Inderpreet Singh1, Sana Bint Aziz 2, Gurkeerat Singh3

  1. New Delhi
  2. Department of Orthodontics – Sudha Rustagi College of Dental Sciences & Research-Faridabad
  3. Department of Orthodontics – Sudha Rustagi College of Dental Sciences & Research-Faridabad

Clear aligners have become the treatment of choice for treating mild to moderate malocclusions in patients who are concerned for esthetics compromise of fixed orthodontic appliance treatment. Two case reports are presented to demonstrate the effectiveness of clear aligners in resolving crowding due to orthodontic relapse and spacing in the anterior teeth region. In both the cases, predicted results were achieved using clear aligners which was simple and convenient for both the patient and the clinician.

Keywords: Clear aligners, Relapse, Crowding, Midline diastema, Relapse


The introduction of clear aligners has added a new dimension to orthodontic treatment worldwide. Patients who would never accept the aesthetic and/or functional compromise of fixed orthodontic appliances may be offered a more comfortable option with significant dental health advantages1. Clear aligners were introduced by Align Technology (San Jose, California, USA) marketed as “Invisalign”* in 2000 and the majority of the published data revolves around this brand. With the advent of 3D printing and more predictable software additional companies are now entering the market. Initially aligners were not capable of controlling root movement and more complex tooth movement but advances in design and placement of bonded composite attachments have seen expansion of the range of tooth movement over substantial distances2. Experienced clinicians have found that clear aligner therapy for more complex treatment needs often fails to yield the same degree of precision anticipated with fixed appliances. This necessitates more careful case selection and counselling when offering this treatment to patients. Two suitable cases are presented, illustrating the ease and simplicity with which clear aligners could resolve the malocclusion in patients who refused fixed orthodontic alternatives.

A 21 year old female patient presented with relapse of her malocclusion two years after cessation of removable retainer wear after treatment with full fixed appliances involving extraction of all first pre-molars. The patient was now in college and did not want re-treatment with fixed appliance. She presented with Class I molar and canine relationship and mild upper and lower crowding.

A 32 year old female patient presented with a chief complaint of spacing between her upper front teeth. The clinical examination revealed a midline diastema in the upper arch and spacing between the lower anterior teeth with Class I molar and canine relationship.


Clear aligner therapy was introduced to resolve minor tooth irregularity and treat problems of orthodontic relapse.3Clear aligners have become a treatment of choice for esthetically concerned patients who do not want fixed appliance treatment and present with mild to moderate crowding, spacing or relapse problems. In this study, a case of mild crowding due to orthodontic relapse was successfully treated using K line clear aligners. It was convenient and simple to treat the relapse problem with aligners and the treatment did not take more than 5 months to completely resolve the problem. A second case of spacing, where the patient did not want fixed orthodontic treatment, was managed easily with aligners. Moreover, with use of this appliance, excellent patient cooperation with minimal discomfort, better esthetics and oral hygiene was experienced when compared to fixed appliances. The point that needs to be mentioned here is patient compliance and the initial diagnosis of the case. The diagnosis of the individual case is paramount and it cannot be delegated to a lab or technician. For the success of cases treated with the clear aligner systems both patient cooperation as well as a correct diagnosis is essential.

The cases presented here show the efficacy of aligners in managing mild to moderate malocclusions. Boyd et al4successfully treated similar malocclusions which involved mild to moderate crowding and space closure using the Invisalign* system. However, there are currently some limitations to the clear aligner appliance regarding case selection, cost, experience for computer treatment planning, difficulty in certain tooth movements and cases involving the mixed dentition or impacted teeth.5 According to Duncan1, quality results with aligners can be achieved if attention is given to case selection, treatment planning, software modifications, clinical management and resolving treatment tracking issues. With the innovation of new attachments, advances in material science and the detailed anlaysis and comprehension of outcomes from specific strategies, , the scope of aligners will most likely expand for correcting more complex cases involving rotations, deep bites, open bites and unusual extractions in the near future.6

  1. Duncan G. Invisalign is only for simple cases, isn’t it? Australasian Dental Practice, March/April 2011; 136-140
  2. Giancotti, A. and Di Girolamo, R.: Treatment of severe maxillary crowding using Invisalign and fixed appliances, J ClinOrthod, 2009;43:583-89.
  3. Kim TW, Wilhelmy B, Gaugel Clear Aligner. An Alternative Orthodontic Appliance. URL: http://www. andersson-gaugel. de/pdf/SD_Clear-Aligner_klein. pdf (Access Date: 20.01. 2013). 2007.
  4. Boyd RL, Miller RJ, Vlaskalic The Invisalign system in adult orthodontics: mild crowding and space closure cases. J ClinOrthod, 2000 Apr;34(4):203-12.
  5. Boyd RL, Vlaskalic Three-dimensional diagnosis and orthodontic treatment of complex malocclusions with the invisalign appliance. In Seminars in Orthodontics, WB Saunders, 2001;7(4):274-293.
  6. Ojima K, Dan C, Nishiyama R, Ohtsuka S, Schupp W. Accelerated extraction treatment with Invisalign. J ClinOrthod. 2014 Aug;48(8):487.