Removable orthodontic appliances KRISTNA DANDOV Removable orthodontic appliances
Removable orthodontic appliances KRISTÝNA DANDOVÁ
Removable orthodontic appliances Used for correction of different orthodontic defects Defects of bite - open bite - crossbite - under bite � Defects of individual teeth - rotation - protrusion, retrusion -crowding �
� Removabe orthodontic appliances are composed of acrylic body and clasps � The clasps are twisted of wire by special pliers (bird beak, cutter)
The double helical spring � Made of 0. 5 mm wire � Double helical spring is maximizing the elasticity of the protrusion spring
� The double helical spring ( Z-spring) is usualy used on rotated incisors � The spring is located on the tooth neck � The right sided and left sided z springs are fabricated accordingly
The Adams clasp � 0, 7 mm stainless steel wire � Adams clasp is used as anchorage of the appliance � Usualy situated on molars
Twisting of Adams clasp 1 st step
2 nd step
3 rd step
The Adams clasps on the upper jaw
The Adams clasps on the lower jaw
No contact with palate
The ball clasps � 0, 7 mm wire � Used as anchorage of the removable appliances � Situated on incisors or in between premolars
The ball clasp on the upper jaw
No contact with palate
The ball clasp on the lower jaw
The labial bow � Made of 0, 7 mm wire � Used for harmonic alignment of the anterior segment
The labial bow is situated is composed of three parts: � Horizontal bow portion � „U“ loops � Retentive arms The bow is situated between the canines
The labial bow on the upper jaw
The labial bow on the lower jaw
Example of another modification of the labial bow
The upper jaw with all retentive clasps
The lower jaw with all retentive clasps
� All clasps are fixed on models by wax
� Before the application of acrylic models have to be put into the water isolation
Application of acrylic � After choosing of the color we can start with application of acrylic � We change application of powder and liquid untill we have appropriate shape of the appliance
Orange liquid Red liquid Acrylic powder
� The poymerization proceeds in the polymerization unit (10 min, 55°C, 3 -3, 5 bar)
� Polymerized applicances are machined by milling frases.
Instruments to produce an orthodontic appliance Separating disc rubber
Machined appliance before polyshing
Polyshing
The upper jaw
The lower jaw
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