Removable Clear Appliance

removable clear appliances, history, Kesling retainer, potiz retainer, Essix retainer, and Invisalign retainer, how clear appliances work, and patient compliances.

1. Removable clear appliance Dr. Shweta A. Kolhe BDS. MDS. PhD (scholar)

2. History Patients seeking orthodontic treatment are increasingly demanding more aesthetic options. Use of ceramic and lingual braces to a large extent satisfied the aesthetic demand of many patients. Thermoformed appliances or clear plastic appliances are used to bring about active orthodontic treatment.

3. Kesling (1945) introduced a tooth positioner for refining the final stage of orthodontic treatment after debanding . A positioner was a rubber appliance fabricated on the idealized wax set-ups for patients whose basic treatment was complete. Advantage- positioner include ability to position teeth esthetically. - To retain the alignment of the teeth achieved.

4. Ponitz (1971) introduced invisible retainer, made of a thin thermoplastic acrylic sheet. Used - as retainer after active phase of orthodontic treatment. - for bringing about minor tooth movement. - to treat minor relapses . - for detailing of the occlusion. Appliance is accomplished by resetting teeth in the working model an then fabrication of the appliance.

5. Essix retainer (1993) – similar to the invisible retainer, made up of a clear thin material that snap-fits over the dentition. Essix system can be modified by the orthodontist to bring about minor tooth movements.

6. Invisalign appliance (1997) introduced by Align technology. This system made use of computer – aided – design and computer-aided-manufacturing (CAD-CAM) technology to fabricate a series of positioners (aligners) that can move teeth in small increments of about 0.25 to 0.3 mm. This system revolutionized the use of clear esthetic plastic appliances to effectively bring about tooth movement without the need for making successive model setups to fabricate the appliances.

7. Invisalign System The Invisalign system makes use of a series of aligners made from a thin, transparent, thermoplastic plastic material formed with CAD-CAM techniques. These aligners are similar to the invisible retainers and cover the clinical crowns and the marginal gingiva. Each aligner is designed to move the teeth a maximum of about 0.25 to 0.3 mm over a 2 week period. The aligners are worn in a specific sequence each bringing about 0.25 to 0.3 mm of tooth movement.

8. Patient compliance : Invisalign, removable appliance. Patient motivation and compliance are critical in achieving the desired result. Patient must wear it for 20 to 22 hours a day. Each aligner should be worn 400 hours to be effective. They may remove it only when eating, when drinking hot drinks or beverages that contain sugar and when brushing and flossing.

9. Indications of Invisalign - Crowding of 1-6 mm. Mild to moderate spacing of 1-6 mm Constricted arches of non-skeletal nature. Mild relapse cases after fixed appliance therapy. ( Treating mid to moderate malocclusions: space closure, tooth alignment, limited dental expansion, incisor advancement and limited distalization of teeth)

10. Contraindications of Invisalign- Crowing and spacing over 5 mm. Skeletal anterior-posterior discrepancies of more than 2 mm. (Include class II and class III cases.) Centric-relation and centric-occlusion discrepancies. Severely rotated teeth (more than 20 ) Open bites (anterior and posterior) that need to be closed. Patients who require extractions. Severe deep bite Extrusion of teeth Severely tipped teeth (more than 45 ) Teeth with short clinical crowns. Arches with multiple missing teeth.

11. Steps In Treatment With Invisalign Pre-appliance requirements Patient records, diagnosis and treatment plan Records submission 3-D Computer modeling The doctor reviews and approves Clincheck Aligner manufactured and shipped to practitioner for delivery to patient Monitoring treatment, obtaining desired results and retention.

12. 1. Pre-appliance requirements Prior to the initiation of this treatment all necessary restorative treatment must be competed. An important prerequisite is that the patient should not exhibit active periodontal disease. Informed consent should be completed before treatment begins.

13. 2. Patient records, diagnosis and treatment plan As with any orthodontic treatment including fixed – appliance therapy, a through patient history, clinical examination, diagnosis and a treatment plan is mandatory. A comprehensive evaluation of the patient is advised.

14. 3. Records submission The most important step in fabricating aligners is obtaining accurate Polyvinyl siloxane (PVS) upper and lower impressions. A Polyvinyl siloxane (PVS) bite registration should also be made. Eight photographs are required to be submitted :- Extraoral: frontal smiling Frontal repose Lateral profile repose Intraoral anterior intraoral right and left buccal Intraoral maxillary and mandibular occlusal.

15. A prescription form is to be filled containing the patient’s diagnostic data. Doctors can register their general priorities and preferences for the treatment. Align technology provides disposable impression trays and boxes for packing and postage of the impressions and bite registration. The patient’s diagnostic data can be submitted online

16. 4. 3-D Computer modeling Once the records including the impressions and bite reach Align Technology, the patient’s PVS impressions are transformed into 3-D images to prepare a three – dimensional computer graphic image of the patient’s teeth and associated tissues. The ClinCheck software uses the practitioner’s treatment form and stated preferences to generate a computerized final status of the dentition. It also generates stages between the start and finish to bring about approximately 0.25 mm of movement anticipated in each increment.

17. 5. The Doctor Reviews And Approves Clincheck After computerized pan of treatment, the dentist is notified that the case is ready for review of its ClinCheck . Careful review of Clincheck is essential to achiee the best possible results. Clinicians can request modification at this time if he fees it is required.

