residual ridge resorption in edentulous arch

residual ridge resorption in edentulous arch

1. RESIDUAL RIDGE RESORPTION Sreya Jyothibas Dept of Prosthodontics

2. CONTENTS 2 1 3 5 6 4 2 Introduction Pathogenesis P athophysiology P athology C lassification Consequences

3. CONTENTS 3 7 3 5 6 4 8 Epidemiology Prosthetic factors Conclusion Etiology Management References

4. INTRODUCTION 4

5. I ntroduction Residual ridge resorption is a major disease that results in functional impairment of stomatognathic system. Treatment of these patients require maintainence of this phase throughout the life 5

6. R esidual alveolar ridge Portion of the alveolar ridge and its soft tissue covering which remains following the loss of teeth -GPT 10 6

7. R esidual ridge resorption Term used for diminishing quantity and quality of residual ridge after the teeth are extracted -GPT 10 7

8. PATHOLOGY OF RRR 8

9. Gross Pathology : Reduction in the size of the bony ridge under the mucoperiosteum. It is primarily a localized loss of bone structure 9

10. Microscopic Pathology : Microscopic studies have revealed evidence of osteoclastic activity on the external surface of the crest of residual ridges. 10

11. Microscopic Pathology : The scalloped margins of Howship’s lacunae sometimes contain visible osteoclasts. 11

12. 12 Wide variation in the configuration, density, and porosity of not only the residual ridges but also the entire cross-section of the anterior mandible

13. 13 Microradiographic evidence of mandibular osteoporosis including increased variation in the density of osteons, increased number of incompletely closed osteons, increased endosteal porosity, and increased number of plugged osteons

14. 14 Attachment of osteoclasts to mineralized surface of bone Creation of a ruffled border & a sealed acidic envrnt through action of the proton pump Dissolution of the Hydroxy apatite Fall in pH to 2.5-3 in the osteoclast resorption space Digestion of the organic components of the matrix by proteolytic enzymes The sequence of resorptive events is considered to be:

15. 15 The organic components of the intercellular substance are removed by proteolytic action of the osteoclasts. Then, the ca salts (inorganic) are dissolved by a chelating action of the osteoclasts. Atwood DA. Reduction of residual ridges: a major oral disease entity. Journal of Prosthetic Dentistry. 1971 Sep 1;26(3):266-79.

16. 16 As resorption takes place, the osteocytes released may revert to osteoblasts or become osteoclasts, depending on the physiologic and pathologic demands. Histologically, bone apposition and resorption take place in close approximation, making possible the bone balance of shape and size

17. PATHOGENESIS OF RRR 17

18. 18 RRR is chronic, progressive, irreversible, and cumulative Immediately following the extraction, any sharp edges remaining are rounded off by external osteoclastic resorption, leaving a high, well-rounded residual ridge.

19. 19 Resorption continues from the labial and lingual aspects -become knife-edged. knife edge becomes shorter and disappears- low well-rounded or flat ridge. Later, depressed ridge.

20. CLASSIFICATION OF RRR 20

21. 21 ATWOOD’S CLASSIFICATION(1983)

22. 22 The original alveolar crest height= 3 times the distance from inferior border of mandible to lower edge of mental foramen WICAL AND SWOOPE CLASSIFICATION Class 1 Upto 1/3 rd of the original vertical height lost Class 2 From 1/3 rd to 2/3 rd of the original vertical height lost Class 3 2/3 rd or more of the original vertical height lost

23. 23 Based on relation with the floor of the mouth and mylohyoid ridge: NEIL CLASSIFICATION

24. 24 Branemark classified residual ridge resorption depending on bone quality and quantity: Bone quantity BRANEMARK CLASSIFICATION

25. 25 Bone quality

26. 26 Based on bone height(mandible only)   Type I : Residual bone height of 21 mm or greater measured at the least vertical height of the mandible. Type II : Residual bone height of 16 - 20 mm measured at least vertical height of the mandible. AMERICAN COLLEGE OF PROSTHODONTIST

