Residual ridge resorption - RRR

1. DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

2. RESIDUAL RIDGE
RESORPTION
DR. EAKETHA P LOKESH
2ND YEAR PGDR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

3. CONTENTS
Introduction
Basic concept of bone
Mechanism of bone resorption
Pathology of RRR
Pathophysiology of RRR
Pathogenesis of RRR
Changes in maxilla and mandible
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

4. Epidemiology of RRR
Etiology of RRR
Management of RRR
Summary
References
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

5. INTRODUCTION
• Residual ridge - term used to describe the shape of
the clinical alveolar ridge after healing of bone and
soft tissues after tooth extractions.
• Consists of the denture-bearing mucosa, submucosa
and periosteum, and the underlying residual alveolar
bone.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

6.  After tooth extraction, a cascade of inflammatory
reactions is immediately activated, and the
extraction socket is temporarily closed by the blood
clot.
 Epithelial tissue begins its proliferation and
migration within the first week and the disrupted
tissue integrity is quickly restored.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

7. • The most striking feature of the extraction wound
healing is that even after the healing of wounds, the
residual alveolar ridge bone undergoes a life-long
catabolic remodeling.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

8. • after extraction (complete healing)
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

9. • The size of the residual ridge is reduced most rapidly
in the first 6 months, but the bone resorption
activity continues throughout life at a slower rate,
resulting in removal of a large amount of jaw
structure.
• This unique phenomeneon has been described as
RESIDUAL RIDGE RESORPTION (RRR).
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

10. Basic Concept Of Bone
• The structural elements of bone are:
a)Osteocytes found in bone lacunae
b)The intercellular substance or bone
matrix consisting of fibrils and calcified
cementing substance
c) Osteoblasts
d)Osteoclasts
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

11. DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

12. (A) OSTEOCYTES
 Small, flattened and rounded cells embedded in the bone
lacunae.
 The main cells, of the developed bone and are derived
from the matured osteoblasts.
 Function:
Help to maintain bone as a living tissue because of their
metabolic activity.
Play an important role in maintaining the exchange of
calcium between bone and extra cellular fluid
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

13. (B) CALCIFIED CEMENTING SUBSTANCE
Consists of mainly polymerized glycoproteins and
mineral salts namely CaCo3 and phosphate which are
bound to these protein substances.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

14. (C) OSTEOBLASTS
• Concerned with bone formation and are situated on
the outer surface of bone in a continuous layer.
• Functions:
 Responsible for synthesis of bone matrix.
 Role in calcification.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

15. (D) OSTEOCLASTS
• They are the giant multinucleated cells found in the
lacunae of bone matrix.
• Functions:
 Responsible for bone resorption during bone
remodeling.
Bone resorption always requires the simultaneous
elimination of organic and inorganic components of the
intercellular substance.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

16. MECHANISM OF BONE
RESORPTION
 The organic components of the intercellular
substance are removed by proteolytic action of the
osteoclasts.
 Then, the Ca salts (inorganic) are dissolved by a
chelating action of the osteoclasts.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

17.  As resorption takes place, the osteocytes released
may revert to osteoblasts or become osteoclasts,
depending on the physiologic and pathologic
demands.
 Histologically, bone apposition and resorption take
place in close approximation, making possible the
bone balance of shape and size.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

18. PATHOLOGY OF
RRR
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

19. GROSS PATHOLOGY
The basic structural change in RRR - a reduction in
the size of the bony ridge under the
mucoperiosteum.
It is primarily a localized loss of bone structure.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

20. In some situations, this loss of bone may leave the
overlying mucoperiosteum excessive and redundant.
In order to provide a simplified method for
categorizing the most common residual ridge
configurations, a system of six orders of RR form has
been described.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

21. • Order 1 - Pre extraction
• Order 2 - Post extraction
• Order 3 - High, well- rounded
• Order 4 - Knife edge
• Order 5 - Low, well- rounded
• Order 6 - Depressed
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

22. Atwood DA: Post extraction changes in adult mandible as illustrated by
microradiographs of midsagittal sections and serial cephalometric
roentgenograms. J Prosthet Dent 1963;13:810-24
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

23. • It is clear that RRR does not stop with the residual
ridge , but may well go below where the apices of the
teeth were, sometimes leaving only a thin cortical
plate on the inferior border of the mandible or
virtually no maxillary alveolar process on the upper
jaw.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

