“Generalities on the senescence of tissues of the oral cavity”
Plan :
- Introduction
- Definition
- Effects of aging on the body
- Effects of aging on oral mucosa
- Effects of aging on the salivary glands
- Effects of aging on dental tissues
- Effects of aging on periodontal tissues
Conclusion
1- INTRODUCTION:
- The tissues and organs of the oral cavity undergo profound changes during aging, which alters their functions and their potential for adaptation and healing.
2- DEFINITIONS:
- Older person: WHO defines older person as a person aged over 60 years.
- Old age: it is a period of life which is characterized by the decline of the physiological and mental functions of the person.
- Senescence: This is aging, which is a set of physiological and psychological processes that modify the structure and functions of the organism with age, while senility represents pathological aging.
- Gerontology: This is the study of old age and aging, while Geriatrics is the medical discipline that takes care of the elderly.
3- EFFECTS OF AGING ON THE BODY:
3-1- At the cellular level:
- Cells have a limited longevity; as they age, the proportion of fatty and fibrous elements increases and modifies their functioning.
- Cell multiplication and cell repair are functions that are impaired during changes to the cell nucleus.
- Specialized cells lose their special abilities. There is a gradual loss of cells, 30% between the ages of 20 and 70.
- All of these changes will disrupt the functioning of different metabolisms, the capacities and the structure of the organs.
3-2- At the organization level:
- Aging consequently results in a decrease in the functional capacities of the organism.
- This alteration is evident in situations that involve functional reserves (stress, acute illnesses, effort). Similarly, the systems regulating physiological parameters prove less effective.
- It should be noted that these functional reductions vary greatly from one organ to another and especially from one individual to another.
4- EFFECTS OF AGING ON THE ORAL MUCOUS MEMBRANES:
4-1- HISTOLOGICAL ALTERATIONS:
- Decreased thickness of the epithelium.
- Decreased keratinization.
- Functional arrangement of collagen and elastic fibers of the lamina propria and chorion gradually changes.
- Diffuse conjunctival fibrosis.
4-2- BIOLOGICAL ALTERATIONS:
- Reduction of defenses against external microbiological (bacterial, viral, fungal) or traumatic attacks.
- General information on senescence of oral cavity tissues
5- EFFECTS OF AGING ON THE SALIVARY GLANDS:
- With age, histological changes in the salivary glands appear.
- They are represented mainly by:
- atrophy and decrease in volume of the acini,
- an irregularity of the secretory ducts.
Loss of acinar tissue is found for all salivary glands and would represent:
- More than 30% for the parotids;
- 40% for the submaxillary; and
- 45% for labial accessory salivary glands.
This will lead to a decrease in salivary flow, but the salivary composition is not modified. The decrease in the secretory potential of the glandular parenchyma associated with other risk factors such as polymedication or dehydration, promotes the appearance of dry mouth syndrome in the elderly.
5- EFFECTS OF AGING ON DENTAL TISSUES:
- All the tissues constituting the dental organ; enamel, dentin, pulp tissue and cement undergo a process of senescence.
1- At the enamel level:
- It changes through progressive wear, which makes the surfaces more fragile.
- The color becomes darker.
- Cracks, loss of substance through erosion, and abrasions are very often observed.
2- At the dentin level:
- The secondary physiological dentin, which is built throughout life, gradually reduces the volume of the pulp.
3- At the pulp level:
- Partial or total fibrosis is noted associated with a narrowing of the pulp cavity, sometimes to the point of complete obliteration, which reduces the potential for dental repair and healing.
- With age, the fibrous content increases while the cell population decreases as well as the vascularization and innervation. The tooth becomes less sensitive.
- Calcification of the pulp is also observed.
- Thus, the risk of caries increases significantly in the elderly. Carious lesions affecting the neck and roots of teeth constitute a specific pathology of the elderly and their prevalence increases from 18 to 51% with age.
- They mainly affect the dentin and cementum and spread in sheets.
6- EFFECTS OF AGING ON THE PERIODONTAL:
- Periodontal tissues appear to undergo changes during aging, including loss of elasticity, slight recession, and increased fragility to microbial and mechanical aggression.
The gum : clinically, the gum shows few age-related changes; the height of the attached gum no longer changes after the age of 45.
The gingival epithelium shows a thinning of approximately 30% compared to young adults and the connective tissue is characterized by significant collagen fibrosis associated with a decrease in the number of fibroblasts and their synthesis capacity.
The alveolar bone : it undergoes progressive atrophy which results in:
- Thinning of the cortices;
- An increase in the number of resorption cavities ;
- A decrease in the proliferation of osteogenic cells;
- Decrease in the number and thickness of cancellous bone trabeculae;
- The alveolar crest is getting lower and lower.
- These alterations result in the elderly, in reduced remodeling, healing and adaptation capacities of the alveolar bone.
General information on senescence of oral cavity tissues
Alveolodental ligament:
With age, the LAD undergoes atrophy which results in:
- Decrease in its width;
- Decrease in cell density and their metabolism;
- Decrease in fibrillar diameter without change in bundle orientation;
- Collagen becomes insoluble (Calcifications on and between collagen fibers);
- Chemical modification of the fundamental substance;
- Increased fat cell count;
These changes decrease its potential to resist occlusal functional forces and its potential for repair.
Cement:
- Its thickness increases with age by apposition of secondary cement.
- It is more important at the level of the apical third of the root and on the distal side, thus compensating for passive eruption due to dental attrition.
Conclusion :
- Morphological and physiological changes in periodontal tissues during aging play a major role in the defense and healing capacities of these tissues against microbial aggression.
- In addition, the pathologies of elderly subjects and the resulting disabilities compromise the performance of oral hygiene care and periodontitis is found in 55 to 85% of elderly people.
Dental crowns are used to restore the shape and function of a damaged tooth.
Bruxism, or teeth grinding, can cause premature wear and often requires wearing a retainer at night.
Dental abscesses are painful infections that require prompt treatment to avoid complications. Gum grafting is a surgical procedure that can treat gum recession. Dentists use composite materials for fillings because they match the natural color of the teeth.
A diet high in sugar increases the risk of developing tooth decay.
Pediatric dental care is essential to establish good hygiene habits from an early age.