Oral changes due to aging /certified fixed orthodontic courses by Indian dental academy

ORAL CHANGES DUE
TO AGING
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com


• Introduction
• Age changes in hard tissue
• Teeth
• Enamel
• Dentine
• Cementum

• Alveolar bone
• TMJ

• Age changes in soft tissue
•
•
•
•

Pulp
Oral mucosa
Periodontium
Tongue

• Age changes in oral functions
•
•
•
•

Salivary glands and flow
Taste
Mastication and Deglutation
Speech

INTRODUCTION
• Ageing is a slowing of natural function.
• A disintegration of the balanced controlled and
organization that is

characteristic of

the

young adult.
• It

is

a

process

of

morphological

physiological disintegration.

and

Graph


• It shows how the body efficiency gradually
reaches peak, at the end of adolescence and
from than on there is a gradual decline in
powers

which

becomes

accentuated

senescence.


in

DETERMINANTS OF AGING
• Genetics
• Environmental exposure
• Lifestyle
• Psychosocial factors


GENERAL EFFECTS OF AGING

• Tissue dessication
• Decreased elasticity.
• Diminshed reparative capacity
• Altered cell permeability

THEORIES OF AGING
• Physiologic theories
– Free radical theory
– Cross linkage theory
• Immunological theory
• Somatic mutation theory
• Stress theory
• Collagen theory
• Integrated theory

FREE RADICAL THEORY
• Free radicals are atoms or molecules bearing an
unpaired electron.
• They are very reactive due to the tendency to pair.
• Because the reaction of a free radical with a stable
molecule produces another radical, chain reactions
often result, in which a single free radical initiates a
process
that
consumes
stable
molecules.
Free radicals arise from
– Exposure of cells and their organelles to ionising
radiation
– Enzymatic reactions and oxygen reduction
– Non enzymatic reactions

• Because free radicals are highly reactive, all
cells are susceptible to random changes
caused by them.
• Free radical damage may be prevented by
antioxidants
• According to this theory aging reflects the sum
total of the harmful effect of free radical
reactions.

CROSS LINKAGE THEORY
• According to this theory, when two

or more

macromolecules become linked by a hydrogen bond,
such linkages are said to be reversible and accumulate
with time.
• Molecular aggregation and immobilization increases
the resulting inert molecules
• Non removable cross linked aggregates may block
glandular process reducing the production or release
of hormones and other cellular secretions.

• Critical Evalution
• Many of the vital molecules that may be cross
linked undergo metabolic turnover implying
that only non renewable cellular population
exhibits the age changes


ENAMEL
• Enamel does not undergo any further
deposition after it has been laid down.
• Color of enamel becomes darker with age and
it is associated with addition of organic
material to the enamel from bacteria or food.
• Perikymeta – These are transverse wave like
grooves which lie parallel to each other and
also to cemento -enamel junction.
• They are present on recently erupted teeth and
begin to disappear with age.
• The rate at which it is lost depends on the
location of the surface of the teeth and the
location of the tooth in the mouth.

• Presence of longitudinal cracks
These cracks may be
developmental in origin and although
their numbers do not increase with age ,
they become more obvious.
• Permeability and water content
Decreases with age due to reduction
in pore size within the substance of
enamel. This reduction in size may be
due to acquisition of ions from saliva

LONGITUDINAL CRACKS


DENTIN
• Throughout life there is continuous
deposition of secondary dentine due to
physiologic or pathologic stimuli.
• Mantle Dentine
• It is the first formed dentine .It is the
outer most layer of the dentine under
lying the dentino enamel junction.
• Circumpulpal
dentine
forms
the
remaining primary dentine formed prior
to root completion .

Secondary dentin
• Regular secondary dentine is the continuation
of circumpulpal dentine, which is laid down
throughout life after root completion.


Reparative or Tertiary Dentin
• In case of injury , exposure of odontoblastic
processes leads to formation of a new layer of
dentine which acts as a healing process,
initiated by pulp resulting in resolution of the
inflammatory process and removal of dead
cells. This is called as reparative dentine.

PERITUBULAR DENTINE
• As dentine ages there is deposition of more
highly calcified material on the walls of
dentinal tubules. This is known as peritubular
dentine.


DEAD TRACTS
• Loss of odontoblastic process in the dentinal
tubule can be as a result of carries , attrition
,abrasion etc.
• This is seen in the area of narrow pulp horns
due to crowding of odontoblasts
• When reparative dentine seals off the dentinal
tubules, these tubules filled with fluid or gases
appear black in transmitted light , known as
dead tracks
• This is the initial step in the formation of
Sclerotic Dentine .

