Clear aligner therapy for adult patient-A case report

Aligners have become the alternative treatment of choice in adult patients who do not want fixed orthodontic appliance therapy due to esthetic concerns. This case report demonstrates the effectiveness of Clear aligners used to treat an adult female patient with severe proclination and generalized spacing in the upper and lower arches, good periodontal condition and a high DMFT Index. Predicted results were achieved with the clear aligners as per the virtual setup with reduction in proclination, closure of generalized spacing and a pleasing facial profile with competent lips. Keyword Clear Aligner, Adult patient, Periodontally compromised. Introduction The clear overlay orthodontic appliances was introduced in 1946, when Kesling devised the concept of using a series of thermoplastic tooth positioners to progressively move malaligned teeth. In the recent years, increasing number of adult patients have sought orthodontic treatment and expressed a desire for esthetic and comfortable alternatives to conventional fixed appliances. Orthodontic treatment with clear aligners is a quickly growing sector in the field of Orthodontics. Experienced clinicians have found that the clear aligner therapy for complex malocclusion often fails to yield the same degree of precision anticipated with fixed appliances. This necessitates careful case selection and counseling when offering this treatment to patients. A suitable case has been selected, illustrating the ease and simplicity with which the clear aligners can be used for treating certain malocclusions where the patient was reluctant to undergo fixed orthodontic therapy. Case Report A 53 year old female patient reported with a chief complaint of spacing and forwardly placed upper front teeth. She had class I molar relation, proclined maxillary and mandibular anteriors, generalized spacing of 7mm in maxillary and 3mm in mandibular arch, overjet of 8mm and overbite of 4mm, overall good periodontal support, Bolton’s discrepancy showed a 2.5mm tooth material excess in the lower arch, ANB of 2 and incompetent lips (Table 2, Fig. 1-3). It was decided to treat the patient with clear aligners as only tipping of the anterior teeth was needed without complex tooth movement and to address the esthetic concerns of the patient. The available space in the upper and lower arch was used to retract the proclined teeth. The computer-generated virtual setup developed by the aligner company was reviewed, modified, and accepted (Fig. 4 a&b). The case was treated with 15 aligners in the upper arch and 10 aligners in the lower arch with no interproximal reduction indicated until the later. Stages of treatment to correct the Bolton’s discrepancy which indicated a tooth material excess in the lower arch. Treatment Progress Zero aligners are passive aligners with no tooth movements incorporated were delivered within 48 hours of the PVS impressions sent to the laboratory so that the patient gets used to wearing the aligners. First, set of upper and lower aligners (U1, L1) were delivered on the 5th day and the patient asked to wear it for nearly 22 hours for 3 weeks a day except while eating. The patient was seen every 3 to 4 weeks to check for the aligner fit, any breakage, treatment progress, and patient cooperation in regularly wearing the aligners. The overall treatment duration was 1year 1month. Canine to canine upper and lower bonded fixed retainers were placed to maintain the corrections achieved. The following table below shows the duration of each aligner worn by the patient. (Table 1) Table 1: The upper and lower aligners were changed every 3-4weeks accordingly as and when the current aligners showed a loose fit. The lower 10 aligner was continued wearing till the end of the treatment until upper 15 aligner which was the last aligner. Upper Aligner Lower Aligner Duration U1 L1 3 Weeks U2 L2 4 Weeks U3 L3 3 Weeks U4 L4 4 Weeks U5 L5 4 Weeks U6 L6 4 Weeks U7 L7 4 Weeks U8 L8 3 Weeks U9 L9 3 Weeks U10 L10 4 Weeks U11 L10 4 Weeks U12 L10 4 Weeks


Introduction
The clear overlay orthodontic appliances was introduced in 1946, when Kesling devised the concept of using a series of thermoplastic tooth positioners to progressively move malaligned teeth. 1 In the recent years, increasing number of adult patients have sought orthodontic treatment and expressed a desire for esthetic and comfortable alternatives to conventional fixed appliances. 2 Orthodontic treatment with clear aligners is a quickly growing sector in the field of Orthodontics. 3 Experienced clinicians have found that the clear aligner therapy for complex malocclusion often fails to yield the same degree of precision anticipated with fixed appliances. This necessitates careful case selection and counseling when offering this treatment to patients. A suitable case has been selected, illustrating the ease and simplicity with which the clear aligners can be used for treating certain malocclusions where the patient was reluctant to undergo fixed orthodontic therapy. 4

