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

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 and

physiological disintegration. www.indiandentalacademy.com

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 in

senescence.


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 theorywww.indiandentalacademy.com

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.www.indiandentalacademy.com

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. www.indiandentalacademy.com

• 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.www.indiandentalacademy.com

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 . www.indiandentalacademy.com

• 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 www.indiandentalacademy.com

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. www.indiandentalacademy.com

• 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. www.indiandentalacademy.com

• 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. www.indiandentalacademy.com

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 undercutwww.indiandentalacademy.com

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. www.indiandentalacademy.com

• 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 forces

decreases with age.


• 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 in bone occurs because

osteoblasts are less efficient , estrogen

production declines and there is overall

reduction in calcium absorption from the GIT

in old age www.indiandentalacademy.com

• 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.www.indiandentalacademy.com

• 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. www.indiandentalacademy.com

• 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. www.indiandentalacademy.com

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 www.indiandentalacademy.com

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 become

progressively narrower and shorter. www.indiandentalacademy.com

• View of mandible from lateral side

• Apparent decrease in the angle from childhood

to mature adulthood.

• Increase in angle from adulthood to

senescence www.indiandentalacademy.com

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. www.indiandentalacademy.com

Genial tubercles

• The genial tubercles project above the

upper border of the mandible in the

symphyseal region.

• These sharp prominence make the

wearing of the lower denture painful.


• 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. www.indiandentalacademy.com

• 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.www.indiandentalacademy.com

• 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. www.indiandentalacademy.com

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. www.indiandentalacademy.com

• 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.www.indiandentalacademy.com

• 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.www.indiandentalacademy.com

• 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

tissuewww.indiandentalacademy.com

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. www.indiandentalacademy.com

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. www.indiandentalacademy.com

HISTOLOGICAL CHANGES

• Epithelial thinning

• Decreased keratinization

• Less prominent rete pegs

• Decreased cellular proliferation

• Loss of submucosal elastin and fat

• Increased fibrotic connective tissue with

degenerative alteration in the collagen. www.indiandentalacademy.com

– 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.www.indiandentalacademy.com

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 more obvious , it has been

calculated that their actual number also

increases with age.


• 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 in

connective tissue than epithelium. www.indiandentalacademy.com

GINGIVA • With the aging there is decreased

keratinization and stippling

• 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. www.indiandentalacademy.com

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. www.indiandentalacademy.com

• 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

fiberswww.indiandentalacademy.com

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.www.indiandentalacademy.com

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. www.indiandentalacademy.com

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 they

were wearing dentures or not. www.indiandentalacademy.com

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 www.indiandentalacademy.com

• 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 www.indiandentalacademy.com

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

• 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


CONCLUSIONwww.indiandentalacademy.com

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


oral changes due to aging /certified fixed orthodontic courses by indian dental academy

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