Effectiveness of Clear Aligner Therapy in Orthodontic Management for Children with Mixed Dentition: A Scoping Review

Abstract

Aims and background

Clear aligners have become a popular orthodontic treatment option due to their esthetic appeal. However, their efficacy in managing malocclusions during mixed dentition, a developmental stage involving both primary and permanent teeth, has not been fully explored. This review aims to evaluate the effectiveness of clear aligners in treating malocclusions in mixed dentition and compares them to traditional orthodontic methods such as fixed appliances and myofunctional devices.

Methods

A scoping review was conducted using Arksey and O'Malley's framework and the preferred reporting items for systematic reviews and meta-analyses scoping review (PRISMA-ScR) guidelines. Studies examining the use of clear aligners in mixed dentition were retrieved from four major databases. The inclusion criteria focused on studies that compared clear aligners with other orthodontic treatments. A total of 21 relevant studies were included in the analysis.

Results

The reviewed studies primarily assessed Invisalign® clear aligners for treating class II, open bite, and dental crowding in mixed dentition. Treatment durations varied between 6 and 18 months. While clear aligners were effective in correcting dentoalveolar issues, their impact on skeletal changes was less significant compared to traditional methods like the twin block appliance. The clear aligners provided notable benefits in terms of patient comfort, compliance, and esthetics.

Conclusion

Clear aligners present a viable treatment option for correcting malocclusions in mixed dentition, particularly for dentoalveolar adjustments. However, for skeletal changes, traditional appliances like fixed devices may be more effective. Clear aligners should be considered for patients seeking esthetic and comfortable orthodontic treatment.

Clinical significance

Clear aligners offer a noninvasive, comfortable, and esthetic solution for orthodontic treatment in mixed dentition. They can be particularly beneficial for mild to moderate malocclusions, though careful patient selection is crucial for optimal outcomes.

How to cite this article

Rai K, Kote AR, Priya K, et al. Effectiveness of Clear Aligner Therapy in Orthodontic Management for Children with Mixed Dentition: A Scoping Review. Int J Clin Pediatr Dent 2025;18(10):1294–1304.

Introduction

Malocclusion is often perceived to be detrimental to a child's self-esteem and their physical, social, and psychological well-being. Consequently, orthodontic treatment is sought to improve their smile and, in turn, the overall quality of life.¹ The optimal (or) biological timing for orthodontic intervention is a topic of significant debate, yet definitive treatment typically begins in the late mixed or early permanent dentition phase.^2–4 This period aligns with peak growth, thus allowing for effective correction with the advantageous use of leeway space and the availability of permanent teeth for appliance retention and definitive malocclusion correction.⁵ However, children are hesitant to undergo orthodontic treatment due to the lengthy duration, associated discomfort, cost, and unattractive appearance of conventional buccal fixed appliances. While lingual appliances offer an esthetic advantage over buccal appliances, their use is limited due to various associated difficulties. Advancements in orthodontics have led to the development of more esthetically pleasing treatment options.¹

The concept of transparent aligners is not particularly novel, as it dates back to the early 20th century. Inspired by Remensnyder's “Flex-O-Tite” appliance (1925) and Kesling's tooth positioner for incremental movements, Nahoum created the first transparent thermoplastic appliance for tooth movement in the 1960s. In this stride, Ponitz developed the first “invisible retainer,” following which McNamara made further advancements in the 1980s. A similar design, termed the Essix retainer (ESSIX), was created by Sheridan in 1993.⁶

In addition to enhanced esthetics, clear aligners cause less pain than fixed appliances during the initial days of orthodontic treatment. The reported decrease in discomfort may be attributed to the intermittent forces exerted, which allow tissues to reorganize before reapplying pressure, resulting in less pain than the continuous forces from fixed appliances.⁷ Additionally, the ability to remove aligners for pain relief further contributes to lower reported pain levels, thus enhancing the overall experience of clear aligners.⁸

Although various systematic reviews have been conducted to assess different aspects of clear aligner therapy (CAT), the use of aligners in the mixed dentition phase requires further investigation. This scoping review seeks to address lacunae regarding the treatment modality and efficacy of CAT in mixed dentition.

