CATEGORY AUSTRALASIAN DENTIST 59 LINICAL Patterns of Staging Simultaneous staging First suggested by Foy (2004) and then refined by David Paquette (2005). This standard simultaneous staging pattern is also referred to as X staging pattern. The basis for simultaneous movement is that all of the teeth within each arch are moved together from the initial stage through the final stage. the anterior teeth. It typically applies only to the upper arch. Example., correcting a Class II Angle molar relationship to a Class I molar Angle relationship. Moving molars from a Class II relationship to a Class I relationship and then holding the teeth motionless, simulating maximum anchorage while the rest of the arch moves distally to a Class I relationship. A staging pattern: The opposite of V staging pattern, in which the anterior teeth move anteriorly, followed by posterior teeth moving anteriorly (Mesialization). This pattern could be used in either arch to open previously closed extraction spaces or to attempt to mesialize an entire arch in a segmental fashion. M staging pattern: Follows for bicuspid extraction treatment. In this staging pattern, movement starts by first closing the extraction spaces, followed by levelling and alignment of anterior teeth, and finishing. determining toothwould decrease to nearly 0.12 mm per stage, and all of the other teeth in the arch would be significantly less than 0.12 mm linear movement per aligner. Reducing tooth movement per aligner then allows an accelerated changing schedulebecauseof lesselasticdeformation of the aligner material. Many orthodontists who increase the number of active stage aligners deliver fresh aligners on a weekly basis to have the aligners provide a more consistent force, with less force diminution between aligner changes. Although twice as many aligners are the result, the total treatment time remains the same. According to Simon et al (2004), the study concluded that in addition to the amount of derotation, the staging (amount of derotation/aligner) also has a considerable impact on the treatment efficacy: u for premolar derotations with a staging <1.5°/aligner, the total efficacy was 41.8%, whereas with a staging >1.5°/ aligner, the accuracy decreased to 23.2%. u also analysing premolar rotations of >10°, concluded that the use of attachments and the amount of movement per aligner had a great impact on the treatment predictability. Simultaneous Staging Pattern Simultaneously moving the other teeth from the first to the last stage reduces the velocity for all the other movements and increases their predictability without increasing the overall number of aligners. Segmented staging This pattern was based on the classic notion of anchorage in which one group of teeth is held stationary while a smaller group of teeth is moved. Types of segmented staging pattern involves; V staging pattern: Follows for Distalization of the maxillary dentition, starting with the molars, followed by the bicuspids, and ending with the retraction of Velocity for various tooth movements The staging of orthodontic tooth movement refers to the sequential movement of the teeth with the aligner trays. The tooth that is moved the most is known as the leading tooth. It is the staging of the leading tooth that determines the total number of aligner trays. The degree of movement of a tooth with each tray determines its velocity in terms of staging. Velocities can be, u up to 2 degrees/aligner for rotation, u up to 1 degree/aligner for incisor torque and u up to 0.25 mm/aligner for distalization are possible. If the number of active stages were doubled, then the movement of the rateu reducing the staging and using attachments increase the predictability of tooth movement. u it is always recommended to plan overcorrections, especially if rotations exceed 15º, to use attachments, and to reduce staging to less than 1.5º per aligner. Conclusion Although significant clinical testing has gone into the development of staging patterns, understanding that the orthodontist can always request custom staging is important, when the clinician feels it is necessary to improve treatment outcomes. Ultimately, the orthodontist controls all aspects of the treatment, including howmuch movement per aligner is desired. Some orthodontists greatly reduce the amount of linear movement per stage by increasing the number of active stage aligners using simultaneous tooth movement or X pattern staging for complex movements. Increasing the number of active stages with simultaneous tooth movement effectively reduces the amount
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