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Basic Concepts Of Occlusion
CONTENTS
 INTRODUCTION
 TERMINOLOGIES
 MASTICATORY SYSTEM
 TYPES OF OCCLUSION
 FORCES OF OCCLUSION
 BRUXISM
 PATHOL...
INTRODUCTION
 Ramjford and Ash
 Latin word
Occ—up
Clusion—closing
Meaning :
Contact relationship of teeth resulting from...
Evidence based decision making
Nunn and Harrell 2001—retrospective study
---periodontitis patients
---loss of attachment--...
 Occlusal forces----broad spectrum
 Biological basis of occlusal function
 Consider components as a functional unit—not...
TERMINOLOGIES
 Maximum intercuspation(centric occlusion and intercuspal
position)
 Centric relation
 Initial contact in...
MASTICATORY SYSTEM
1
4
2
3
5
2
4
3
1
DYNAMICS OF EQUILIBRIUM
 Primary requirements of a successful occlusal
therapy
1. Comfortable and stable TMJ’S
2. Anterior teeth in harmony with ...
 Formula for a perfected
occlusion
1. Simultaneous equal
intensity contacts on all
teeth---condyle disk
assembly complete...
3. Posterior teeth ---centric and eccentric
4. Anterior guidance + condyles---disclussion of
posteriors
 REASON
 Elevato...
TYPES OF OCCLUSION
 FUNCTIONAL CLASSIFICATION OF OCCLUSION
Physiologic occlusion—is present when no signs of
dysfunction or disease are pres...
ORGANISATION OF OCCLUSION
1)Bilateral balanced occlusion: works of Von Spee and
Monson
 Maximum number of teeth contact i...
Unilateral balanced occlusion(group function): Shyyler et al
 Concept :Natural teeth –cross-arch balance not necessary
--...
Mutually Protected Occlusion (canine protected occlusion or
“organic occlusion” ): D’Amico, Stuart, Stallard et al
Concept...
 Cases its not possible
FORCES OF OCCLUSION
1. Antagonistic forces: muscle of mastication and
counteracting oral musculature
2. Inclined planes of...
3. Proximal contacts: malpositioned contacts(cervico incisal or
faciolingual)----deflect forces of occlusion---dispacement...
 Intraoral Occlusal Evaluation
Identification
of occlusal
contacts in
max
intercuspation
Guidance in
excursive
movements
...
BRUXISM
 Bruxism :
Definition:An oral habit consisting of involuntary rhythmic or
spasmodic non-functional gnashing, grinding, or...
 Evaluation :
Bite guard
 Etiology :
OCCLUSAL INTERFERENCES :
 1901 Karolyi—postulated that occlusal interference in
combination with psychic str...
 Trigger parafunctional jaw movement which were not
present earlier to interference
 “Erasure mechanism”
Coarse food of ...
 Rugh and Solberg 1975
 Habitual nocturnal bruxism continued despite removal of
occlusal interferences.
 EMG recordings...
 Satoh and Harada 1971
Nocturnal bruxism---from a deeper stage of sleep to a lighter
stage
REM stage---most damaging
 Ol...
Bruxism Clenching
•Severe attrition, Split
teeth
•Hypermobility
•Ulcer associated
sometimes
•Adaptive changes in
TMJ—flatt...
 Evaluation :
 EMG
 Bite strip
0-No sleep bruxism—less than
40 events
1-Mild sleep bruxism—40-74
events
2-Moderate slee...
PATHOLOGICAL TOOTH
MIGRATION
 Definition :
Tooth displacement that results when the balance among
the factors that maintain physiologic tooth position...
 In occlusal/incisal direction termed as extrusion
 Prevalence :
Martinez-Canut et al 1997  55.8%
Towfighi et al 1997 ...
Etiologic factors for pathologic migration
A. Destruction of periodontal supporting tissues
B. Occlusal factors
C. Soft ti...
Destruction of periodontal supporting tissues
Selwyn S 1973
Bone loss in 30 patients with periodontitis + incisal
migratio...
 Role of transseptal fibres
Moss and Picton 1982
 Abnormal proximal contacts---Anterior component
of force
Wedging force
Occlusal factors
1. Posterior bite collapse –unreplaced first molars
2. Arch integrity  Interproximal contacts destroyed ...
4. Occlusal interferences supracontacts --Thielman’s law
Occlusal factors may become more destructive in
patients who hav...
Protrusive pattern of mastication
 Yaffe et al 1992
27/131 patients had protrusive mastication
16/27 patients---anterio...
