§Age changes in oral and dental tissues occur in the oral hard and soft tissues as well as bone, TMJ and oral mucosa. §These changes vary from cell to cell and from tissues to tissues. §The most obvious change in the oral cavity is the loss of the dentition. §However, most of these changes are a combination of physiologic age changes with superimposed pathological and iatrogenic effects

¨ Age changes in: ¨ Oral hard tissues ¨ Oral soft tissues ¨ Bone ¨ TMJ

§ The enamel tends to become more brittle and susceptible to chipping, cracking and fracture

§ The ridges of enamel are worn down with advancing age leaving a smooth occlusal surface.

§ With advancing age there is adsorption of material from saliva, diet, medicaments leading to a change in the composition of enamel.

§ With advancing age the colour of the teeth becomes darker and this has been suggested to occur from the addition of organic materials from bacteria and ingested foods

¨ In addition, the wearing down of enamel allows

the inner dentine core to become more obvious thus giving the tooth a darker hue.

¨ With advancing age there is decreased permeability of enamel to all substances.

¨ This has been said to occur as a result of a reduction in the pores and spaces within the enamel.

¨ The water content of enamel decreases with increase in age.

¨ The incidence of new carious lesions decreases with advancing age.

¨ This has been attributed to the fact that caries susceptible surfaces have earlier on been attacked when the individual was younger.

¨ Secondly, the process of natural attrition has eliminated stagnation points on the occlusal surfaces of the teeth.

¨ It has also been observed that there is a change in dietary habits from refined to non-refined food substances as individual ages.

¨ Similarly, the loss of some teeth allows cleaning of difficult areas to be effectively carried out and lastly increased mineralization that takes place with advancing age reduces the susceptibility of tooth to decay.

¨ The rate of deposition of dentine decreases with age as a result there is reduction in the size of the pulp chamber and pulpal canal.

¨ The reduced deposition of dentine with advancing age might be caused by certain factors such as trauma, infections leading to the formation of irregular secondary dentine or reactionary dentine.

¨ With increase in age the diameter of the dentinal tubules reduces due to the laying down of peritubular dentine.

¨ The rate of deposition of dentine might sometimes be accelerated through various insults to the tooth - thermal, mechanical and traumatic.

¨ The response through dentine deposition to these insults might be so high as to give rise to complete closure or occlusion of the dentinal tubules resulting in the formation of sclerosed dentine.

¨ With advancing age there is loss of the odontoblasts as a result of a generalized reduction in the cellularity of the pulp.

¨ The elasticity of the tooth decreases with increase in age due to increased mineralization.

¨ Subsequently, the tooth becomes more brittle. ¨ There is decreased permeability of the dentine with

advancing age. ¨ The water content of the dentine also reduces with

age. ¨ There is high probability as increased formation of

dead tracts – these are dentinal tubules that do not contain odontoblastic process.

¨ There is decreased cellularity of the pulp. ¨ There is increase in the fibrous tissue content of the

pulp. ¨ There could be reticular atrophy or fatty degeneration

within the substance of the pulp. ¨ There is constriction and reduction in the size of the

dental pulp. ¨ The root canal may become completely obliterated. ¨ There is a higher incidence of calcification occurring

within the dental pulp. ¨ These calcifications are referred to as pulp

stones/denticles and they could be nodular, spherical, or diffuse.

¨ They could occur freely within the pulp canal.

¨ Cementum is laid down throughout an individual’s lifetime especially in the apical region and bifurcation of multi-rooted teeth.

¨ The laying down of cementum is often times regular but this could be affected by disease conditions especially chronic infections in the periapical regions of the teeth.

¨ This could lead to exuberant cementum formation with obliteration of the periodontal space and fusion of the root with the inner walls of the alveolar sockets, a condition referred to as Hypercementosis.

¨ With advancing age the thickness of cementum increases with a narrowing of the apical foramen.

¨ The permeability of cementum also decreases with age.

¨ Cementum exposure in the oral cavity increases with advancing age because of the increased incidence of gingival recession.

¨ This causes an apparent increase in the length of the clinical crown.

¨ With advancing age there is a higher incidence of caries attack in the cementum.

¨ This has been confirmed through various studies which show an increased incidence of root caries amongst the elderly.

¨ The periodontium consists of the supporting

structures of the tooth, the periodontal ligaments and the surface of the alveolar bone to which the periodontal ligaments are attached.

¨ All these structures undergo changes with increasing age.

¨ Studies show that the prevalence and severity of periodontal disease increases with advancing age

¨ There is a decrease in the width of the periodontal ligaments.

¨ There could be calcifications occurring within the substance of the periodontal ligament.

¨ The blood vessels of the periodontal ligament may undergo atherosclerosis resulting in ischemia of the periodontal ligament and subsequent decay There is increase in the fibrous tissue content of the periodontal ligament.