24. • Sometimes a knife edge ridge maybe masked by a
redundant or inflamed soft tissue, which can be
detected by palpation or by Lateral cephalometric
radiographs.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

25. • It is a normal function of bone to undergo constant
remodeling throughout life through the process of
bone resorption and bone formation.
Growth ↑se Bone formation
Osteoporosis/localized periodontal disease
↓se Bone resorption
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

26. PATHOPHYSIOLOGY OF RRR
• RRR is a localized pathologic loss of bone that is not
built back by simply removing the causative factors.
• Yet, the physiologic process of internal bone
remodeling goes on even in the presence of this
pathologic external osteoclastic activity that is
responsible for the loss of so much of bone
substance.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

27. • It has been shown that remodeling takes place in 3
dimensions such that certain portions of bone
become narrower to the extent that all existing
cortical bone in that area is removed by external
osteoclastic activity and is replaced by a new cortical
layer that is formed by simultaneous endosteal bone
formation.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

28. • Even if a great deal of RR is removed in total, there is
often a cortical layer of bone over the crest of the
ridge.
• This means that new bone has been laid down inside
the RR in advance of the external osteoclastic
removal of bone.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

29. The mechanism of the reduction of
the mandibular residual ridge actually
represents a modified version of the
Enlow’s “V” principle, showing
external resorption accompanied by
endosteal deposition
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

30. DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

31. Based on the clinical fact that
RRR is not inevitable
Its rate varies
The rate of resorption is greater that the rate of
formation in some patients
….RRR should be considered a pathologic process
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

32. PATHOGENESIS OF RRR
Immediately following extraction (Order II),any
sharp edges remaining are rounded off by
external osteoclastic resorption
Leaving a high, well rounded residual ridge
(Order III)
As resorption continues from labial and lingual
aspects, the crest of the ridge becomes
increasingly narrow, ultimately becoming knife
edged (Order IV)
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

33. As the process continues,the
knife edge becomes shorter and
eventually disappears, leaving a
low well rounded or flat ridge
(Order V)
Eventually ,this too
resorbs, leaving a
depressed ridge (Order VI)
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

34. • RRR is chronic, progressive, irreversible and
cumulative.
• Usually, RRR proceeds slowly over a long period of time
flowing from one stage imperceptibly to the next.
• Autonomous regrowth has not been reported.
• Annual increaments of bone loss have a cumulative
effect leaving less and less residual ridge.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

35. CHANGES IN MAXILLA AND
MANDIBLE
• Maxillary teeth are generally directed
downward and outward, so bone
reduction generally is upward and
inward.
• Since the outer cortical plate is thinner
than the inner cortical plate, resorption
from the outer cortex tends to be
greater and more rapid.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

36. • As the maxilla becomes smaller in all dimensions,
the denture bearing area (basal seat) decreases.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

37. • The bone of the maxillae resorbs primarily from the
occlusal surface and from the buccal and labial
surfaces.
• Thus the maxillary residual ridge looses height and
maxillary arch becomes narrower from side to side
and shorter anteroposteriorly.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

38. • The anterior Mandibular teeth generally incline upward
and forward to the occlusal plane, whereas the posterior
teeth are either vertical or incline slightly lingually.
• mandibular ridge resorbs primarily from the occlusal
surface.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

39. • Because the mandible is wider at its inferior border
than at the residual alveolar ridge in the posterior
part of the mouth, resorption, in effect, moves the
left and right ridges progressively farther apart
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

40.  The mandibular arch appears to become wider, while
the maxillary arch becomes narrower.
 Thus, RRR is centripetal in maxilla and
centrifugal in mandible.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

41.  The cross section shrinkage in the molar region, is
downward and outward.
 In the anterior region it is first downward and backward
,and then moves forward.
 The surface of the arches may be resorbed out of
parallelism which can result in diminished stability of
dentures.
 Severe ridge resorption can also result in increased inter
arch space.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

42. EPIDEMIOLOGY OF RRR
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

43. • Unrelated to the primary reason for the extraction of
the teeth (caries / periodontal disease).
• Rate of RRR is variable -between persons
Within the same person at different times
Within the same person at different sites.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

44. CLASSIFICATION OF
RESIDUAL RIDGES
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

45. Resorptive pattern of edentulous ridges
(Mercier, 1995)
• Type I – Minor ridge remodeling
The ridge is wide enough at its crest to accommodate the
recently extracted teeth
• Type II- Sharp atrophic residual ridge
The ridge becomes thin and pointed
Samyukta et al. Residual ridge resorption in complete denture wearers. J.Pharm.
Sci& Res.Vol. 8(6);2016:565-9DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