Soft tissue pressure of the tongue, cheek, and lips
 Can move teeth especially after loss of periodontal support---
long ...
Periodontal and periapical inflammation
 Hirschfeld 1933--PTM of teeth is due to pressure of
inflammatory tissue
 Moveme...
Extrusive forces
 Eruption forces are 2 to 10 gms and present
throughout life
 No direct association links eruptive forc...
Habits
 Lip and tongue habits, fingernail biting, thumb
sucking, pipe smoking, bruxism
 Martinez et al ---no association...
Basic Concepts Of Occlusion
CONTENTS
 INTRODUCTION
 TERMINOLOGIES
 MASTICATORY SYSTEM
 TYPES OF OCCLUSION
 FORCES OF OCCLUSION
 BRUXISM
 PATHOL...
TRAUMA FROM OCCLUSION
 Introduction
 Historical perspective
 Definitions
 Classification
 Clinical and radiographic s...
INTRODUCTION
MAGNITUDE DIRECTION DURATION FREQUENCY
Increase in the magnitude of occlusal force
Widening of the periodontal ligament space
Number and width of periodontal lig...
 Changing the direction of occlusal forces causes a re-
orientation of the stresses and strains within the periodontium.
...
HISTORICAL PERSPECTIVE
In 1901, Karolyi indicated that there appeared to be a
correlation between excessive occlusal force...
 In 1917 and 1926, Stillman stated that excessive occlusal
forces were the primary cause of periodontal disease and
that ...
Definition:-
Trauma from occlusion refers to a condition
where injury results to the supporting structures of teeth by the...
Trauma from occlusion is defined as when occlusal forces
exceed the adaptive capacity of tissue, tissue injury
results. Th...
 Traumatic occlusion
An occlusion that produces such injury is called as a
traumatic occlusion.
Other terms
1. Occlusal d...
CLASSIFICATION
1)Acute trauma from occlusion
2)Chronic trauma from occlusion
1)Primary trauma from occlusion
2)Secondary t...
ACUTE TRAUMA FROM
OCCLUSION
CHRONIC TRAUMA
FROM OCCLUSION
Less common More common
Definition:- Result from abrupt change i...
PRIMARY TRAUMA FROM
OCCLUSION
SECONDARY TRAUMA
FROM OCCLUSION
Definition:- Result of alterations in occlusal
forces.
Resul...
CLINICAL SIGNS OF OCCLUSAL TRAUMA
1) Mobility (progressive)
2) Pain on chewing or percussion
3) Fremitus
4) Occlusal prema...
RADIOGRAPHIC SIGNS OF TFO
 Increased width of the periodontal ligament space, with
thickening of the lamina dura along th...
Increased width of the PDL space
Increased density of alveolar bone
Radiographic signs of TFO
Tissue response occur in 3 stages:-
1) Injury
2) Repair
3) Adaptive remodeling of the
periodontium
STAGES OF TISSUE RESPON...
Stage I: Injury.
• Tissue injury ….. excessive occlusal forces.
• The body then attempts to repair the injury and restore ...
Stage I: Injury
• Slight excessive pressure-- Resorption of alveolar
bone(direct bone resorption)
• Widening of periodonta...
Greater pressure
Compression of PDL fibers Areas of hyalinization
Fibroblasts & other connective tissue cells
necrosis
Vas...
Stage I: Injury
Widening of the periodontal ligament
Tearing of the periodontal ligament
Severe tension
Thrombosis, hemorr...
Stage I: Injury
 Furcation most susceptible to injury
 Injury to the periodontium produces a temporary
depression
in mi...
Stage II: Repair
 TFO stimulates increased reparative activity.
Damaged tissues are removed, and new connective tissue
ce...
Stage II: Repair
 Excessive occlusal forces…. resorption of bone…. Body
reinforces the thinned bony trabeculae with new b...
Stage III: Adaptive Remodeling of the Periodontium.
 Periodontium is remodeled in an effort to create a structural
relati...
Carranza FA1970
Reversibility of traumatic lesions
 Trauma from occlusion is reversible.
 When the impact of the artificially created fo...
• Thinning of the periodontal ligament
• Atrophy of the fibers
• Osteoporosis of the alveolar bone
• Reduction in bone hei...
Effect on progression of marginal periodontitis
Blood supply of marginal gingiva—not affected
 Important to eliminate the marginal inflammatory component
in cases of trauma from occlusion because the presence of
inf...
