1. GUIDED BY : DR.A.S. KAUL
PROF &HEAD OF
DEPT OF PROSTHODONTICS
K.D.D.C., MATHURA
Presented by:-
Preety dagar
29th june 2009

2.  INTRODUCTION
 BASIC CONCEPT OF BONE
 DEFINITIONS
 ETIOLOGY
 PATHOLOGY
 PATHOPHYSIOLOGY
 PATHOGENESIS

3.  EPIDEMIOLOGY
 TREATMENT & PREVENTION OF RRR
 SUMMARY
 BIBLIOGRAPHY

4.  Anatomic changes will invariably take place
within the alveolar processes of the jaws
following dental extractions. After the
extraction of teeth, the empty dental alveoli fill
up with blood, which sequentially clots,which
is organized, and is replaced with new bone.
To this newly formed ridge dentures are
constructed, and the ridge undergoes changes
in shape and reduces in size . The ridge
changes occur because of the changes in the
whole distribution of forces after the extraction.
Over the long period of time, with the use or
without the use of dentures there is the atrophy
of the residual alveolar ridge or REDUCTION
OF RESIDUAL RIDGE.

5.  THE STRUCTURAL ELEMENTS OF BONE
ARE:
1)OSTEOCYTES:-Are found in bony lacunae.
 Responsible for metabolic activity of bone .

6. 2)OSTEOBLASTS:-Active bone forming cells.
During bone formation some osteoblasts
become engulfed in intercellular substance and
become osteocytes

7.  3)THE INTERCELLULAR SUBSTANCE:-Bone
matrix consist of fibrils and calcified cementing
substance.
 Consist mainly of polymerized glycoprotein
 Mineral salts namely calcium and phosphate
are bound to these protein substances

8. 4)OSTEOCLASTS:-Responsible for bone
resorption.

9.  Normal bone is in constant state of flux.
 Bone is never static but rather there is contantly
rebuilding, resorbing and remodelling subject
to functional and metabolic stresses.

10. LEVELS
EQUILIBRIUM:-The
two antagonists
actions are in
balance.
ATROPY:-Decrease
osteoblastic activity
as in osteoporosis
and disuse atropy.
RESORPTION:-
Caused by increase
osteoclastic activity.
GROWTH:-Increase
osteoblastic activity
help in remodelling
of bone as they
grow.

11.  The normal equilibrium may be upset and
pathological bone loss may occur if either bone
resorption is increased or bone formation is
decreased or if both occur.jpd;1962;12(3);441-450

12.  Bone resorption always require the simultaneous
elimination of organic and inorganic components
of intercellular substances.

RESORPTION
Organic component Inorganic component
Proteolytic action Chelating action of
of osteoclasts osteoclasts

13.  As resorption takes place ,osteocytes released
may revert to osteoblasts or osteoclasts
depending on the physiological or pathological
demands at that time.
 Weinman and sicher(6) have proposed three
possible causes of bone resorption:-
 1)Aging with necrosis of bone.
 2)Increase in pressure in adjacent tissue namely
Periosteum and bone marrow.

14.  3)Direct action of the elements of the blood and
tissue fluids.
 Changes in chemistry of bone play a dominant
part as a stimulus for fibrocytes from
connective tissue and osteocytes from bone to
metamorphose into osteoclasts and to
commence resorption.

15.  Residual ridge resorption :- A term used for the
diminishing quantity & quality of residual
ridge after teeth are removed. (G.P.T -8)
 Residual ridge :- The portion of the residual
bone & its soft tissue covering that remains
after the removal of teeth. (G.P.T -8)
 Residual bone :- That component of maxillary
& mandibular bone that remains after the teeth
are lost. (G.P.T -8)

16. RRR : A
MAJOR
ORAL
DISEASE
ENTITY
ETIOLOGY
PATHOGENESIS
EPIDEMIOLOGY
TREATMENT
AND
PREVENTION
PATHO-
PHYSIOLOGY
PATHOLOGY

17.  RRR is a multifactorial disease.
 Rate of RRR depends not only on one single
factor but on the concurrence of two or more
factors which may be called cofactors.

