periodontal response to external forces

GOOD MORNING!!!!

PERIODONTAL RESPONSE TO EXTERNAL FORCES

DEEPTHI P.R. FINAL YEAR BDS

CONTENTS

• Introduction• Trauma from Occlusion-Definitions• Classifications• Extension of Gingival inflammation to bone• Different concepts of Periodontal Response to

Occlusal Trauma • Stages of tissue response to increased occlusal

forces

CONTENTS

• Effects of Insufficient Occlusal Force• Reversibility of traumatic lesions• Effects of excessive Occlusal Forces on Dental

Pulp• Influence of Trauma from Occlusion on

Marginal Periodontitis• Studies and researches in Occlusal trauma

CONTENTS

• Signs of Trauma from Occlusion• Treatment Planning • Occlusal treatment • Physiologic & Pathologic Occlusion• Pathologic Tooth Migration• Conclusion• Bibliography

INTRODUCTION

• Adaptive capacity of periodontium to forces exerted is variable

Occlusal forces

magnitude direction duration frequency

• Magnitude -widening of the PDL space -increase in the no. & width of PDL fibers -increase in the density of alveolar bone

INTRODUCTION• Direction -Reorientation of stress & strain -Principal fibers of PDL Occlusal forces

along the long axis of the tooth -Lateral/Horizontal & Torque/Rotational: Injure

the periodontium• Duration -Constant pressure > intermittent• Frequency -Frequent application of intermittent force:

injurious

TRAUMA FROM OCCLUSIONDEFINITIONS ‘When occlusal forces exceed the adaptive

capacity of the tissues , tissue injury results. The resultant injury is termed as trauma from

occlusion’ - Carranza ‘A term used to describe pathological

alterations or adaptive changes which develop in the periodontium as a result of undue force produced by the masticatory muscles’

-Lindhe

TRAUMA FROM OCCLUSION

DEFINITIONS‘A condition where injury results to the

supporting structures of the teeth by the act of bringing the jaws into a closed position’

-Stillman(1917)‘Damage in the periodontium caused by stress

on teeth produced directly or indirectly by teeth of the opposing jaw’

-WHO(1978)

DEFINITIONS‘An injury resulting in tissue changes within

the attachment apparatus as a result of occlusal forces’

- Rose & Mealey‘An injury to the attachment apparatus as a

result of excessive occlusal forces’ -Glossary of Periodontal Terms (AAP in 1986)

SYNONYMS• Traumatizing occlusion• Occlusal trauma• Traumatogenic occlusion• Periodontal traumatism• Overload• Traumatism NBOcclusal trauma: DiagnosisTraumatogenic occlusion: Etiology

TRAUMATIC OCCLUSION/ TRAUMATOGENIC OCCLUSION‘An occlusion that produces forces that cause an

injury to the attachment apparatus’

CLASSIFICATIONSI. Acute & Chronic

II. Primary & Secondary

ACUTE TFOCauses :• An abrupt occlusal impact• Restorations/prosthetic appliancesManifestations :• Tooth pain• Sensitivity to percussion• Increased tooth mobility

Force dissipatedi. Shift in tooth position healsii. Wearing &iii. Correction of restoration subsides Or elsePeriodontal injury Necrosis+ perio. abscess or Cementum tears

CHRONIC TFO• More common & significant• Gradual changes by: - tooth wears - drifting movement & extrusion - parafunctional habits• Malocclusion not necessarily TFO

• Traumatic Occlusal relationships -Effect of the occlusion on the periodontium

Also known as:Occlusal disharmonyFunctional imbalanceOcclusal dystrophy

PRIMARY TFO Definition: Injury resulting in tissue changes from excessive

occlusal forces applied to a tooth or teeth with normal support

• TFO – the only etiology in periodontal destruction

• Occlusion results in the only local alteration of teeth

• Parafunctional habits

TRAUMA FROM OCCLUSIONCauses• High filling• Prosthetic replacement• Drifting / extrusion• Orthodontic movement into functionally unacceptable positionsPrimary TFO no changes in connective tissue

attachment level & no pocket formation

CLASSIFICATION OF PARAFUNCTIONAL HABITS

Tooth to Tooth Bruxism Clenching Oral musculature to tooth Lip biting Tongue thrusting Foreign objects to tooth Finger nail biting Pipe/Cigar biting Other objects