27. 27 Based on bone height(mandible only)   Type III : Residual alveolar bone height of 11 - 15 mm measured at the least vertical height of the mandible. Type IV : Residual vertical bone height of 10 mm or less measured at the least vertical height of the mandible. AMERICAN COLLEGE OF PROSTHODONTIST

28. 28 MERCEIR’S CLASSIFICATION

29. 29 ZELSTER’S CLASSIFICATION

30. 30 SEIBERT’S CLASSIFICATION (1983)

31. PATHOPHYSIOLOGY OF RRR 31

32. 32 Bone undergoes constant remodeling throughout life. Normally bone formation is equal to bone resorption. Residual ridge resorption is a confined pathologic loss of bone that is not built back by removing the causative factors. Bone remodeling takes place even in the presence of this pathologic osteoclastic activity.

33. 33 A cortical layer of bone is present over the crest of the ridge even during RRR, which clearly shows the formation of new bone. If endosteal bone growth fails to keep pace with external osteoclastic activity, then medullary bone would be exposed resulting in defects on the crest of the ridge.

34. Direction of bone resorption RRR – centripetal(maxilla) and centrifugal (mandible) Maxilla resorbs upward and inward to become progressively smaller Mandible resorbs outward and becomes progressively wider according to edentulous age 34

35. 35 Changes in maxilla and mandible

36. Amount of bone resorption According to Boucher, During the first year after tooth extraction, the reduction in residual ridge height in the midsagittal plane is 2-3 mm for maxilla 4-5 mm for mandible 36

37. Annual rate of reduction in height 0.1-0.2 mm for mandible 4 times less in the maxilla 37

38. 38

39. CONSEQUENCES OF RRR . 39

40. 40 Apparent loss of sulcus width and depth. Displacement of the muscle attachment closer to the crest of the residual ridge Morphological changes such as sharp, spiny, uneven residual ridges.

41. 41 Loss of vertical dimension of occlusion. Reduction of lower face height. An anterior rotation of the mandible. Changes in inter-alveolar ridge relationship

42. 42 Resorption of the mandibular canal wall and exposure of the mandibular nerve. Location of the mental foramina close to the top of the mandibular residual ridge. El Maroush MA, Benhamida SA, Elgendy AA, Elsaltani MH. Residual ridge resorption, the effect on prosthodontics management of edentulous patient: an article review. International Journal of Science and Research Methodology. 2019 Sep;7(9):260-7.

43. Maps 43 RRR is worldwide, occur in males and females, young and old, sickness and in health, with and without denture and is unrelated to the primary reason for the extraction(caries/periodontal disease) EPIDEMIOLOGY

44. ETIOLOGY

45. 45 •It is postulated that RRR is a multifactorial, biomechanical disease

46. ANATOMIC FACTORS RRR α Anatomic factors Size of ridge Type of bone removed Amount of bone Quality of bone 46

47. 47 RRR varies with the quantity and quality of the bone of the residual ridges i.e , the more bone there is, the more RRR ultimately be evaluate the present status of the residual ridge to determine what has gone on before(amount and density of bone) large well-rounded ridges and broad palates - favorable anatomic factors

48. METABOLIC FACTORS RRR varies directly with certain systemic or localized bone resorptive factors and inversely with certain bone formation factors.   48

49. 49 LOCAL SYSTEMIC Endotoxins from dental plaque Incorrect amount of circulating estrogen, growth hormone, calcium , phosphorous. Osteoclast activating factor Osteoporosis Prostaglandins Hypophosphetemia Human gingival bone resorption factor Vitamin D deficiency Trauma Parathormone and calcitonin BONE RESORBING FACTORS

50. MECHANICAL FACTORS Disuse V/S Abuse Bone that is used by regular physical activity will attend to strengthen within certain limits, than the bone that is in “ disuse atrophy ”; denture wearing RRR is caused due to an “ abuse ” bone resorption. The fact is that with or without dentures some patients have little or no RRR and some have severe RRR 50

51. 51 Wolff’s law of bone transformation (1892) : “Every Change In The Form And Function Of Bone , Or Of Their Function Alone, is Followed By Certain Definite Changes In Their Internal Architecture, And Equally Definite Alteration In Their External Conformation, In Accordance With Mathematical Laws.”, Bone remodels in response to the forces applied.