19.  RRR varies with quantity and quality of bone
of residual ridges.
 RRR α ANATOMIC FACTORS
 AMOUNT OF BONE
 QUALITY OF BONE:-

20. AMOUNT OF BONE
 More the amount of bone,more will be the RRR.
 But the amount of bone is not a good prognosticator
of the rate of RRR.
 If a low depressed ridge has existed for many years,
future RRR will be at a low rate.

22. FACIAL MORPHOLOGY : ( JPD; 1979;41(1) 90-100)
 The longer the face, the more alveolar bone there is
and the less chance there is for an individual to reach a
stage of severe atrophy in wearing dentures.
 The further closed the vertical dimension of occlusion,
the more compressive are the forces applied on the
residual ridges and the greater are the chances for an
individual with a closed vertical dimension of
occlusion to reach the stage of extremely severe
atrophy with the dentures, especially for the mandible.

23. MANDIBULAR SHAPE : ( JPD; 1972; 27(2)120-132)
 Correlations between the shape of the mandible and the anterior
mandibular bone loss indicated a pronounced resorption in subjects with a
marked mandibular base bend, and a less marked resorption in subjects
with a flattened mandibular base.

24. QUALITY OF BONE:-
 Mclean & urist (5) state that a loss of 24-30% of bone
salt is necessary to produce a appreciable
change in x-ray of bone.
 The denser the bone ,faster the rate of
resorption because there is more bone to be
resorbed per unit of time.

25.  RRR varies directly with certain systemic or
localized bone resorbing factors & inversely
with bone formation.
 RRR α BONE RESORBING FACTORS
BONE FORMATION FACTORS

26.  Therefore certain local bone resorbing factors
could be very important.
 These factors include:-
 Endotoxins from dental plaque
 Osteoclasts activating factors
 Prostaglandins
 Human gingival bone resorption stimulating factor.

27.  Heparin :-shown to be a cofactor in bone resorption.
 observed in microscopic sections of residual ridge close to
bony margin.
 Other possible local bone resorption factors could be
related to trauma(especially under ill fitting denture)which
leads to increase or decrease in vascularity & change in
oxygen tension.

28.  Whatever the local resorbing factors may be
they must be considered in the environment of
systemic factors that influence the balance
beween bone formation &bone resorption.
 Systemic factors:-
Hormonal influences Dietary influences on
bone on bone

29.  Hormonal influence is important to dentist
because they involve the general health of
patient which is reflected in the oral cavity.
 1)Pituitary gland:-The anterior pitutary gland
release ACTH.
 ACTH protein catabolism
Interferes with the formation
of organic bone matrix .
causes

30.  2)Thyroid gland:-regulates the rate of
metabolism.
 Hyperthyroidism increases the metabolic rate
negative nitrogen balance
protein deficiency
osteoporosis

31.  Thyroxine :- increases excretion of calcium &
phosphorus,which leads to osteoclastic activity.
 3)Parathyroid gland:-influence the excretion of
phosphorus in kidney & directly influence
osteoclasts.
 parathormone maintains blood calcium level by
mobilizing it from bone by osteoclastic activity

32.  Islets of langerhans:-decrease insulin ,which
leads to decrease utilization of glucose ,which
in turn causes diabetes mellitus.
 Poor healing of tissue
 Rapid resorption of bone
 Low tissue tolerance

33.  Gonads:-Anabolic hormone(estrogen & testosterone)
& antianabolic(cortisone & hydrocorticosone)
 According to Reifenstein (5),in young person there is
predominance of anabolic hormone, resulting in
continued growth & maturation of skeleton.
 In adult the anabolic & antianabolic hormones are in
balance ,with the result that bone formation & bone
resorption are in equilibrium ,and bone mass
remains constant.
 In older people the anabolic hormones are so
reduced that the antianabolic hormones are in
relative excess, bone resorption takes place faster
than bone formation & bone mass is reduced.

