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UPPER REMOVABLE APPLIANCE (URA)
GROUP 1
Removable appliances
Work by simple tipping movements of the Work by simple tipping movements of the crowns of the teeth about a fulcrum close to the crowns of the teeth about a fulcrum close to the
middle of the toothmiddle of the toothalso allow differential eruption of teeth, for also allow differential eruption of teeth, for
example by using bite planes. example by using bite planes. They differ from fixed appliances, which are They differ from fixed appliances, which are capable of complex movements of multiple capable of complex movements of multiple
teeth, including bodily movement, root torque teeth, including bodily movement, root torque and rotation.and rotation.
Classification
Function/Role• Interceptive treatment during mixed dentition
– Eg : crossbite correction space maintainer expansion to reopen space
• Facilitate of distal movement of the molars using headgear.• As an adjunct to fixed appliance tx.
– Eg : anterior bite planes for overbite reduction• Maxillary restrain
– Eg: maxillary intrusion splint
• Assess motivation and compliance before more complex tx.
INDICATIONS &CONTRAINDICATIONS
INDICATIONS• Growth modification during
mixed dentition• Limited (tipping) tooth
movements desired (arch expansion, individual tooth mal position).
• Retention following orthodontic treatment
• Adjunct to fixed orthodontic appliances,
• Interfere with (or prevent the development of) abnormal orofacial habits
CONTRAINDICATIONS• Severe skeletal discrepancy• Upper and lower arch
correlate treatment• Severe rotation• Bodily movement needed• Vertical discrepancy• Severe crowding• Very dense bone
ADVANTAGES & DISADVANTAGESADVANTAGES
• Removable for social function• Suitable for simple
malocclusion• Smaller anchorage
requirement• Uncompromised oral hygiene• Short chair-side time• Ease of adjustment• Require less training for
management
DISADVANTAGES
• Dependent on patient compliance
• Less precise control of tooth movement
• Unable to perform complex tooth movement
• Difficult to control space closure• Fewer tooth movement• More difficult to correct
rotation• Affect speech• Retention poor in lower arch• Prone to breakage and loss
ACTIVE COMPONENTS
•Springs•Screws•Elastics
Z-spring• Stainless steel wire• 0.5mm diameter• Function:
-proclination of 1 or 2 incisors-to correct mild rotation if only 1 helix is activated
T-spring
• For incisor, 0.5mm diameter stainless steel(SS) wire• For premolar, 0.6mm diameter SS wire• Function:
-for proclination of incisors or premolar
Finger spring
• For incisor, 0.5mm SS wire• For canine and premolar, 0.6mm SS wire• Function:
-for mesial or distal movement
Labial bow
• 0.7mm diameter SS wire• Function:
-for retraction of anterior teeth
Split labial bow
• 0.7mm diameter SS wire• Function:
-retraction of anterior teeth-to close diastema
Robert retractor
• 0.5mm diameter SS with sleeve• Function:
-retraction of anterior teeth
Buccal canine retractor
• 0.7mm diameter SS wire• Function:
-palatal and distal movement of mesially angulated canine
Coffin spring
• 1.25mm diameter SS wire• Function:
-transverse expansion-buccal crossbite correction
Screw
• Function:-for expansion of arch-for distalization of molar teeth
• 1 turn / week = 0.25mm(1/4 turn)
Elastics • Rubber or latex rings• Function:
-extra-oral traction-inter-maxillary traction
• However, it depends largely on the patient cooperation
RETENTIVE COMPONENTS
• Clasps– Adam’s clasp– C-clasp
(Circumferential clasp)– Lingual extension clasp– Ball clasp
Adam’s Clasp
• The most useful clasp in removable appliances.
• It is designed to engage the MB, DB undercuts of posterior teeth.
• Advantage, it does not separate teeth and has excellent retention.
Adam’s Clasp fabrication
• Components of Adam’s Clasp
• 1- Arrow heads• 2- Bridge• 3- Tags• 4- Retentive parts
• It is made of 0.7 mm diameter hard St. round wire
Adam’s Clasp
• Design modifications
Long bridgeOne arrow head Solder a HG tube to the bridgeSolder hook to he bridge
Adam’s clasp adjustment
• 1. To tighten/loosen: Adjust the arrowhead to grip the undercut of the tooth. Hold arrowhead with pliers at A and bend using finger inwards in direction shown.
• 2. To adjust the height: Hold adams clasp wire the wire exits the acrlyic at pint B and bend the wire up or down to adjust verical position of arrowhead.
Circumferential clasp
• Circumferential clasp– Useful for second molars and canines– Easier to keep it out from occlusal contact– It is only supportive, not as retentive as Adam’s
clasp– It can be adequate for a retainer, but not for an
active appliance
Ball Clasp
• Ball Clasp– It like Adam, extends across the embrasure– Uses buccal undercuts for retention– Easy to fabricate– It is stiff that could not be extended deep into the
undercuts
Lingual Extension Clasp
• Lingual Extension Clasp– It works only from the lingual aspect without crossing the
occlusal surface or embrasures– Short loop of (0.4 mm) wire– Can be placed in the first molar second premolar lingual
embrasure– Difficult to adjust– Break easily– May cause tissue irritation– Can separate teeth if active– Can be used for retainers, – not for active appliance
ANCHORAGE
Resistance to unwanted tooth movementBY
equal in magnitude and opposite in direction
BASEPLATE• It must be:
-hold components-clear acrylic = heat cure, cold cure polymethyl-methacrylate, autoresin-comfortable-good fit-can be active as additional functions-act as bite plane
References • http://www.retainerlab.com/Pages/Springs.htm• http://universal-dental-techniques.com• http://www.intelligentdental.com/2011/10/02/agapbetween-your-
upper-front-teeth/• http://dentallecnotes.blogspot.com/2011/10/note-on-active-
components-of-removable.html• http://o-atlas.de/eng/kapitel5_156.php• http://askanorthodontist.com/braces/what-do-the-elastic-rubber-
bands-on-braces-do/• Lecture by Dr. Norzakiah(principles of removable appliance
therapy-part 1)• Lecture by Dr. Fitri Octavianti(types of orthodontic appliances)