Glickman’s concept
 Claimed that the pathway of the spread of a plaque-
associated gingival lesion can be changed if forc...
Zone of irritation
Zone of co-destruction
Glickman (1967), “trauma from occlusion is an etiologic factor
of importance in ...
Waerhaug’s concept
 Waerhaug (1979) examined autopsy specimens similar
to Glickman’s.
 Measured in addition the distance...
 Loss of connective tissue attachment & the resorption of
bone around teeth are, exclusively the result of
inflammatory l...
 Excessive occlusal forces had no relationship to the
underlying bony defect and that vertical defects were
found equally...
 Conclusion :
Angular defects and infrabony pockets occur when the
subgingival plaque of one tooth has reached a more
api...
Trauma-induced areas
favorable environment
plaque and calculus
development of deeper lesions
Sottosanti JS.
Theories of tr...
Orthodontic tooth movement Drifting into edentulous space
Transformation of suprabony pocket into infrabony
Supragingival ...
Increased tooth mobility
pumping effect on plaque metabolites
Increasing their diffusion
Vollmer WH
Theories of trauma and...
Clinical and Animal Trials
EASTMAN DENTAL CENTER GROUP-ROCHESTER NY---SQUIRREL MONKEYS
REPITITIVE INTERDENTAL WEDGING
MILD TO MODERATE GINGIVAL INFLA...
UNIVERSITY OF GOTHENBURG GROUP IN SWEDEN—BEAGLE DOGS
CAP SPLINTS AND ORTHODONTIC APPLIANCES
MILD TO MODERATE GINGIVAL INFL...
 Rosling et al. (1976)… “infrabony pocket located at
hypermobile teeth exhibited the same degree of healing
as those adja...
Orthodontic type traumaTipping movement
JIGGLING- TYPE TRAUMA
Healthy periodontium with normal height
Healthy periodontium with reduced height
Suprabony pockets and advanced bone loss
Infrabony pocket and advanced bone loss
The conclusions of these studies are as follows:
1) Occlusal trauma does not initiate gingival inflammation.
2) In the abs...
3) In the presence of gingival inflammation, excessive
jiggling forces did not cause accelerated attachment loss in
squirr...
CONCLUSION
References
 Functional occlusion :From TMJ to Smile design : Peter
Dawson
 Ramfjord and Ash. Occlusion. 3rd edition.
 C...
 Clinical Periodontology and Implant Dentistry – Jan
Lindhe 4th Edition.
 Pathologic tooth migration;Brunsvold 2008
Thank
u!!!!!
Occlusion basic
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Occlusion basic

  1. 1. Basic Concepts Of Occlusion
  2. 2. CONTENTS  INTRODUCTION  TERMINOLOGIES  MASTICATORY SYSTEM  TYPES OF OCCLUSION  FORCES OF OCCLUSION  BRUXISM  PATHOLOGICAL TOOTH MIGRATION  TRAUMA FROM OCCLUSION  CONCLUSION  REFERENCES
  3. 3. INTRODUCTION  Ramjford and Ash  Latin word Occ—up Clusion—closing Meaning : Contact relationship of teeth resulting from neuromuscular control of masticatory system
  4. 4. Evidence based decision making Nunn and Harrell 2001—retrospective study ---periodontitis patients ---loss of attachment---presence/absence of occlusal interferences ---Result positive influence of occlusal correction on surgical/non-surgical outcome
  5. 5.  Occlusal forces----broad spectrum  Biological basis of occlusal function  Consider components as a functional unit—not in isolation
  6. 6. TERMINOLOGIES  Maximum intercuspation(centric occlusion and intercuspal position)  Centric relation  Initial contact in centric  Excursive movement  Laterotrusion  Working side  Non-working side ( balancing side )  Protrusion  Retrusion  Guidance
  7. 7. MASTICATORY SYSTEM 1 4 2 3 5
  8. 8. 2 4 3 1 DYNAMICS OF EQUILIBRIUM
  9. 9.  Primary requirements of a successful occlusal therapy 1. Comfortable and stable TMJ’S 2. Anterior teeth in harmony with the envelope of function 3. Non –interfering posterior teeth
  10. 10.  Formula for a perfected occlusion 1. Simultaneous equal intensity contacts on all teeth---condyle disk assembly completely seated 2. “Dots in back,lines in front”
  11. 11. 3. Posterior teeth ---centric and eccentric 4. Anterior guidance + condyles---disclussion of posteriors  REASON  Elevator muscles shut off---reduce forces on TMJ and anterior teeth  Bruxers
  12. 12. TYPES OF OCCLUSION
  13. 13.  FUNCTIONAL CLASSIFICATION OF OCCLUSION Physiologic occlusion—is present when no signs of dysfunction or disease are present and no treatment is indicated Non-physiologic(or traumatic) occlusion—is associated with dysfunction or disease caused by tissue injury, and treatment maybe indicated.(criteria—whether it contributes to tissue injury,not how teeth occlude) Therapeutic occlusion—is the result of specific interventions designed to treat dysfunction or disease.It is an occlusal scheme employed in restoring or replacing