Translucent or Sclerotic dentin
• The process of narrowing of dentinal tubules
starts at the periphery and it is accelerated by
thermal and mechanical stress or carries
lesion.
• This results in complete closure of dentinal
tubules and this tract of affected dentine
becomes translucent in ground section and
hence it is called translucent dentin .

• This translucency is seen first in the root near
the apex in a middle aged person.
• It

spreads upwards from the apex with

advancing age.
• This is one of the criteria used in forensic
odontology to assess the age of an a individual

BRITTLENESS
• As the root portion of the tooth becomes
translucent it brittleness increases, hence
older teeth become harder and lose some of its
elasticity and tend to fracture.
• The increase in brittleness is due to increase in
amount of minerals salts within the dentinal
tubule

Cementum
• Gets deposited throughout life mainly in the
apical region of the root and the bifurcation
area of multi-rooted teeth.
• Thickness is one of the criteria to the assess
the age of an individual
• The coronal 2/3 of the root has acellular
cementum and apical 1/3 has cellular
cementum.
• The permeability of the cementum decreases
with age.

• Older teeth show sign of root resorption due to
local injury in the form of mechanical stress.
• This reflexly continues passive eruption and
migration of teeth associated with continuous
reattachment of periodontal ligament
• The cementum exposed in the oral cavity
become smooth and is often gradually worn
away unless covered by a deposit of calculus.
Thus in old age persons are more prone to root
caries

ATTRITION
• DEFINITION
Physiological wearing away of a tooth as
a result of tooth to tooth contact as in
mastication.
• It occurs on the occlusal surface and the
interproximal surfaces of all teeth.
• First clinical manifestation of attrition is
the appearance of small polished facet
on the cusp tip or a slight flattening of
incisal edge.

• The factors affecting the amount of attrition are
:
• Type of food eaten
• Masticatory force
• Bruxism
• Disharmony in occlusal relationship
• Loss of few teeth resulting in excess force on
remaining teeth.
• Rate of attrition is more in males
• In
severe cases the secondary dentition
formation does not keep up with the rate of
attrition and there is pulpal exposure

• In the interproximal areas the teeth contact
each other at their contact point but with
attrition these points become flattened areas.
•

The average loss of tooth substance in the
interproximal area is approximately 1cm by the
age of 40yrs.

• The degree of attrition can be estimated and
recorded in the following stages.
• Stage I
• Wear of enamel of cusps and incisal edges
without exposure of dentine.
• Stage II
• Wear of enamel and exposure of dentine on
incisal edges and isolated area over individual
cusps.


• Stage III
• Wear of enamel forming a broad strip on
incisal edges and the confluence of two are
more areas of wear over adjacent cusps.
• Stage IV
• Wear of enamel and dentine on incisors to
form a plateau and on the cheek teeth to form
a central area of dentine surrounded by a
peripheral rim of enamel.

Attrition


ABRASION
• DEFINITION
•
It is the pathologic wearing away of tooth substance
through some abnormal mechanical process.
• It seen on the exposed root surface of the teeth but
can also be seen on the incisal or proximal surface.
• Usually it is in the form of v-shaped or wedge shaped
ditch on the root side of CEJ.
• Common causes of abrasion
- Abrasive dentrifice
- Forceful brushing
- Habits such as pipe smoking
- Occupations - Tailors, carpenters

• If an abrasive defect is deeper than 2 mm than
an attempt should be made to prepare the
margin apical to the notch , thereby reducing
risk for tooth fracture . In this case the defect
can be blocked out by a suitable base material
• If the notch is shallow the margin can end at
the cervical edge thereby needing minimal or
no blockout of the undercut

Dentrifice abrasion


EROSION
• Loss of tooth substance by a chemical
process that does not involve any

known

bacterial action.
• It is a smooth lesion occurs most frequently on
the labial and buccal surface of the teeth.
• It is manifested by a shallow, broad, smooth,
highly polished, scooped out depression on
the enamel surface.

• Causes
•

Increased Citrate content of saliva due to
local acidosis in the periodontial tissue
(released due to traumatic occlusion )

• Occupation

-

workers

in

battery

manufactures , soft drink manufactures.
• Patients with anorexica nervosa

Erosion


BONE
• Alveolar

bone

constantly

adapts

to

accommodate the functional demands of a
person
• i.e. with increasing age less teeth are present
in the oral cavity then the occlusal forces
acting on the remaining teeth will increase,
• On

the

other

hand

masticatory

decreases with age.

forces

• Bone mass is at it's maximum in midlife
• It is more in males than in females and also
more in some racial groups than in others
• The

decrease

osteoblasts
production

are

in

bone

less

declines

occurs

efficient
and

because

,

there

estrogen
is

overall

reduction in calcium absorption from the GIT
in old age

• According to Henrikson and Wallenius (1974)
between the age of 45 to 90 yrs in both males
and females the density of the mandibular
bone decreases from 1.9 to 1.5 but throughout
this age ,the density is 8% less in women.


