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Removable appliances /certified fixed orthodontic courses by Indian dental academy


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 ,or call

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  • 1. REMOVABLE APPLIANCES: DESIGN AND USE INDIAN DENTAL ACADEMY Leader in continuing dental education
  • 2. Removable appliances - can be taken out of the mouth for cleaning by the patient and adjustment by the orthodontist - apply their forces by means of springs, screws, and bows of various types - can tip teeth only
  • 4. ANCHORAGE - DEFINITION “For every action there is an equal and opposite reaction” (Newton’s 3rd law) “Resistance to unwanted tooth movement” - Proffit, 1993 The area from which the force is applied to move the teeth.
  • 5. HOW TO CONSERVE / INCREASE ANCHORAGE 1. Clasp more teeth 2. Move only one or two teeth at a time 3. Use lighter forces 4. Occlusal capping 5. Add headgear
  • 6. FORCES TO MOVE TEETH Single tooth movement: no more than 25 - 40 grams per tooth Apply to the cervical margin of the tooth to reduce the tipping tendency to minimum
  • 7. RETENTION - Achieved by clasps of various types - Adams’ cribs - molars and premolars - Southend clasps - incisors - ball hooks - interdental embrasure
  • 8. CLASP CONSTRUCTION Adams’ cribs - molar clasps in 0.7mm stainless steel round wire - premolar / deciduous clasps in 0.6mm wire Southend - 0.6 mm wire Ball hooks - 0.7 or 0.6 mm wire with soldered ball on end
  • 9. ACTIVE COMPONENTS SPRINGS - 0.5mm or 0.7mm wire to move single teeth or groups of teeth Constructed in 18/8 austenitic stainless steel The more wire incorporated, the greater the range of the spring and the lighter the force exerted
  • 10. FORCE AND DEFLECTION OF STAINLESS STEEL SPRINGS F = k .d .r4 l3 where r = radius of the wire d = deflection of the wire l = length of the spring k = stiffness of the wire (Young’s Modulus)
  • 11. FORCE AND DEFLECTION OF STAINLESS STEEL SPRINGS Increasing the radius of the wire by 2 will result in the force applied increasing by 16 times; Increasing the length of the spring by 2 will reduce the force applied by 8 times
  • 12. FITTING A REMOVABLE APPLIANCE 1. Check that the appliance is the one for the patient! 2. Check acrylic for sharp edges (esp. in palatal rugae area) 3. Fit appliance in patients mouth. Note any rocking, or areas that do not fit and adjust if necessary 4. Tighten clasps and check retention 5. Activate springs and check that teeth are free to move (trim acrylic if necessary)
  • 13. FITTING A REMOVABLE APPLIANCE (cont’d) 6. Chat to the patient with appliance in place. Ask about any discomfort 7. Give written and verbal instruction to patient and parent. Normally removable appliances are worn 24 hours/day. Warn of initial discomfort, etc. 8. Dismiss patient and arrange next appointment
  • 14. AT THE FIRST REVIEW VISIT: 1. Chat to patient and note speech with appliance in place. Ask about any problems. 2. Check appliance out of mouth. Note loss of surface lustre, tooth impressions on bite planes etc. 3. Check condition of mouth - palatal mucosa should have indentation or redness if good URA wear. Note any trauma from springs etc 4. Check position of teeth that are being moved and the anchor teeth from the original study models
  • 15. AT THE FIRST REVIEW VISIT (cont’d): 5. Teeth should be slightly mobile if movement is occurring. If teeth are not moving, look for a cause (acrylic in the way, insufficient activation of springs, unerupted teeth, retained roots, etc) 6. Reactivate springs 1-2mm and tighten cribs. 7. Congratulate patient if appropriate and reappoint * approx. 1mm of tooth movement should occur each month
  • 16. Clinical Scenarios •These are designed to facilitate the understanding of which components carry out which functions during removable appliance therapy; and also to provide diagramatic illustrations of the various components to facilitate the instructions to the orthodontic laboratory technician.
  • 17. Clinical scenarios • • • • 1. Upper incisor behind bite 2. Class III incisors & deep bite 3. Increased OJ - extract 1st premolars 4. Palatal displacement of upper premolar • 5. Upper canine displaced buccally • 6. Class 2 div 1 & compromised 6’s • 7. Lower 2nd premolar impeded
  • 19. RETENTION: Adams cribs 6/6 and 4/4
  • 20. Active component: Z-spring to 1/
  • 21. BITE OPENING: Posterior bite capping to 654 / 456 (more comfortable for patient)
  • 22. BASEPLATE: to connect everything together, also some anchorage
  • 24. ...VOILA!