46. • Type III- Basal bone ridge
The pointed ridge flattens to the level of the basal
bone
• Type IV – basal bone resorption
Flattened ridge becomes concave as the basalbone
Samyukta et al. Residual ridge resorption in complete denture wearers. J.Pharm.
Sci& Res.Vol. 8(6);2016:565-9DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

47. Residual ridge form ( Cawood and Howell)
• Class I – dentate
• Class II – Post extraction
• Class III –convex ridge form, with adequate height
and width of alveolar process
Samyukta et al. Residual ridge resorption in complete denture wearers. J.Pharm.
Sci& Res.Vol. 8(6);2016:565-9DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

48. • Class IV – knife edge formwith adequate height but
inadequate width of alveolar process
• Class V – Flat ridge form with loss of alveolar process
• Class VI- loss of basal bone that may be extensive but
followa no predictable pattern
Samyukta et al. Residual ridge resorption in complete denture wearers. J.Pharm.
Sci& Res.Vol. 8(6);2016:565-9
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

49. DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

50. ETIOLOGY OF RRR
Anatomic
Metabolic
Functional
Prosthetic factors
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

51. • It is postulated that RRR varies with the quantity and
quality of the bone of the residual ridges
RRR α anatomic factors
The amount of bone Quality of bone
ANATOMIC FACTORS
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

52. 1. The amount of bone
• It is not a good prognostic factor for the rate of RRR,
• because it has been seen that some large ridges
resorb rapidly and some knife edge ridges may
remain with little changes for long periods of time.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

53. • Although the broad ridge may have a greater
potential for bone loss, the rate of vertical bone loss
may actually be slower than that of a small ridge
because there is more bone to be resorbed per unit of
time and because the rate of resorption also depends
on the density of bone.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

54. 2. Quality of bone
On theoretic grounds, the denser the bone, the slower
the rate of resorption
because there is more bone to be resorbed per unit of
time.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

55. METABOLIC FACTORS
• Generally, body metabolism is the net sum of all the
building up (anabolism) and the tearing down
(catabolism) going on it the body.
• RRR α bone resorption factors
bone formation factors
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

56. METABOLIC FACTORS
Local
biomechanical
factors
Systemic
factors
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

57. LOCAL BIOMECHANICAL FACTORS
Endotoxins
from dental
plaque
Osteoclast
activating
factor
(OAF)
Bone
resrption
stimulating
factor
Heparin
Trauma
(esp: due to
ill fitting
denture)
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

58. SYSTEMIC FACTORS
Circulating
eostrogen
Thyroxine
Growth
hormones
Androgens Calcium Phosphorus
Vitamin D Protein fluoride
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

59. Since bone metabolism is dependent on
cell metabolism, anything that
influences cell metabolism of
osteoblasts and osteoclasts is important.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

60. • The degree of absorption of Ca, P and proteins
determines the amount of building blocks available
for the growth and maintenance of bone.
• Vit C aids in bone matrix formation.
• Various members of Vit B complex are necessary for
bone cell metabolism.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

61. • The thyroid hormone affects the rate of metabolism
of cells in general and hence the activity of both, the
osteoblasts and osteoclasts.
• Parathyroid hormone influences the excretion of
phosphorous in the kidney and also directly
influences osteoclasts.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

62. Vit D & Bone resorption
• Small amounts of vitamin D given to normal subjects
probably do not stimulate resorption,
• whereas very large amounts, i.e., pharmacologic
doses, cause a marked stimulate resorption of bone
resorption
• The reasons for these differential dosage effects are
not well understood.
Baylink et al. Systemic factors of alveolar bone loss. J prosthet Dent 1974;31:486-505
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

63. Glucocorticoids
• Glucocorticoid hormones – for treating cushing’s
syndrome
• ↓se bone formation and cause severe osteoporosis
• By suppressing enteral calcium absorption
Baylink et al. Systemic factors of alveolar bone loss. J prosthet Dent 1974;31:486-505
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

64. Hypophosphatemia
• Hypophosphatemia – may represent direct effect of
serum phosphorus on bone to enhance bone
resorption
• Hypophosphatemia enhances the synthesis of 1,25-
dihydroxycholecalciferol which is the active
metabolite of vitamin D and which has been shown
to stimulate bone resorption.
Baylink et al. Systemic factors of alveolar bone loss. J prosthet Dent 1974;31:486-505
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

