Trauma from Occlusion Flashcards
What are the 4 main occlusal scheme philosophies?
Gnathology, Bioesthetics, Pankey-Dawson, Neuromuscular control
How do the different occlusal schemes relate/differ?
Similar in that the goal is to have even contacts - Different in the position by which intercuspation is built/patterns and pathways of guidance/vertical dimension
How big a difference can there be in centric relation and occlusion?
0.1 to 2mm
What is a normal CR to CO shift?
1.25mm (Clayton 1986)
What is Gnathology?
Condyle posterior superior
Occlusal scheme based off seating of condyle.
Anterior guidance in relation to the angle of articular eminence
What is Bioesthetics?
Similar to Gnathology in condylar seating and anterior guidance/posterior disclusion
Different from Gnathology in that Bioesthetics has strict measurements for anterior teeth size and depth of overbite/overjet
What is the Panky-Dawson model?
Similar to Gnathology in that it used condylar position (but anterior superior), used manual manipulation, and anterior guidance/posterior disclusion
Different from Gnathology in that the patient needs a custom anterior guidance
What is Neuromuscular control model?
Use a Neuromonitor/TENS unit - watch the motion and build occlusion in that position
Dont care about overbite/overjet
What is the Conformative model?
Most used technique in dentistry - Use current occlusion (have patient bite - make sure no heavy contact on filling/crown)
Centric Relation
The most posterior relation.
The most retruded physiologic relation that allows for lateral movements.
Centric occlusion
The repeatable intercuspal position in centric relation
Eccentric Occlusion
Set of contacts NOT in maximum Intercuspation
Centric slide
the physical movement of sliding from CO to MI
Curve of Spee
Curved plane tangent to the incisal edges and buccal cusps of the mandibular teeth viewed in sagittal plane
Curve of Wilson
Posterior occlusal plane or arch curvature when viewed in frontal plane
Curve of Monson
The curve of the dentition where the incisal edges/cusps contact an 8inch diameter sphere with center at glabella (incorporates spee and wilson)
Who defined Traumatic Occlusion and Occlusal Trauma?
Passanezi and Sant’Ana 2019
Occlusal forces which lead to changes in the periodontium depend on what factors? (Citation)
Magnitude
Duration
Frequency
Direction
(Passanezi and Sant’Ana 2019)
What are the most damaging directions for natural dentition?
Lateral and Rotational (Torque)
How does the periodontium respond to Pressure “within certain limits”?
PDL remains vital
Widening of PDL
OCs present on alveolus
“Direct bone resorption” is initiated
How does the periodontium respond to Tension “within certain limits”?
PDL fibers elongate
Apposition of Alveolar bone and cementum
How does the periodontium react to Pressure at “higher magnitude”?
PDL becomes necrotic and hyalinization occurs
OCs present in areas of less stress (marrow spaces) causing “indirect bone resorption”
Root resorption and/or cemental tears
hemorrhage
thrombosis
How does the periodontium respond to Tension at “Higher magnitude”?
PDL fibers tear
Alveolar bone resorption
Widening PDL space
Hemorrhage
Thrombosis
Where do pressure zones occure during tipping forces?
Apical and Coronal
What 3 types of loading forces are there?
Tipping
Bodily
Jiggling
Citation for loading “within certain limits” and at “higher magnitude”
Fan and Caton 2018
3 stages of tissue response to increased occlusal forces
Injury
Repair
Adaptive Remodeling
Describe “Injury”
Initiated by excessive forces
Body will attempt repair if forces decrease or if tooth drifts away
Decrease in mitotic activity for fibroblasts and osteoid cells
Chronic - body creates a cushion (widened PDL/Angular defect/No PDs/ Mobility)
What area is most susceptible to Injury from TFO?
Furcation
Describe “Repair”
Ongoing in the periodontium
Damage > Repair = traumatic forces
Damaged tissues removed - new CT/Fibers/Bone/Cementum formed
How does reparative activity react to TFO?
it increases
Describe “Adaptive Remodeling”
Damage > Repair = Adaptive remodeling
Body creates structure to help avoid further damage
What kind of adaptations take place during Adaptive Remodeling?