  • 25. PROBLEM 2: All four incisors inside bite, with deep reverse overbite
  • 26. RETENTION: Adams cribs 6/6 and 4/4
  • 27. ANTERIOR RETENTION: Southend clasp 1/1
  • 28. ACTIVE COMPONENT: Expansion screw to section 21/12
  • 29. BITE OPENING: occlusal capping posteriorly
  • 30. Screw is opened by one quarter turn twice a week and pushes upper incisors forward over the bite
  • 31. PROBLEM 3: Increased overjet, proclined incisors
  • 32. Extract 4/4 to allow overjet reduction
  • 33. RETENTION: Adams cribs on 6/6 , Southend clasp 1/1
  • 34. ACTIVE COMPONENTS: Palatal finger springs 3/3 with wire guards for stability
  • 35. Trim acrylic BITE OPENING: flat anterior bite plane
  • 36. 3/3 at end of canine retraction
  • 37. Canines retracted. Now the incisors must be retracted
  • 38. RETENTION: Adams cribs 6/6 with arrowhead extensions to 5/5
  • 39. Metal stops mesial to 3/3 to prevent these teeth from moving forward
  • 40. ACTIVE COMPONENT: Labial bow in 0.7 mm wire with large U-loops to allow activation
  • 41. BITE OPENING: flat anterior bite plane
  • 42. Labial bow activated 1-2 mm at each visit by squeezing vertical legs of U-loops together. Palatal acrylic must be trimmed away by the same amount.
  • 43. End of incisor retraction
  • 44. Where canines are bucally placed, use buccal canine retractors, made in either 0.7mm wire or 0.5mm wire supported by 0.5mm internal diameter tubing where it emerges from the acrylic
  • 45. Canines can be pushed palatally into the line of the arch as they move distally
  • 46. The labial segment can be retracted also with a 0.5mm labial bow with tubing support.
  • 47. ACTIVATION OF LABIAL BOW: Press the vertical leg towards the tubing
  • 48. Position of helix is very important - it must be placed half-way between the starting position of the tooth and the desired finishing position
  • 49. Helix too far anteriorly - tooth will move palatally
  • 50. Helix too far distally - tooth will move buccally
  • 51. WHY IS IT NECESSARY TO REDUCE THE OVERBITE BEFORE REDUCING THE OVERJET? As incisors tip, the lower incisors prevent further overjet reduction due to increasing overbite
  • 52. By incorporating an anterior bite plane, the overjet can be successfully reduced without increasing the overbite as the incisors tip palatally
  • 53. Trimming to allow the incisors to retrocline: trim on palatal aspect, with bur parallel to palatal surface. Don’t trim from the occlusal surface - reduces width of bite plane excessively.
  • 54. Bite opening - posterior teeth erupt into the space
  • 55. PROBLEM 4: /5 deflected palatally, /6 has drifted mesially
  • 56. RETENTION: Adams cribs 6 / 46 , southend clasp 1/1
  • 57. ACTIVE COMPONENT: Screw section to /6 , Z-spring to /5
  • 58. PROBLEM 5: Buccally placed canine /3
  • 59. Retention: Adams cribs 6/6 and 4/4
  • 60. ANCHORAGE REINFORCEMENT: Headgear tubes on 6/6
  • 61. ACTIVE COMPONENT: Screw section to distalise /456
  • 62. ANCHORAGE REINFORCEMENT: headgear to tubes on 6/6
  • 63. Problem 6: Class II div 1, and both upper first permanent molars are carious
  • 64. Adams cribs on 73/37, finger springs 5/5 and 4/4, fitted labial bow 21/12
  • 65. Extract 6/6
  • 66. Retract 5/5 (with or without headgear support)
  • 67. Retract 4/4
  • 68. Adams cribs 74/47, finger springs 3/3, Southend clasp 1/1
  • 69. Upper 3/3 retracted
  • 70. URA with labial bow to retract 21/12
  • 71. Problem 7: an unerupted 5/ where extraction of the 4/ would give too much space
  • 72. FIN they say at the end of all French films