35.  VITAMIN A:-It influence the activity &
position of osteoblasts & osteoclasts.
 VITAMIN B COMPLEX:-Produce effect similar
to protein deficiency.
 essential for normal cell metabolism including bone
cell.

36.  VITAMIN C:-Bone matrix formation
 Vitamin c deficiency leads to:-
 collagen content of bone is decreased
 loosening of teeth .
 disorganization of periodontal fibres & membrane.
 Periosteum is affected in similar way :-it thickens &
cell appear immature & resemble fibroblasts.

37.  This condition may make the periosteum more easily
injured by denture base.
 Therefore ,inflamatory process are triggered by the
denture base at lower pressure level.
 VITAMIN D:-necessary for maintaining the
calcium phosphorus level.

38.  Osteoporosis :-due to insufficient formation of
the organic matrix.
 Disturbance of protein metabolism & involve
vitamin ,hormone & nutritional factors.
 Usually found in edentulous mouth.
 Osteomalacia :-faulty calcification of organic
matrix.
 Results from faulty calcium metabolism
influenced by vitamin D & parathyroid
glands.

39.  Osteitis fibrosa :-normal cementing substance is
replaced by fibrous tissue.
 It is usually a result of hypeparathyroidism.

40.  Periodontal disease is related to prosthetic
problems,because both are concerned with differences
in bone factor between different individual.
 Stress regardless of its cause always produce a alarm
reaction which increase the rate of bone resorption.
:-Protein balance is lost by dual effect of stress.
 Age & sex are other factors which influence bone resorption.

41.  The remodelling of bone is influenced by force
factors.
RRR α FORCE
 When considering force one must concern about:-
 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.

42. Is paradoxic since it can cause both apposition and
resorption.
Within the physiologic limit Beyond the physiologic limit
APPOSITION
BONE RESORPTION
PRESSURE

43.  Denture bearing bone has a complex blood
supply from :
1) Internal from interdental arteries :-main supply pass
through canals in intraalveolar septa
2) Externally from periosteum
 Interference with blood supply leads to bone
necrosis.

44.  There is tendency for more RRR in mandible than
maxilla.
 Woelfel et al(1) have cited a patient with projected
maxillary denture area of 4.2inches sq. And
projected mandibular denture of 2.3inches sq.
 Ratio is 1.8:1
 If such patient bites with a pressure of 50lb
 This calculates pressure of 12 lb/inches sq in
maxilla & 21 lb/inches sq under mandibular
denture.
 This shows the difference in RRR of two jaws.

45.  The amount of force applied to the bone is
inversely proportional to damping effect or energy
absorption.
RRR α I
DAMPING EFFECT
:-Damping effect may take places in mucoperiosteum
which can be considered a viscoelastic material
:-since the overlying mucoperiosteum varies in its
viscoelastic properties from patient to patient
&from maxilla to mandible ,its energy absorption
qualities may influence the rate of RRR.

46.  Frost (1)has stated that “bones which are
subjected largely to compression loads &
experience no significant bending loads are
composed largely of cancellous bone which is
ideally constructed for the absorption &
dissipation of energy.”
 The fact that the maxillary residual ridge is
frequently broader,flatter & more cancellous than
mandibular couterpart & may be a factor in
frequenty observed differences in RRR of two
jaws.
 Resistance offered by hard palate play an role
in less resorption of upper ridge.

47.  Frost(1) points outs that trabeculae when oriented
parallel to direction of compression deformation
allows for maximal resistance to deformation.
 Neufeld(1) cut the dry human jaws at right angles
through the crest of ridge & demonstrated that the
trabeculae were oriented at right angle to the crest &
thus parallel to occlusal forces transmitted
through the denture.
 Gibbs et al(1) reported that 2o individual with
healthy dentition bit with an average force of 162 lbs
& 5 edentulous patient with an average force of
35lbs.overall loading of edentulous mandible is less
than dentulous mandible.