¨ There is increased tendency for resorption to occur on the inner surfaces of the alveolar bone leading to loosening of the teeth.

¨ The ability of the periodontal ligament to fight infectious diseases is decreased with advancing age.

¨ There is a decrease in the cellularity of the gingiva.

¨ The fibrous tissue content of the gingiva increase with advancing age.

¨ There may also be loss of the stippling effect. ¨ There is decrease in keratinization ¨ There is increased predisposition to gingival

recession. ¨ The resistance of the gingiva to infections

decreases because of decreased cellularity, reduction in blood supply, and reduced keratinization.

¨ Oral mucosa changes with ages occur from mucosal trauma, mucosal diseases and salivary gland hypofunction

¨ The stratified squamous epithelium becomes thinner, loses elasticity and atropies with age.

¨ With increase in age there is also dryness of the oral mucosa from salivary gland hypofunction .

¨ There is abnormal taste perception and sometimes burning sensation.

¨ The Fordyce granules on the cheek increase in size.

¨ A declining immunological responsiveness further increases the susceptibility to infection and trauma

¨ An increased incidence of oral and systemic disorders along with the increased use of medications may lead to oral mucosal disorders such as vesicobullous, desquamative, ulcerative, lichenoid and infectious lesions

¨ There is increase in laying down of collagen fibers within the connective as a result the fibrous tissue content increases.

¨ There is reduction in vascularity resulting in decrease in the healing power of the oral mucosa with advancing age.

¨ There is an increase in tendency for malignant changes to occur as an individual ages.

¨ There is loss of the Filliform papillae ¨ There is a degeneration of taste buds and a

reduction of the number of taste buds ¨ The threshold for taste decreases ¨ There may be fissuring on the dorsum of the

tongue ¨ Like the oral mucosa, abnormal taste sensations

may be perceived

¨ Complaints of a dry mouth and diminished salivary output are common in older people

¨ Approx 30% of people older than 65 years of age experience these disorders and their oral and pharyngeal consequences

¨ The viscosity of saliva decreases with advancing age

¨ The calcium and phosphorus levels increases with age

¨ The amount of ptyalin secreted is also reduced ¨ The salivary glands become more prone to

pathological conditions because of reduction in vascularity and increase in the fibrous tissue content

¨ Fatty degeneration may occur with increase in age ¨ The fibrous tissue content also increases ¨ There is decreased tendency for lymphocytic

infiltration into the ductal system

¨ muscle function is dependent on the performance of the nervous system and both exhibit independent age-related changes.

¨ Nerve cell lossis universal in old age and is exhibited in the brain and spinal cord.

¨ There are also age related changes in neurotransmitters resulting in motor dysfunction

¨ Peripheral nerve function reduces with age

¨ There is also reduction in conduction velocity, increased latencies in multi-synaptic pathways , decreased conduction at neuromuscular junctions and loss of receptors

¨ There is a reduction total muscle mass due to a reduction in the number of muscle fibres rather than a major reduction in muscle fibre size

¨ There is also a loss of motor units which manifests as a reduction in muscle strength and reduced masticatory forces.

¨ Age induces a lengthening of the chewing process associated with a reduction in muscle activity

q With advancing age, there is progressive reduction in bone mass resulting in generalized osteoporosis

q Loss of dentition q Reduced blood supply resulting in slow healing of

fractures in the jaw bones with increase in age q Atrophy of the mandibular alveolar ridges and

adjacent basal bone reduces bony surface area, strength, bone density and stock.

q There is falling in of the lips and cheeks with advancing age due to alveolar resorption both in height and width

q Subsequently there is loss of facial height with upwards and forwards posturing of the mandible.

¨ Loss of alveolar bone occurs more rapidly in the mandible than the maxilla

¨ Increased brittleness ¨ Levels of the cyclo-oygenase2 (COX 2) enzyme

essential for healing decline causing delayed healing

q Inferior alveolar neurovascular bundle and mental nerve travels near the top of the remaining mandible.

q Hypertrophy of the genial tubercles is common especially in atrophied mandibles

AGE CHANGES IN THE JAWS….....

¨ There is also resorption of the muscular processes of the mandible

¨ The mental foramen becomes superficially due to bony resorption in the mandible

¨ In the maxilla alveolar resorption causes a flattening of the palatal vault

¨ Difficult to distinguish age changes from osteoathrosis

¨ There is often remodelling of the articular surfaces and disc in response to functional changes following tooth loss

¨ Remodelling may result in disc displacement particularly anterior displacement

¨ The retrodiscal tissues may show adaptive changes associated with decreased cellularity and vascularity and increased density of collagen and may eventually function as an articular disc.

¨ Disc displacement may lead to perforation of the disc particularly of its posterior attachment resulting in progressive joint damage.

¨ With advancing age osteoclastic changes (resorption) occurs within the substance of the temporo-mandibular joint (TMJ) leading to an increased prevalence or frequent episodes of TMJ dislocations