Clear aligners use for early orthodontic treatment: virtual planning, features and clinical application

Abstract

When providing orthodontic care for pediatric patients, clinicians often question whether to begin treatment early — during the primary or early-transitional dentition — or wait until all or most of the permanent teeth are present.

The benefits of early treatment extend beyond aesthetics, encompassing improved oral health, functionality, and overall well-being. The purpose of this article is to illustrate how treatment with clear aligners can be an excellent method for correcting malocclusions involving dental crowding. However, the outcome of treatment depends not only on the accuracy of the diagnosis but also on the ability to plan treatment with respect to feature selection and staging virtually. All of these aspects are addressed and highlighted in the article.

Introduction

The history of clear devices dates back to 1945, when Kesling first proposed a clear, vacuum-formed tooth-positioning appliance for minor tooth movement. This technique was designed for every tooth movement, in a series of stages, until the teeth were aligned. However, it was applicable for minor tooth alignment issues, not ideal for correcting more complex malocclusions. The real breakthrough in orthodontics came several years later, when two graduate students at Stanford University in 1997 applied three-dimensional [3D] computer imaging to the field and created the world’s first customized clear aligner system.

This new technology revolutionized the world of orthodontics, projecting it towards the third millennium. Clear aligner technology represents a revolutionary, transformational change in orthodontics that challenges the conventional thinking of how orthodontists move teeth and requires a radical paradigm shift in our mindset. [1–9]

However, the introduction of clear aligner technology doesn’t mean the last 150 years of orthodontic principles are less important. The concepts of bone biology, biomechanics, anchorage, and occlusion should always be the basis for every therapeutic decision. Clear aligners have already evolved since they were released to the market in 1999. In the early days of clear aligners, most clinicians understood them to be an orthodontic appliance suitable for treating Class I cases with minor crowding, resolved primarily with interproximal reduction. Today, clear aligners can be moved using a sophisticated computer.

Algorithms, and it is evident that this will be the future of orthodontics. It is important to understand that clear aligner treatment is a system and not simply a product. Today, the clear aligner can be considered a comprehensive orthodontic system capable of treating a wide range of malocclusions.

The final occlusal outcome can be customized according to the individual’s dental arch form, smile esthetics, and soft tissue lip support. The tip, torque, in-and-outs, and occlusal contacts could be designed uniquely for each individual. Actually, the future evolution of orthodontics has already arrived in the present, as Clear aligners utilize digital technology for diagnosis, treatment planning, and the design of the final occlusal outcome. The rate of tooth movement may also be adjusted based on the individual’s bone physiology by altering the scheduled number of days for aligner changes, depending on the individual’s response to tooth movement. The final occlusion setup in the software is customized to the individual’s dental arch form and smile aesthetic preferences.

Indeed, over the last decade, aligners have emerged as an effective alternative to conventional fixed orthodontic treatments. Thanks to radical improvements in their biomechanical properties, clear aligners can now address a broader range of dental movements, as their indications have been extended. [10–12,15–16.]

More recently, the use of clear aligners in pediatric orthodontics has been gaining increasing popularity and appreciation among clinicians. It is a proactive approach to intercept occlusal issues during the transition from mixed to permanent dentition. The current protocols are designed to optimize dentofacial development in growing patients through advanced technological innovation. Specifically, by managing arch space, modulating dentoalveolar discrepancies, and correcting crowding, interceptive orthodontic treatment with clear aligners can help achieve occlusal harmony, improved function, and enhanced dentofacial aesthetics in the growing patient.

Despite these challenges, technological innovations in both manufacturing and materials, in digital treatment planning, and in pediatric-specific design features have improved the predictability of interceptive clear aligner therapy.

Paediatric-Specific features have been specifically engineered to address the biological and biomechanical characteristics of growing patients.

Key features include:

• - Eruption guide design, allowing space preservation for unerupted permanent teeth.
• - Customized trimline design and retention protocols adapted for shorter clinical crowns.
• - Space management protocols, including arch development and dentoalveolar expansion strategies.

These features allow clinicians to intervene early while respecting natural growth patterns and minimizing overtreatment.

