Space closure 2 /certified fixed orthodontic courses by Indian dental academy

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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.

Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078

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Space closure 2 /certified fixed orthodontic courses by Indian dental academy

  1. 1. INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com 2 www.indiandentalacademy.com
  2. 2. Ongoing Innovations in Biomechanics & Materials for the New Millennium- Robert P. Kusy www.indiandentalacademy.com
  3. 3. Conventional Begg o Attritional occlusion in Australian Aborigines o Concept of differential forces www.indiandentalacademy.com
  4. 4. Space closure in Begg Stage II- Objectives : 1. To maintain all corrections achieved during stage I 2. To close all extraction spaces  Controlled tipping of incisors  Preventing excess tipping www.indiandentalacademy.com
  5. 5. Space closure in Begg Stage II- Archwires o - 0.018” P/P+, 0.020” P o Anchor bands reduced- maintain correction o Maintain rotation, deepbite correction, archform o Resist rotational tendency of molars- class I elastics o No sliding of brackets- no slow down www.indiandentalacademy.com
  6. 6. Controlled tipping of incisors o MAA- lingual root torque- root control from the beginning. 0.009” o Uprighting spring- canine o Incisors upright or slightly retroclined www.indiandentalacademy.com
  7. 7. www.indiandentalacademy.com
  8. 8. Elastics o Differential configuration o U/L class I www.indiandentalacademy.com
  9. 9. Elastics o Class II with lower class I- molar relation not corrected www.indiandentalacademy.com
  10. 10. Elastics o Z configuration (class II part time) www.indiandentalacademy.com
  11. 11. Elastics o Class II only- U/L anteriors do not retract at the same rate www.indiandentalacademy.com
  12. 12. Elastics o Lower class I only (anteriors in crossbite) www.indiandentalacademy.com
  13. 13. Braking mechanics o For protracting the posteriors 1. Braking pins 2. Angulated T pins 3. Combination wires 4. Torquing auxiliaries www.indiandentalacademy.com
  14. 14. Braking mechanics o Braking pins- passive uprighting springs, 0.018” almost fill the bracket channel www.indiandentalacademy.com
  15. 15. Braking mechanics o Angulated T pins- maintain tipping www.indiandentalacademy.com
  16. 16. Combination wiresSS/Alpha- titanium Anterior segment0.022” x 0.018”- ribbon mode Posterior segment- 0.018” round Greater torque in anterior segment = more bite deepening effect www.indiandentalacademy.com
  17. 17. Braking mechanics o Torquing auxiliaries- 2 spur or 4 spur - MAA 0.010”/0.011”(0.020” base wire) www.indiandentalacademy.com
  18. 18. o Duration of stage II–  2 stages together approximately 1 year-not more than 1 year 3 months www.indiandentalacademy.com
  19. 19. KB Technique o Kamedanized Begg- Akira Kameda o Modifications to Conventional Begg technique. o Stage II- torquing and space closure o Rectangular tube with round or ribbon archwirephilosophy of low friction www.indiandentalacademy.com
  20. 20. o Pre-Torqued brackets o Combination archwire www.indiandentalacademy.com
  21. 21. KB Technique o Round wire in round tube - Anchor molars tend to roll in. - Correcting lingually inclined anchor molarsdifficult. - Directing forces- difficult - Bite opening efficiency decreased www.indiandentalacademy.com
  22. 22. KB Technique o Rectangular tube with round or ribbon archwiro Pre-Torqued brackets o Combination archwires Alpha titanium 100% humidity= titanium hydrite- harden in the mouth www.indiandentalacademy.com
  23. 23. KB Technique o By-Pass Loop- 3 dimensional control of 2nd PM www.indiandentalacademy.com
  24. 24. KB Technique o Torquing and en masse tooth movement o E-link or 0.010” sectional supreme - maintain inter canine distance o Ribbon archwire into buccal tubes o Power pins- for hooking elastics o E- links or power chain- control rotation of anchor molar www.indiandentalacademy.com
  25. 25. www.indiandentalacademy.com
  26. 26. www.indiandentalacademy.com
  27. 27. www.indiandentalacademy.com
  28. 28. J- Hook Headgear- John Hickam o Straight pull type o High pull type- bodily movement, aid in bite opening o Variable pull J-hook assembly www.indiandentalacademy.com
  29. 29. J- Hook Headgear- John Hickam www.indiandentalacademy.com
  30. 30. o Disadvantages o Force application is intermittent o Patient co-operation o Trauma of the soft tissues from the J-hook www.indiandentalacademy.com