Widened PDL
Funnel Shaped defect
Angular defects
NO POCKET
Increased vascularization
Gottlieb and Orban 1931
Dog study
Histological analysis
Axial forces = no mobility
Lateral forces = mobility SOMETIMES
No evidence that TFO is the primary cause of Perio
Stones 1938
Monkey Study
Histological analysis
TFO is an etiologic factor fo vertical pocket formation
TFO is not the ONLY factor - but may CONTRIBUTE to periodontitis
Glickman 1963
TFO alone doe NOT cause gingivitis/perio/CAL
2 zones: Zone of Irritation and Zone of Co-Destruction
Glickman, Stein et al. 1961
Rhesus Monkeys
Effect of increased functional forces on splinted and non-splinted teeth
First study to show furcation is greatest area of risk for TFO
Splinted teeth had little change in furcation area
Non-splinted showed resorption of crest in the furcation (mesio-apical and disto-apical forces)
What is the Zone of Irritation?
Glickman 1963
- Contents:* interdental and marginal gingiva
- Inflammation:* created by local irritants within the zone - degeneration and necrosis of epithelium/CT
- Progression*: lesion will result in horizontal bone destruction
TFO: DOES NOT affect this zone
What is the Zone of Co-Destruction?
Glickman 1963
- Contents*: Cementum/PDL/Alveolar bone
- Inflammation:* When spreading apically into this zone, TFO will accelerate tissue damage
- Progression:* angular defect
TFO: Etiologic factor for angular defects with infrabony PD formation
Waerhaug 1979a
in response to Glickman 1963 Waerhaug tried to prove him wrong
Apical border of plaque - PDL = 0.96mm
Apical border of plaque - Alveolar crest = 1.63mm
Fan and Caton 2018
Thermal sensitivity
Fremitus
Occlusal discrepancies
Cemental tears
Root resorption
Mobility
Widened PDL
Tooth migration
Discomfort on chewing
Fractured tooth
Wear facets
How does mobility affect probing depth?
Probe will penetrate 0.5mm deeper
Neiderud, Ericsson et al. 1992
Burgett, Ramfjord et al. 1992
RCT 50pts
Perio Tx +/- occlusal adjustment
SSD: Patients who had OA had greater CALgain
Harrel and Nunn 2001
Occlusal adjustment can decrease progression of periodontal disease
What are treatment options for TFO?
Occlusal adjustment
Bite Splint
Splinting
Articles to support Occlusal Adjustment
Burgett, Ramfjord et al. 1992
Harrel and Nunn 2001
What are the ideal characteristics of a bite splint
According to Ramfjord and Ash
Maxillary bite plane with flat occlusal surface
Centric stops for all teeth
Cuspid rise to allow posterior disclusion while in lateral and protrusive movements
What are some indications for a bite splint?
TMD
Severe bruxism
TFO on any part of the masticatory system
Stabilize maxillary mobile teeth to prevent mandibular hypereruption
Holding teeth after ortho or after extraction of opposing teeth
Tension headaches
Articles for Splinting
Ramfjord and Ash 1981 (Splinting will not eliminate the cause of mobility)
Alkan, Aykac at el. 2001
SRP alone vs SRP then splint vs Splint then SRP
NSSD
SRP alone had greatest decrease in mobility vs baseline
Signs of Successful treatment of TFO
Mobility decrease/absent
Arrest migration
Radiographic changes decrease/stabilize
Pain relief/improved comfort
Relief of premature contacts/fremitus/interferences
Stable occlusion
AAP 2000
What is the current understanding in terms of TFO’s impact of perio
TFO cannot induce periodontal tissue breakdown, but with plaque-associated periodontal disease, trauma may enhance the rate of progressions Lindhe and Lang 2015
What is the plaque free zone and how large is it?
Zone where there is no buildup and no bone - 0.96mm apicocoronal and 1.63mm from tooth to crest
(Waerhaug 1979)
How can the periodontium respond to TFO if someone is or is not susceptable?
Jin & Cao 1992
Name a study that shows numbers for boneloss and furcation having the most
Mohgaddas & Stahl 1980
Interradicular: 0.23mm
Radicular: 0.55mm
Furcation: 0.88mm
