Trauma from Occlusion - Teeth & Dental Implants

occlusal trauma

an injury to the attachment apparatus (periodontal tissues) that results from excessive occlusal forces

term used to describe pathologic alterations or adaptive changes which develop in the periodontium as a result of undue force produced by the masticatory muscles

occlusal trauma

periodontal tissues (3)

1. PDL

2. alveolar bone

3. gingiva

primary occlusal trauma

tissue reactions (damage) elicited around a tooth with NORMAL periodontium height

(healthy)

secondary occlusal trauma

occlusal forces cause injury to a periodontium of REDUCED height

(periodontal disease)

concepts of occlusal trauma based on human autopsy studies (2)

1. glickman

2. waerhaug

glickman's concept of occlusal trauma

traumatic occlusion could be an etiologic/co-destructive factor in angular bony defects

glickman's concept of occlusal trauma:

the zone of __________ will spread directly into the "trauma exposed" ______ (not via the ______ )

this alteration of the "normal" pathway of spread of the plaque-associated inflammatory lesions results in the development of _________ bony defects

irritation

PDL

bone

angular

glickman's concept of occlusal trauma:

2 zones

1. zone of irritation

2. zone of co-destruction

waerhaug's concept of occlusal trauma:

pattern of loss of supporting structures is the result of an interplay between (2)

1. form & volume of alveolar bone (width)

2. apical extension of microbial plaque on adjacent root surfaces

*not necessarily occlusal trauma

you are more likely to observe vertical bone loss in the presence of [thinner/wider] interdental bone

you are more likely to observe horizontal bone loss in the presence of [thinner/wider] interdental bone

wider

thinner

orthodontic tipping movement create 2 zones

1. pressure

2. tension

[pressure/tension] zones are in the same direction of the tipping movement

pressure

[pressure/tension] zones are in the opposite direction of the tipping movement

tension

orthodontic forces cause mild inflammation characterized by increased number of ___________, increased vascular ___________, and _______________ of cells & collagen fibers

vessels

permeability

disorganization

osteoclasts are located in [pressure/tension] zones to initiate direct bone resorption

pressure

osteoblasts are located in [pressure/tension] zones resulting in bone formation

tension

result of normal orthodontic forces on PDL

widened PDL

with higher magnitude orthodontic forces, the PDL in the pressure zone may become ___________ & undergo ___________

this is called "[indirect/direct] bone resorption"

necrotic

hyalinization

indirect

apposition of bone occurs in the ________ zone to maintain the normal width of the PDL in this area

tension

due to the tissue reactions in the pressure & tension zones during orthodontic movement, the tooth becomes

hypermobile

when the tooth has moved (tilted) to a position where the effect of the forces is nullified what happens?

healing of the periodontal tissues & the tooth becomes stable in its new position

[T/F]: in orthodontic tilting (tipping) movements, neither gingival inflammation or loss of CT attachment will occur at teeth with a healthy periodontium

T

jiggling forces

forces from alternating directions (chewing)

jiggling type trauma in healthy periodontium with reduced height

following occlusal adjustments, PDL is stabilized & returns to its normal width

[T/F]: there are distinct pressure & tension zones with jiggling forces in healthy periodontium with reduced height

F

result of jiggling type trauma in plaque associated periodontal disease

may enhance the rate of progression of the disease

acts as a co-factor in destructive process

result of treatment directed towards the jiggling trauma alone for plaque associated periodontal disease

may reduce the mobility of the traumatized teeth & result in some regrowth of bone

will not influence the features of the plaque-associated lesion

[T/F]: periodontium will adapt to occlusal forces when it is healthy

T

[T/F]: trauma from occlusion can induce periodontal tissue breakdown and is an etiologic factor for periodontal disease

F

[T/F]: in plaque induced periodontal disease, trauma from occlusion may enhance progression of periodontal disease

T

clinical & radiographic indicators of trauma from occlusion (11)

1. fremitus

2. mobility

3. occlusal discrepancies

4. wear facets

5. tooth/pathologic migration

6. fractured tooth

7. thermal sensitivity

8. discomfort/pain on chewing

9. widened PDL

10. root resorption

11. cemental tear

most common sign of occlusal trauma

progressive occlusal mobility

teeth with mobility have ________ PDL space, ________ probing depths, and [did/did not] gain clinical attachment as much as non-mobile teeth following treatment

wider

greater

did not

teeth with mobility present [increased/decreased] clinical attachment loss during maintenance period

increased

[T/F]: mobile teeth respond to regenerative treatments as well as non-mobile teeth

F

an abfraction is a _______-shaped defect that occurs at the _______ of affected teeth as a result of _______ and eventual fatigue of enamel and dentin

wedge

CEJ

flexure

[T/F]: clinical evidence is adequate to support a causal relationship with occlusal forces on MIP (bruxism) and NCCLs

F

[T/F]: clinical evidence is adequate to support a causal relationship with occlusal forces and gingival recession

F

reshaping occlusal contact relationships to create a harmonious relationship between maxillary & mandibular teeth

occlusal adjustment

[T/F]: routine occlusal adjustment is not recommended

T

occlusal adjustments in addition to conventional periodontal therapy presented _______ of clinical attachment levels, and _______ probing depths

gain

decreased

[T/F]: in the presence of clinical indicators of occlusal trauma, occlusal adjustments may slow down progression of periodontal disease and improve prognosis

T

tooth vs. implant:

connection

tooth = PDL

implant = osseointegration & functional ankylosis

tooth vs. implant:

proprioception

tooth = mechanoreceptors

implant = osseoperception

tooth vs. implant:

tactile sensitivity

tooth = high

implant = low

tooth vs. implant:

axial mobility

tooth = 25-100 micrometers

implant = 3-5 micrometers

tooth vs. implant:

load bearing characteristics

tooth = stress distribution and shock absorption

implant = stress concentration at crestal bone

tooth vs. implant:

signs of overloading

tooth = PDL thickening, mobility, fremitus, & pain

implant = screw loosening or fracture, implant fracture, & bone loss

[T/F]: dental implants react biomechanically in the same fashion to occlusal force

F

dental implants may be more prone to _________ which is often regarded as one of the potential causes for peri-implant bone loss and failure of the implant/implant prosthesis

occlusal overloading

orthodontic forces on implants up to a certain threshold, 3400-6600 microstrain led to

whereas above that threshold, greater than 6700 microstain, led to

increase in bone density

bone resorption

functional loading of dental implants __________ bone-implant contact

enhances

excessive and early loading of implants [does/does not] result in loss of bone density or change integrity of dental implant in the presence of peri-implant health

does not

factors that can lead to overloading of dental implants (7)

1. overextended cantilever

2. parafunctional habits (bruxism)

3. excessive premature contacts

4. large occlusal table

5. steep occlusal table

6. poor bone density/quality

7. inadequate number of implants

occlusal guidelines for an overdenture

bilateral balanced occlusion using lingualized occlusion

monoplane occlusion on a severely resorbed ridge

occlusal guidelines for a posterior fixed prosthesis

anterior guidance with natural dentition

group function occlusion with compromised canines

centered contacts

narrow occlusal tables

flat cusps

minimized cantilever

cross bite posterior occlusion when necessary

natural tooth connection with rigid attachment when compromised support

occlusal guidelines for a single implant prosthesis

anterior or lateral guidance with natural dentition

light contact at heavy bite and no contact at light bite

centered contacts (1-1.5mm flat area)

no offset contacts

increased proximal contact

potential solutions for implant occlusion (3)

1. increase support area

2. improve force direction

3. reduce force magnification