48.  Disuse atropy & fracture are examples of extremes of
functional forces.
 DISUSE ATROPY
 The deficiency is in the formation of the new protein matrix
with no disturbance of calcification.
 Atropy of disuse is directly proportional to the extent of
disuse.
 After the loss of the natural teeth,the bone cannot be
stimulated by a denture base as the teeth did internally.
 This loss of internal stimuli & reduction of closing force
are signals for disuse atrophy & a remodeling of bone
in accordance with WOLFF ‘S LAW OF
TRANSFORMATION(6)

49. Prosthetic factors
 The traditional design of denture includes many
features whose goal is to reduce the amount of force
to ridge &thereby to reduce RRR.
 The prosthetic factors include:-
 Broad area coverage (to reduce force per unit area)
 Decrease bucco-lingual width of teeth.
 Decreased number of dental units

50.  Improved tooth form(to decrease the amount of
force required to penetrate a bolus of food)
 Avoidance of inclined plane(to minimize
dislodgement of denture & shear forces)
 Centralization of occlusal contacts(to increase
stability of denture )
 Provision of adequate tongue room(to improve
stability of denture in speech & mastication)
 Adequate interocclusal distance during rest jaw
relation (to decrease frequency & duration of tooth
contact).

51.  For convenience ,since the functional factors
must function through the prosthetic factors
;they may be grouped together as
mechanical factors.

52. In addition to three major categories ,the importance of time
since extraction to bone loss should be emphasized in inverse
relation.
RRR α ANATOMIC FACTORS + FORCE FACTORS
DAMPING EFFECT
+ BONE RESORPTION FACTOR
BONE FORMATION FACTOR
+ 1
TIME

53. GROSS PATHOLOGY:-
 A lay man expression of RRR is” my gums
have shrunk”.
 Basic structural changes in RRR is reduction in
size of bony ridges under the mucoperiosteum.
 It is primarily localized loss of bone structure

54.  In some situations ,this loss of bone may leave
overlying mucoperiosteum excessive and
redundant.
 LAMMIE(1) has postulated that one factor in RRR
may be a cicatrizing mucoperiosteum that is seeking
a reduced area, resulting in pressure resorption of
underlying bone.
 Numerous longitudinal radiographic
cephalometric studies have provided excellent
visualization of the gross pattern of bone loss
from a lateral view point.

55.  The superimposition of tracing of three lateral
cephalographs which clearly show the
reduction in size & shape that occurs on
external surface on the labial,crestal & lingual
aspect of residual ridge.jpd;1971;26(3);266-279

56.  The study of morphologic changes in facial
skelton during seven years of complete denture
wear revealed that there is decrease in facial
height due to :- jpd;1972;27(2);120-132
 Pronounced reduction of mandibular ridge
 Forward & upward rotation of mandibular ridge
 The changes in mandibular position was accompanied
by a marked increase in mandible prognathism.
 Despite alterations in jaw relations ,no dimensional
changes were found in the cranial base ,the upper part
of face,or the basal part of mandible.

57.  Gross anatomic studies were done on dried jaw
bone which have shown a wide variety of
shape & size of residual ridge.
 The residual ridge is categorized in 6 orders:-
I ORDER – PRE EXTRACTION
II ORDER - POST EXTRACTION
III ORDER – HIGH , WELL ROUNDED
IV ORDER - KNIFE EDGE
V ORDER- LOW ,WELL ROUNDED
VI ORDER - DEPRESSED

58.  This classification is helpful clinically as well as
for research purposes &help one to
differentiate the various stages of RRR in
individual patient . jpd;1971;26(3);266-279

59. :- Panoramic radiograph described by wical &
swoope (3)provide a graphic picture of bone
resorption ,particularly of mandible.
:-But in films of edentulous patients ,the only
remaining radiographic landmarks in body of
mandible are the superior & inferior border of
bone & the mental foramen .
:-Mental foramen is taken as a reference point .

60.  Three measurements were recorded on
panoramic radiograph of jaws of adult subjects
:-
1)from the inferior border to superior border of the
alveolar bone.
2)from the inferior border of mandible to lower edge of
foramen.
3)from the inferior border to upper edge of the
foramen .
Films of 130 subjects met the criteria & were used in
the study.