PARAFUNCTIONAL HABITS

• Duration of tooth contact greatly increased • Magnitude of force during bruxism much

greater• Bruxism / clenching involve most of the teeth• Occlusal appliances

PARAFUNCTIONAL HABITS

• Foreign object biting – localized to few teeth• Encourage habit elimination• Distinguish between adaptive periodontium &

one that is in trauma

• Normal bone levels & attachment levels• Excessive occlusal forces • Normal periodontium with normal bone

height• A state of stability through Adaptive

remodeling *mobility no longer increasing *clinical, radiographic, histologic changes

don’t worsen

SECONDARY TFODefinitionInjury resulting in tissue changes from normal or

excessive occlusal forces applied to a tooth with reduced support

• Adaptive capacity – impaired by bone loss due to inflammation

• Reduces periodontal attachment area• Alters the leverage on the remaining tissues

• More vulnerable to injury• Previously well tolerated forces become

traumatic• Normal periodontium/Marginal periodontitis

with reduced bone height• Tooth displaced into the remaining alveolus by

any force

• Active periodontitis/ after resolution of inflammatory periodontitis

• Condition serious if- progressively increasing mobility, bone loss, widening of PDL

• Splinting indicated- if teeth are to be retainedAlternate Mechanism for Secondary TFO• Systemic disease

• The distinction between primary & secondary TFO – no meaningful purpose

• The alterations in the periodontium are similar & independent of the height of the target tissue, i.e. the periodontium.

EXTENSION OF GINGIVAL INFLAMMATION TO BONE

• Gingival inflammation collagen fiber bundles blood vessels alveolar bone

• Interproximally, through the vessels perforating the crest of the interdental septum

• Directly into the PDL & from there into the interdental septum

• Facially & lingually , spreads along the outer periosteal surface & penetrates into the marrow spaces through vessel channels

• Destroys the transseptal & gingival fibers on the course

Once bone is reached:• Spreads into the marrow spaces & replaces

marrow with exudate

• Bone resorption proceeds from within the marrow spaces

• Thinning of bony trabeculae & enlargement of the marrow spaces

• Bone destruction & a reduction in bone height• Fatty bone marrow replaced with fibrous

marrow

GLICKMAN’S CONCEPT

• Concept given in 1965,1967• 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

• Character of progressive tissue destruction of periodontium at a “traumatized” tooth different from that in a “non-traumatized” tooth

• Even destruction of periodontium & bone- suprabony pockets & horizontal bone loss in uncomplicated plaque associated lesions

• Angular bony defects & infrabony pockets when exposed to abnormal occlusal force + inflammation

Periodontal structures divided into two zones

1. Zone of Irritation2. Zone of co-destruction

GLICKMAN’S CONCEPTZONE OF IRRITATION

• Marginal gingiva & interdental gingiva• Soft tissues bordered by the hard tissue on one

side • Not affected by the occlusal forces• Gingival inflammation not induced by TFO;but by

irritation from microbial plaque• Lesion in a non-traumatized tooth propagates in

apical direction by first involving the alveolar bone & later the PDL

ZONE OF CO-DESTRUCTION• PDL, Root cementum & alveolar bone• Coronally demarcated by the transseptal & the

dentoalveolar collagen fiber bundles• TFO may cause a lesion here

• Fiber bundles separating the two above mentioned zones from two different directions:

Inflammatory lesion by plaque in the zone of irritation

Trauma induced changes in the zone of co-destruction

• Fiber bundles dissolved or oriented parallel to the root surface

GLICKMAN’S CONCEPT• The spread of inflammation is from the zone

of irritation directly down into the PDL; not via the interdental bone.