This article aims to illustrate the proper use of clear aligners in pediatric orthodontics for cases involving crowding and compromised smile esthetics. The application of the concepts of virtual planning, with specific movement sequencing and the selection of dedicated attachments, is illustrated and debated here.

Clinical report

The young patient was 8.6 years old, and her parents were concerned about her front teeth being misaligned, particularly the anterior crossbite, and the crowding in her smile.

She and her parents were aware that this bite was not functional and could affect chewing and jaw development. They were motivated by aesthetic concerns and preferred a treatment that would be comfortable, discreet, and convenient, allowing her teeth to align naturally without the appearance of traditional braces (Fig. 1).

Clinical examination and diagnosis

The patient presented a mesofacial growth pattern with a skeletal Class I relationship. She was in the mixed dentition stage, consistent with both her chronological and skeletal age. Clinical examination revealed a Class I molar and canine relationship bilaterally.

Periodontal evaluation identified early signs of involvement, primarily affecting tooth 41. Radiographic assessment demonstrated root convergence between 11 and 21 incisors.

On initial examination, the patient showed significant dental crowding consistent with a dentoalveolar discrepancy. Midline shifts were present, and the maxillary lateral incisors were in crossbite, contributing to impaired dental symmetry and compromised occlusal harmony. Based on these findings, an orthodontic treatment plan was formulated in time to achieve effective space arch management, maintain periodontal health, and establish the prerequisites for functional and stable occlusion.

(Fig. 1) (Tab. 1)

Treatment plan and clinical instructions

The orthodontic treatment plan (Fig. 2) was designed to address crowding, transverse discrepancies, and midline deviations while maintaining optimal periodontal health and achieving stable Class I molar and canine relationships. Specific objectives of macro-staging in this treatment plan (Fig.3) included correction of anterior crossbite requiring occlusal pads, simultaneous and symmetric expansion and coordination of the arches, complete derotation of upper molars, and selective intrusion of maxillary molars with root buccal torque. A clear aligner option was selected to allow precise, controlled tooth movement, with particular attention to root parallelism in the anterior region. In the lower arch, the goals were the preservation of incisor inclination and derotation of mandibular posterior teeth with lingual root torque. The digital plan required leveling the curve of Spee, controlling incisor intrusion and extrusion of deciduous teeth, and using retention and extrusion precision attachments.

The treatment was carried out in two phases: an initial phase, including 20 aligners, focused primarily on anterior alignment, arch space management, and preliminary correction of malocclusion, with an emphasis on optimizing overbite and overjet. At the end of the first step, a refinement phase with 10 aligners was aimed at finalizing tooth positioning, improving intercuspation and enhancing overall occlusal stability. The refinement phase was considered an integral component of the treatment strategy.

Taking into consideration the planned microstaging (Fig. 4), in the initial phase, occlusal pads were placed on teeth 3.6 and 4.6 to provide localized bite opening and facilitate proper anterior guidance to correct the anterior crossbite. In addition, root torque-controlled dual attachments were placed on the upper anterior teeth to ensure controlled root parallelism and precise root divergence expression. In the lower arch, posterior teeth received lingual root torque to maintain proper axial inclinations and to support transverse stability of the occlusal outcome. Furthermore, the interproximal reduction [IPR] was performed only on deciduous teeth to create the needed space, carefully avoiding any proclination of the lower incisors. Therefore, a periodontal-safe protocol was created.

During the refinement phase (Figs. 5, 6), given that the required movements in the finishing setup were negligible compared to those prescribed in the initial phase of treatment, the use of attachments to enhance aligner biomechanics was considered unnecessary; instead, to optimize the finalization of occlusal contacts, a high trimline design was selected. In this case, the high trimline configuration alone improved force delivery and increased patient satisfaction while concurrently ensuring patient comfort. As suggested by recent literature, employing an extended trimming design enhances control and may be a viable alternative to attachments while maintaining aligner efficiency [17–18].

Treatment results

The clear aligner system allowed precise control over tooth movement, including root torque, derotation, and vertical adjustments. The planned attachments, occlusal pads, and IPR strategies facilitated predictable biomechanics, enabling the clinician to efficiently achieve the treatment objectives while closely monitoring tooth movement and occlusal development. Overall, the combination of patient-centered comfort and clinician-controlled mechanics resulted in a smooth, collaborative, and successful early treatment process.

