General principle

Dr. Ahmed AL-MayaliB.D.S M.Sc. Orth.

ahmed.almayali@uokufa.edu.iq

TYPES OF ORTHODONTIC APPLIANCE1-Removable appliance

2-Fixed appliance

3-Myofunctional appliance

4-Combination between Removable and Fixed appliance

Removable orthodontic appliance

Active componentRetentive componentAcrylic base plateAnchorage

Material in orthodontic appliance

• Pliers• cutter• stainless steel wire • acrylic

Types of pliers •Angle plier•Adam plier

Properties of plier

short blade Large comfortable handleTaper of bladeSharp edges of beaksNo roughnessNot rusted

stainless steel wire

18-8 s.s wire1-ClassificationsoftHardExtra hard

2-Advantage

Does not harm the mouth Does not tarnish Supplied hard or soft Annealed Welded Soldered Once adjusted maintain its displacement Economical

3-Physical properties

FatiqueDeflectionFlexibilityRigidity

4-Mechanical properties of S.S. wire

• F= D *R4/L3• F force• D deflection• R diameter of wire• L length of wire

Tooth movement by removable appliance

TippingRotation less than 90

Orthodontic force

LightIntermittentPressure 25-30 g/cm2

Types of wire bend

•Soft curve•Right angle bend•Acute bend

Art principle of wire bend• Sitting position• Cutting the wire• Wire straight• Non traumatic end• Plier gripping • Area of contact × point of contact• Firm wire gripping• Clean left hand• Marker pen• Avoid notching• Avoid repetition• Don’t go back• Imagination• Follow the anatomy• Parallel to the gum, …….