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


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

  1. 1. ORAL CHANGES DUE TO AGING INDIAN DENTAL ACADEMY Leader in continuing dental education
  2. 2. • 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
  3. 3. 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
  4. 4. Graph
  5. 5. • 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
  6. 6. DETERMINANTS OF AGING • Genetics • Environmental exposure • Lifestyle • Psychosocial factors
  7. 7. GENERAL EFFECTS OF AGING • Tissue dessication • Decreased elasticity. • Diminshed reparative capacity • Altered cell permeability
  8. 8. THEORIES OF AGING • Physiologic theories – Free radical theory – Cross linkage theory • Immunological theory • Somatic mutation theory • Stress theory • Collagen theory • Integrated theory
  9. 9. 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
  10. 10. • 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.
  11. 11. 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.
  12. 12. • 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
  13. 13. 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.
  14. 14. • 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
  16. 16. 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 .
  17. 17. Secondary dentin • Regular secondary dentine is the continuation of circumpulpal dentine, which is laid down throughout life after root completion.
  18. 18. 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.
  19. 19. 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.
  20. 20.
  21. 21. 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 .
  22. 22.
  23. 23. 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 .
  24. 24.
  25. 25. • 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
  26. 26. 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
  27. 27. 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.
  28. 28. • 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
  29. 29.
  30. 30. 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.
  31. 31. • 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
  32. 32. • 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.
  33. 33. • 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.
  34. 34. • 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.
  35. 35. Attrition
  36. 36. 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
  37. 37. • 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
  38. 38. Dentrifice abrasion
  39. 39. 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.
  40. 40. • 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
  41. 41. Erosion
  42. 42. 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
  43. 43. • 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 there because estrogen is overall reduction in calcium absorption from the GIT in old age
  44. 44. • 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.
  45. 45. • 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.
  46. 46. • 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 .
  47. 47. • 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
  48. 48. • 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.
  49. 49. • 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.
  50. 50. 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
  51. 51. 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
  52. 52. • 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
  53. 53. • View of mandible from lateral side • Apparent decrease in the angle from childhood to mature adulthood. • Increase in angle from adulthood senescence to
  54. 54.
  55. 55. 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.
  56. 56. 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
  57. 57. • 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.
  58. 58. 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.
  59. 59. • 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.
  60. 60. • Condylar head Articulator surface flattened with age. Gradual reduction in size
  61. 61. 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.
  62. 62. 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.
  63. 63. • 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.
  64. 64. 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.
  65. 65. • 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.
  66. 66. • 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
  67. 67. 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.
  68. 68. True Denticle
  69. 69. False Denticle
  70. 70. Diffuse Calcification
  71. 71. Denticles
  72. 72. 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.
  73. 73. 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
  74. 74. 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.
  75. 75. 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.
  76. 76. 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
  77. 77. – These changes in the histology of oral mucosa are more marked in women oral mucosa of vascular especially post menopausal. – Vascular include changes the in the development nodules and nevi.
  78. 78. 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
  79. 79. • 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 than epithelium. in
  80. 80. 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.
  81. 81. • 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.
  82. 82. Chronic atrophic senile gingivitis
  83. 83. PERIODONTAL LIGAMENT • In young individuals junctional epithelium is located Junction close to the where as with Cemento- Enamel increasing age the location of the Junctional epithelium migrates towards root tip.
  84. 84. • 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
  85. 85. • 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
  86. 86. Periodontitis
  87. 87. Periodontitis
  88. 88. 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.
  89. 89. Caviar tongue
  90. 90. 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 .
  91. 91. • 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.
  92. 92. Bald tongue with deep fissures
  93. 93. 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
  94. 94. • 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.
  95. 95. 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.
  96. 96. 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.
  97. 97. ONCOCYTE
  98. 98.
  99. 99. Fatty infiltration
  100. 100. 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.
  101. 101. • 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
  102. 102. 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.
  103. 103. • 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.
  104. 104. 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
  105. 105. • 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
  106. 106. • 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
  107. 107. SPEECH • The process of articulation is little affected • The main identifying feature of older speech is an increase in the fundamental frequencies
  108. 108. CONCLUSION
  109. 109. 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
  110. 110. • 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
  111. 111.