URA Components

Marshitah binti Ab Wahid (1090040)Mohd Azizul Mohd Atan (1090042)

Abdullah Zahid Azhari (1090043)

Components Of Removable Applaince

• Active Components• Retentive Components• Anchorage• Base Plate

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-May be used for moving one tooth or group of teeth (usually more than one tooth to be moved with a screw)-Have different sizes and range of activation-Useful only when a few millimeters of space is needed-Clasps for retention

• Expansion is 1 mm. per one full turn i.e. 0.25 mm. per quarter turn

Elastics • Rubber or latex rings• Function:

-extra-oral traction-inter-maxillary traction

• However, it depends largely on the patient cooperation

Retentive components

• Adam’s clasp• Southend clasp• Labial bow• Ball-ended clasp• Delta 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.

Fabrication of Adam’s Clasp

• 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. St. round wire

Southend clasp

• 0.7mm diameter SS wire• Useful when distal movement of canine is

required

Labial bow

• 0.7mm diameter SS wire• Function:

-retention- important when mesial/distal movement is planned

Ball-ended 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• Provide minimal retention• Use 0.7mm diameter stainless steel wire

Delta clasps

• 0.7mm diameter SS wire• Difficult to adjust• Function like adams clasps, but it utilizes a

helix on the mesial and distal undercuts for retention

Anchorage

Resistance to unwanted tooth movementBY

equal in magnitude and opposite in direction

Types of intra-oral anchorage

Simple-active movement of few

teeth versus several anchor teeth

Reciprocal-when 2 teeth or 2 sets of teeth move to an equal extent in an

opposite direction

Stationary-bodily movement of 1 group

of teeth against tipping of another

Intermaxillary- when the anchorage units situated in 1 jaw used to provide the force

required to move teeth in opposing jaw

Baseplate

• It must be:-hold components-clear acrylic = heat cure, cold cure, autoresin-comfortable-good fit-can be active-act as bite plane

References • http://www.retainerlab.com/Pages/Springs.htm• http://universal-dental-techniques.com• http://www.intelligentdental.com/2011/10/02/agapbetw

een-your-upper-front-teeth/• http://dentallecnotes.blogspot.com/2011/10/note-on-ac

tive-components-of-removable.html• http://o-atlas.de/eng/kapitel5_156.php• http://askanorthodontist.com/braces/what-do-the-elasti

c-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)