Case Report
A 53 year old female patient reported with a chief complaint of spacing and forwardly placed upper front teeth. She had class I molar relation, proclined maxillary and mandibular anteriors, generalized spacing of 7mm in maxillary and 3mm in mandibular arch, overjet of 8mm and overbite of 4mm, overall good periodontal support, Bolton's discrepancy showed a 2.5mm tooth material excess in the lower arch, ANB of 2 0 and incompetent lips (Table 2, Fig.  1-3). It was decided to treat the patient with clear aligners as only tipping of the anterior teeth was needed without complex tooth movement and to address the esthetic concerns of the patient. The available space in the upper and lower arch was used to retract the proclined teeth. The computer-generated virtual setup developed by the aligner company was reviewed, modified, and accepted ( Fig. 4 a&b). The case was treated with 15 aligners in the upper arch and 10 aligners in the lower arch with no interproximal reduction indicated until the later. Stages of treatment to correct the Bolton's discrepancy which indicated a tooth material excess in the lower arch.

Treatment Progress
Zero aligners are passive aligners with no tooth movements incorporated were delivered within 48 hours of the PVS impressions sent to the laboratory so that the patient gets used to wearing the aligners. First, set of upper and lower aligners (U1, L1) were delivered on the 5th day and the patient asked to wear it for nearly 22 hours for 3 weeks a day except while eating. The patient was seen every 3 to 4 weeks to check for the aligner fit, any breakage, treatment progress, and patient cooperation in regularly wearing the aligners. The overall treatment duration was 1year 1month. Canine to canine upper and lower bonded fixed retainers were placed to maintain the corrections achieved. The following table below shows the duration of each aligner worn by the patient. (Table 1)

Treatment Results
The final result showed a fairly good alignment in the upper and lower arches with a mild degree of open bite in the posteriors which did settle down after 6 months of treatment completion due to occlusal biting forces. (Fig. 9) At the end of the treatment all the spaces were closed and the maxillary and mandibular incisors were kept upright, the molar and canine were in classic relationship, lip strain reduced and lip Competency achieved and an ideal overbite and overjet was achieved, as compared favorably with many published cases treated with fixed appliances. (Table 2) (Fig. 6-8) Mesiobuccal rotation of 31 was left unresolved as the patient was satisfied with the treatment outcome and did not want any further refinement aligners to resolve the rotated 31.

Discussion
Clear Aligners have become the current generation treatment option for adults wanting to undego orthodontic tooth correction with esthetic concerns. However, patient selection for clear aligner therapy is very crucial and predictable results can be achieved in mild to moderate tooth corrections involving space closure, retraction and decrowding.
It is important to compare the clinical positions of the teeth with the virtual setup images after every 4-5 sets of aligners. If the comparison is not within 10%, the clinician should stop the treatment at that point and ask the laboratory to deliver a new set of aligners with all the necessary corrections incorporated into the aligners.
In this case report, the efficacy of the clear aligner can be appriciated where the proclination, spacing of the anterior teeth has been treated. The patient reported with a good periodontal status which was maintained during the treatment and post treatment as well. The overjet of 8mm was reduced to 2mm and the spacing of 7mm in the upper arch and 3mm in the lower arch were closed. Mesiobuccal rotation of 31 was left unresolved as the patient was satisfied with the treatment outcome and did not want any further refinement aligners to resolve the rotated 31. There was an overall improvement in the facial profile with decreased lip strain, increased nasolabial angle and lip competancy was achieved.

Conclusion
Clear Aligners are an effective and esthetic mode of orthodontic tooth movement in adults provided the case has been accordingly selected as complex tooth movements and very precise occlusal finishing is difficult to achieve with aligners. Simple tooth movements like proclination and spacing can be corrected along with an overall improvement in the facial esthetics as seen in the above mentioned case report. Source of Funding None.