Methods

This scoping review adhered to the Arksey and O'Malley framework⁹ and complied with the preferred reporting items for systematic reviews and meta-analyses scoping review (PRISMA-ScR) checklist for reporting the results.¹⁰

Review Question

“Is there a difference in the effectiveness of CAT in orthodontic management for children with mixed dentition in comparison to conventional treatment modalities?”

Eligibility Criteria

The PICO (population, intervention, comparison, and outcome) question was as follows:

• Population: Children in the mixed dentition phase who required orthodontic therapy.

• Intervention: CAT is used for orthodontic correction of malocclusion.

• Comparison: Other orthodontic treatment modalities, such as myofunctional appliances and fixed orthodontic therapy.

• Outcome: Effectiveness of CAT in the treatment of orthodontic malocclusion in the mixed dentition phase.

Information Sources

A comprehensive search strategy was conducted across four databases (PubMed, Scopus, Web of Science, and Google Scholar) using the keywords “clear aligner,” “aligner,” “orthodontics,” “malocclusion,” and combined with Boolean operators “AND” and “OR” to refine the search. The articles were screened using the following inclusion and exclusion criteria.

Eligibility Criteria

The criteria for the search strategy were as follows:

Inclusion Criteria

• Studies involving participants in the mixed dentition phase.

• Studies assessing the effectiveness of CAT.

• Studies published in the English language.

Exclusion Criteria

• Studies conducted in vitro, ex vivo, and animal studies.

• Studies published in languages other than English.

• Literature or systematic reviews.

All reviewers were precalibrated by KR using a sample of the first 100 citations. The initial search yielded a total of 21,012 articles: 1,332 in PubMed, 220 in Web of Science, 1,260 in Scopus, and 18,200 in Google Scholar. The search in Google Scholar was limited to screening 1,000 articles due to database constraints. Therefore, the total number of articles initially retrieved was 3,812. Six reviewers, working in pairs [ARK and KP, MS, and SS (SS1), SS (SS2), and DAT], independently screened all titles and abstracts using Rayyan (Rayyan Systems, Inc., Cambridge, Massachusetts, United States). This process was repeated during the full-text review, which included two additional reviewers (KR and MRN). Any disagreements were resolved through consensus, and if necessary, a third researcher addressed any remaining discrepancies. A final set of 21 articles was selected for inclusion in the present review. Data charting on Microsoft Excel was conducted by three reviewers (ARK, DAT, KP) and was thoroughly cross-checked by another three reviewers (MS, SS, SS) using a pilot-tested form (Fig. 1).

Fig. 1:

Flowchart of study selection process

The characteristics of the data—such as title, authors, year, number of patients assessed, age, gender, study design, dentition status, type of aligners, mode of treatment (hybrid/aligners), comparison with treatment outcomes assessed, parent compliance, duration, and follow-up—were summarized in Table 1.

Table 1:

