3. Learning outcomes
1. Describe what are relief areas, support
areas and stress bearing areas.
2. Name the maxillary edentulous
anatomical landmarks.
3. Name the mandibular edentulous
anatomical landmarks.
4. Memorize the primary and secondary
stress bearing areas of maxilla and
mandible.
4. In order to properly construct a
denture, one must understand
the anatomy and physiology of
the edentulous patient’s mouth.
5. A thorough knowledge of the
origins and functions of the
muscles of mastication, facial
expression, tongue and floor of
the mouth is essential.
6. When the key anatomic
landmarks and their role with
respect to retention, stability,
support are mastered, dentures
can be fabricated as important
parts of each patient’s oral cavity
and not just mechanical artificial
substitutes.
8. Relief areas
The reduction or elimination of
undesirable pressure or force
from a specific region under a
denture base.
9. Support areas
Those areas of the maxillary
and mandibular edentulous
ridges that are considered best
suited to carry the forces of
mastication when the dentures
are in function.
10. Stress bearing areas
The surfaces of oral
structures that resist forces,
strains, or pressures brought
on them during function.
Primary stress bearing area
Secondary stress bearing
area
11. The primary stress-bearing areas
generally have thicker mucosa
and /or underlying bone that is
less subject to resorption because
it is cortical bone.
12. The residual ridge is generally a
secondary stress-bearing area as it
is made up of cancellous bone.
20. Alveolar (Residual) Ridges
Following full mouth extractions, the
alveolar ridges undergo major bony
changes, with the largest changes
seen on the mandibular arch.
21. Studies indicate that the
mandibular ridge resorps
approximately four times as
much as the maxillary arch.
22. The direction of mandibular
resorption is downward and
outward, while maxillary
resorption is upward and inward.
27. It overlies the incisive foramen,
through which the incisive nerve and
blood vessels exit.
28. Because of the sensitivity of this
structure, care must be taken when
inserting the maxillary denture to
relieve almost all pressure in this area.
29. The incisive papilla is a good
landmark when arranging teeth
because studies indicate that the
facial surfaces of the natural central
incisors, when present, were
approximately 8-10 mm anterior to the
middle of the incisive papilla,
30. and the tips of the canines were
approximately in line with the middle
of the incisal papilla.
32. The palatine rugae are irregular
mucous membranes that extend
bilaterally from the midline of the hard
palate in relation to the upper six
anterior and sometimes bicuspid
teeth.
34. Torus Palatinus
When present, the torus palatinus is
a bony prominence of variable size
and shape, which is located in the
middle of the hard palate.
35. The tissue overlying a palatal
torus is usually very thin. Care
must be taken during insertion
to relieve any pressure to the
torus caused by the denture.
37. The midpalatine raphe is a line in
the middle of the mucosa of the
hard palate that overlies the mid-
palatine suture.
Midpalatine
suture
Hard palate
38. The tissue in this area is very thin,
and any pressure from a denture will
not be tolerated by patients. Care
must be taken when inserting the
denture to provide necessary relief.
Midpalatine
raphe
40. The fovea palatini are two
depressions that lie bilateral to
the midline of the palate, at the
approximate junction between
the soft and hard palate.
Fovea Palatini
41. They represent the sites of
opening of ducts of small mucous
glands of the palate.
43. The hamular process is a bony
projection of the medial plate of the
pterygoid bone and is located distal
to the maxillary tuberosity.
44. Lying between the maxillary
tuberosity and the hamular process
is a groove called the hamular notch.
hamular notch
45. This notch is a key clinical landmark
in maxillary denture construction
because the maximum posterior
extent of the denture is the vibrating
line that runs bilaterally through the
hamular notches.
47. The vibrating line is very important to
locate for proper construction of the
maxillary complete denture.
48. The vibrating line can be considered
as the junction between the hard
and soft palates and is important
because it is the maximum posterior
limit to the maxillary denture.
49. This line runs from about 2 mm buccal to
the center of the hamular notch on one
side of the arch, follows the junction of
the hard and soft palates across the
palate, and ends about 2 mm buccal to
the center of the opposite hamular notch.
51. T- burnisher
The posterior palatal seal area is
very important in maxillary
complete denture fabrication and
must be identified and evaluated.
