occlusion qs

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occlusion qs
2013-03-16 18:15:06
occlusion qs

occlusion qs
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  1. occlusal forces reduced further forward tooth position is in contact in arch is what lever system:
    Class III lever
  2. If RCP-ICP slide and resistance from lateral pterygoid what occurs?
    stretches lateral pterygoid
  3. worn and flat occlusions result from which chewing movements?
    horizontal and wide
  4. custom incisal guidance table w/ self cure acrylic modled by incisal pin that copies the contact movements of stone cast crowns used for:
    tranfer exact anterior guidance characteristics worked up in temp crowns in the mouth to articulator and final restoration.
  5. patient: class I occlusion
    crowns #5, 6 contribute to smile esthetics
    #5 esthetically correct but laterotrusive interference w #28 in R lateral
    What is best option?
    Adjust, reshape or groove distal cusp ridge of #28 buccal cusp
  6. #31 crown w/Class I
    poor anterior guidance little posterior disclusion
    How do you adjust opposing occlusion to accomodate ML of #2 which mediotrusion interference
    DB groove in #31 by dividing DB into Distal and DB cusp
  7. fremitus
    tooth movement in ICP or contact movements
  8. clinical TMJ clicking
    1mm RCP-ICP slide
    what worsens a TM anterior disc displacement with reduction
    performing bit adjustment to remove slide (ICP=RCP)
  9. anterior teeth survive guidance without traumatic occlusion because:
    • brief contacts
    • not in every stroke-> program proprioception of chewing position when contact does occur
    • disadvantagous or demagnified forces from masseter
  10. progressive protrusion guidance
    for pt w/ large overjet to avoid molar interferences in protrusion
    1st guidance 2ND PREMOLARS-> 1st premolars -> canines
  11. restoring 11-15 w/ extensive bruxing poor remaining group function guidance
    What is most predictable occlusal guidance?
    Place group function occlusion with gradual disclusion guidance
  12. Most fundamental requirement for occlusion?
    Stable and single end point of jaw closure
  13. pt w no repeatable ICP
    consider CR and RCP as alternative for multi unit bridge
    CR and RCP will mean functinal position quite posterior to current functional position.
    How do you test pt tolerance to CR and consequences of altering ICP to CRO as a functional position?
    • 1. Test TMJ symptoms produced when manipulating joints in CR
    • 2. Occlusal appliance (splint, orthotic, night guard adjust for CR to RCP) for 1-2 weeks
    • 3. study articulated casts mounted in CR using CR interocclusal checkbite record and facebow and perform diagnostic (trial) coronoplasty (bite adjustment)
  14. full crown, lower molar, fractured buccal cusp
    very flattened by wear-> wide occlusal table with sharp square occluso-buccal and occluso-lingual line angles
    • 1. Opposing worn tooth should be reshaped before constructing above restoration to reduce non-axial forces falling on tooth
    • 2. Examine rest of arch and reshap and round off similarly worn flattened broadened occlusal surface edges to reduce risk of similar cusp fractures
  15. TMJ what kind of model:
    • NOT ball & socket
    • spheroid held against and moving down an inclined plane
  16. half arch non anatomic dental articulators
    Double bite
    • used to construct 1-2 posterior crowns if sufficient teeth allow seating in ICP
    • no error in ICP if working casts articulated in ICP on non-anatomic articulator and no facebow
    • likely to be error in lateral and mediotrusive movements requiring clinical adjustments
    • risk or lateral, medio contacts or interference is likely to occure when patient has MINIMAL anterior guidance
  17. "close-packed" position for joint is
    Centric Relation
  18. which jaw manipulation to CR is most consistent
    Bimanual jaw manipulation (Peter Dawson)
  19. co-axial translation of jaw along horzontal axis is
    mandibular side shift
  20. heavy bruxer
    reflexive resists proper or full lateral contacts
    best advice to make full range for accuracy?
    night guard and retake in 4 weeks
  21. Contraindication for crown reconstruction segmentally
    if increasing VDO
  22. good anterior guidance
    disclusion of ICP contacts and separation of posterior teeth in protrusion
    Christiansen's phenomenon
  23. (T/F) unusual to find lack of molar ICP holding contact in jaw of normal functioning dentate patient
  24. presence of jaw dysfunction related to Angle Class?