Study characteristics

Author/Year/Country of Origin	Number of patients assessed	Age of the patient (mean ± SD)	Gender	Study design	Dentition status	Type of aligners	Interproximal reduction	Mode of treatment—hybrid/CA	Compared with	Type of malocclusion assessed	Treatment outcome assessed	Parental/patient compliance—if mentioned (yes/no)	Number of aligner trays	Duration of treatment (years and months)	Follow-up (months)	Retention—if mentioned (yes/no)
Meuli et al., 2018 Spain	1	8 years	Male	Case report	Mixed dentition	Invisalign®	Not mentioned	CA	NIL	Anterior crossbite	Crossbite correction Esthetic improvement Improving periodontal condition	No	14	2 months 10 days	3 months	Not mentioned
Staderini et al., 2019 Italy	1	11 years 11 months	Female	Case report	Late mixed dentition	Multi-phase Invisalign® “Teen” package	Yes	Hybrid (CA with intermaxillary elastics)	NIL	Class III	Dental and skeletal changes	No	63	31 months	12 months	Not mentioned
Staderini et al., 2020 Italy	2	8 years	1 male 1 female	Case series	Mixed dentition	Invisalign®	Not mentioned	CA	NIL	Anterior crossbite	Dental and skeletal changes	No	Case 1: 28; Case 2: 14	Case 1: 4.6 months; Case 2: 2.3 months	Not mentioned	After achieving proper overbite, the final aligners were worn nightly for 3 months post-treatment as vacuum-formed retainers.
Giancotti et al., 2020 Italy	2	10 years	1 male, 1 female	Case series	Mixed dentition	Invisalign® MA	Not mentioned	CA	NIL	Case 1: Class II with unilateral posterior crossbite; Case 2: Class II	Dental and skeletal changes	No	Case 1: 26 + 6 transitional sets; Case 2: 26 + 6 transitional sets	Case 1: 10 months; Case 2: 12 months	Not mentioned	Not mentioned
Caruso et al., 2021 Italy	20 (TB = 10, MA = 10)	10 ± 1.03 years	TB = five males, five females, MA = five males, five females	Retrospective study	Mixed dentition (or) early permanent dentition	Invisalign®	Not mentioned	CA	TB	Class II	Dental and skeletal changes	No	Not mentioned	Not mentioned	Not mentioned	Not mentioned
Ravera et al., 2021 Italy	72 (SG = 72, CG = 32)	8–15 years	Not specified	Prospective case–control study	Not specified	Invisalign® MA	Not mentioned	CA	Untreated controls	Class II	Dental and skeletal changes	Mentioned but not addressed	Not mentioned	18 months	Not mentioned	Not mentioned
Lione et al., 2021 Italy	23	9.4 ± 1.2 years	Nine females, 14 males	Prospective study	Mixed dentition	Invisalign® First System (IFS)	Not mentioned	CA	NIL	Posterior transverse discrepancy	Dental changes	Likert scale used—all patients had good/moderate cooperation	Mean number of trays: 37	8.1 months	Not mentioned	Not mentioned
Dianiskova et al., 2022 Slovakia	49 (MBT = 25; CA = 24)	MBT = 13.1 ± 1.8 years; CA = 12.7 ± 1.7 years	MBT = 16 female, nine males; CA = 16 females, 8 males	Retrospective study	Mixed dentition (or) early permanent dentition	Invisalign®	Not mentioned	Hybrid (CA with intermaxillary elastics)	MBT (Mini Sprint® II, Forestadent)	Mild Angle's class II division 1 malocclusion	Dental and skeletal changes	No	Not mentioned	28 days	Not mentioned	Not mentioned
Camcı and Salmanpour, 2022 Turkey	24 (EA = 12; TB = 12)	EA = 12.2 ± 1.0 years; TB = 11.8 ± 1.1 years	10 males, 14 females	Retrospective study	Not specified	ESSIX® plates (Dentsply Sirona, USA)	Not mentioned	Hybrid (ESSIX® plates + Class II elastics)	TB	Class II	Dental and skeletal changes	Increased patient compliance	Not mentioned	1 year	Not mentioned	Not mentioned
Pinho et al., 2022 Portugal	23	8.3 ± 1.0 years	13 females, 10 males	Retrospective case series	Mixed dentition	Invisalign® First System (IFS)	Not mentioned	CA	NIL	Molar derotation Crossbite Open bite Class II Class III Crowding	Dental and skeletal changes	Increased patient compliance	Not mentioned	18 months	Not mentioned	Not mentioned