  31. 31. Sliding mechanics Advantages o Minimal wire bending o Less time consuming o Enhances patient comfort o No running out of space for activation www.indiandentalacademy.com
  32. 32. Sliding mechanics Disadvantage o Lack of efficiency compared to frictionless mechanics o Uncontrolled tipping o Deepening of overbite o Loss of anchorage www.indiandentalacademy.com
  33. 33. Space closure in Tip Edge Tip-Edge vs Original Edgewise bracket o Unique slot- permits free crown tipping o Allows differential tooth movement o Light forces, minimal archwire deflectiondiminished anchorage demand o Increased horizontal & vertical control www.indiandentalacademy.com
  34. 34. o Tip-Edge vs Ribbon Arch Bracket www.indiandentalacademy.com
  35. 35. www.indiandentalacademy.com
  36. 36. www.indiandentalacademy.com
  37. 37. www.indiandentalacademy.com
  38. 38. Dr. SAFEENA www.indiandentalacademy.com
  39. 39. Frictionless mechanics o Teeth moved without the bracket sliding along the arch wire o Retraction accomplished with loops or springs o Offers more controlled tooth movement than sliding mechanics www.indiandentalacademy.com
  40. 40. o Continuous arch- nonbroken archwire formed around the dental arch, connects one bracket or tube with the bracket on an adjacent tooth o Segmented arch- sections of continuous arch which are joined or connected together to form a semblance of a continuous archwire o Sectional arch- contains portions of a continuous archwire that are not joined in any way to form an integral unit www.indiandentalacademy.com
  41. 41. Rationale of Segmented arch o Consolidation of teeth into units- 2 buccal segments and one anterior segment. o Buccal segments- TPA, lingual arch o Each segment- multirooted tooth o Intrasegmental mechanics- alignment by segmental archwires o Segments consolidated into complete arch o Allows use of wires of varying cross-section of archwire o Side effects of forces easily controlledprefabricated/precalibrated o www.indiandentalacademy.com
  42. 42. Loops used in frictionless mechanicsRetraction Loops (springs) Ideal loop design o Deliver relatively low, nearly constant forces o Accommodate large activation o Comfortable to the patient o Easy to fabricate www.indiandentalacademy.com
  43. 43. o Burstone and Koenig Ideal characteristics for effective physiologic tooth movement 1. High M/F ratio required for translatory movement 2. Low LDR, to maintain optimum force levels over a long range www.indiandentalacademy.com
  44. 44. Components of force system o Alpha moment: acting on anterior teeth o Beta moment: acting on posterior teeth o Horizontal forces: mesiodistal o Vertical forces: intrusive-extrusive www.indiandentalacademy.com
  45. 45. Vertical loop o Dr. Robert Strang- originator, for retraction mechanics o 2types 1. When used for opening spaces- legs should be separated 3/32”, ¼” in height 2. When used for closing spaces, legs are close together and parallel www.indiandentalacademy.com
  46. 46. www.indiandentalacademy.com
  47. 47. Standard vertical loop o Simplest loop o Fabricated as independent devices/incorporated into continuous archwire o Used for alignment and space closure www.indiandentalacademy.com
  48. 48. Vertical Loop o Open Vertical Loop o Closed vertical loop www.indiandentalacademy.com
  49. 49. Modifications of Vertical loop o Bull loop- Dr. Harry Bull (1951) o Loop legs tightly abutting each other. o Omega loop- As mentioned by Dr. Morris Stoner resemblance with Greek letter ‘omega’ o Believed to distribute stresses more evenly through the curvature, instead of concentrating them at apex www.indiandentalacademy.com
  50. 50. Height restricted by anatomy of oral cavity www.indiandentalacademy.com
  51. 51. www.indiandentalacademy.com
  52. 52. o Forces optimum for canine retraction 1-2 N (1N=102gms) o Force levels at activation of vertical loop 4.4N o Force-deflection relationship linear o At 0.5mm activation- force levels half of those at 1mm o Small movement of teeth- large in force levels o M/F below ideal for controlled tipping and translation o Change in design geometry www.indiandentalacademy.com
  53. 53. o Closed loop- greater range of activation than open loop= additional wire and o Bauschinger effect- range of activation is always greater in the direction of the last bend www.indiandentalacademy.com