  25. unusual for lack of ICP holding contacts at incisors for normal?
  26. movement of mandibular supporting cusps on mediotrusive side
    downward, forward, medial
  27. notable mandibular side shift (1-2mm) is more likely to increase risk for interference in which types of contact movement, side
    mediotrusion side in lateral jaw movement?
  28. supporting cusp exit pathways observed on opposing occlusal surface make what kind of pathway in latertrusion movement viewed from horizontal plane
    right angles to line of upper or lower arch in latertrusion side movements
  29. arrow traced from ICP toward excursion pathway direction matched the read direction of actual jaw movement when:
    mandibular cusp movements across upper occlusal surface
  30. ICP, Class I
    MB cusp of 15 aligns with?
    B groove of 18
  31. most frequent response to placing high filling or high cusp for single tooth restoration?
    posturing of jaw to avoid interference
  32. Increase curve of wilson increases what risk?
    mediotrusion interference
  33. What determinant of occlusion is only testable clinically and not represented in articulator?
    neuromuscular system
  34. Class I
    lingual cusp #13 occludes distal fossa of 20
    what increases risk for intereference?
    A. protrusion
    B. left laterotrusion
    C. right lateral due to interference of ML #19 and Lingual #13
    D. right lateral due to interference of MB#19 and Lingual #13
  35. anterior guidance angle greatest influence on cusp angles the closer the teeth are to anterior guidance control
    condyle guidance exerts greatest influence on teeth closer they are to TMJ
  36. careful setting of condylar angles on articulator critical for
    • 1. occlusion goal of balanced rather than posterior disclusion
    • 2. when there is poor anterior guidance
  37. protrusive and lateral cheek bite in occlusal records are:
    100% correct in the location of the jaw position at which they were actually recorded.
  38. pt discomfort in upper premolars
    check w/ mylar find equal holding ICP in premolars and adjacent teeth
    fremitus was detected #5 and propose occlusal reshaping.
    • 1. steady tooth with finger and retest contacts
    • 2. mark and adjust premature ICP contact
    • 3. bring latertrusion guidance into group function to share eccentric contact loading
    • DO NOT first adjust premature excursive contact on tooth #5 unless stablized
  39. under-set protrusive condyle angle
    what is the effect
    more disclusion between crowns in patients mouth than seen when crowns were in articulator
  40. when would you see most posterior tooth attrition?
    • Class III
    • Class II, div 2=least posterior wear
  41. which pattern recruits the least jaw elevator muscle activity in voluntary clench or bruxing movement?
    canine or canine segment guidance
  42. natural deep bites displace mandible posteriorly and are associated with muscle pain and TMJ clicking
  43. increased or increasing incisor overjet can be consequence of what disorder?
    TMJ osteoarthritis or osteoarthritis
  44. what way does steepness of occlusal plane affect ability to accomodate steeper cusp angles and deeper fossas?
    • flatter and lower OP->┬ásteeper Cusp inclination
    • Condylar inclination * Incisal guidance/
    • Occlusal Plane * Cuspal inclination * Compensating Curve
  45. crowns for 12-15
    12 and 14 are supported by implants
    don't want to leave crowns high in contact and implants out of contace and vice versa
    need to refine ICP because it is high
    How do you instruct patient to close to properly mark and adjust occlusion
    have patient clench more firmly so the supported teeth matches the occlusion on natural teeth when they are loaded and slightly intruded.
  46. multifactor studies on chronic occlusal variation suggest that the contribution of dental occlusal variation to TMJ disorders is
    only about 4% to 25%