  14. 14. ORGANISATION OF OCCLUSION 1)Bilateral balanced occlusion: works of Von Spee and Monson  Maximum number of teeth contact in all excursive movements  Concept :distribution of stresses  Complete denture--non-working side contacts— tipping prevented  Demerit :excessive frictional wear of teeth
  15. 15. Unilateral balanced occlusion(group function): Shyyler et al  Concept :Natural teeth –cross-arch balance not necessary --Elimination of non-working contacts  Restorative dentistry  Lateral excursions---working side—all teeth in contact  Group function of teeth on working side distributes the occlusal load  Absence of non-working side contacts prevents the those teeth from being subjected to obliquely directed forces found in non- working interferences
  16. 16. Mutually Protected Occlusion (canine protected occlusion or “organic occlusion” ): D’Amico, Stuart, Stallard et al Concept :Observation Posterior teeth contact—centric relation only Incisor contact –protrusion only Canine contact—lateral excursions Why canine????? --greater no of pressurecoeptors/mechanorecptors --good crown-root ratio --position in the arch
  17. 17.  Cases its not possible
  18. 18. FORCES OF OCCLUSION 1. Antagonistic forces: muscle of mastication and counteracting oral musculature 2. Inclined planes of the teeth and the anterior component of force Closure of the mandible Force Distribution by inclined planes Resultant occlusal forces – anterior force Tend to move teeth mesially ANTERIOR COMPONENT OF FORCE(ACF) ACF –pushes teeth mesially in their sockets ---release of force ---previous position --proximal contact flatenned by wear --physiological mesial migration --overall reduction of 0.5cm in length
  19. 19. 3. Proximal contacts: malpositioned contacts(cervico incisal or faciolingual)----deflect forces of occlusion---dispacement of teeth and create abnormal forces on the periodontium 4. Design and inclination of teeth: Maxillary central incisor—inclined mesially—provide maximim efficiency of cutting edge—in function— driven mesially—root shaped—greater areas of attachment on the palatal and distal side—counteracts tendency towards facial and mesial displacement during function. Molars –inclined mesially---to transmit component of vertical occlusal forces to premolars and canines 5. Atmospheric equilibrium during breathing and swallowing
  20. 20.  Intraoral Occlusal Evaluation Identification of occlusal contacts in max intercuspation Guidance in excursive movements Initial contact in centric- relation closure arc Tooth mobility Attrition
  21. 21. BRUXISM
  22. 22.  Bruxism : Definition:An oral habit consisting of involuntary rhythmic or spasmodic non-functional gnashing, grinding, or clenching of teeth, in other than chewing movements of the mandible, which may lead to occlusal trauma (Glossary Of Prosthodontic Terms)  Clenching :
  23. 23.  Evaluation : Bite guard
  24. 24.  Etiology : OCCLUSAL INTERFERENCES :  1901 Karolyi—postulated that occlusal interference in combination with psychic stresses---important factor  Also without stress Premature contacts---activate high levels of muscle activity  1961 Ramfjord  Ramfjord and Ash 1983, Williamson 1983—EMG studies Result : “marked reduction in muscle tonus and harmonious integration of muscle action follows the elimination of occlusal disharmony”
  25. 25.  Trigger parafunctional jaw movement which were not present earlier to interference  “Erasure mechanism” Coarse food of premodern man---abrasive enough to wear away interfering cusps and inclines when the bruxism mechanism was triggered and adjust occlusion within tolerable limits  Modern diet
  26. 26.  Rugh and Solberg 1975  Habitual nocturnal bruxism continued despite removal of occlusal interferences.  EMG recordings---same masticatory muscle contraction before and after occlusal correction  Equally in children as in adults
  27. 27.  Satoh and Harada 1971 Nocturnal bruxism---from a deeper stage of sleep to a lighter stage REM stage---most damaging  Olkinuora 1972 divided bruxers 1)Stress associated 2)Non-associated with stress Conclusion :heriditary bruxism more common in the non- stress group  Stress –bruxers-----more muscular symptoms and more emotionally disturbed  Stress causing stimuli—directly correlated with time of muscle contraction  Clenching(increased muscle tonus) –physical
  28. 28. Bruxism Clenching •Severe attrition, Split teeth •Hypermobility •Ulcer associated sometimes •Adaptive changes in TMJ—flattening of condyles,gradual loss of convexity of ementiae •Fractured fillings •screeching ,grating sound at night •Masseter muscle enlarged •Lateral pterygoid tender Occluso-muscle pain Tooth wear not common Linea alba seen sometimes Lateral indentations on tongue Temporalis affected