da Silva et al., 2023 Brazil	27	CA = 9.33 ± 1.01 years; FA = 9.65 ± 0.80 years	CA = Six males, eight females; FA = nine males, four females	Randomized clinical trial	Mixed dentition	Not mentioned	Not mentioned	Hybrid (RME + CA)	RME with 2 × 4 appliance		Plaque index ICDAS index Dental and skeletal changes	No	Ten aligners (treatment phase) Six aligners (Refinement phase)	8 months	Not mentioned	Not mentioned
Sarfraz, 2023 Columbia	15	Mean age of 8.9 years	20 females, 19 males	Retrospective study	Mixed dentition	Invisalign® First System (IFS)	Not mentioned	CA	ClinCheck-prediction	Class I Class II Anterior open bite	Dental changes	No	Not mentioned	8 months	Not mentioned	Not mentioned
Wu et al., 2023 China	63	van Beek: 10.71 ± 1.44 years; Herbst: 11.55 ± 0.69 years; TB: 11.00 ± 1.04 years; MA: 12.11 ± 1.16 years; CG: 10.41 ± 0.90 years;	37 females, 26 males	Cohort study	Not specified	Not mentioned	Not mentioned	CA	van Beek Herbst TB Untreated controls	Class II	Dental and skeletal changes	No	Not mentioned	van Beek: 7.28 ± 2.30 years; Herbst: 10.18 ± 3.06 years; TB: 10.16 ± 5.46 years; MA: 22.84 ± 8.98 years; CG: 10.25 ± 3.74 years	Not mentioned	Not mentioned
Ortu et al., 2023 Italy	20	ED:10.4 ± 1.57 years; CA: 10.8 ± 1.53 years	10 females, 10 males	Cohort study	Mixed dentition	Not mentioned	Not mentioned	CA	ED	Class I	Dental and skeletal changes	No	Not mentioned	12 months	Not mentioned	Not mentioned
Dianiskova et al., 2023 Slovakia	56	Mean age: CA = 9.33 years; FA = 9.65 years	Males EA = 21, CA = 16; Females EA = 7, CA = 12	Cross-sectional and case–control study	Mixed dentition	Not mentioned	Not mentioned	CA	ED	Not defined	Patients' and parental satisfaction with the provided therapy	Yes	Not mentioned	Not mentioned	Not mentioned	Not mentioned
Cretella Lombardo et al., 2023 Italy	32	RME: 8.1 ± 0.8 years; CA: 8.4 ± 1.1 years	RME: eight males, nine females; CA: seven males, eight females	Retrospective cohort study	Mixed dentition	Invisalign®	Not mentioned	CA	RME	Posterior transverse discrepancy	Dental changes	Yes	Not mentioned	8 months	3 months	Not mentioned
Yue et al., 2023 China	32	10.2 ± 0.84 years	MA: seven males, nine females; TB: eight males, eight females	Retrospective cohort study	Mixed dentition (or) early permanent dentition	Invisalign® MA	Not mentioned	CA	TB	Class II	Changes in upper airway morphology Hyoid bone position assessed via CBCT	No	Not mentioned	MA: 11.45 ± 1.1 months; TB: 12.11 ± 1.3 months	Not mentioned	Not mentioned
Al Subaie et al., 2024 Saudi Arabia	70	SG: 11.98 ± 2.18 years, CG: 11.75 ± 1.59 years	SG: 23 males, 27 females; CG: 13 males, seven females	Retrospective study	Mixed dentition	Invisalign® with mandibular wings	Not mentioned	CA	Untreated controls	Class II	Dental and skeletal changes	No	Not mentioned	SG: 18.38 (±5.05) months; CG: 19.2 (±9.85) months	Not mentioned	Not mentioned
Kim et al., 2024 Korea	90	8.42 (±0.93) years	48 females, 42 males	Retrospective cohort study	Mixed dentition	Invisalign® First System (IFS)	Not mentioned	CA	NIL	Not defined	Predictability of arch expansion and clinical factors influencing the same	Mentioned in the inclusion criteria	Not mentioned	Not mentioned	Not mentioned	Not mentioned
Meade and Weir, 2024 Australia	195	12.62 (±2.20) years	104 females, 91 males	Retrospective study	Not specified	Invisalign® MA	Not mentioned	CA	NIL	Not defined	Pretreatment, planned, and achieved overjet measurements, as well as changes in intermaxillary anteroposterior first permanent molar (FPM) relationships	Not mentioned	Not mentioned	Not mentioned	Not mentioned	Not mentioned