62.  The mean ratio between the total height of mandible
& the height of lower edge of the foramen in 260
samples was 2.90:1 with a standard deviation of 0.23
 The mean ratio between the total height of the
mandible & the height of upper edge of the foramen
in 260 samples was 2.34:1, with a standard deviation
of 0.20.
 Clinically the lower edge of the mental foramen
appears to be more useful reference mark in
panoramic radiograph.
By measuring the distance from inferior border of
the mandible to the lower edge of foramen & using
the approximate ratio of 3:1;the original length of
mandible before resorption can be estimated.

64.  Based on method of estimating bone loss there
are three divisions used for epidemiological
studies are:-
1. Class I –Upto one third of original vertical
height lost
2. Class II – From one third to two third of vertical
height resorbed
3. Class III – two thirds or more of vertical height
resorbed lost

65.  Microscopic studies have revealed evidence of
osteoclastic activity on external surfaces of
residual ridge .
 The scalloped margin of howship’s lacunae
sometimes contain visible osteoclasts.

66.  A microradiographic study of 21 edentulous
mandible has shown variation in :-
 Density of osteons
 Number of incompletely closed osteons
 Endosteal porosity
 Number of plugged osteons.

67. PATHOPHYSIOLOGY
 RRR is a localized pathologic loss of bone that
is not built back by simply removing the
causative factors.
 Physiologic process of internal bone
remodeling goes on even in the presence of
pathologic external osteoclastic activity.

68.  A modified version of ENLOW V(2) principle of bone
remodelling illustrate dramatically the mechanism of
reduction of mandibular residual ridge by external
resorption accompanied by endosteal deposition.

69.  Structurally , the configuration of endosteal
bone is dependent upon the configuration of
the bony surface on which the inward
endosteal bone is deposited.
 Thus endosteal bone may be characterized by a
convoluted whorled appearance if the bone
growth is in a trabecular area or by a zone of
even ,regular ,uninterrupted circumferential
lamellae if the bone is laid on endosteal side of
smooth cortical bone.

70.  The type of bone commonly found on the crest
of ridge appears to be endosteal bone of the
whorled convoluted type due to the
compacting of trabecular bone by the
deposition of layers of new bone on old
trabeculae.
 As the endosteal bone become compacted ,it is
invaded by resorption spaces & new haversian
systems are formed within the compacted
bone.

71.  After the extraction of tooth ,any sharp edges
remaining (order II) are rounded off by
external resorption leaving a high well
rounded ridge(orderIII).
 As resorption continues from the labial &
lingual aspect ,the ridge becomes increasingly
narrow ultimately becoming knife edge
(orderIV).

72.  As resorption continues further,the knife edge ridge
becomes shorter & eventually disappear ; leaving a
low, well rounded or flat ridge(orderV).
 Eventually this too resorbs leaving a depressed
ridge.(order VI)
 The reduction of residual ridge is chronic ,
progressive , irreversible & cumulative.
 The reduction of residual ridge usually proceeds
slowly over a long period of time from one stage to
next.

73.  Within a given individual the rate is usually
most rapid in first six months following
extraction. jpd ;1971;26(3);266-279

74.  The RRR curves in one subject studied over a 19 yrs
period illustrates various principles of variation within a
given subject. jpd;1971;26(3);266-279
 The anterior vertical RRR in maxilla was 3mm during
the first 3yrs & immeasurable thereafter.
 While in mandible ,after a dramatic early bone loss ; it
continues to show a steady reduction rate i.e.
0.4mm/year to a total of 14.5mm in 19yrs.

75.  The longitudinal study of edentulous individuals covering 25
years of complete denture wearing revealed a continued
reduction of the residual ridges throughout the observation
period . Jpd;1972;27(2);120-132
 The mean reduction in anterior height of bony alveolar ridges of
group A during 13.5 yrs of complete denture wearing & in group C
between the 10year & 25year stages of denture wearing.