  29. 29.  Evaluation :  EMG  Bite strip 0-No sleep bruxism—less than 40 events 1-Mild sleep bruxism—40-74 events 2-Moderate sleep bruxism—75- 124 events 3-Severe sleep bruxism—125 or more events
  30. 30. PATHOLOGICAL TOOTH MIGRATION
  31. 31.  Definition : Tooth displacement that results when the balance among the factors that maintain physiologic tooth position is disturbed by periodontal disease.  May be an early sign of disease and associated with gingival inflammation and pocket formation  Anteriors > Posteriors  Any direction---Associated with mobilty and rotation
  32. 32.  In occlusal/incisal direction termed as extrusion  Prevalence : Martinez-Canut et al 1997  55.8% Towfighi et al 1997  30.03%
  33. 33. Etiologic factors for pathologic migration A. Destruction of periodontal supporting tissues B. Occlusal factors C. Soft tissue pressure of the tongue, cheek and lips D. Periodontal and periapical inflammation E. Extrusive forces F. Habits
  34. 34. Destruction of periodontal supporting tissues Selwyn S 1973 Bone loss in 30 patients with periodontitis + incisal migration v/s no migration Conclusion: more bone loss in PTM teeth Martinez-Canut et al 1997 852 periodontitis patients Conclusion: Bone loss, tooth loss and gingival inflammation : PTM 2.95 to 7.97
  35. 35.  Role of transseptal fibres Moss and Picton 1982  Abnormal proximal contacts---Anterior component of force Wedging force
  36. 36. Occlusal factors 1. Posterior bite collapse –unreplaced first molars 2. Arch integrity  Interproximal contacts destroyed during tooth loss, dental caries, faulty restorations & severe attrition 3. Class II malocclusion  Selwyn 1973, class II malocclusion 17/30 PTM pts
  37. 37. 4. Occlusal interferences supracontacts --Thielman’s law Occlusal factors may become more destructive in patients who have lost significant alveolar bone
  38. 38. Protrusive pattern of mastication  Yaffe et al 1992 27/131 patients had protrusive mastication 16/27 patients---anterior attrition and flaring of incisors Conclusion: etiologic factor for anterior PTM
  39. 39. Soft tissue pressure of the tongue, cheek, and lips  Can move teeth especially after loss of periodontal support--- long duration  Light forces even1.0 gm by facial muscles at rest—initiate displacement of incisors  Stable dentition is the result of an equilibrium between tongue and cheek pressures is disproven  Proffit stated that the forces of the tongue, cheek, and lips together with the forces of the periodontal tissues are the (Proffit W et al. 1975)
  40. 40. Periodontal and periapical inflammation  Hirschfeld 1933--PTM of teeth is due to pressure of inflammatory tissue  Movement occurs in a direction opposite to the deepest part of the pockets  Sutton P (1985)  Hydrodynamic and hydrostatic forces within the blood vessels and inflamed tissues in the pocket  Spontaneous correction following periodontal treatment Verendra kumar SC ,Anita S, SN Thomas 2009
  41. 41. Extrusive forces  Eruption forces are 2 to 10 gms and present throughout life  No direct association links eruptive forces to PTM  Extrusion of incisors is very common, eruptive forces can be said to be a contributing factor
  42. 42. Habits  Lip and tongue habits, fingernail biting, thumb sucking, pipe smoking, bruxism  Martinez et al ---no association between oral habits and PTM Out of 475 PTM cases only 11% had oral habits  Duration of force more imp. than magnitude (Proffit 1973)
  43. 43. Basic Concepts Of Occlusion
  44. 44. CONTENTS  INTRODUCTION  TERMINOLOGIES  MASTICATORY SYSTEM  TYPES OF OCCLUSION  FORCES OF OCCLUSION  BRUXISM  PATHOLOGICAL TOOTH MIGRATION  TRAUMA FROM OCCLUSION  CONCLUSION  REFERENCES
  45. 45. TRAUMA FROM OCCLUSION  Introduction  Historical perspective  Definitions  Classification  Clinical and radiographic signs  Stages of tissue response to increased occlusal forces  Reversibility of traumatic lesions  Influence on progression of marginal periodontitis  Clinical and animal experiments
  46. 46. INTRODUCTION MAGNITUDE DIRECTION DURATION FREQUENCY
  47. 47. Increase in the magnitude of occlusal force Widening of the periodontal ligament space Number and width of periodontal ligament fibers Density of alveolar bone
  48. 48.  Changing the direction of occlusal forces causes a re- orientation of the stresses and strains within the periodontium.  Principal fibers- arranged--accommodate occlusal force—long axis of tooth  Lateral (horizontal) forces and torque (rotational) forces…..INJURY  Duration and frequency of occlusal forces affect response of alveolar bone.
