Written by: Melissa Shotell, DMD, MS
INTRODUCTION
The digital evolution of dentistry has had a significant impact across multiple disciplines, particularly in orthodontics and the use of clear aligner therapy. Initially, clear aligners were viewed as a limited treatment option, primarily indicated for minor tooth movements and adult patients. However, continued advancements in aligner materials, attachment design, biomechanics, and digital treatment planning have expanded their clinical applications. Today, clear aligners are widely used to treat patients of varying ages and increasingly complex orthodontic cases.
Adult orthodontic treatment represents one of the fastest-growing segments within orthodontic practice. Traditionally, many orthodontic practices focused predominantly on adolescent patients treated with bracket-and-wire appliances, and as the demand for adult orthodontic care has increased, greater emphasis has been placed on the overall patient experience. While adolescent patients often view orthodontic treatment as a rite of passage or even a fashion statement, adult patients typically prioritize aesthetics, comfort, and convenience. Many adults are hesitant to pursue treatment with conventional metal brackets and wires due to their visibility. As a result, clear aligners and aesthetic bracket systems have grown in popularity because of their discreet appearance and improved comfort.
Despite the widespread adoption of clear aligner therapy, some clinicians remain cautious due to historical limitations associated with aligners, including restricted tooth movement capabilities and longer treatment times. However, recent advances in digital aligner technology have led to the development of systems capable of more predictable and efficient tooth movement. Improvements in digital treatment planning software, aligner materials, and force delivery have enhanced both treatment outcomes and patient comfort.
Digital dentistry has evolved into a fully integrated ecosystem that includes intraoral scanning, CBCT, and advanced treatment-planning software. This digital workflow enables comprehensive case evaluation and facilitates interdisciplinary treatment planning. Historically, interdisciplinary cases relied on hard-copy radiographs, stone models, and diagnostic wax-ups. In contrast, modern digital workflows enable clinicians from multiple disciplines to simultaneously evaluate the same digital records, improving communication and coordination of care.
Intraoral scanning has been rapidly adopted for clear aligner therapy, not only for the efficiency and accuracy of digital impressions but also as a powerful visual communication tool. Effective communication and expectation management are particularly important in adult orthodontic patients. Intraoral scanners allow clinicians to visually demonstrate existing conditions and proposed tooth movements, providing patients with a clearer understanding of treatment objectives and anticipated outcomes. This enhanced visualization improves patient engagement and supports more informed decision-making. Additionally, digital records can be easily shared among interdisciplinary providers, further improving treatment planning and clinical outcomes.
Treating adult patients often presents unique challenges, including heavily restored dentition, periodontal considerations, medical complexity, long-standing functional habits, and lifestyle factors such as smoking or alcohol consumption. Clear aligner therapy has become an attractive option for many adult patients due to increased comfort, improved access to oral hygiene, fewer dietary restrictions, and the ability to clearly communicate expected treatment outcomes. The purpose of this article is to discuss the use of a fully digital workflow for planning and executing a complex, interdisciplinary treatment approach combining clear aligner therapy with fixed prosthodontic restorative treatment in an adult patient.
Case Report
A 53-year-old female patient presented for an interdisciplinary prosthodontic and orthodontic consultation, referred by her treating dentist. The patient had maxillary crowns on teeth Nos. 8 and 9 to close a midline diastema and was displeased with the size and the color of the crowns. Prerestorative radiographs and photos were received from the treating dentist, showing a midline diastema, large natural teeth Nos. 8 and 9, and small maxillary lateral incisors (Figure 1). The patient recalled her dentist had recommended an orthodontic consult prior to restorative treatment. Still, she preferred to proceed with crowns to close the midline diastema, as she did not want to wear traditional bracket-and-wire appliances and wanted more expedited treatment.
Upon examination, the patient had numerous previously restored teeth with fixed ceramic crown restorations (Figure 2). The patient also had several composite and amalgam restorations. The patient’s occlusion was Angle Class I molar and canine. There was mild spacing in the upper arch and moderate crowding in the lower arch. There was a moderate overbite of 40%, and 3.0 to 5.0 mm of overjet due to the crowding of the lower incisors. The upper incisors appeared flared and made the restorations of Nos. 8 and 9 appear more prominent. The restorations on Nos. 8 and 9 were lighter than the surrounding teeth, and the patient reported she initially wanted to try bleaching to lighten the surrounding teeth. The upper midline was shifted right 1.0 mm, and the lower midline was shifted right 2.0 mm. The patient had a high gingival smile line with 4.0 to 5.0 mm of gingival display on full smile, and a thick gingival biotype. There was no detectable shift between centric occlusion, and centric relation, and the patient had been restored in a cusp-to-fossa functional relationship with crowding and the Angle Class I malocclusion.