78.  In group A the mean decrease in anterior height of the
lower ridge between the seven year and 13.5 year
controls was 1.4 mm and that of the upper ridge was
0.4 mm
 The mean decrease in mandibular height during the
total period of 13.5 years was 7.7 mm, and the
maxillary reduction was 2.2 mm.
 In group C the mean reduction in anterior height of the
lower residual ridge between the 10 year and 25 year
stages of denture wear was 3 mm and that of the upper
ridge was 0.8 mm.
 In both sample , the mean reduction in anterior height
of the lower ridge during the follow up period was
about four times greater than that of upper ridge(4:1).

79.  The magnitude of alveolar resorption showed great
individual variation jpd;1972;27(2);120-132
 The tracings show the bony contour of anterior residual ridge
at the stage of insertion , at 1year, 7year, & 13.5 year stages of
observation.
 The marked alveolar bone loss during the first year of denture
wearing and the gradual decrease in the rate of resorption is
clearly noticeable.

81.  It is the study of distribution & determinants
of disease in man.
 It can contribute to an understanding of the
etiology of a specific disease .
 There have been no large scale studies of RRR
in man.
 Most studies till today have been meticulous
longitudinal cephalometric studies of relatively
few subjects.

82.  Such studies are time consuming & expensive
& not really good examples of epidemiologic
methodology.
 The panoramic method , however , could be
used to screen large population of edentulous
subjects.
 RRR is a world wide disease ,occurs in males &
females, young & old ,in sickness & in health
,with & without dentures; & is unrelated to the
primary reason for extraction of teeth.

83.  One vertical study made measurements on
casts & calculated mean differences in
residual ridge size in a group of patients
,some of whom wore denture & some of
whom did not .
 In this investigation ,there seemed to be a
difference in mean size of ridges between
the two groups ,but within each group there
were wide variations
 The more statistically significant an
association between a determinant & disease
, the more likely there is meaningful
relationship.

84.  However such relationship is not necessarily a
casual association because both the
determinant & the disease may have been
caused by other determinants.
 Following factors tend to obscure the etiology
of a disease:-
 Sometime a disease is caused by single determinant ,
sometime by multiple factor
 The resistance of host to causative factors may affect
the frequency or severity of disease.

85.  Sometime a certain dose of causal factor is necessary to
cause a disease.
 Sometime a casual factor must be present a certain length
of time to be effective.
 Therefore, until one gathers sufficient evidence
one must first develop a hypothesis & then test
this hypothesis by appropriate means.

86. 1)The disease is almost universal,but there are
variation in amount & rate between
individuals.
2)The amount is cumulative so that a single
examination does not reveal the present rate.
3) The rate is slow , therefore lengthy
longitudinal studies are required to determine
the rate.

87. 4)The rate may vary at different times & in
different sites within an individual . Therefore
repeated readings at intervals are needed to
reveal changes in rate.
5)The rate is very likely to be dependent, not on a
single factor , but on coexistence of several
factors.
6)Not all cofactors are easily measured.
7)It is possible that not all cofactors are even being
considered.

88.  SWENSON(4) stated, “ The ideal ridge is one that is
broad in its bearing surface and has practically
parallel sides.”
 But in the degenerative denture ridge, undercut
ridges, V- shaped ridges, thin knife edge ridges,
and flat or non- existent denture ridges may be
seen.
 Prosthodontists must correct dentures on all of
these degenerated ridges and should aim not only
to replace the lost structures and lost function but
also to preserve the remaining ridge.

89.  PREPARATION OF MOUTH :-
Patients with degenerate denture ridges need
careful mouth health restoration before
construction begins.
1. Physical health :- Any systemic illness that is
contributing to the degenerate bone condition
must be corrected or stabilized.
2. Diet :- One of the most neglected facets of
treatment in degenerate denture ridge patients
is the prescribing of a diet.
These patients need a diet high in
protein, vitamin, and mineral content.
3. Tissue treatment therapy :- The use of soft
conditioning material to rejuvenate the tissue
bearing area has been well established.