  49. 49. HISTORICAL PERSPECTIVE In 1901, Karolyi indicated that there appeared to be a correlation between excessive occlusal forces and periodontal destruction. “Karolyi effect”
  50. 50.  In 1917 and 1926, Stillman stated that excessive occlusal forces were the primary cause of periodontal disease and that occlusal therapy was mandatory for the control of periodontal disease.  Orban & Weinman, in 1933, used the histologic observation of human autopsy material Occlusal forces did not have a major effect on periodontal destruction and gingival inflammation
  51. 51. Definition:- Trauma from occlusion refers to a condition where injury results to the supporting structures of teeth by the act of bringing jaws into a closed position. STILLMAN (1917) Trauma from occlusion is defined as damage in periodontium caused by stress on teeth produced directly or indirectly by teeth of opposing jaw. WHO (1978) Occlusal trauma was defined as an injury to the attachment apparatus as a result of excessive occlusal force.
  52. 52. Trauma from occlusion is defined as when occlusal forces exceed the adaptive capacity of tissue, tissue injury results. This injury is termed trauma from occlusion. (CARRANZA) Other terms 1. Traumatizing occlusion. 2. Occlusal trauma. 3. Traumatogenic. 4. Periodontal traumatism.
  53. 53.  Traumatic occlusion An occlusion that produces such injury is called as a traumatic occlusion. Other terms 1. Occlusal disharmony. 2. Functional imbalance. 3. Occlusal Dystrophy.
  54. 54. CLASSIFICATION 1)Acute trauma from occlusion 2)Chronic trauma from occlusion 1)Primary trauma from occlusion 2)Secondary trauma from occlusion
  55. 55. ACUTE TRAUMA FROM OCCLUSION CHRONIC TRAUMA FROM OCCLUSION Less common More common Definition:- Result from abrupt change in occlusal force Result from gradual change in occlusion Cause:- ●Biting on a hard object ●Restoration ●Prosthetic appliances ●Tooth wear ●Drifting movement with Parafunctional activity Clinical Features:- ●Tooth pain ●Sensitivity to percussion ●Increased tooth mobility ●Cementum tears. ●Tooth mobility Management:- ●Dissipate the force by shift in the position of tooth ●By wearing away or correction of restoration. ●Removal of cause
  56. 56. PRIMARY TRAUMA FROM OCCLUSION SECONDARY TRAUMA FROM OCCLUSION Definition:- Result of alterations in occlusal forces. Results from reduced ability of periodontium to resist occlusal forces. Etiology:- ●Insertion of high filling ●insertion of prosthetic replacement ●Drifting movement or extrusion of teeth into spaces created by unreplaced missing teeth. ●Orthodontic movement of teeth into functionally unacceptable position. ●Bone loss resulting from marginal inflammation. Reduction PDL attachment area Alteration of leverage on remaining tissue www.rxdentistry.blogspot.com
  57. 57. CLINICAL SIGNS OF OCCLUSAL TRAUMA 1) Mobility (progressive) 2) Pain on chewing or percussion 3) Fremitus 4) Occlusal prematurities/discrepancies 5) Wear facets in the presence of other clinical indicators 6) Tooth migration 7) Chipped or fractured tooth (teeth) 8) Thermal sensitivity
  58. 58. RADIOGRAPHIC SIGNS OF TFO  Increased width of the periodontal ligament space, with thickening of the lamina dura along the  lateral aspect of the root,  in the apical region, and  in bifurcation areas  A “vertical” rather than “horizontal” destruction of the interdental septum.  Radiolucency and condensation of the alveolar bone.  Root resorption
  59. 59. Increased width of the PDL space Increased density of alveolar bone Radiographic signs of TFO
  60. 60. Tissue response occur in 3 stages:- 1) Injury 2) Repair 3) Adaptive remodeling of the periodontium STAGES OF TISSUE RESPONSE WHEN OCCLUSAL FORCE IS INCREASED
  61. 61. Stage I: Injury. • Tissue injury ….. excessive occlusal forces. • The body then attempts to repair the injury and restore the periodontium….. if the forces are diminished or if the tooth drifts away from them. • Force is chronic, the periodontium is remodelled to cushion its impact. • The ligament is widened at the expense of the bone, • Angular bone defects without periodontal pockets, • Tooth becomes loose.