Results

Overall, 752 articles were excluded as they did not fit the age criteria of this study, 225 articles were review articles, 105 articles were book chapters, consensus statements, comments and editorials, full text was unavailable for 26 articles, 104 articles had an in vitro, ex vivo, or animal study design, the outcome measured in 1,329 articles was irrelevant to this study, and 32 articles were conducted on individuals with special health care needs. Following the removal of duplicates, a final set of 15 articles was included in this present review, of which one was translated from Spanish to English. Of those, four articles^11–14 were case reports, nine articles were retrospective studies,^15–23 four articles were prospective, and one article was a randomized controlled trial.

Most of the articles relevant to this review (15 articles) utilized the Invisalign® clear aligner system. Various applications of the aligner systems were assessed in different studies, wherein 10^{14–17,19,21,23–26} evaluated the efficacy of clear aligners when used for mandibular advancement, one study¹⁵ assessed the correction of open bite malocclusion, four studies evaluated the skeletal expansion induced by clear aligners, nine studies^{11–14,20,23,25,27,28} evaluated the correction of crowding, open bite, crossbite and intercanine and intermolar width, and five studies^{16,22,23,25,29} evaluated the parental and/or patient satisfaction and compliance.

Discussion

Need for the Study

Early diagnosis and treatment during mixed dentition is pivotal for guiding optimal dental development and preventing future orthodontic complications.²⁵ Interceptive orthodontics in this phase focuses on optimizing jaw growth and establishing a stable occlusion, which can reduce the need for more invasive treatments later in life.²⁵ The pubertal growth phase presents a prime opportunity to effectively address skeletal issues, including both functional and esthetic concerns.¹⁴ Clear aligners offer a convenient alternative to traditional braces, providing esthetic advantages and minimal disruption to daily activities.^18,24 Thus, early intervention using clear aligners may improve dental health outcomes and enhance overall well-being as children progress into adulthood.

Type of Aligners

Among all the clear aligner systems used and described in the literature, Invisalign is one of the most popular choices due to the extensive research and development associated with the brand, thus further establishing its standing in the growing esthetic market.^30,31 Since its development in 1997 (Santa Clara, California, United States),³² it has been established worldwide as an esthetic alternative to labial fixed appliances.^33,34

In the present review, eight studies used the Invisalign technology alone,^{11–14,18,20,25,29} one study used the ESSIX technology,¹⁶ and four studies did not mention the type of aligner used.^23,26–28 Of these four, da Silva et al.²⁷ compared clear aligners to rapid maxillary expansion (RME) with 2 × 4 appliance, Wu et al.²⁶ compared them to functional appliances such as van Beek, Herbst, twin block appliances, and untreated controls, and Ortu et al.²⁸ and Dianiskova et al.²³ compared clear aligners to an elastodontic appliance.

Ten studies compared the skeletal and dentoalveolar changes of the clear aligners for the correction of class II malocclusion.^{14–17,19,21,23–26} Two studies evaluated the effects for correction of class III malocclusion.^11,25 Three studies evaluated the changes in the upper arch dimensions following clear aligners, with no comparison group.^18,20,21 Three studies^13,15,35 assessed the effectiveness of clear aligners for the correction of anterior crossbite, and one study evaluated the patient and parental satisfaction following the use of clear aligners.²³

Four studies compared the effects of clear aligners with the twin block appliance.^16,17,21,26 All three authors reported favorable dentoalveolar, skeletal, and other outcomes, such as an improved airway space, especially with the hypopharyngeal airway space, and reduced respiratory resistance when compared to the twin block appliance.

On comparison of CAT with untreated controls, the notable correction was majorly skeletal with some dental changes.^19,24 This implies that CAT can be used to address the growth modification problem in skeletal class II malocclusion in conjunction with occlusal discrepancies.

The present review comprised 21 studies, of which a hybrid approach to aligner therapy was attempted in two studies^16,23 whereas the others included the use of aligners with no combined therapy.

Dianiskova et al. in 2023 compared the treatment efficacy of CAT combined with intermaxillary elastics to that of fixed multibracket therapy in the correction of class II malocclusion.²³ At the end of the treatment period, both treatment modalities were found to be comparable in terms of achieving the treatment outcomes, with the CAT group exhibiting better control of lower incisor proclination. A similar result was obtained by Camcı and Salmanpour in 2022, wherein ESSIX plates with intermaxillary elastics were attempted in the correction of class II malocclusion and compared with twin block therapy.¹⁶ The reason for a greater incisor inclination control was attributed to the aligner's rigidity, which aided in better distribution of the forces produced by the elastics, which is not achieved with brackets, where the combination of elastics often results in molar extrusion, causing a further clockwise rotation of the occlusal plane.²⁷ In the case of twin block, although incisal capping does reduce the extent of incisor proclination, it does not completely prevent it.³⁶

