CDEN0210

08 I I MICD _ Inman Aligner 3. Crowding or spacing should be less than or equal to 3 mm. Arch evaluation must be performed to determine the amount of space required. Cases with over 3 mm of crowding require additional spacecreationtechniques,aspioneeredintheUK, which should only be attempted with training. It isquitepossibletotreatcaseswith5.5mmcrowd- ing easily and predictably in less than 16 weeks. 4. Cases should have fully erupted posterior teeth to facilitate retentive clasps, with a reasonably well-aligned arch form to facilitate the path of insertion of the appliance. 5. Cases should be stable and preferably free from periodontal disease. 6. Patients must agree to wear the Aligner for about 20 hours a day and be responsible for good appli- ance and oral hygiene. Should the patient wear theAlignerfor14hoursadayonly,treatmentwill still be successful. Modelevaluation/archanalysiswithSpacewize Arch analysis should be performed before any Aligner case is attempted in order to ensure that thecaseissuitableand,ifnot,whatadditionalspace creation techniques will be needed to allow the InmanAlignertowork.Theextentofcrowdingpres- ent is calculated3 by measuring the sum of the mesial-distal widths of the teeth to be moved. This distance is called the required space or the teeth. If canines and incisors are to be moved, this distance will be measured from the distal surface of one canine to the distal surface of the other canine. Usinganorthodonticretainingorjeweller’schainor a polishing strip, the ideal arch form is then measured from the distal of each canine in alignment with the ideal arch form following orthodontic correction. Critically,thearchneedstopassthroughthesuggested positionofthecontactpointsandnottheincisaledges. Thisisdescribedastheavailablespaceorthecurve. It is possible to perform this task more quickly and just as accurately with software such as Spacewize. Just one simple occlusal photograph is required, which can be taken chairside. One tooth needstobemeasuredforcalibration.Acurvecanbe digitally established and this is normally easier when observing the patient’s aesthetic require- ments and occlusion directly. The extent of crowd- ing is immediately calculated using such software. Laboratoryrequirements Accurateupperandlowerimpressionsaretaken, preferably two of the arch being treated. Simple al- ginate can be used if cast quickly. A bite registration and prescription should be completed and sent to acertifiedInmanAlignerLaboratory.Thetechnician should be informed of the amount of crowding calculated. The teeth to be repositioned should be noted clearly. The prescription should provide full details to the technician regarding the teeth to be moved, the area they are to be moved to and the distance they are to be moved. A Spacewize trace of the ideal curve can also be submitted. Interproximalreduction Interproximal reduction (IPR) is begun at the fitting appointment using abrasive strips or discs. The model analysis will have already calculated the extent of IPR required. Manyauthorsacknowledgethatthereductionof half of the interproximal enamel on the mesial and distal of each incisor tooth is a safe technique.4–7 This equates to 0.5 mm per contact point, creating 2.5mmofspacebetweenthecanines.Insomecases, the distal of the canine and mesial of the premolar can be reproximated allowing for a total of 3.5 to 4.5 mm. These cases will require more experience in using the system but offer a number of possibilities forcliniciansoncetrainedtousethesystemcorrectly. Meticulous records of the amount of stripping performed should be kept. An in-surgery fluoride rinse or application of topical fluoride is recom- mended after any enamel reduction procedure. cosmeticdentistry 2_2010 Fig. 7_Smile view before treatment. Fig. 8_Smile view after treatment. Fig. 8Fig. 7