• This altered pathway of spread angular bony defects“TFO is an etiologic factor (co-destructive

factor) of importance in situations where angular bony defects combined with infrabony pockets are found at one or several teeth ”

-1967 Review Paper

WAERHAUG’S CONCEPT

• Examined autopsy specimens(1979)• Distance between subgingival plaque & the periphery of the associated

inflammatory cell infiltrate in the gingiva the surface of the adjacent alveolar boneConclusion : Angular bony defects & infrabony

pockets occur equally at periodontal sites of teeth which are not affected by TFO

• The loss of connective attachment & bone resorption - exclusively due to inflammation associated with subgingival plaque

• Angular bony defects & infrabony pockets --subgingival plaque has reached a level more apical than the microbiota on the neighbouring tooth

--when the volume of the alveolar bone surrounding the roots is comparatively large

• Supported by findings by Prichard (1965) & Manson(1976)

The pattern of loss of supporting structures: the form & volume of the alveolar bone the apical extension of the microbial

plaque on the adjacent root surfaces

STAGES OF TISSUE RESPONSE TO INCREASED OCCLUSAL FORCES

3 STAGES:

INJURY REPAIRADAPTIVE REMODELLING OF THE

PERIODONTIUM

INJURY

• Excessive Occlusal forces: Tissue Injury• Repair of injury & Restoration of periodontium

if-i. Forces are diminishedii. Tooth drifts away from them • Chronic forces: Remodeling of periodontiumi. Widened at the expense of boneii. Angular bone defects without pockets loose

INJURY

• Occlusal forces: Tooth rotation around a Fulcrum/ Axis of Rotation

Junction of middle & apical third of clinical root

• Areas of pressure & tension created on opposite sides of the fulcrum

INJURY

SLIGHTLY EXCESSIVE PRESSURE• Resorption of the alveolar bone• Widening of the PDL space• Numerous blood vessels- reduced in sizeSLIGHTLY EXCESSIVE TENSION• Elongation of the PDL fibers• Apposition of alveolar bone• Enlarged blood vessels

INJURY

GREATER PRESSUREGradation of Changes• Compression of fibers Areas of hyalinization• Injury to fibroblasts & other cells: Necrosis of

PDL• Vascular Within 30 minutes

INJURY

Impairment & stasis of blood flow in 2-3 hoursBlood vessels packed with RBC’s fragment in

1-7 daysDisintegration of blood vessel walls- contents

discharged into the surrounding

• Increased resorption of alveolar bone & tooth surface

INJURY

SEVERE TENSION

• Widening of PDL• Thrombosis• Haemorrhage • Tearing of the PDL• Resorption of the alveolar bone

INJURY

SEVERE PRESSURE

• Force the root against bone• Necrosis of the PDL & bone• Bone resorption from viable PDL & marrow

spaces Undermining Resorption

• Most susceptible areas of Injury- Furcations

INJURY

Injury to Periodontium: Temporary depression

• Mitotic activity• Proliferation & Differentiation of Fibroblasts• Collagen & Bone formation• Normal after dissipation of forces

REPAIR

• Normal periodontium: Constant repair• TFO - increased reparative activity• Damaged tissues removed & formation of new Cells Fibers Bone Cementum

REPAIR

• Forces : Traumatic as long as the damage exceeds the reparative capacity

• Bone resorbed by excessive occlusal forces• Thinned bony trabeculae reinforced with new

REPAIR

BUTTRESSING BONE FORMATION• Important feature of Repair after TFO• Inflammation• Osteolytic tumorsCentral Buttressing: Within the jaw New bone deposition

REPAIR

Peripheral Buttressing: Facial & lingual surfaces of the alveolar plate LIPPING : Severe ‘shelf like’ thickening of the

alveolar margin Pronounced bulge in the contour of the facial

& lingual bone Following trauma:Cartilage like materialCrystal formation from RBC’s