An additional contributory factor could be the posterior bite block effect noted with CAT, wherein intrusion of the posterior teeth occurs due to the aligners, thus adding to the improved control of the vertical growth.³⁷ Although a similar effect is noted with twin block therapy,³⁶ the improved incisor inclination control in tandem with the posterior bite block effect could be the potential reasons for the improved treatment outcomes with CAT. Therefore, clear aligners may be considered as a treatment modality that is more favorable in individuals with a hyperdivergent facial plane.³⁷ Although the treatment duration was not mentioned, Dianiskova et al.²³ did report that the period of application of intermaxillary elastics was also reduced in the CAT group, with the use of elastics beginning at 34 days, whereas the fixed group did not begin elastics until 180 days. This implies that the treatment duration could be significantly affected by the use of CAT. Treatment duration was not mentioned in the majority of the studies; clear aligner treatment can range from 6 to 18 months, whereas traditional braces typically range from 18 to 24 months. However, this can vary widely based on individual treatment needs.

Duration of Treatment

Clear aligner therapy in mixed dentition, as highlighted by studies by Staderini et al. and Meuli et al., demonstrates variable treatment durations.^11,12 Staderini et al. reported a range of 2.3 months for correcting anterior crossbite to 31 months for addressing class III malocclusion using clear aligners.¹ Meuli et al. noted a treatment duration of 2 months and 10 days for correcting an anterior single-tooth crossbite.¹² These findings underscore the flexibility and effectiveness of clear aligners for managing diverse orthodontic issues during the developmental phase of mixed dentition.³⁸

In contrast, fixed orthodontic treatment in mixed dentition presents a spectrum of treatment durations, influenced by specific conditions and treatment modalities. Wiedel and Bondemark discussed variations in treatment duration between fixed and removable appliances for correcting anterior crossbite with functional shift, highlighting potential advantages in duration for fixed appliances.³⁹ Wagner and Berg indicated that fixed appliance treatments integrated with early serial extraction in mixed dentition could be notably shorter compared to treatments initiated solely in permanent dentition.⁴⁰ Phase I orthodontic treatment, including fixed appliances, typically lasts 12–20 months, as suggested by Lee and Dugoni, followed by a supervision phase.⁴¹ Although fixed appliances may lead to significant root length shortening, as suggested by Smeyers et al., specific average treatment durations were not specified, reflecting the diverse treatment approaches and outcomes in fixed orthodontics for mixed dentition cases.⁴²

Treatment Outcomes

In the present review, eight studies^{14,16,17,19,21,23,24,26} assessed the treatment outcomes in class II malocclusion; two studies reported the treatment outcomes after maxillary expansion,^22,29 two studies evaluated crossbite correction,^12,13 one study reported on anterior open bite correction,¹⁵ and three studies elaborated on the treatment outcomes after class I malocclusion correction,^25,27,28 and one study reported on class III malocclusion.¹¹ A single study assessed the patient and parental satisfaction as a primary treatment objective.²³ Though all other surveys were not included as they did not fulfil our inclusion criteria, this study was included as it was the primary objective of the authors.

Class I Malocclusion

da Silva et al. confirmed effective outcomes with clear aligners in the mixed dentition phase while correcting the position of maxillary incisor positions.²⁷ Ortu et al. found no statistically significant differences between the use of clear aligners and elastodontic devices in terms of arch expansion.²⁸

Pinho et al. conducted a case series involving various types of dentoalveolar malocclusion, such as open bite, crossbite, arch discrepancies, etc., and observed significant enhancements in the overbite and overjet, expansion, derotation, and space recovery, thus implying that clear aligners have favorable outcomes in comprehensive orthodontic treatment.²⁵ These findings are in agreement with a systematic review conducted by Papadimitriou, which concluded that the Invisalign system showed sufficient accuracy in resolving anterior crowding and distalizing maxillary molars.³¹ However, contrary to the above findings, our review of the literature in this context concluded that clear aligners offer superior control of upper incisor roots, enhanced bodily expansion of maxillary posterior teeth, and more effective overbite control compared to conventional orthodontic therapy.