90. PROCESSED, RESILIENT, LINED DENTURE
BASES
 Its greatest advantages are its cushioning effect
upon the mucosa and its ability to distort and
spring back.
 It is really indicated in the cases of
1. Severely undercut ridges where surgery is
contraindicated
2. Patients with no ridge
3. Patients with a flat ridge and delicate tissues.
4. Spinous ridge, tori, the mental foramen, and
the genial tubercles

91.  The lining is best when there is a 2 mm
thickness. So, it cannot be used in the cases of
small interridge distance.
 The biggest disadvantage is deterioration of the
resilient liner in few months

92.  ARTICULATING METHODS :- Success or failure
of treatment of the degenerate ridge patient is
dependent on a good occlusion and occlusal
vertical dimension.
 If rehabilitation of the articulator apparatus is impossible,
teeth with a flat occlusal pattern are best.
 SELECTION OF OCCLUSAL PATTERNS :- The
patient with impaired chewing ability should have
non-anatomic posterior teeth.
 The most important factor in articulation is that centric
occlusion be harmonious with centric relation.
 A balanced occlusion is important for denture base
stability

93. POST INSERTION CARE :-
 The delicate tissues will require many
adjustments.
 These should be done carefully with a pressure
sensitive paste.
 A periodic assessment of the denture and the
ridge is advocated. It is best to see these
patients every 72 hours for atleast three
appointments.
 These patients should be seen at regular
intervals of at least every six months.

94.  Reduction of residual ridges needs to be recognized for
what it is: a major unsolved oral disease which causes
physical, psychological, and economic problems for millions
of people all over the world. RRR is a chronic, progressive,
irreversible, and disabling disease, probably of
multifactorial origin. Much is known about the pathology
and pathophysiology of this oral disease, but we need to
know much more about its pathogenesis, epidemiology, and
etiology. The ultimate goal of research of RRR is to find
better methods of prevention or control of the disease. So,
more research in RRR with new methods and new thinking
are badly needed in order to provide the best possible oral
health care for millions of edentulous patients.

95.  1) SHELDON WINKLER : ESSENTIALS OF
COMPLETE DENTURE PROSTHODONTICS –
SECOND EDITION
 2) DOUGLAS ALLEN ATWOOD : REDUCTION OF
RESIDUAL RIDGES : A MAJOR ORAL DISEASE
ENTITY; 1971; 26(3);266-279
 3) WICAL AND SWOOPE : STUDIES OF RESIDUAL
RIDGE RESORPTION. USE OF PANORAMIC
RADIOGRAPHS FOR EVALUATION AND
CLASSIFICATION OF MANDIBULAR RESORPTION;
; 1974;32(1); 7-12
 4) DOUGLAS C. WENDT : THE DEGENERATIVE
DENTURE RIDGE – CARE AND TREATMENT; 1974;
32(5);477-492

96.  5) DOUGLAS ALLEY ATWOOD : SOME CLINICAL
FACTORS RELATED TO RATE OF RESORPTION OF
RESIDUAL RIDGES ;1962;12(3) ;441-450
 6) HAROLD R. ORTMAN : FACTORS OF BONE
RESORPTION OF THE RESIDUAL RIDGE ;
1962 ;12(3); 429-440
 7)ANTJE TALLGREN:THE CONTINUING REDUCTION
OF RESIDUAL ALVEOLAR RIDGE IN COMPLETE
DENTURE WEARERS:A MIXED LONGITUDINAL
STUDY COVERING 25YEARS;1972;27(2);120-132

97.  8)PAUL MERCIER :RESIDUAL ALVEOLAR
RIDGE ATROPY :CLASSIFICATION AND
INFLUENCE OF FACIAL MORPHOLOGY
;1979;41(1);90-100.

98. THANK YOU

100.  Masticatory & non masticatory force is
transmitted to dentoalveolar bone through
periodontal ligament.
 Once teeth are removed the residual alveolar
ridge is subjected to entirely different types of
forces.
 Bassett(1) has suggested that mechanism by which
force is translated into bone remodelling
(wolff’s law) may be through a bioelectric
properties of bone.