic muscles
 Styloglossus
 Palatoglossus
 Genioglossus
 hyoglossus

70. Importance of Tongue In Prosthodontics
 After loss of teeth, tongue expands
into the space created by lost
teeth, this enlargement make the
impression more difficult, and
reduce the stability of denture.
 The level of occlusal table in
relation to tongue level is so
important because high occlusal
level reduces the retention of
denture, while low occlusal level
contributes in tongue biting during
function.

71. Muscles Of Soft Palate
1. Tensor veli palatini : It influences
the denture border in the hamular
notch
2. Levator veli palatini: it helps in
determining the vibrating line.
3. Palatoglossus: it exerts pressure on
the lingual extension of the lower
denture mainly when the tongue is
moved toward the cheek.
4. Palatopharyngeous
5. The uvula: is unpaired

72.  Classification of soft palate:
House’s classification
 Class I: the soft palate is almost
horizontal curving gently
downwards
 Class II: the soft palate turns
downward at about 45 angle from
the hard palte
 Class III: the palate turns
downward sharply at about 70
angle to the hard palate.

73. Physiology Of Oral Cavity
 Physiology Of Muscles
 Physiology Of Bone
 Saliva

74. Physiology Of Muscles

75. Physiology Of Muscles

76. Isotonic
Relaxation
Isometric

77. Physiology Of Bone
 The reduction of bone may occur
due to:
 -Anatomical factor
 -Prosthodontic factor (pressure
mediated resorption )
 -Functional Factor
 -Metabolic and systemic factor:
 1-Osteoporosis
 2-Hyperthyroidism

78. Anatomical factor

79. Prosthodontic factor
 Intensive denture wear
 Unstable occlusal contact
 Immediate denture treatment

80. Functional Factor
 Loss of stimulation is essential in
accelerating the bone resorption.

81. Metabolic and systemic factors:
 Osteoporosis
 Hyperthyroidism

82. Saliva
 Saliva is a watery substance
formed in the mouth.
 Human saliva comprises 99.5%
mostly water, plus electrolytes,
mucus, white blood cells,
epithelial cells (which can be used
to extract DNA), glycoproteins,
enzymes, antimicrobial agents such
as secretory IgA and lysozyme

83. Roles Of Saliva
 Lubrication
 Digestion
 Role In Taste
 Immune
 Other ( In prosthodontics )

84. Major Salivary Glands
 Parotid
 Submandibular
 Sublingual
They produce about 90 % of total
salivary production.

85. Minor Salivary Glands
 Labial, buccal and lingual mucosa
 Soft palate
 Lateral parts of hard palate
 Floor of the mouth
The produce about 10 % of saliva.

86. Sialorrhea
 Excessive production of saliva
(hypersalivation).
 Make impression procedure more
difficult.
 May occur temporarily after
insertion of denture.

87. Xerostomia And Hyposalivation
 Injury due to losing lubricant
abilities of saliva.
 Loss of retention
 Causes
 Treatment

88. Conclusion

89. Thank You For Listening