ADAPTIVE REMODELING OF THE PERIODONTIUM

Repair = Destruction: remodeled so that the forces are not injurious

• PDL - Thickened & funnel shaped at the crest• Angular defects in the bone• No pockets• Teeth become loose

HISTOMETRIC DIFFERENTIATION

• Injury phase: resorption formation

• Repair phase: resorption formation

• Adaptive remodeling: both return to normal

EFFECTS OF INSUFFICIENT OCCLUSAL FORCE

• Injurious to periodontium• Thinning of the PDL• Atrophy of fibers• Osteoporosis of the alveolar bone• Reduction in bone height

EFFECTS OF INSUFFICIENT OCCLUSAL FORCE

Can result from:Open-bite relationshipAbsence of functional antagonistsUnilateral chewing habits

REVERSIBILITY OF TRAUMATIC LESIONS

• TFO –Reversible• Artificially created TFO- extrusion & intrusion

& repair on removal• Not always correct itself• Injurious force- relieved for repair

REVERSIBILITY OF TRAUMATIC LESIONS

• Conditions not permitting adaptation to occlusal forces- damage worsens/persists

• Plaque induced inflammation- impairs the reversibility of traumatic lesions

EFFECTS OF EXCESSIVE OCCLUSAL FORCES ON DENTAL PULP

• Not established• Disappearance of pulpal symptoms after

correction of excessive occlusal forces- reported

• Pulpal reactions in animals subjected to increased

INFLUENCE OF TFO ON PROGRESSION OF MARGINAL PERIODONTITIS

• Accumulation of plaque that initiates gingivitis & results in pocket formation affects the marginal gingiva, but TFO occurs in the supporting tissues & does not affect the gingiva

• Marginal gingiva unaffected by TFO• TFO doesn’t cause gingivitis

• No effect on inflammatory process confined to the gingiva

• When gingivitis periodontitis; occlusion influencesIt is important to eliminate the marginal

inflammatory component in case of TFO because the presence of inflammation affects bone regeneration after the removal of the traumatizing contacts

• No progressive destruction in regions kept healthy after elimination of periodontitis

• Change in the shape of the alveolar crest:Widening of the marginal PDL spaceNarrowing of the interproximal alveolar boneShelf like thickening of the alveolar margin

• Thus there’s alteration in the architecture of the inflamed site

• Inflammation absent: adaptation to increased forces• Inflammation present: Angular bone lossPockets become infrabony

INTERACTION OF TFO & INFLAMMATION

• TFO alter the pathway of inflammation to the underlying tissues

collagen density & no.of

LeukocytesOsteoclasts increasingly mobileBlood vessels teeth

• Inflammation proceeds to PDL • Angular bone loss & infrabony pockets• Areas of root resorption exposed without

gingival attachment – plaque & calculus

• Supragingival plaque SubgingivalOrthodontically tiltedMigration into edentulous areaSuprabony pocket becomes intrabony

• Increased mobility : Pumping effect on plaque metabolites increase diffusion

STUDIES & RESEARCHES ON OCCLUSAL TRAUMA

Early investigators - important role to TFO-etiology

• High crowns & restorations in dogs & monkeys• High crown + orthodontic appliance ‘jiggling

forces’• Interproximal wedging• Jiggling trauma + plaque induced

inflammation

Eastman Dental Center• Squirrel monkeys• Repetitive interdental wedging• Mild to moderate inflammation• 10 weeks• No increase in attachment loss

University of Gothenburg• Beagle dogs• Cap splints & orthodontic appliances• Severe inflammation• 1 year• Increase in the periodontal destruction

induced by periodontitis

Wentz & coworkers• Monkeys- PDL widening up to 3 times more

• ‘At one point , the damaging effect of jiggling trauma was nullified by the extreme width of the PDL space & no future resorption occured’