  62. 62. Stage I: Injury • Slight excessive pressure-- Resorption of alveolar bone(direct bone resorption) • Widening of periodontal ligament space • -- Blood vessels numerous and reduced in size • Slight excessive tension-- Elongation of periodontal ligament fibers…apposition of bone • -- blood vessels --Enlarged
  63. 63. Greater pressure Compression of PDL fibers Areas of hyalinization Fibroblasts & other connective tissue cells necrosis Vascular changes Impairment & stasis of blood flow Fragmentation of RBCsDisintegration of bv Increased resorption of alveolar bone Stage I: Injury 1-7 days 30 mins 2-3 hours
  64. 64. Stage I: Injury Widening of the periodontal ligament Tearing of the periodontal ligament Severe tension Thrombosis, hemorrhage Resorption of alveolar bone
  65. 65. Stage I: Injury  Furcation most susceptible to injury  Injury to the periodontium produces a temporary depression in mitotic activity and the rate of proliferation and differentiation of fibroblasts, in collagen formation, in bone formation  These return to normal levels after dissipation of the forces.
  66. 66. Stage II: Repair  TFO stimulates increased reparative activity. Damaged tissues are removed, and new connective tissue cells and fibers, bone, and cementum are formed to restore the periodontium Forces remain traumatic only as long as the damage produced exceeds the reparative capacity of the tissues.
  67. 67. Stage II: Repair  Excessive occlusal forces…. resorption of bone…. Body reinforces the thinned bony trabeculae with new bone… Buttressing bone formation Central buttressing Endosteal cells deposit new bone , Restores bony trabeculae & reduces the size of marrow spaces Peripheral buttressing Shelf like thickening of the alveolar margin… Lipping-bulge in the contour of facial/lingual bone
  68. 68. Stage III: Adaptive Remodeling of the Periodontium.  Periodontium is remodeled in an effort to create a structural relationship in which the forces are no longer injurious to the tissues.  Thickened periodontal ligament, which is funnel shaped at the crest  Angular defects in the bone, with no pocket formation.
  69. 69. Carranza FA1970
  70. 70. Reversibility of traumatic lesions  Trauma from occlusion is reversible.  When the impact of the artificially created force is relieved, the tissues undergo repair  It does not correct itself..not always temporary  Presence of inflammation may impair the reversibility  Injurious forces relieved for repair to occur--if not periodontal damage persists & worsens Polson M 1976
  71. 71. • Thinning of the periodontal ligament • Atrophy of the fibers • Osteoporosis of the alveolar bone • Reduction in bone height Effects Of Insufficient Occlusal Force
  72. 72. Effect on progression of marginal periodontitis Blood supply of marginal gingiva—not affected
  73. 73.  Important to eliminate the marginal inflammatory component in cases of trauma from occlusion because the presence of inflammation affects bone regeneration after the removal of the traumatizing contacts.
  74. 74. Glickman’s concept  Claimed that the pathway of the spread of a plaque- associated gingival lesion can be changed if forces of an abnormal magnitude are acting on teeth harboring subgingival plaque.  Plaque-associated lesions…suprabony pockets & horizontal bone loss.  Sites also exposed to abnormal occlusal force…angular bony defects & infrabony pockets
  75. 75. Zone of irritation Zone of co-destruction Glickman (1967), “trauma from occlusion is an etiologic factor of importance in situations where angular bony defects combined with infrabony pockets are found at one or several
  76. 76. Waerhaug’s concept  Waerhaug (1979) examined autopsy specimens similar to Glickman’s.  Measured in addition the distance between the subgingival plaque and 1. Periphery of the associated inflammatory cell infiltrate in the gingiva and 2. The surface of the adjacent bone Refuted the hypothesis that TFO played role in the spread of a gingival lesion into the “zone of co- destruction”.
