Transcript General principle

General principle
Dr. Ahmed AL-Mayali
B.D.S M.Sc. Orth.
[email protected]
TYPES OF ORTHODONTIC
APPLIANCE
1-Removable appliance
2-Fixed appliance
3-Myofunctional appliance
4-Combination between Removable and Fixed
appliance
Removable orthodontic appliance
Active component
 Retentive component
 Acrylic base plate
 Anchorage
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Material in orthodontic
appliance
Pliers
cutter
stainless steel wire
acrylic
Types of pliers
•Angle plier
•Adam plier
Properties of plier
short blade
Large comfortable handle
Taper of blade
Sharp edges of beaks
No roughness
Not rusted
stainless steel wire
18-8 s.s wire
1-Classification
 soft
 Hard
 Extra hard
2-Advantage
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Does not harm the mouth
Does not tarnish
Supplied hard or soft
Annealed
Welded
Soldered
Once adjusted maintain its displacement
Economical
3-Physical properties
Fatique
Deflection
Flexibility
Rigidity
4-Mechanical properties of
S.S. wire
• F= D *R4/L3
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F
D
R
L
force
deflection
diameter of wire
length of wire
Tooth movement by
removable appliance
Tipping
Rotation less than 90
Orthodontic force
 Light
 Intermittent
 Pressure
25-30 g/cm2
Types of wire bend
•Soft curve
•Right angle bend
•Acute bend
Art
principle
of
wire
bend
• Sitting position
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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, …….