65. • The amount and frequency of stress and its
distribution and duration are important factors.
• The reaction of bone to pressure can cause both
apposition and resorption
• Whenever pressure interferes with the blood or
nerve supply of the bone, resorption occurs
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

66. OESTROGEN & TESTOSTERONE
According to Reifenstein, in the
young person, there is a relative
predominance of anabolic
hormones (estrogen and
testosterone) over the anti anabolic
hormones( cortisone and
hydrocortisone) resulting in
continued growth of skeleton.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

67. • He further states that, as people get older, the
anabolic hormones are so reduced that the
antianabolic hormones are in relative excess with the
result that bone resorption may take place faster
than bone formation and that bone mass may be
reduced
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

68. Bone Resorption And Calcium
Homeostasis
• The only sources of Ca for the body are
Diet
Bone reservoir.
Factors controlling
Calcium
homeostasis
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

69. • This can occur by altering internal absorption
mechanisms (income) or tubular reabsorption
(recycling) or by liberation of Ca from the skeleton via
resorption (savings).
• There is a RECIPROCAL RELATIONSHIP between Ca
concentration and bone resorption to maintain Ca
homeostasis.
• As the level of serum calcium develops, resorption is
stimulated and factors that would inhibit resorption are
depressed.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

70. • Skeletal depletion of calcium occurs as a result of
stimulation of parathyroid gland and the alveolar
bone is the first to be affected.
• This is due to the function of parathyroid hormone
in maintaining the blood calcium level by mobilizing
it from bones by osteoclastic activity.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

71. • Simultaneously , there is an increased renal
excretion of phosphate, which disturbs the blood
calcium:phosphorous ratio by raising the blood
calcium level.
• This results in mobilization of phosphates from
bones by osteoclastic activity.
• Under these conditions , alveolar bone becomes
susceptible to diseases like osteoporosis
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

72. OSTEOPOROSIS AND RRR
Osteoporosis is
characterized by low
bone mass and micro
architectural
deterioration of the bone,
which leads to increased
bone fragility and risk of
fracture.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

73. The more prevalent
Type I (post
menopausal) affects
women for a decade or
so after menopause.
The Type II ( senile or
idiopathic) attacks
males and females at
any age for no obvious
reason.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

74. • RRR may be a manifestation of Type I osteoporosis .
• Both cortical and trabecular bone are affected
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

75. MECHANICAL FACTORS
• Forces within the physiological limits are beneficial
in their massaging effect.
USE V/S DISUSE ATROPHY
• Bone that is “used”, as by regular physical activity ----
tend to strengthen within certain limits
• Bone that is in “disuse” ---- will tend to atrophy
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

76. • Masticatory & non-masticatory force – ususally
transmitted to dentoalveolar bone thr’ the PDL
• Once the teeth are removed, the residual alveolar
ridge is subjected to entirely different types of forces
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

77. Some postulate RRR as
an inevitable “disuse
atrophy”
Some others………RRR –
“abuse” bone resorption
due to excessive forces
transmitted thr’ the
dentures.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

78. Bassett has suggested that the mechanism
by which force is translated into bone
remodeling (Wolff’s Law) may be through
the bioelectric properties of bone
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

79. Amount of force
Frequency of force
Duration of force
Direction of force
Area over which
force is distributed
( force per unit
area)
Damping effect of
underlying tissue
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

80. • Tendency of RRR more in mandible than in maxilla
RRR α FORCERRR α FORCE
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

81. • Damping effect / energy absorption
• May take place in the mucoperiosteum which is
considered as a viscoelastic material
• Since the overlying mucoperiosteum from patient to
patient and from maxilla to mandible
RRR α 1
Damping effect
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

82. PROSTHETIC FACTORS
1. Excessive stress resulting from artificial
environment:
• Human tissues have not evolved in nature to
accept ranges of artificial things and the
denture acts as an artificial entity
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

83. 2. Abuse of tissues from lack of rest:
• Abused tissues are always manifested with a slung,
glistering surface.
• Bone is moldable ------ It can tolerate masticatory
forces within the limits of physiologic tolerance but
exceeding that it causes damaging forces which will
result in resorption of the alveolar bone and
alteration in tissue form
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