Radiographic exam with CBCT reconstructed panoramic radiograph (Figure 3) showed crowns and root canals in the anterior and posterior, and regular root morphology. The panoramic x-ray showed a fully erupted adult dentition from second molar to second molar. The TMJ joints were well corticated on radiographic exam of the CBCT. There are no signs of TMJ pathology or any dental pathologies. The patient was periodontally healthy and demonstrated excellent oral hygiene for orthodontic treatment.
After comparison of the pretreatment radiographs and photos with the patient’s occlusion, upper arch spacing, and small maxillary laterals, a tooth-size analysis was performed, and the patient appeared to have an initial tooth-size discrepancy. The size of the maxillary laterals was small in comparison to the maxillary centrals prior to the current restorations, which contributed to the diastema and the spacing in the upper arch with crowding in the lower arch. To create harmony in tooth size, and to close all upper spacing, it was determined that teeth in the upper arch would need to be restored to an aesthetically pleasing size, and the lower teeth would need to be mildly reduced in size.
Treatment Options: Traditional Braces vs Clear Aligners
The patient was presented with 2 treatment options. Option 1 would involve the use of clear aligner treatment, with interproximal reduction of the crowns on Nos. 8 and 9, to reposition the teeth to a natural position for diastema closure. Space would then be opened around the maxillary lateral incisors to facilitate minimal preparation crowns on teeth Nos. 7 and 10. Interproximal reduction (IPR) would also be performed on the lower arch to resolve crowding and create a size balance for overbite and overjet with the opposing arch. At the end of aligner treatment, teeth Nos. 7 to 10 would have crowns placed to create a more aesthetic smile, with a balanced ratio of tooth size between the upper central and lateral incisors, and balanced occlusion in the lower arch. Option 2 would utilize traditional braces, with the same plan for the upper and lower arch, with IPR and positioning of the upper teeth to be restored. The patient was advised that the lower midline may not coincide with the upper midline at the end of treatment, and that the upper midline would improve with the facial midline but may not be completely centered. The patient was also informed that due to the excess amount of IPR required on the crowns, they may fracture or chip during treatment, and composite repair may be required.
The patient was given the option of traditional bracket-and-wire appliances or treatment with clear aligners using ClearCorrect. In the treatment discussion, the patient expressed that she worked in a professional career, interacted with large numbers of people in her position and expressed a strong interest in clear aligner treatment. The patient also discussed a preference for clear aligners so she could remove them to enjoy foods not recommended with braces and maintain proper oral hygiene. The patient wanted to pursue treatment with the aligner therapy utilizing ClearCorrect.
After discussing the findings of the clinical exam and discussing the patient’s concerns for an aesthetic appliance option for treatment, the focus of treatment would be to reposition teeth Nos. 7 to 10 for final restorations with porcelain crowns. We reviewed the patient’s goals for treatment and the desire to complete treatment quickly and utilizing aligners. Treatment options were designed to correct the upper and lower midlines using IPR, but limitations of the correction for coincidental midlines were discussed. The patient was not concerned with addressing the lower midline and was primarily looking for an aesthetically pleasing smile and having smaller, more aesthetic anterior crowns.
With the patient’s limited goals for treatment in consideration, a treatment plan with the following treatment goals was established:
- Reposition teeth Nos. 8 and 9 for future restoration.
- Reposition teeth Nos. 7 and 10 for minimal prep crowns.
- Maintain posterior restored occlusion.
- Resolve lower arch crowding.
- Improve excess overbite.
- Improve overjet.
- Improve lower midline.
- Improve smile aesthetics.
A digital treatment planning approach was utilized for this patient, including diagnostic impressions made with a TRIOS intraoral scanner (3Shape), photographs using a Canon T6i dSLR camera, and a 15 x 15 CBCT using a Green CT2 scanner (Vatech). The combination of the intraoral scans, photograph images, and CBCT is a powerful patient communication tool and helps to explain the current state of the malocclusion and discuss goals for treatment.
Selecting Aligner Systems
The ClearCorrect system of aligners was selected for this patient based upon several clinical considerations. Given the patient’s desire for an aesthetic treatment option, we wanted to limit the use of engagers/attachments and the time spent in treatment and avoid bonding engagers to the porcelain restoration. The straight extended trimline gives the aligners increased retention while accomplishing the aforementioned reduction of engagers.1-3 The tri-layer material also gives the aligner a lower insertion force and more sustained forces.4-7 This creates a system with increased comfort and an increased activation time per aligner. The use of the aligner system allowed us to reduce the number of engagers and treatment steps, provide a course of treatment with enhanced patient comfort, and support the digital workflow.