  54. 54. Standard vertical loop Disadvantages o Very high forceso Force & M/F extremely sensitive to small changes in activation o Discomfort to patient o Loss of anchorage & root control o Dumping of teeth o Small activations-Rapid force decay, intermittent force delivery www.indiandentalacademy.com
  55. 55. Use of vertical loops in retraction systems- Faulkner et al. AJO 1991 Effect of Helix o Single apical helix- force= M/F o Lateral helices- moment o Combination- M/F slightly above 2 & activation www.indiandentalacademy.com
  56. 56. o Apical helix www.indiandentalacademy.com
  57. 57. o Preactivation www.indiandentalacademy.com
  58. 58. Preactivation o Same force/deflection o Shifted moment/deflection o M/F greater at low activation o Spring very sensitive to small errors in manufacture and installation- difficult to use in practice. www.indiandentalacademy.com
  59. 59. o Preactivation and Helices www.indiandentalacademy.com
  60. 60. o Larger activation without permanent deformation o Preactivation allows application of larger moments o Resultant moment still not large enough to produce translation www.indiandentalacademy.com
  61. 61. o Increasing size of apical and lateral helices www.indiandentalacademy.com
  62. 62. Clinical Implications www.indiandentalacademy.com
  63. 63. Clinical Implications www.indiandentalacademy.com
  64. 64. L-loop o Boot loop- horizontal extension added o Force system becomes asymmetric o Direction in which ‘L’ is placed- smaller moment or force alone o Generates greatest moment differential between 2 teeth o Length of horizontal = differential force www.indiandentalacademy.com
  65. 65. T- loop o Addition of wire apically at the loop= M/F, LDR o Segmented T-loop- 0.017 x 0.025 TMA www.indiandentalacademy.com
  66. 66. T- loop D=L–A 2 D – length of anterior & posterior arm L – Inter bracket distance A - Activation www.indiandentalacademy.com
  67. 67. o A – Passive o B – Neutral position o C – full insertion www.indiandentalacademy.com
  68. 68. T- loop o Passive www.indiandentalacademy.com
  69. 69. www.indiandentalacademy.com
  70. 70. o Group A- loop closer to canine. Gable bend added nearer the molar, larger β moment, increases posterior anchorage o Group B- Loop midway between posterior and anterior segment o Group C- loop closer to posterior segment www.indiandentalacademy.com
  71. 71. T-loop position and anchorage control AJO 1997–Kuhlberg and Burstone o Effect of off-center positioning on force systems produced by segmented 0.017 x 0.025 TMA T-loop o Spring tested in 7 positions, centered, 1,2 &3mm towards anterior attachment and 1,2 & 3mm towards posterior attachment o Measured over 6mm of spring activation & 23mm IBD o Spring tester apparatus- University of Connecticut o Alpha and beta moments, horizontal and vertical forces measured www.indiandentalacademy.com
  72. 72. Conclusion 1. Centered T-loop, equal and opposite momentsnegligible vertical forces www.indiandentalacademy.com
  73. 73. 2. Off-center positioning- differential moments. More posterior= β moment More anterior= α moment www.indiandentalacademy.com
  74. 74. Standard T-loop can be used for differential anchorage requirement by altering activation and m-d position of spring www.indiandentalacademy.com
  75. 75. o Results consistent with the effect of V-bend activation in archwires for obtaining differential force. o Even 1mm of eccentricity produced marked difference in α & β moments o Spring positioning can be readily used as an effective means of obtaining differential moments o With vertical force, positioning a loop off-center for convenience may produce undesirable results www.indiandentalacademy.com
  76. 76. o For off-centered position magnitude of α,β & horizontal forces was dependent on both activation and position o Horizontal force increased with increase in eccentric position by aprox. 6 to 8gm/mm o Moments increased for the side closer to the T-loop and decreased for the further side. o Vertical forces increased with greater off-centering www.indiandentalacademy.com
  77. 77. o Design features to optimize force system 1. Material used-TMA-excellent spring back, good formability 2. Additional wire apically to activation & M/F 3. Loop centricity 4. Large IBD- allows for sufficient activation www.indiandentalacademy.com
  78. 78. Clinical Implications www.indiandentalacademy.com
  79. 79. Thank you For more details please visit www.indiandentalacademy.com www.indiandentalacademy.com

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