Crossbite Correction

Clear aligners have proven to be a highly effective alternative to traditional orthodontic treatments across various studies. Meuli et al. reported desirable treatment outcomes for the correction of crossbite and gingival recession in a period of two months using clear aligners.¹² Staderini et al. demonstrated significant improvements in sagittal jaw relationships and anterior crossbite corrections, thus showcasing the potential of clear aligners in complex cases.^11,13

Mandibular Advancement

Caruso et al. and Ravera et al. highlighted the effectiveness of mandibular advancement with clear aligners in terms of jaw positioning and overall dental alignment while treating skeletal class II malocclusions.^17,24 Dianiskova et al. and Camcı and Salmanpour have also reported notable skeletal and dentoalveolar improvements with the use of clear aligners for mandibular advancement.^16,23

Wu et al. found significant skeletal changes with various mandibular advancement methods using clear aligners.²⁶ Al Subaie et al. highlighted mandibular advancements and soft tissue changes with Invisalign,¹⁹ while Kim et al. confirmed the predictability of arch expansion using clear aligners.¹⁸ Meade and Weir demonstrated effective overjet reduction with mandibular advancement appliances in growing patients.²⁰ Giancotti et al. reported significant skeletal and dental improvements in treating class II, division 1 malocclusion with unilateral posterior crossbite using Invisalign mandibular advancement appliance.¹⁴

Apart from dentoalveolar changes, another aspect that has been assessed with the advent of clear aligner usage is the changes in airway dimensions and hyoid bone position. Yue et al. observed significant improvements in airway dimensions and hyoid bone position with aligner treatment, underscoring its benefits beyond dental alignment.²¹

Collectively, these studies highlight clear aligners as a versatile and effective option compared to traditional orthodontic therapies, particularly for mandibular advancement, although the limited literature on airway effects, aside from the one reported above, suggests a need for further research in this area.

Cephalometric Outcomes

Cephalometric changes observed with the use of clear aligners in pediatric patients show promising results across various types of malocclusions, often comparable to other orthodontic modalities. For instance, in the treatment of class III malocclusion, Staderini et al. reported significant improvements in the sagittal jaw relationship, incisor inclination, and ideal overjet and overbite after aligner therapy.¹¹ Ravera et al. observed similar outcomes in class II malocclusion and found substantial reductions in the A point–Nasion–B point (ANB) angle and improvements in the Wits appraisal (Wits) index, and linear Go–Gn measurements.²⁴ These changes indicate effective control of jaw positioning and occlusal relationships, akin to traditional orthodontic treatments such as fixed appliances or functional devices.

Wu et al. and Al Subaie et al. reported advancements in the Sella–Nasion–B point (SNB) angle and mandibular base positions, similar to those achieved with traditional functional appliances such as twin block.^19,26 These studies also noted improvements in soft tissue profiles and reductions in ANB angle, indicating effective skeletal and dentoalveolar corrections.

Patient Compliance

Patient compliance is an important consideration when using removable functional appliances.⁴³ Orthodontic treatment often spans several years and has a significant impact on patients' lives. Patient motivation for orthodontic treatment varies significantly, ranging from complete disinterest in some children and adolescents to a strong eagerness to undergo treatment.⁴⁴ Based on our research, parental satisfaction with orthodontic treatment was specifically reported in only one study. This reflects the current state of understanding regarding parental perspectives in the reviewed literature.

Several studies have suggested that clear aligners might have distinct advantages when compared to traditional orthodontic therapy in children.^19,21,24 Certain contributing factors may be the reduced discomfort and difficulty wearing the appliance, ease of eating, easier adjustment to the appliance, improved oral hygiene, fewer emergency visits, fewer missed school days, and an increased self-perception of attractiveness.^23,24,27 El-Huni et al. observed impairments in speech, sleep, schooling, and social interaction with the use of functional appliances.⁴⁵ Zhang et al. evaluated the changes in oral health-related quality of life (OHRQoL) during fixed orthodontic therapy and reported that compared with pretreatment, a patient's OHRQoL is frequently worse during the therapy (oral symptoms, functional limitations), although it is better in some aspects (emotional well-being).⁴⁶ This arose the interest of orthodontists toward more esthetic and comfortable appliances.