• Post menopausal women frequently develop
excessive loss of mineral from bone which
manifests as osteoporosis.
• Osteoporosis affects collagen metabolism and
bone mineralization with a decrease in bone
mass.
• Severe osteoporosis significantly reduces the
mineral content of the jaws.

• The alveolar process of the jaws are dependent on the
presence of teeth and hence changes in shape due to
age are more marked in persons who are edentulous.
• During the first year after tooth

extraction the

reduction of the residual ridge height in the mid
sagittal plane is about 2 to 3 mm for maxilla and 4 to 5
mm for mandible .


• Shapiro et al (1985) stated that the lamina dura
is often lost and that the cortical bone at the
angle of the mandibular is thinner


• Alkinson and Hallsworth demonstrated an
increase in porosity of bone with aging
• This is due to increase in vascular spaces
• Walls of blood vessels are

thickened with

age , this causes decrease in blood supply.
• The lacunae are decreased in number but
occupy a greater volume.
• The number of osteocytes are decreased.

• They are fewer but larger canaliculi
• Collagen shows greater cross linkage and
there is replacement of reducible cross links
with non reducible and acid stable cross links.
• Bone appears more brittle despite its lower
density.


Consequences of Residual Ridge
Resorption
1. Apparent loss of sulcus width and depth
2. Displacement of muscle attachment closer to
crest of the residual ridge
3. Loss of vertical dimension of occlusion
4. Reduction of the lower face height

5. Anterior rotation of mandible
6. Increase in relative prognathism
7. Changes in interalveolar ridge relation
8. Morphological changes in alveolar bone such
as sharp ,shiny uneven residual ridge

• Resorption of residual ridge after removal of
the teeth radically changes it’s cross sectional
form .
• When the teeth are first removed the ridge is
broad at it’s occlusal surface but as resorption
occurs

the

residual

ridges

progressively narrower and shorter.

become

• View of mandible from lateral side
• Apparent decrease in the angle from childhood
to mature adulthood.
• Increase

in

angle

from

adulthood

senescence

to

Mental foramen
• With the resorption of the alveolar process the
mental foramen lies at or near the level of the
upper border of ramus.
• Denture wearers might face problems due to
application of pressure on the mental nerve.


Genial tubercles
• The genial tubercles project above the
upper border of the mandible in the
symphyseal region.
• These

sharp

prominence

make

wearing of the lower denture painful.

the

• Chin prominence
The loss of vertical dimension in the
lower part of the face is not only due to loss of
dentition but also due to loss of alveolar
process giving rise to increased prominence
to the chin with the foremost point of mandible
lying in front of the foremost point of maxillary
when the gums are brought together.
• Loss of alveolar process results in flattening of
the vault of the palate.

TEMPROMANDIBULAR JOINT
• With increasing age the joint tends to lose its
ability to withstand degenerative changes and
shows progressive change comparable to
those seen in osteoarthritis.
• These changes are
more severe with
advancing age and more intense when there is
loss of the posterior teeth.
• These changes vary from slight fraying of the
articular surfaces to cleft formation between
the fibrous tissue.

•

Articular disc
– May show islands of cartilage and nodules of
calcification
Joint space
– Encroachment

of

large

villi

of

the

synovial

membrane into the joint cavities after the age of 50
yrs.

• Condylar head
Articulator surface flattened with age.
Gradual reduction in size


PULP
•

Age changes in the pulp can be summarized
as follows.

1. Reduction in the size and volume of the pulp.
•

Is seen in individuals above 45 yrs of age.

•

There is a progressive reduction in the pulpal
area as a result of a continuous deposition
of dentine.


2. Decrease in the number of cells:
• Cellular composition of the human pulp is
modified during the aging process.
• 50% reduction in the number of cells in aging
pulp
• By 70 yrs, cell density has decreased by half.
• Fibroblasts show degeneration with advancing
age.


• Decreases in size and decreases in the number
of cell organelles.
• Odontoblasts also exhibits degeneration with
age
• Ultrastructural studies reveal an increase in
vacuole numbers and gradual degenerative
changes leading to the absence of cells.

3. Dystrophic Calcification / Pulp Stones.
• They are nodular, calcified masses appearing
in either or both the coronal or root portions of
the pulp organ.
•

They

develop in teeth that appear quite

normal in other respects.
•

They are seen in functional as well as
embedded unerupted teeth.