Treatment objectives, although limited to reducing the complexity of the evolving malocclusion, have been achieved (Fig. 8). The bilateral Class I molar relationships were maintained, and there was improvement, including molar derotation and uprighting, as well as coordination of both arches. The curve of Spee was flattened while promoting a mild retroclination of the lower incisors. A periodontally oriented staging protocol, aimed at preserving and prioritizing periodontal health, proved effective in reshaping the arch form while concurrently maintaining lower incisor inclination. An improvement in the soft-tissue profile was observed, attributable to both compensatory growth and treatment (Fig 8).

Overall, active Phase 1 treatment lasted 5 months. The patient tolerated the aligners well, and no adverse effects were reported. Finally, the refinement phase, consisting of 10 pairs of aligners, lasted 3 months. This phase allowed for the optimization of occlusal contacts and torque.

Discussion

Early orthodontic treatment remains a controversial topic in orthodontics worldwide, primarily due to uncertainty about its benefits and long-term stability.

Several studies have shown that 46% of children aged 6 to 12 and 85% of adolescents aged 12 to 17 have crowded teeth.

This is because, without appropriate early treatment, mild and easily correctable crowding in the mixed dentition becomes persistent and significant in the permanent dentition [19–20].

The maximum increase in the size of both dental arches occurs during the first two years of life; thereafter, the length of the dental arch continues to increase until age 13 in the upper jaw and until age 8 in the lower jaw; after this age, the length decreases in both arches [21]. In light of this, dental crowding is considered a malocclusion that never corrects itself but tends to worsen over time [22–23].

One of the primary challenges in pediatric orthodontics with aligners is achieving predictable control of partially erupted tooth movement with reduced clinical crown height. Clinicians must emphasize dentoalveolar development and incorporate space management strategies that accommodate future eruption.

The decision-making on anchorage could also be complex due to exfoliating primary teeth and erupting permanent successors. Moreover, attachment design and aligner retention may be less stable in mixed dentition due to morphological variability.

Additionally, compliance remains critical, particularly in pediatric patients, where consistent wear time may directly influence treatment outcomes.

Early treatment with clear aligners offers several clinical benefits. Firstly, early arch development and proactive space management reduce the severity of future crowding and may decrease the need for extractions during subsequent comprehensive treatment. Furthermore, their removability allows for better plaque control than fixed appliances, which is particularly important in pediatric patients, who are more prone to tooth decay.

The functional improvement resulting from early correction of transverse discrepancies, anterior crossbite, and mild sagittal imbalances contributes to improved masticatory efficiency and muscular balance.

Finally, we must consider the psychosocial benefits.

The aligner’s discreet approach supports emotional well-being during formative years when appearance concerns can significantly impact self-esteem. The removable nature of the aligners further enhances daily life by permitting normal eating during meals and unimpeded oral hygiene practices, eliminating food restrictions that complicate nutrition with traditional braces.

Finally, it is worth noting that a very recent article compared the aligners and a Hyrax-type expander, finding that both were effective and that the results were maintained throughout the transitional dentition.

Moreover, clear aligners also demonstrated stable mandibular arch expansion, supporting their use for mild crowding or transverse deficiencies without long-term vertical effects [23].

Conclusion

Early orthodontic treatment is a proactive and effective approach to addressing dental and skeletal issues in young patients. By intervening at an early age, clinicians can guide the development of the jaw and teeth, preventing more complex problems in the future and ensuring a healthier, more confident smile. Aligner represents a forward-thinking approach to pediatric orthodontics, combining digital innovation with growth-oriented biomechanics. While clear aligner therapy in mixed dentition presents inherent challenges, pediatric-specific design modifications enhance clinical control and treatment predictability.

By managing arch space, guiding eruption, and addressing early dentoalveolar discrepancies, aligner treatment may contribute to functional equilibrium, occlusal harmony, and balanced dentofacial development.

When carefully planned and monitored, it can serve as an effective interceptive modality that complements the natural growth of young patients.

In conclusion, further in-depth research is needed to determine the role of clear Aligners in paediatric orthodontics.