DEFINITION
Fixed Appliances are devices or equipments that are attached to the teeth , cannot be removed by the patient and are capable of causing tooth movement.
ARCHWIRES
Ideal Properties
Materials
Stainless steel/ Cobalt chromium
Precious metal
Nickel-Titanium
Beta-Titanium
Composite Plastics
BANDS
MOLAR TUBE
BANDS FOR ATTACHMENTS.
Indications for Banding
Teeth that will receive heavy intermittent forces against the attachments.
Teeth that will require both labial and lingual attachments.
Teeth with short clinical crowns.
Teeth with extensive restorations.
STEPS IN BANDING
BONDED ATTACHMENTS
Mechanical locking of an adhesive to irregularities in the enamel surface of the tooth and to mechanical locks formed in base of the 0rthodontic attachment.
Armamentarium
Direct Bonding
Indirect Bonding
ACCURACY IN PLACEMENT!
Debanding/Debonding
Bends
Disadvantages of Angle’s edgewise appliance
Heavy forces required Complex wire bending
Increased friction
Extraoral forces for anchorage required
Difficulty in opening deep bites
TWEED’S MODIFICATION OF EDGEWISE
Advocated extraction of teeth in selected cases for better stability
Tweed moved the teeth bodily and used the subdivision approach for anchorage control, first sliding the canines distally the arch wire and then retracting the incisors
BEGG’S APPLIANCE
Modified ribbon arch technique and introduced the Begg’s light wire differential force technique
Concluded extraction of teeth was necessary and set out to adapt ribbon arch appliance so that it could be used for better root positioning control.
Begg’s adaptation took 3 forms:
Replaced precious metal wire with high strength 16 mil stainless steel
Retained the original ribbon arch bracket but turned it upside down so that the bracket slot pointed gingivally rather than occlusally
He added auxillary springs to the appliance for the control of root position
Resulting in reduced friction as the area of contact between the narrow ribbon arch bracket and the archwire was very small and the force of the wire was also small
Begg’s strategy for anchorage control was tipping/uprighting
LABIOLINGUAL, TWIN WIRE
First half of the 20th century, Labiolingual appliance & Twinwire appliance were major competing appliances for repositioning teeth
Bands on first molars and a combination of heavy lingual and labial archwires to which fingersprings were soldered to move individual teeth ? Labiolingual appliance
Twin wire appliance used bands on incisors as well as molars and featured twin 10mil steel archwires for alignment of the incisor teeth.
Delicate wires were protected with long tubes that extended forward from the molars to the vicinity of canines.
None of these appliances were capable of more than tipping
CONTEMPORARY EDGEWISE
Major steps in evolution of edgewise include :
Bends
SELF LIGATING BRACKETS
INDIVIDUALLY CUSTOMIZED BRACKETS
ARCH FORM AND ARCH WIRE FABRICATION
WIRE BENDING ROBOTS
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
الرجوع الى لوحة التحكم
|