A more discrete approach could be illustrated by clear aligners, which have the potential to enhance esthetics and comfort, and their various forms allow for the forward posturing of the mandible. Clear aligners have thin, separate maxillary and mandibular components, which may facilitate easy speaking or drinking during daytime wearing hours.²³

Overall Patient and Parental Satisfaction and Perspective

Parents' treatment expectations appear to be based on perceived socio-occupational advantages and improved dental health for their children.⁴⁷ Understanding patient and parental satisfaction helps ensure that the care provided is tailored to meet their needs and expectations, promoting a patient-centered approach, which further improves the treatment outcomes.^48,49

Evidence from a literature review indicated that clear aligners may improve the patients' perceptions of the treatment process and outcomes compared to fixed therapy.⁸

A questionnaire study by Dianiskova et al. assessed parental and patient satisfaction, and reported that both the children and the parents were highly satisfied with clear aligners in terms of comfort.²³ Furthermore, the treatment with aligners demonstrated a slight improvement in the children's school performance and overall quality of life of the children who participated in this particular study.

Ortu et al. reported similar outcomes in terms of comfort and also mentioned the reduced number of dental appointments required with CAT.²⁸ However, in this scoping review, only five studies^{16,22,23,25,29} reported the overall patient and parent satisfaction using clear aligners. As it was not a primary outcome, it was not included as a part of the outcome analysis of this particular review.

Therefore, the lack of reporting in this field only further emphasizes the need for more research in this area in order to compare the level of satisfaction with traditional orthodontics and improve the treatment outcomes of CAT.

Limitations of Aligners

Although aligners have multifold advantages, there are certain constraints that limits the wide-range use of CAT. The treatment protocol is largely dependent upon patient compliance, which may be a disadvantage with the adolescent group, as the patients who are not inclined toward the treatment may not adhere to the treatment protocol.⁵⁰

Case selection plays a substantial role in CAT as the use of aligners is limited to minor tooth movement. Therefore, in the case of mixed dentition, when there is a need for a functional appliance to achieve skeletal changes, aligners would play a rather limited role as they are more effective in achieving dentoalveolar changes than skeletal changes.²² However, contrary to reporting by Lombardo, reporting from Hosseini et al. has brought about clinically appreciable skeletal and dental changes.⁵¹ Future studies will need to focus on these parameters.

The increased expense associated with the use of aligners is an insurmountable limitation. The number of trays involved and the need for digital scans, two of the most influential factors of treatment planning for the aligner therapy, are also the major reasons for the higher cost. While fixed mechanotherapy may not be esthetic, a significant difference exists between the two treatment modalities when cost-effective therapy is considered.⁵²

Although the pursuit of “metal-free” orthodontic treatment has paved the way for the advent of aligner therapy, these appliances are associated with certain significant drawbacks. One of the concerns with the usage of aligners is the risk of allergy.⁵³ The polyurethane resins used in aligners are often associated with an increased prevalence of allergic reactions, some of which have been severe, as previously reported.^54,55 However, no allergic reactions were reported in the included studies of the present review.

Conclusion

Clear aligner therapy offers a multitude of advantages in the mixed dentition; however, the level of evidence currently available is insufficient to reach a definitive consensus regarding the case scenarios that could benefit from the usage of clear aligners. Further qualitative research is required in this field in order to explore the regime of clear aligners in the pediatric population.

Clinical Significance

Clear aligner therapy offers early intervention benefits during mixed dentition, aiding in skeletal and dental development and preventing future complications. It provides an esthetic, comfortable alternative to traditional braces, improving patient satisfaction and compliance. CAT has shown effectiveness in treating class II malocclusion and other issues, with potential for shorter treatment times and fewer emergency visits. However, more research is needed to define ideal case selection and treatment protocols for children.

Orcid

Ananya Rao Kote https://orcid.org/0009-0004-6190-6268

Krishna Priya https://orcid.org/0009-0003-8939-2329

Shreya S https://orcid.org/0000-0002-3474-5110

Swagata Saha https://orcid.org/0000-0002-2343-5977

Dhvani Abhijit Tanna https://orcid.org/0009-0008-4999-5818

Mohanaram Selvaraj https://orcid.org/0009-0001-2531-0051

Manju Raman Nair https://orcid.org/0000-0002-9391-6223