52. 52 RRR α FORCE the amount of force, the frequency of force, the duration of force, the direction of force, the area over which the force is distributed damping effect of the underlying bone.

53. 53 RRR α 1/Damping effect The damping effect is due to the viscoelastic property of the mucoperiosteum The amount of force applied to the bone may be affected inversely by the damping effect or energy absorption. may vary from pt to pt and also from maxilla to mandible. Cancellous bone helps in the absorption and dissipation of forces

54. 54 In addition to the 3 major categories of factors (anatomic, metabolic and mechanical) the importance of TIME since extraction is also important. This can be added to the formula by an inverse relation

55. RESIDUAL RIDGE RESORPTION Sreya Jyothibas Dept of Prosthodontics

56. CONTENTS 56 1 3 5 6 4 2 Introduction Pathogenesis P athophysiology P athology C lassification Consequences

57. CONTENTS 57 7 3 5 6 4 8 Epidemiology Prosthetic factors Conclusion Etiology Management References

58. PROSTHETIC FACTORS 58

59. Intensive Denture wearing: long continued use of ill-fitting denture use of under extended denture excessive stress resulting from artificial environment abuse of tissues from lack of rest . 59 Jadhav MS, Rathod P, Hasban S, Pustake S. Residual Ridge Resorption A Challenge To Conquer: A Review.

60. Unstable occlusal condition Incorrect centric relation record Incorrect orientation jaw relation Lack of freeway space Overclosure Fault in selection and placement of posterior teeth 60

61. MANAGEMENT OF RRR 61

62. Evaluation Of Bone Loss Radiographs Cephalometrics Panoramic. CBCT Mercury porosimetry Anatomic studies 62

63. SYSTEMIC EVALUATION Any systemic condition that can contribute to the degeneration of the bone condition should be corrected and stabilized, for e.g.: osteoporosis, hyperparathyroidism, diabetes mellitus. Any dental treatment should follow only after the condition is under control and the patient is fit for treatment 63

64. DIET Patients with bone disease need a diet high in proteins, vitamins and mineral content. Denture patients with excessive RRR report lower calcium intake and poorer calcium phosphorus ratio, along with less vitamin D. Diet counselling consistency of food prescribed - patients ability to masticate. 64

65. TISSUE TREATMENT THERAPY S oft conditioning materials - rejuvenate the tissue-bearing area. Hypertrophied tissues, previously treated by surgery, can be reconditioned by using this material. Aims at providing a good healthy surface for the insertion of the dentures 65

66. STIMULATION OF EDENTULOUS AREAS Exercise stimulation – practical and desirable For a period of 12 weeks – adequate in most severe cases Intermittent use of exogenous pulsed electromagnetic fields → ↓rate of RRR 66

67. PRE-PROSTHETIC SURGERY surgical procedures by virtue of which an ideal smooth, healthy U shaped ridge , without any unfavorable undercuts or bony growths and with sufficient vestibular depth is achieved. 67 Ridge correction. •Ridge extension/ vestibuloplasty . •Ridge augmentation •Surgical correction of maxillomandibular relation

68. Ridge Corrective surgery: Bony deformities Sharp irregular ridge. Alveoloplasty . Alveolectomy . Excision of tori and genial tubercles 68 Soft tissue deformities Labial frenectomy. Lingual frenectomy. High buccal frenal attachments. Hyperplasia of soft tissues.

69. Ridge extension surgery/ vestibuloplasty : 69 Labial Lingual. High mental foramen. Zygomaticoplasty . Tuberoplasty .

70. Ridge augmentation 70 Increase in the ridge height and width providing a large denture bearing area Protection of neuro vascular bundles Restoration of proper maxillomandibular arch relationship.