  77. 77.  Loss of connective tissue attachment & the resorption of bone around teeth are, exclusively the result of inflammatory lesions associated with subgingival plaque.  Relationship of the plaque level between adjacent teeth (either at the same of different apico-coronal levels) would yield either horizontal or vertical interproximal bone loss.
  78. 78.  Excessive occlusal forces had no relationship to the underlying bony defect and that vertical defects were found equally around traumatized and non-traumatized teeth.  Bone loss was always associated with the down growth of plaque and there was no relationship between excessive occlusal forces and vertical bone loss.
  79. 79.  Conclusion : Angular defects and infrabony pockets occur when the subgingival plaque of one tooth has reached a more apical level than the microbiota on the neighbouring tooth, and when the volume of the alveolar bone surrounding the roots is comparatively large
  80. 80. Trauma-induced areas favorable environment plaque and calculus development of deeper lesions Sottosanti JS. Theories of trauma and inflammat Other theories of trauma and inflammation
  81. 81. Orthodontic tooth movement Drifting into edentulous space Transformation of suprabony pocket into infrabony Supragingival plaque Subgingival plaque Ericsson I Theories of trauma and inflammat
  82. 82. Increased tooth mobility pumping effect on plaque metabolites Increasing their diffusion Vollmer WH Theories of trauma and inflammat
  83. 83. Clinical and Animal Trials
  84. 84. EASTMAN DENTAL CENTER GROUP-ROCHESTER NY---SQUIRREL MONKEYS REPITITIVE INTERDENTAL WEDGING MILD TO MODERATE GINGIVAL INFLAMMATION UPTO 10 WEEKS RESULT:PRESENCE OF TRAUMA DID NOT INCREASE LOSS OF ATTACHMENT INDUCED BY PERIODONTITIS
  85. 85. UNIVERSITY OF GOTHENBURG GROUP IN SWEDEN—BEAGLE DOGS CAP SPLINTS AND ORTHODONTIC APPLIANCES MILD TO MODERATE GINGIVAL INFLAMMATION UPTO 1 YEAR RESULT:PRESENCE OF TRAUMA INCREASED PERIODONTAL DESTRUCTION INDUCED BY PERIODONTITIS
  86. 86.  Rosling et al. (1976)… “infrabony pocket located at hypermobile teeth exhibited the same degree of healing as those adjacent to firm teeth”.  Fleszar et al. (1980)… “pockets of clinically mobile teeth do not respond as well to periodontal treatment as do those of firm teeth exhibiting the same disease severity”.  Burgett et al. (1992)… Probing attachment gain was on the average about 0.5mm larger in patients who received the combined treatment, i.e. scaling and occlusal adjustment.
  87. 87. Orthodontic type traumaTipping movement
  88. 88. JIGGLING- TYPE TRAUMA Healthy periodontium with normal height
  89. 89. Healthy periodontium with reduced height
  90. 90. Suprabony pockets and advanced bone loss
  91. 91. Infrabony pocket and advanced bone loss
  92. 92. The conclusions of these studies are as follows: 1) Occlusal trauma does not initiate gingival inflammation. 2) In the absence of inflammation, a traumatogenic occlusion will result in increased mobility, widened PDL, loss of crestal bone height and bone volume, but no attachment loss.
  93. 93. 3) In the presence of gingival inflammation, excessive jiggling forces did not cause accelerated attachment loss in squirrel monkeys but increasing occlusal forces may accelerate attachment loss in beagle dogs. 4) Treating the gingival inflammation in the presence of continuing mobility or jiggling trauma will result in decreased mobility
  94. 94. CONCLUSION
  95. 95. References  Functional occlusion :From TMJ to Smile design : Peter Dawson  Ramfjord and Ash. Occlusion. 3rd edition.  Clinical Periodontology – Carranza 8th ,10th,11th Edition  Clinical update-Trauma from occlusion: a review;Commander R. “Dave” Rupprecht, DC, USN 2004
  96. 96.  Clinical Periodontology and Implant Dentistry – Jan Lindhe 4th Edition.  Pathologic tooth migration;Brunsvold 2008
  97. 97. Thank u!!!!!

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