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Presentation on theme: "UPPER REMOVABLE APPLIANCE (URA)"— Presentation transcript:


2 Removable appliances  Work by simple tipping movements of the crowns of the teeth about a fulcrum close to the middle of the tooth also allow differential eruption of teeth, for example by using bite planes. They differ from fixed appliances, which are capable of complex movements of multiple teeth, including bodily movement, root torque and rotation.

3 Classification Active (produce tooth movement/growth modification)
Removable appliance Active (produce tooth movement/growth modification) Mechanical appliances Functional appliances Passive Retainer Space maintainer

4 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.

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 Severe skeletal discrepancy Upper and lower arch correlate treatment Severe rotation Bodily movement needed Vertical discrepancy Severe crowding Very dense bone

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 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

URA DESIGN PRINCIPLES RETENTIVE Clasp ANCHORAGE Simple Reciprocal Stationary Intermaxillary BASEPLATE Heat cure Cold cure Autoresin ACTIVE Springs Screws Elastics

8 Springs Screws Elastics
ACTIVE COMPONENTS Springs Screws Elastics

9 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

10 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

11 Finger spring For incisor, 0.5mm SS wire
For canine and premolar, 0.6mm SS wire Function: -for mesial or distal movement

12 Labial bow 0.7mm diameter SS wire Function:
-for retraction of anterior teeth

13 Split labial bow 0.7mm diameter SS wire Function:
-retraction of anterior teeth -to close diastema

14 Robert retractor 0.5mm diameter SS with sleeve Function:
-retraction of anterior teeth

15 Buccal canine retractor
0.7mm diameter SS wire Function: -palatal and distal movement of mesially angulated canine

16 Coffin spring 1.25mm diameter SS wire Function: -transverse expansion
-buccal crossbite correction

17 Screw Function: -for expansion of arch
-for distalization of molar teeth 1 turn / week = 0.25mm(1/4 turn)

18 Elastics Rubber or latex rings Function: -extra-oral traction
-inter-maxillary traction However, it depends largely on the patient cooperation

19 RETENTIVE COMPONENTS Clasps Adam’s clasp
C-clasp (Circumferential clasp) Lingual extension clasp Ball clasp

20 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.

21 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

22 Adam’s Clasp Design modifications Long bridge One arrow head
Solder a HG tube to the bridge Solder hook to he bridge

23 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.

24 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.

25 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

26 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

27 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

28 ANCHORAGE Resistance to unwanted tooth movement BY equal in magnitude and opposite in direction

29 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

30 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

31 References
Lecture by Dr. Norzakiah(principles of removable appliance therapy-part 1) Lecture by Dr. Fitri Octavianti(types of orthodontic appliances)


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