84. 3. Long continued use of ill fitting dentures:
In ill fitting dentures, there is an improper relation of
the denture base to the supporting tissue.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

85. 4. Ill fitting dentures may be due to :
Long use
Loss of bone
Incorrect occlusion
Incorrect jaw relation
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

86. 5. Under extended dentures:
• Lead to less retentive dentures and increase load per unit
area.
• Common sites are:
Lingual flange
Buccal shelf area
Retromylohyoid area
Retromolar pad
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

87. 6. Faulty improper procedures employing compression
forces:
• Before impression procedures, care has to be taken
on selection of trays.
• If the tray selected is too large, it will distort the
tissues around the borders of the impression, away
from the tissues.
• If it is too small, the border tissues will collapse
inward onto the residual ridge.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

88. • This will reduce the support of the lips by the
denture flange.
• The use of minimal and selective pressure
impression techniques should be implicated in order
to avoid distortion of the mucosa and ridge area
which may be under considerable pressure
otherwise.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

89. 7. Error in relating maxilla to the cranial landmarks
(orientation relation):
• The plane of the maxilla should be oriented to the
facial reference line (Camper’s plane or ala tragus
line).
• If not, may cause instability of denture leading to
resorption.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

90. 8. Lack of freeway space due to increased vertical
dimension of occlusion:
• Freeway space is present in the teeth in the physiologic
rest position.
• It is normally 2-8mm but in complete dentures it is
around 2mm.
• At times, due to lack of freeway space the bone resorbs
because of increased vertical height in an attempt to
create the space.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

91. Changes In Inter-alveolar Ridge
Relationship
 Morphological changes such as sharp, spiny, uneven residual
ridges.
 Resorption of the mandibular canal wall and exposure of the
mandibular nerve.
 Location of the mental foramina close to the top of the
mandibular residual ridge.
 This provides serious problems to the clinician on how to
provide adequate support, stability and retention of the
denture
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

92. Consequences of RRR
Apparent loss of sulcus width and depth
Displacement of the muscle attachment closer to the
crest of the residual ridge
Loss of vertical dimension of occlusion
Reduction of lower face height
An anterior rotation of the mandible
Increase in relative prognathia
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

93. MANAGEMENT OF RRR
• Systemic evaluation
• Diet
• Tissue treatment therapy
• Pre prosthetic surgery
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

94. • Prosthetic management: -
Impression techniques.
Denture base selection.
Teeth selection and arrangement.
Implant supported prosthesis.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

95. SUMMARY
• Residual ridge resorption is a chronic, progressive,
irreversible, and disabling disease , of multifactorial
origin.
• Much is known about its pathology and pathophysiology,
but a lot remains to know about its pathogenesis,
epidemiology and etiology.
• RRR requires a multiple approach for diagnosis and
treatment planning.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

96. • The cause must be detected, by the aid of a
physician, and then eliminated or stabilized before
dentures are constructed.
• Construction of a stable functioning denture and a
regular follow up treatment can help in the
restoration of function, and thus, the restoration of
the physical and mental vitality of the patient.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

97. CONCLUSION
• The preservation of supporting tissues is a sacred
trust that cannot be ignored.
• The application of the basic concepts and the
advances made in the basic sciences will help to keep
this trust in the hands of the dental profession.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

98. • As prosthodontists, we need to perform the most
meticulous and intelligent prosthodontic care of the
patient within our capabilities.
• …and then , it would not seem a nebulous hope that
some day there will be control over residual ridge
resorption.
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

99. REFERENCES
1. Winkler S : Essentials of complete denture
prosthodontics. 2nd edition,2000.
2. Zarb Hobkirk Eckert Jacob: Prosthodontic
treatment for edentulous patients. South Asia
edition
DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION

100. JOURNAL REFERENCES
1. Baylink et al. Systemic factors of alveolar bone loss. J prosthet Dent
1974;31:486-505
2. Samyukta et al. Residual ridge resorption in complete denture
wearers. J.Pharm. Sci& Res.Vol. 8(6);2016:565-9
3. Atwood DA: Post extraction changes in adult mandible as
illustrated by microradiographs of midsagittal sections and serial
cephalometric roentgenograms. J Prosthet Dent 1963;13:810-24
4. Klemetti et al. A review of residual ridge resorption and bone
density. J Prosthet Dent 1996;75:512-4
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101. DR EAKETHA P LOKESH RESIDUAL RIDGE RESORPTION