Digital Workflow and Treatment
The intraoral scans and photographs were submitted to ClearCorrect to create a treatment setup (Figure 4). The first setup included 12 treatment steps and utilized limited engagers on the upper first premolars and upper right canine, and the lower anterior teeth to aid larger tooth movements (Figure 5). A total of 3.0 mm of IPR was planned between the maxillary central incisors, on the mesial surface of Nos. 8 and 9. This was done to remove the excess crown material that was used to close the midline diastema, and to bring the teeth to a more natural shape (Figure 6). The central incisors were then mesialized to create space distal to them (Figure 7). The restorative plan was that when the existing crowns were removed from Nos. 8 and 9, there would be space between teeth Nos. 7 to 10 that would be spaced for aesthetic restoration with tooth size balance. The lower arch was planned for IPR to resolve crowding and to create the size balance necessary to occlude with the upper teeth. Aligners were planned to be worn for 22 hours per day, with each aligner worn for a 14-day cycle.
Aligners were delivered to the patient with home care instructions, and a 22-hour-per-day wear schedule was provided. She was also given orthodontic chews to use when seating the aligners but was instructed to discontinue if any signs of TMD were experienced. The patient was given the first 2 sets of aligners and rescheduled in 4 weeks to bond engagers. Engagers were bonded using Assure Plus bonding agent (Reliance Orthodontics) and Go-To bracket paste (Reliance Orthodontics). The patient was seen for periodic aligner checks, and the IPR was performed in 4 phases at step Nos. 1, 3, 6, and 9, to avoid opening a large, unaesthetic diastema (Figure 8). IPR was performed using diamond burs and discs (Brasseler USA) (Figure 9), and the space created was measured with a gauge to ensure the precise amount of crown material had been removed (Figure 10).
The patient completed the initial set of 12 aligners in 6 months (Figure 11). The aligners were fitting well at the completion of the first phase of 12 aligners; however, we felt we could improve the tooth position with additional aligners and IPR. At the progress evaluation visit, it was determined that further improvement in tooth position could be achieved, including additional midline correction with selective IPR. The engagers were removed, and an additional 2.0 mm of IPR was performed on the mesial of tooth Nos. 8 and 9, and progress records were made, including photographs and new intraoral digital impression scans (Figure 12). The IPR was performed at the progress records to allow for measurement of the final tooth size prior to creating the refinement aligners. Progress records were sent to ClearCorrect, and a treatment revision was requested. A total of 6 additional aligners were planned with no attachments (Figure 13). Detailing of the incisor position was planned for smile aesthetics and spacing for the final restorations.
The patient completed her revision aligners in 12 weeks and was seen once during the revision aligner sequence. The patient chipped the porcelain of crown No. 8, and a temporary composite repair was placed. An office visit was scheduled for the completion of the revision aligner sequence and at this visit the engagers were removed and the patient was placed into temporary retention with retainers made by ClearCorrect. New digital records were taken including intraoral scans and photos to move into the restorative phase of the treatment plan (Figure 14).
The patient was seen by the prosthodontist to remove the existing crowns on teeth Nos. 8 and 9. Revision of the existing crown preps was performed, and teeth Nos. 7 and 10 had minimal preparation for future crowns. The patient was placed into temporary provisional crowns to assess the size and contour of the future restorations. One revision was made to the shape and length of the provisional crowns. Throughout the restorative process, temporary Essix-style retainers were designed to be worn over the provisional crowns to prevent any orthodontic relapse. Digital impressions for the restorations were made with the TRIOS intraoral scanner. Final restorations of Nos. 7 to 10 in monolithic zirconia crowns were fabricated and delivered (Figure 15). A new intraoral scan was taken, and a final retainer was ordered from ClearCorrect. The patient was given a temporary Essix-style retainer until the ClearCorrect retainer was delivered.
Treatment Results
Orthodontic treatment was completed in a total of 11 months and a total of 18 sets of aligners. The final restoration of Nos. 7 to 10 was completed in 2 months, to allow the patient time in provisional restorations to evaluate aesthetics. The patient was placed in final retention with ClearCorrect retainers. The final treatment results addressed the patient’s chief complaint and fulfilled the patient’s goals and expectations. The patient was very pleased with the final aesthetic results. Overall smile aesthetics were improved, the excess overbite and overjet both improved, and lower arch crowding was resolved (Figure 16). The patient reported that she was comfortable in clear aligner retention. The patient indicated that her aesthetics were greatly improved, and she was incredibly pleased with her overall treatment results and experiences of using clear aligners.
CONCLUSION
ClearCorrect aligners were able to deliver the treatment results that the patient was expecting in a limited amount of time. The use of unique aligner design and materials allowed us to limit the number of treatment steps and engagers used including minimizing the number of attachments. Utilizing a unique approach to IPR enabled us to reposition the patient’s teeth for final restorations while maintaining an aesthetic appearance throughout treatment. Further, selective areas of IPR allowed us to improve the midlines. The high level of patient compliance, combined with the design and materials of the ClearCorrect system, allowed the patient to complete treatment in a short period of time, with an excellent patient experience, and to achieve the necessary alignment for successful final restorations.
REFERENCES
1. Elshazly TM, Keilig L, Salvatori D, et al. Effect of trimming line design and edge extension of orthodontic aligners on force