• Though these calcification are present in teeth
of all ages but their incidence increase with
age.
• The

frequency increase

with

pathological

conditions like deep carries and restoration.


•

They are of different types

1. True denticles
The structure of true denticles is similar
to dentin
2. False denticles
They do not exhibit dentinal tubule
Appear as concentric layers of calcified
tissue

3. Diffuse Calcification
• They appear as irregular calicific deposits in
the pulp tissue, usually following collagenous
fiber bundles or blood vessels
• Sometimes they develop into larger masses
but usually persist as fine calcified spicules.

True Denticle


False Denticle


Diffuse Calcification


Denticles


4. Changes in collagenous elements
•

The amount of collagen actually decreases
with age

•

Although the aggregation of fine fibrils into
larger fibrils and the reduction in pulp size
gives an impression that the amount is
increasing.

•

The rate of synthesis actually decreases and
there is more cross link formation.

5. Changes in vascular distribution.
• There is a narrowing of the circumference of
the blood vessels
• Atherosclerotic

changes

are seen in small

arteries in the root pulp of aging teeth.
• Intimal layer of the vessel is thickened
resulting in a small lumen

6. Changes in nerve distribution.
• Nerves aggregating in the core of the pulp
,appear very prominent.
• Old age axonal and perineural changes are
also seen.
• Degeneration and loss of pulpal nerve fibres
may
affect
transmission
from
pulpal
structures, resulting in increased thresholds to
pain stimuli.
• Myelin sheath changes and terminal axon
remolding due to age related axon injury could
be sources of abnormal pain in the oral region.

ORAL MUCOSA
• The clinical appearance of the oral mucosa in
many

healthy

older

persons

is

indistinguishable from that of younger people.
• The age changes seen in the oral mucosa is
less acute than that seen in the skin because
the moist environment of the mouth helps to
maintain the turgor of the tissue.

HISTOLOGICAL CHANGES
• Epithelial thinning
• Decreased keratinization
• Less prominent rete pegs
• Decreased cellular proliferation
• Loss of submucosal elastin and fat
• Increased

fibrotic

connective

tissue

degenerative alteration in the collagen.

with

– These changes in the histology of oral
mucosa

are

more

marked

in

women

especially post menopausal.
– Vascular changes in the oral mucosa include
the development of vascular nodules and
nevi.

FORDYCE’S SPOTS
• Fordyce’s spots are ectopic sebaceous glands
present in the buccal and labial mucosa
• Though the thinness of the mucosa also tends
to make them
calculated

that

more obvious , it has been
their

actual

number

increases with age.

also

• Oral mucosal immunity is also believed to
undergo some age related changes. The
number of langerhan’s

cells decreases with

age which contributes to a decline in cell
medicated immunity.
• Wound healing and regeneration of tissue may
be delayed with age. This decrease in rate of
wound

healing

is

more

pronounced

connective tissue thanwww.indiandentalacademy.com
epithelium.

in

GINGIVA
• With
the
aging
there
keratinization and stippling

is

decreased

• Though gingival recession increases with age
it is not necessary a physiologic process.
• There is decreased width of attached gingival
with constant relocation of the mucogingival
junction throughout the adult life.

• There is stiffening of the walls of the blood
vessels and decrease in their diameter due to
arthrosclerosis.
• Decreased connective tissue cellularity and
oxygen consumption.
• An increase or no change in the mitotic index
of gingival epithelium in aged human has been
reported.


Chronic atrophic senile gingivitis


PERIODONTAL LIGAMENT
• In young individuals junctional epithelium is
located close to the Cemento- Enamel Junction
where as with increasing age the location of
the Junctional epithelium migrates towards
root tip.

• The study conducted on

autopsy specimen

gives the average width of PDL as follows
11-12 yrs – 0.21mm
21-52 yrs – 0.18mm
51-67 yrs – 0.15mm
• The width of the PDL depends on the
masticatory forces of the teeth

• The teeth which are subjected to more load
have thickened PDL, whereas teeth which are
non functional or out of occlusion have
narrower PDL.
• Aging also results in greater number of elastic
fibers and decrease in the number of collagen
fibers

Periodontitis


TONGUE
• With age the dorsum of the tongue may show
a reduction in the number of filiform papillae
which may make the folliate papillae more
prominent.
• The fissures on the dorsal surface of the
tongue also increases with age.
• The ventral surface of the tongue shows the
presence of nodular varicose enlargement also
known as caviar tongue.