52. It is the area of compressible
tissue located anteriorly to the
vibrating line and lateral to the
midline in the posterior third of
the hard palate.
53. The distal extent of this area is the
vibrating line, while the anterior
border is unclear.
57. Histologically and functionally it is the
same as in the maxilla. It is a mucous
membrane without significant muscle
fibers.
Labial Frenum
Labial Frenum
58. Labial vestibule
It runs from one buccal frenum to the
other on the labial side of the ridge.
Labial Vestibule
59. Buccal Frenum
The buccal frenum is a mucous
membrane fold that overlies dense
fibrous connective tissue and fibers of
the depressor anguli oris muscle.
Buccal Frenum
60. Buccal
Vestibule
Buccal Vestibule
The buccal vestibule extends
posteriorly from the buccal frenum to
the posterior lateral aspect of the
retromolar pad.
Buccal frenum
Retromolar
pad
61. The buccal shelf is the primary stress-
bearing area of the mandibular arch.
The buccal shelf consists of thick cortical
bone and lies at right angles to vertical
occlusal forces.
Buccal
shelf
Buccal Shelf
62.
63. It is an area bounded on the medial side
by the crest of the residual ridge, on the
lateral side by the external oblique ridge,
anteriorly by the buccal frenum, and
posteriorly by retromolar pad.
64. A triangular area of thick mucosa is
found distal to the last molar, on the
crest of the ridge, and is referred to
as the retromolar pad.
Retromolar Pad
65. It is composed of:
Loose connective tissue
Glandular tissue
Fibers of the temporalis tendon
Fibers of buccinator muscle
Fibers of superior constrictor
muscle
The pterygomandibular raphe
66. The retromolar pads should be
covered by the denture, and the
plane of occlusion is generally
located at the level of the middle to
upper-third of this pad.
67. Just buccal to the crest of the
mandibular ridge in the distal-buccal
corner of the arch is an area known
as the masseteric notch.
Masseteric Notch
Masseteric Notch
69. It is important in mandibular
denture fabrication because of
its influence on impression
making.
It is formed by the actions of the
masseter muscle.
70. The ventral surface of the tongue
(undersurface) is anchored to the
floor by a mucous membrane fold
known as the lingual frenum.
Lingual Frenum
Lingual Frenum
71. Lingual Sulcus
Space between the
residual alveolar
ridge and the
tongue.
It extends from the
lingual frenum to the
retromylohyoid
curtain.
72. Some patients will exhibit bilateral bony
prominences of the inner surface of the
mandible in the region of the premolar
teeth called the torus mandibularis.
Torus Mandibularis
73. These prominences must usually be
removed prior to denture
fabrication.
Torus Mandibularis
75. Genial Tubercles
These are bony midline lingual
projections and offer attachment to
genioglossus and geniohyoid
muscles.
76. In patients suffering from atrophied
mandibles, the residual ridge
resorbs to the level of the genial
tubercles, which can be easily
palpated.
The dentures should be trimmed
around the genial tubercles in those
cases.
Editor's Notes
Kinetics: dynamics/movement
Kinetics: dynamics/movement
LEVATOR ANGULI ORIS - CANINUS
LEVATOR ANGULI ORIS - CANINUS
LEVATOR ANGULI ORIS - CANINUS
The retro molar pad area is the most stable area of the mandibular alveolar ridge because it is an area where there has been no tooth that has weakened the bone in this area. The lingual frenulum plays a very important role in the stability of mandibular denture as it attaches the tongue to the anterior alveolar ridge area and if it is not allowed freedom of movement it will cause the denture to rise during function. The labial vestibule is an area that the flange of the mandibular denture is most commonly under-reduced during the insertion. The patient will return with a large ulcer and the complaint that the denture moves up and down when he eats or speaks. The retromylohyoid fossa plays an important role in the retention of a mandibular denture by resisting the tendency of the denture to move up in the posterior region when a patient bites down on the anterior teeth. The submaxillary caruncles and the lingual tubercle are major areas that become very sore when the denture flanges are left long in this area. The size, shape, and position of the tongue are very important in the stability of the lower denture. The tongue will either work to hold the denture in place or work against it to dislodge it.