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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  • 1. INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com 2 www.indiandentalacademy.com
  • 2. Ongoing Innovations in Biomechanics & Materials for the New Millennium- Robert P. Kusy www.indiandentalacademy.com
  • 3. Conventional Begg o Attritional occlusion in Australian Aborigines o Concept of differential forces www.indiandentalacademy.com
  • 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. 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. 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. www.indiandentalacademy.com
  • 8. Elastics o Differential configuration o U/L class I www.indiandentalacademy.com
  • 9. Elastics o Class II with lower class I- molar relation not corrected www.indiandentalacademy.com
  • 10. Elastics o Z configuration (class II part time) www.indiandentalacademy.com
  • 11. Elastics o Class II only- U/L anteriors do not retract at the same rate www.indiandentalacademy.com
  • 12. Elastics o Lower class I only (anteriors in crossbite) www.indiandentalacademy.com
  • 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. Braking mechanics o Braking pins- passive uprighting springs, 0.018” almost fill the bracket channel www.indiandentalacademy.com
  • 15. Braking mechanics o Angulated T pins- maintain tipping www.indiandentalacademy.com
  • 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. Braking mechanics o Torquing auxiliaries- 2 spur or 4 spur - MAA 0.010”/0.011”(0.020” base wire) www.indiandentalacademy.com
  • 18. o Duration of stage II–  2 stages together approximately 1 year-not more than 1 year 3 months www.indiandentalacademy.com
  • 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. o Pre-Torqued brackets o Combination archwire www.indiandentalacademy.com
  • 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. 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. KB Technique o By-Pass Loop- 3 dimensional control of 2nd PM www.indiandentalacademy.com
  • 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. www.indiandentalacademy.com
  • 26. www.indiandentalacademy.com
  • 27. www.indiandentalacademy.com
  • 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. J- Hook Headgear- John Hickam www.indiandentalacademy.com
  • 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. 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. 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. 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. o Tip-Edge vs Ribbon Arch Bracket www.indiandentalacademy.com
  • 35. www.indiandentalacademy.com
  • 36. www.indiandentalacademy.com
  • 37. www.indiandentalacademy.com
  • 38. Dr. SAFEENA www.indiandentalacademy.com
  • 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. 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. 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. 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. 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. 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. 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. www.indiandentalacademy.com
  • 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. Vertical Loop o Open Vertical Loop o Closed vertical loop www.indiandentalacademy.com
  • 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. Height restricted by anatomy of oral cavity www.indiandentalacademy.com
  • 51. www.indiandentalacademy.com
  • 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. 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. 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. 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. o Apical helix www.indiandentalacademy.com
  • 57. o Preactivation www.indiandentalacademy.com
  • 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. o Preactivation and Helices www.indiandentalacademy.com
  • 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. o Increasing size of apical and lateral helices www.indiandentalacademy.com
  • 62. Clinical Implications www.indiandentalacademy.com
  • 63. Clinical Implications www.indiandentalacademy.com
  • 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. 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. T- loop D=L–A 2 D – length of anterior & posterior arm L – Inter bracket distance A - Activation www.indiandentalacademy.com
  • 67. o A – Passive o B – Neutral position o C – full insertion www.indiandentalacademy.com
  • 68. T- loop o Passive www.indiandentalacademy.com
  • 69. www.indiandentalacademy.com
  • 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. 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. Conclusion 1. Centered T-loop, equal and opposite momentsnegligible vertical forces www.indiandentalacademy.com
  • 73. 2. Off-center positioning- differential moments. More posterior= β moment More anterior= α moment www.indiandentalacademy.com
  • 74. Standard T-loop can be used for differential anchorage requirement by altering activation and m-d position of spring www.indiandentalacademy.com
  • 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. 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. 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. Clinical Implications www.indiandentalacademy.com
  • 79. Thank you For more details please visit www.indiandentalacademy.com www.indiandentalacademy.com