Caviar tongue


BALD TONGUE
• There is a tendency for the tastebuds to reduce
in number in old age known as Bald tongue.
• The maintainance of the papilla in their normal
condition depends on cell proliferation and
replacement processes which are sensitive to
disturbances of oxygen transport .

• This loss of papillae is associated with
impairement of oxygen transport either by a
lack of iron or by a more direct failure of O2
transport effecting the cardiac system and this
may explain the presence of smooth tongue in
these conditions.

Bald tongue with deep fissures


Salivary Glands And Flow
• Different salivary glands and their secretion.
• I. Major salivary gland
•
Parotid – Serous
•
Submandibular – Mixed both Serous and Mucous
•
Sub lingual – Mixed more serous
• II. Minor
•
Labial and buccal – mixed
•
Glossopalatine and palatine – mucous
•
Lingual
• Anterior – (Blandin and Nuhn)

Anterior – mucous
Posterior - mixed
• Posterior – (Von Ebner’s) - mucous


• With age Acinar content of the gland increases
and there is an increase in fibrous content.
• The relative volume occupied by ductal tissue
is greater in old age than in the young adult.


Age related accumulation of fat
• In major salivary gland fat accumulation
occurs predominantly as progressive fatty
infiltration increases with age.
• Fat accumulation is seen in acinar and ductal
cells
• In this process mature adipose cells
accumulate in the septa and gradually in the
parenchyma exending inwards from the
periphery of the lobules. Some time entire
lobules become replaced by fatty cells.

ONCOCYTE
• – Some of the ductal and acinar cells transform
into non functional cells called oncocytes.
• These cells have swollen appearance
eosinophilic granular cytoplasm and pyknotic
nucleus.
• Protein plugs are found more frequently in
ducts of older salivary glands. These ducts
have a tendency to calcify.

ONCOCYTE


Fatty infiltration


Salivary Flow
• It is generally believed that salivary flow
decreases with age but this reduction in flow is
more

as

a

consequence

of

xerogenic

medication taken by an older individual rather
than due to the physiologic process of aging.

• Change in Composition
• Phosphorous and calcium content increase with age.
• No change in potassium
• Sodium decreases
• Chloride and protein concentration decreases

• Viscosity
It is lower among older subjects than
younger ones irrespective of whether
were wearing dentures or not.

they

TASTE
• The chemosensory function of taste plays a
vital role
in human physiology and in a
persons quality of life.
• While old age has been associated with certain
chemosensory alterations many oral and
systemic conditions have been linked more
strongly to taste dysfunction.
• It is known that subjects complain of loss of
taste as they grow old and it is also known that
the number of taste buds also decline with age.

• The threshold far tasting substances also
decrease with age.
• The basic taste modalities of salt and bitter
have increased threshold in older subjects
while the threshold for sweet and acid remain
very similar to those of younger subjects.
• Abnormal taste perception is more common
among post menopausal women.

MASTICATION AND DEGLUTATION
• The oral motor function of mastication and
swallowing requires the coordination of the
neuromuscular activities that are necessary for
the translocation of food and fluid into GIT
• The most frequent oral motor disturbance in
older persons is related to mastication
• There is reduced efficiency with aging

• Altered masticatory ability is further increased
in those who are partially or fully edentulous
• Biting force is said to be decreased to as little
as 16% of its original value in older subjects
• Ultrasound imaging has estimated the oral and
pharyngeal phases of swallowing to be longer
in older than younger adults

• Swallowing times are 25-50%
subjects over 55 years of age

longer

in

• It has also been observed that older adults
may be capable of fewer swallows in a 10
second period of time than younger adults
• Even healthy older persons open their mouth
less wide and chew with less power which is
thought to be related to loss of muscle bulk
with age and which is worsened in edentulous
persons

SPEECH
• The process of articulation is little affected
• The main identifying feature of older speech is
an increase in the fundamental frequencies


CONCLUSION

REFERENCES
• Boucher ( 2004)Prosthodontic Treatment
for Edentulous Patients 12 edition .
Mosby
• Age changes and the Complete Lower
Denture – J Prosth Dent 1956 ;6 : (4)450
• Ferguson D B ( 1987 )The Aging Mouth
Vol 6 Karger ,Basel
• Burket (2003) Oral Medicine 10 edition B
C Decker

• Shafer (1999) A Textbook of Oral Pathology 4
edition W B Saunders
• Carranza ( 2003)Clinical Periodontology 9
edition Saunders
• Geriatric Dentistry – The Dental Clinics Of
North America ; 89;33: 1 Clinical descision
making in Geriatric Dentistry
The Dental
Clinics Of North America ;1997:41:4
• Dolby A.E Oral Physiology W B Saunders

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