18. 6. Aligner manufactured and shipped to practitioner for delivery to patient After ClinCheck is approved by the dentist, Align Technology uses the sequence of graphical images combined with CAD/CAM to produce clear, lightweight aligners and posts them to the Dentist. If attachments are part of the plan of treatment, an “attachment template” is sent with the aligners and bonded to teeth by the dentist at the beginning of treatment. Attachments serve as “handles” used to assist in the retention of the appliance or specific types of movements.

19. 7. Monitoring treatment, obtaining desired results and retention Careful treatment monitoring helps to identify problems. At each patient visit, check the occlusion and verify fitting of aligner and compare the treatment progress to the CinCheck simulation at three-month intervals. If teeth do not seem to be tracking well in the aligners then treatment needs to be modified. After case completion, the final aligner should not sere as a long term retainer An invisible retainer can be an excellent choice after active phase of treatment is completed using Invisalign.

20. How does the Invisalign system work? The Invisalign system is force-driven The Invisalign aligner, formed in a shape that is intended to impart specific forces to the tooth crown, resulting in the desired tooth movement. By applying a range of M/F values, different types of tooth movement can be accomplished. Force systems are measurable. Invisalign aligners are designed with precise control of the force system to provide excellent control of tooth movement.

21. Lingual root torque The Power Ridge feature is a change in the shape of the aligner designed to apply a lingual force to the tooth and to control the distortion of the aligner near the lingual incisal edge. Treatments for lingual root torque with retraction result in removal of the contact on the lingual incisal edge that is required for control of the root; the lingual Power Ridge feature is designed to restore the contacts in these treatments.

22. Extrusion An Optimised Attachment changes the shape of the tooth so forces can be applied in the correct direction. The Optimised Extrusion Attachment provides a flat planar “active surface”, on which the aligner imparts force. It is the only surface engaged by the aligner. The rest of the attachment material exists only to hold the active surface in place. This force system is considered to provide more successful extrusion of all incisors as a unit and is being used effectively in the treatment of open bite.

23. Root tip control Optimised Root Control Attachments are customized for each patient’s morphology and provide mesiodistal root tip control. Clinical applications include space closure, mesiodistal uprighting , and bodily movement

24. Rotation Rotation of a tooth around its long axis, considered difficult to achieve with aligners. More predictable rotation of canines and premolars can be accomplished using Optimised Rotation Attachments. The active surface of the attachment is automatically positioned on the buccal surface, as far from the long axis of the tooth as possible, and designs the aligner to apply force to this surface.

25. SmartForce features The Invisalign system is the only clear aligner system that combines multiple Smart innovations. It is designed specifically for the treatment of more difficult malocclusions such as open bite, deep bite, or first premolar extraction (planned for maximum anchorage). Proprietary ClinCheck treatment planning software analyses tooth movements to determine the optimal force required and automatically places attachments and features to achieve the desired movement based on specific tooth size and shape. Therefore, it’s the force-driven system that applies the right amount of force necessary to move the teeth, and not through manual placement. With SmartForce Aligner Activation, specific areas on the aligner surfaces are now contoured to apply forces onto the tooth surface in the proper direction to produce the desired movement and minimize unwanted movements

26. The Essix System Essix system unlike the Invisalign system utilizes the skill of the dentist in the fabrication and realization of the treatment objectives. The appliance is made up of a thin, durable thermoplastic material that is practically invisible. Most treatment is accomplished by modifying the appliance a number of times during the course of treatment.

27. The Essix System How the system works : The Essix system can be used to bring about tooth movement in all planes of space. Whenever a tooth movement is planned using the thin plastic appliance, provision should be made for the application of force and also a space should be planned in the appliance in the direction of the moving tooth. E.g. if a tooth is moved palatally , force should be applied by the appliance on the labial aspect and a space should exist on the palatal aspect of the appliance for the tooth to move palatally .

28. Creating space within the appliance: Space can be planned in the appliance in the direction of the moving tooth. Done by blocking out an area on the working model using composites. The amount of block-out used should be proportional to the intended amount of tooth movement. Once the appliance is fabricated we would observe a space in the direction of the tooth movement.

29. Deep-Bite Correction

30. An alternate way to create a space is by cutting out a window in the appliance in the direction of tooth movement. This can be made using plastic trimming burs at a slow speed. The size of the window should be large enough for the intended tooth to move through.

31. Including tooth moving forces in the appliance : There are two method of including a force using the Essix system. First method is by the use of Hilliard thermopiler which induces a spot projection in the appliance in the direction of the desired force. The second method of inducing a force on the appliance is by placing a small mound of composite on the tooth where the force needs to be applied.

32. The first method is by the use of Hilliard thermopliers which induces a spot projection in the appliance in the direction of the desired force. The plier tip is heated to 200 F and is used on the appliance at the planned spot by gripping it. This produces projection in the appliance that produces the desired force to move the tooth. Another method that can be used is to create a small notch on the working model which would produce a small projection on the appliance in the area where the force is desired.

33. The second method of inducing a force on the appliance is by placing a small mound of composite on the tooth where the force needs to be applied. If additional tooth movement is desired more composite can be added. The area where the composite mound is placed can be altered during the treatment to bring about the desired movement of tooth

34. Compliance With Removable Clear Appliances Patient motivation is critical in achieving the desired results when using removable clear appliances. Patients must wear it at least 22 hours a day for these appliance to be effective. They need to be removed when eating; drinking hot beverages that may cause warping or staining or beverages that contain sugar and when brushing and flossing. Transparency of this appliance may increase the likelihood of its being misplaced when it is removed.

35. Thank you