Svanberg & Lindhe• Jiggling trauma in dogs• Increased mobility• PDL space widening• Loss of crestal bone height• Series of cellular alterations

• Thrombosis• Haemorrhage• Increased vascular permeability• Collagen destruction & Bone resorption• Changes ceased after 60 days• Increased mobility & width of PDL remained

constant• Physiologic adaptation in the absence of

plaque induced inflammation

Svanberg & Lindhe- 2nd Swedish study• Physiologic adaptation didn’t occur- presence

of plaque induced periodontitis• ‘Attachment apparatus inhibited in its ability

to adapt to jiggling type trauma in the presence of supracrestal plaque- induced inflammation’

• ‘TFO combined with experimental periodontitis accelerated periodontal breakdown characterized by continuous periodontal pocket formation & loss of fiber attachment’

Nyman & coworkers• Experimental periodontitis – test & control

teeth• Jiggling type trauma- test teeth• attachment loss in 80% of test teeth

• ‘Excessive occlusal forces have the potential to increase the degree of periodontal destruction’

Polson & coworkers• Monkey model• Traumatic forces without periodontal

inflammation• Widening of the PDL space• Increased tooth mobility• Loss of crestal bone height & bone volume

• Changes ceased once physiologic adaptation complete

• Withdrawal of traumatic forces – lost bone volume restored

• Persisting plaque induced inflammation

SIGNS OF TFOMOBILITY

• Measurement of horizontal & vertical tooth displacement created by the examiner’s force

• Blunt ends of two dental instruments approximately at the buccal & lingual height of contour

• Forces applied buccolingually• Assessed in mesiodistal direction when

possible• Comparing a fixed point on the tooth against a

fixed point on the adjacent tooth

SIGNS OF TFO

CLASS I : Less than 1mm buccolingual/mesiodistal CLASS II : 1mm or more – buccolingual/

mesiodistal , no abnormal mobility in an occlusoapical direction

CLASS III : 1mm or more- buccolingual or mesiodistal & abnormal mobility in an occlusoapical direction

SIGNS OF TFO

FREMITUS/FUNCTIONAL MOBILITY• Measurement of the vibratory patterns of the

teeth when the teeth are placed in contacting positions & movements

• A finger – buccal & labial surfaces- maxillary teeth

• Tap the teeth together in the maximum intercuspal position

• Grind symmetrically in lateral, protrusive & lateral-protrusive contacting movements

SIGNS OF TFO

• Mandibular teeth assessed in edge to edge occlusion

CLASS I: Mild vibration detectedCLASS II: Easily palpable vibration but no visible

movementCLASS III: Movement visible with the naked eye

SIGNS OF TFO

Fremitus vs Mobility: Tooth displacement created by patient’s own

occlusal force

• Ability of patient to displace & traumatize teeth

• Mobility without fremitus: Probably no Occlusal Trauma

SIGNS OF TFO

RADIOGRAPHIC ASSESSMENT• Degree of bone loss from the CEJ to Apex• Width of the PDL space around each tooth• Examine for angular bony defects• But these findings not necessarily with TFO

SIGNS OF TFO

OCCLUSAL SUMMARY CHART• Future treatment decisions & response to

therapy• Minimum information • Assess the relation between occlusal forces &

periodontal status

TREATMENT PLANNINGDecide whether occlusal treatment is needed:Surface adjustment/ApplianceSymptoms • Sensitive to temperature changes• Pain on chewing• Mobility• Wear facetsExtent of periodontal destructionPatient’s ability to function

TREATMENT PLANNING

Occlusal treatment indicated• Occlusal discrepancies• Periodontal disease

X Occlusal treatment not indicated• Asymptomatic• No significant periodontal disease

TREATMENT PLANNING

Decision to treat made in the reevaluation appointment :

• Non surgical treatment• Mobility & fremitus reduced• Need for treatment diminished

