Movements with edgewise appliance /certified fixed orthodontic courses by Indian dental academy

395 views

Published on


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

Published in: Health & Medicine, Business
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
395
On SlideShare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
0
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Movements with edgewise appliance /certified fixed orthodontic courses by Indian dental academy

  1. 1. Moments with the edgewise appliance: Incisor torque control INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  2. 2. www.indiandentalacademy.com
  3. 3. www.indiandentalacademy.com
  4. 4.  Will the crowns move or will the roots move?  Which direction will they move?  Will anchorage loss result?  Will the overbite increase or decrease?  Will spaces open or changes in arch perimeter occur?  Are the inherent reciprocal forces that develop recognized?  How are these forces controlled? www.indiandentalacademy.com
  5. 5.  The purpose of this article is to describe the fundamental mechanics used in developing incisor torque and to show clinical examples effectively applying the principle of (1) the moment of a couple and (2) the moment of a force. www.indiandentalacademy.com
  6. 6.  Couple -pair of equal and opposite parallel forces -capable of rotating the tooth around a center of rotation coincident with the center of resistance -cannot move the center of resistance -measured as the magnitude of one of the two equal forces times the distance between the forces -expressed in units, such as gram-millimeters. www.indiandentalacademy.com
  7. 7. www.indiandentalacademy.com
  8. 8. www.indiandentalacademy.com
  9. 9.  To evaluate equilibrium forces- insert wire component only in the bracket part where greater moment is placed. The direction of remaining wire part dictates the direction of equilibrating forces on the adjacent part.  The direction and amount of net equilibrium forces result from the amount of net moment created at adjacent brackets. www.indiandentalacademy.com
  10. 10.  When the two bracket slot-wire axis angles are in the same direction, the moments at each bracket are in the same direction and their equilibrium forces at each bracket are in the same direction.  when the two bracket slot-wire axis angles are oriented in opposite directions, the resulting equilibrium forces at each bracket are in opposite direction and the net equilibrium force is the difference between the larger and smaller force at that tooth.  Point contact at one end www.indiandentalacademy.com
  11. 11.  Length of the molar tube and the depth of the incisor bracket differ markedly, this difference will modify the moment- this issue deserves further investigation.  It is also possible to activate a torquing arch upside down. www.indiandentalacademy.com
  12. 12.  Un-cinched  Cinched - "rowboat" effect www.indiandentalacademy.com
  13. 13.  treatment of an anterior crossbite www.indiandentalacademy.com
  14. 14. www.indiandentalacademy.com
  15. 15. www.indiandentalacademy.com
  16. 16. Moment of a force cannot cause a tooth to rotate around its center of resistance because a force always acts to displace the center of resistance in the direction the force www.indiandentalacademy.com
  17. 17.  So has a center of rotation located somewhere between the center of resistance and infinity determined by the moment to force ratio present.  In this ratio, the moment is the algebraic combination of all moments arising from the forces or couples acting to rotate the tooth. www.indiandentalacademy.com
  18. 18. www.indiandentalacademy.com
  19. 19. www.indiandentalacademy.com
  20. 20.  Point of attachment of basal arch  Effect of insertion of basal arch in to anterior brackets www.indiandentalacademy.com
  21. 21.  No work has ever been reported that shows the extrusive force at the molar results in any greater molar extrusion than that which is readily attributable to normal vertical growth.  It is also possible to activate a base arch upside down to produce extrusion of incisors. www.indiandentalacademy.com
  22. 22.  Uncinched  Cinched- reverse "rowboat" effect www.indiandentalacademy.com
  23. 23. www.indiandentalacademy.com
  24. 24. www.indiandentalacademy.com
  25. 25. www.indiandentalacademy.com
  26. 26.  In the clinical application, the torquing arch is used for incisor crown facial/root lingual movement when open bite tendencies are present.  When excessive incisor overbite is present, the base arch is used for the opposite equilibrium effects.  Arch perimeter changes are a function of cinching or not cinching these systems. www.indiandentalacademy.com
  27. 27.  Inherently present equilibrium forces also create moments of the force that must be used or controlled  Use of TPA www.indiandentalacademy.com
  28. 28.  All orthodontic force systems designed to produce incisor torque must employ either the moment of a couple or the moment of a force.  Moment of a couple -The rotation that a couple produces has its center of rotation at the center of resistance. The equilibrium forces of a torquing arch tend to produce incisor extrusion and molar intrusion. A torquing arch may also produce molar crown facial/root lingual rotation, lose posterior anchorage, and increase arch perimeter depending on how it is employed. Activating a torquing arch upside down produces the same force systems, but all of their directions are reversed. www.indiandentalacademy.com
  29. 29.  moment of a force- rotation occurs with a center of rotation determined by, the moment to force ratio present. The equilibrium forces of a base arch tend to produce incisor intrusion and molar extrusion. A base arch may also produce molar crown lingual/root facial rotation, gain posterior anchorage, and increase arch perimeter depending on how it is employed. Activating a base arch upside down produces the same force systems, but all of their directions are reversed. www.indiandentalacademy.com
  30. 30. www.indiandentalacademy.com For more details please visit www.indiandentalacademy.com

×