71. Ridge augmentation 71 Ridge augmentation has been tried with: Bone transplants Autogenous cartilage Hydroxyapatite

72. 72 Mandibular augmentation Superior border augmentation. Inferior border augmentation. Hydroxyapatite augmentation. Maxillary augmentation Onlay bone grafting. Interpositional bone grafts. Maxillary hydroxyapatite augmentation.

73. Prevention of loss of natural teeth Treatment of RRR is ideally by preventing it Edentulous residual ridge receives vertical, diagonal and horizontal loads applied by a denture with a surface area much smaller than the total area of the periodontal ligament of all the natural teeth that had been present 73

74. 74 Precautions during extraction to reduce RRR When a tooth is removed the labial plate should be preserved. The labial periosteal covering should remain intact as its inner layer is responsible for remodeling of bone. If a bone has to be removed it must be the palatal plate.

75. PROSTHETIC MANAGEMENT Modification in impression techniques Proper design and maintainence Teeth selection and arrangement Overdentures 75

76. Impression techniques Selective pressure Mucodynamic method 76

77. 77 IMPRESSION PROCEDURES FOR RRR

78. 78

79. 79 Winkler’s technique – conditioners Miller – mouth temperature waxes

80. 80 Special techniques, to determine accurately the denture border extension Fish recommended a technique where, sublingual fold space, extending from premolar to premolar region on each side was recorded. This horizontal flange acted as ‘tongue rest’ thereby increasing the stability and support.

81. 81 Bernard Levin suggests making primary impression with alginate (25% less water). Special tray should be wider and heavier in the buccal shelf area. While border molding tongue should be allowed to extend fully. Patient should make only moderate movements. Final impression should be completed with Elastomeric impression material and exaggerated tongue movements should be made.

82. 82 Mc Cord and Tyson admixed technique : Impression compound and green stick compound - 3:7 Both the materials are put in a hot water bowl at 60 C. edentulous non – perforated tray and impression is taken.

83. 83 All green technique : Greenstick material is kneaded at a hot water bath and used to take an impression. One more secondary impression from Zinc oxide eugenol is taken above it.

84. 84 Closed-mouth functional technique : A closed mouth impression technique with rims on the denture base described by Winkler. Tissue conditioner is applied to the impression surface three times at every 8- 10 minutes interval.

85. 85 functional movements like puffing, blowing, whistling, and smiling during impression in the mouth. A secondary impression with light body elastomeric material is taken above it.

86. 86 Cocktail technique : Two pillars or support are made at the posterior region of mandibular denture base opposing maxillary denture base at an increased vertical height. Praveen G., Gupta, S., Agarwal, S. et al. Cocktail Impression Technique: A New Approach to Atwood’s Order VI Mandibular Ridge Deformity. J Indian Prosthodont Soc 11 , 32–35 (2011

87. 87 The patient is asked to run tongue against his lips, suck in his cheek, pull in lips, and swallow, keeping the mouth closed. An impression is taken using McCord and Tyson’s admixed technique.

88. 88 Elastomeric technique : A secondary impression is taken using a light body elastomeric impression material, usually additional silicon with a tray adhesive.

89. Selection of denture bases Methyl methacrylate resin bases Cast metal bases 89

90. Teeth selection and arrangement Retention and stability of dentures Conditions of supporting tissues Buccolingually narrow teeth →↓masticatory forces per unit area of the ridge Width of artificial teeth half of natural teeth 90

91. Teeth selection and arrangement Non-anatomic or zero degree posterior teeth – eliminate horizontal forces and increase stability Acrylic teeth preferred than porcelain teeth – adjust and transmit less force to supporting structures Teeth arrangement in bilateral occlusion in neutral zone 91

92. 92 Optimum tissue health prior to impression Broad area coverage to reduce the force per unit area Decreased number of dental units Decreased buccolingual width of teeth Improved tooth form to decrease the amount of force required to penetrate a bolus of food PROPER DESIGN AND MAINTAINENCE

93. 93 Avoidance of inclined planes to minimize dislodgement of dentures and shear forces Centralization of occlusal contacts to increase stability of dentures and to maximize compressive forces Provision of adequate tongue room to improve stability of denture in speech and mastication Adequate interocclusal distance during rest jaw position to decrease the frequency and duration of tooth contacts PROPER DESIGN AND MAINTAINENCE

94. 94 OVERDENTURES Any removable dental prosthesis that covers & rests on one or more remaining natural teeth, the roots of natural teeth, &/or implants.

