Treating orthodontic relapse

Patrick Puckett presents a recent case study using clear aligners to treat upper and lower orthodontic relapse.

A patient presented at the practice with concerns about the appearance of her smile. She had undergone orthodontic treatment twice previously, but the upper anterior teeth had since drifted forward and the lowers had become crowded again. She expressed an interest in removable appliances due to the convenience of this type of treatment.

As part of the comprehensive orthodontic assessment, clinical photographs, a bitewing registration and an OPG were taken. No obvious pathology was detected. Impressions were also taken and sent to the IAS Laboratory for Spacewize+ digital calculations. These demonstrated that 1.8mm of space would need to be created in the upper arch, confirming suitable case selection for treatment with the Inman Aligner. In the lower arch, 2.4mm of IPR (interproximal reduction) would be required, which was also within the limitations of the appliance.

The entire treatment process was explained to the patient in detail – including benefits, risks and limitations – and she was given the chance to ask any questions. The importance of lifelong retention was also emphasised, which was particularly relevant given the relapse the patient had experienced twice already from previous treatments. This was supplemented with oral hygiene advice and recommendations for before, during and after the orthodontic procedure. Informed consent was obtained to proceed.

Treatment
The customised upper Inman Aligner was returned by the laboratory and fitted into the patient’s mouth, providing removal and placement instructions. The patient was advised to wear the aligner for at least 22 hours each day, removing only to eat and brush her teeth. The patient’s compliance was excellent throughout the treatment process.

The 1.8mm of IPR was performed progressively throughout treatment, with the patient returning to the practice every two weeks for review. Anchors were placed on the UR1 MPa initially, then the UR1 and UL1 DLa to encourage the desired tooth movement.

Once the patient was satisfied with the upper tooth positions achieved, a final impression was taken for upper fixed and Essix retainers, which were fitted in a subsequent appointment.

At this point, the patient was happy to proceed with alignment of the lower arch. A customised lower Inman Aligner was provided. Approximately 2.4mm of IPR was performed progressively throughout treatment, as estimated in the initial treatment set-up, with the patient returning to the practice every two weeks for review.

Once both upper and lower alignment was complete, tooth whitening was discussed with the patient, as per the Align, Bleach and Bond (ABB) concept. As she was more concerned about the position of her teeth than the colour, the patient decided to revisit potential whitening at a later date. Composite edge bonding was not considered necessary for this case, given the harmonious tooth levels achieved.

Case appraisal
This case proceeded very smoothly thanks to the patient’s excellent compliance and the advice provided by the mentors from IAS Academy. One of the main take-home messages learnt from this case was the placement of the labial anchors. The further distal (in this case) the anchor placement on the centrals, the more effective the action of the labial bow on these teeth. In addition, the use of a couple of clear aligners to help finalise upper tooth positioning allowed the lower Inman Aligner to commence concurrently.

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