OCCLUSAL TREATMENT

• After non surgical treatment• Exception: difficulty/ pain on chewing due to

occlusal trauma

2 APPROACHESBITE APPLIANCEALTERING OCCLUSAL RELATIONSHIPS OF

OCCLUSAL TREATMENT

BITE APPLIANCE• Fits over the teeth• An artificial occlusal surface for the opposing

dentition to contact• Hard acrylic: Cushions contact forces• Heat/cold cured hard acrylic over soft acrylic• Maxillary bite Appliance: Stabilise potentially

loose maxillary teeth & prevent flaring

OCCLUSAL TREATMENTOCCLUSAL ADJUSTMENT

• Permanent alteration: - Orthodontic therapy - Selective grinding• Permanent change – distribution of occlusal

forces• Care & skill

PHYSIOLOGIC & PATHOLOGIC OCCLUSION

Determined after diagnosis of occlusal trauma

PHYSIOLOGIC:• Survives despite deviations from the ‘ideal’

occlusion• Maybe anatomic malocclusion• Free of occlusally induced disease

PHYSIOLOGIC & PATHOLOGIC OCCLUSION

PATHOLOGIC:• Disease due to occlusal activity• Requires therapeutic alteration

PATHOLOGIC TOOTH MIGRATION

DEFINITION‘Tooth displacement that results when the

balance among the factors that maintain physiologic tooth position is disturbed by periodontal disease ’

• Common & early sign• Gingival inflammation• Pocket formation• Anteriors frequent• Any direction• Mobility & RotationExtrusion: Pathologic migration in the incisal/

occlusal aspect

PATHOGENESISHealth & normal height of the periodontiumForces exerted on the teeth: Occlusion &

PressureForces of occlusionTooth morphology & cuspal inclinationFull complement of teethPhysiologic tendency towards mesial

migration

Nature & location of contact point relationships

Proximal, incisal & occlusal attritionAxial inclination of teeth

WEAKENED PERIODONTAL SUPORT

• Unable to maintain normal position• Moves away from opposing force unless

restrained by proximal contact• Forces accepted by normal periodontium

become injurious

• Position change - subjected to abnormal force- aggravate periodontal destruction & migration

• Continue after loss of antagonist• Forces from tongue, food bolus, granulation

tissue• Also an early sign of Localized Aggressive

Periodontitis

CHANGES IN FORCES EXERTED ON THE TEETH

A. Unreplaced missing teeth• Drifting into edentulous spaces• Not due to periodontal destruction• Conducive for periodontal diseases• Aggravates the tooth movement• Mesial with tilting / extrusion

• Premolars drift distally• Doesn’t always occur

B. Failure to replace First Molars• Second & third molars tilt reducing the vertical

dimension• Premolars - distally & mandibular incisors-drift

lingually• Anterior overbite increased & mandibular

incisors traumatize the gingiva

• Maxillary incisors pushed labially & laterally• Anterior teeth extrude because incisal

apposition has largely disappeared• Diastemata created- anterior teeth

Proximal contacts disturbed:Food impactionGingival inflammationPocket formationBone lossMobility Altered positions- traumatize supporting

tissues- aggravate destruction

OTHER CAUSESTFO: itself or combinationPRESSURE FROM TONGUE: absence of

disease/ reduced periodontal supportPRESSURE FROM GRANULATION TISSUE OF

PERIODONTAL POCKET: with periodontal destruction ; may return after pocket elimination

CONCLUSION

• Occlusal traumatic forces- the major external force encountered by the periodontium

• Trauma from occlusion - no inflammation of the periodontium by itself

• Alters the pathway of inflammation & aggravates the condition once the periodontitis stage is reached

BIBLIOGRAPHY

• Carranza’s Clinical Periodontology- 10th edition• Clinical Periodontology & Implant Dentistry- Lindhe,4th

Edition• Periodontics –Medicine, Surgery &Implants -

Rose ,Mealey, Genco, Cohen• Fundamentals of Periodontics- Wilson & Kornman, 2nd

Edition -• www.google.com

THANK YOU YOU

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