95. 95 Teeth supported and implant supported Teeth supported – improved stress distribution, integrity of residual ridge Occlusal and parafunctional stresses distributed through abutment Use of implant supported overdenture resembles same clinical situation of teeth supported Residual Ridge Resorption: An Overview of Management Saniya neja

96. 96 Implant supported fixed prosthesis possess challenge - anatomical limitation, quality of bone, sinus pneumatization in case of maxilla etc. Various techniques have been proposed to overcome this. Improving the bone in quality and quantity by graft reconstruction Modifying implant in design and techniques- sinus lift procedure, zygomatic implants, pterygoid implants, mini implants, all on concept and its variations

97. 97 Advantages 1.Denture bearing mucosa of the residual ridges are spared abuse. 2.Maintenance of the alveolar bone 3.Sensory feedback 4.Minimal load thresholds 5.Tactile sensitivity discrimination 6.Masticatory performance 7.Reduction of Psychological trauma

98. 98 Immediate dentures: Some authors claim that extraction followed by immediate dentures reduces the ridge resorption but this has still to be proved.  

99. CONCLUSION 99

100. CONCLUSION Residual ridge resorption is a chronic, progressive, irreversible, and disabling disease , of multifactorial origin. RRR requires a multiple approach for diagnosis and treatment planning. The cause must be detected, by the aid of a physician, and then eliminated or stabilized before dentures are constructed. 100

101. CONCLUSION Construction of a stable functioning denture and a regular follow up treatment can help in the restoration of function, and thus, the restoration of the physical and mental vitality of the patient 101

102. REFERENCES 102

103. 103 Winkler S : Essentials Of Complete Denture Prosthodontics. 2nd Edition,2000. Boucher : Prosthodontic Treatment For Edentulous Patients. 12th Edition,2004. Prosthodontic Treatment for Edentulous Patients: Complete Dentures and Implant-Supported Prostheses; George A. Zarb Prosthodontics for the elderly diagnosis and treatment; Budtz-Jorgensen, Ejvind Complete dentures: Merrill Gustaf Swenson and Charles J Stout

104. 104 Praveen G., Gupta, S., Agarwal, S. et al. Cocktail Impression Technique: A New Approach to Atwood’s Order VI Mandibular Ridge Deformity. J Indian Prosthodont Soc 11 , 32–35 (2011 Atwood DA. Reduction of residual ridges: a major oral disease entity. Journal of Prosthetic Dentistry. 1971 Sep 1;26(3):266-79. El Maroush MA, Benhamida SA, Elgendy AA, Elsaltani MH. Residual ridge resorption, the effect on prosthodontics management of edentulous patient: an article review. International Journal of Science and Research Methodology. 2019 Sep;7(9):260-7.

105. 105 Alidema SH, Bundevska J, Maja S, Dimoski G, Halili R. Prosthodontic Management of Ridge Resorption: An Updated Review. Journal of International Dental and Medical Research. 2022 May 1;15(2):867-73. D’Souza D. Residual ridge resorption–revisited. Oral Health Care Prosthodont . Periodontol . Biol. Res. Syst. Cond. 2012 Feb 29;2:15-24. Abirami G. Residual ridge resorption in complete denture wearers. Journal of Pharmaceutical Sciences and Research. 2016 Jun 1;8(6):565. Jadhav MS, Rathod P, Hasban S, Pustake S. Residual Ridge Resorption A Challenge To Conquer: A Review.

106. THANK YOU 106

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