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| Title |
Evidence Suggests Clear Aligner Mandibular Advancement is Modestly Effective for Class II Correction in Growing Patients
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| Clinical Question |
In growing patients with class II malocclusion, how does treatment with clear aligner mandibular advancement compare to conventional functional appliances in achieving dental and skeletal correction of the class II relationship? |
| Clinical Bottom Line |
In growing patients with Class II malocclusion, clear aligner mandibular advancement therapy results in a reduction of ANB angle and overjet, with improved control of lower incisor inclination compared to conventional functional appliances. However, traditional appliances tend to produce more pronounced effect on skeletal and dental changes. Across all three systematic reviews, the overall quality of evidence was limited, highlighting the need for well-designed randomized controlled trials to confirm these findings. Despite these limitations, clear aligner therapy may be preferred by patients due to its superior comfort and esthetic appeal. |
| Best Evidence |
(you may view more info by clicking on the PubMed ID link) |
| PubMed ID |
Author / Year |
Patient Group |
Study type
(level of evidence) |
| #1) 40357108 | Khalil/2025 | 426 participants in 9 included studies | Systematic review of non-randomized trials | | Key results | This review analyzed nine studies on the dental and skeletal outcomes of clear aligner mandibular advancement therapy for Class II malocclusion. Due to variability in study design and outcome measures (high heterogeneity), results were reported individually. These outcomes were assessed using a lateral cephalometric radiograph or CBCT. Most of the studies concluded that clear aligners effectively improved class II malocclusion, indicated by reduced overjet and ANB angle, and multiple studies showed greater control over lower incisor angulation in comparison to traditional appliances such as Herbst or Twin Block. While some studies held that traditional appliances produced more skeletal changes, results were overall comparable. Overall, the review supports clear aligner mandibular advancement as an effective approach for Class II correction, with higher patient satisfaction in comfort and esthetics. | | #2) 40415149 | Mecenas/2025 | 396 participants in 7 included studies | Systematic review of non-randomized trials | | Key results | This systematic review included seven studies comparing the dental and skeletal correction of class II malocclusion in pediatric patients using Precision Wings Invisalign aligner device versus traditional appliances (Twin Block, Herbst, Van Beek). All seven studies had individual reports synthesized due to heterogeneity concerns, but 3 studies with untreated control groups were eligible for meta-analysis. The meta-analysis demonstrated a statistically significant decrease in ANB (MD=-0.81, 95% CI: -1.04 to -0.58, p<0.001), an increase in SNB (MD=0.55, 95% CI: 0.11 to 0.98, p=0.01) and no statistically significant difference in vertical skeletal changes or incisor inclination. All seven studies documented a decrease in ANB using the Precision Wings aligner. The Precision Wings group provided better control of incisor inclination, but a lower reduction of overjet compared to traditional appliances. This systematic review demonstrates that the Precision Wings treatment offers small but statistically significant skeletal improvements in growing Class II patients. However, the limited magnitude of changes and low certainty of evidence highlight the need for high quality RCTs. | |
| Evidence Search |
((clear aligners OR Invisalign) AND (mandibular advancement)) AND (class II malocclusion) in PubMed * |
Comments on
The Evidence |
In the systematic review by Khalil et al., nine studies were included based on a PRISMA-guided search by two independent researchers. Risk of bias, assessed with the ROBINS-I tool, was moderate, primarily due to confounding factors and selection bias from lack of randomization. The high heterogeneity in study design led to a narrative synthesis, instead of a meta-analysis. Due to limited current research, the majority of studies were retrospective. The authors noted that the clinical results “support its use as a viable alternative to conventional functional appliances” but “high-quality randomized controlled trials are essential to overcome the limitations”. The systematic review by Mecenas et al. included seven studies based on a PRISMA-guided search by two reviewers. Similar to the Khalil review, most of these studies were retrospective in design. The ROBINS-I tool was also employed to evaluate bias and yielded that there was moderate/serious bias risk due to confounding and statistical test choice. A meta-analysis was conducted on three of the seven studies, and GRADE Pro software was used to assess the quality of evidence, which was found to be low. Although statistically significant improvements were noted, the clinical significance is questionable due to the small changes and low certainty of evidence, indicating the further need for high quality RCTs to be conducted. The study conducted by Salek et al. included 13 articles based on PRISMA protocols and evaluated by ROBINS-I (risk of bias) and STROBE (reporting quality). Of the included studies, 12 were retrospective, and the author notes “no randomized controlled trials were available”. The studies contained a moderate risk level of bias due to confounding, selection or participants, and classification of interventions. The large heterogeneity between these studies, along with limited quality of evidence, further emphasizes the need for well-designed RCTs to more definitively assess the efficacy of clear aligned mandibular advancement therapy. |
| Applicability |
All three systematic reviews included studies evaluating pediatric patients with Class II malocclusions—an age group and skeletal discrepancy commonly treated in orthodontic practice. This article notes that “functional appliances are widely favored treatment for addressing Class II”. Clear aligner mandibular advancement therapy is gaining popularity due to increased patient comfort, esthetic appeal, and better control of lower incisor inclination compared to traditional appliances. However, its clinical applicability may be limited by higher costs and the need for strict patient compliance, particularly in younger populations. Additionally, the absence of high-quality randomized controlled trials restricts the strength of current evidence regarding its long-term skeletal and dental efficacy. |
| Specialty/Discipline |
(Orthodontics) |
| Keywords |
Clear aligners, class II malocclusion, mandibular advancement
|
| ID# |
3580 |
| Date of submission: |
06/24/2025 |
| E-mail |
maddieferris14@gmail.com |
| Author |
Maddie Haager |
| Co-author(s) |
Jewelyn dela Cruz |
| Co-author(s) e-mail |
J.delacruz3792@gmail.com |
| Faculty mentor/Co-author |
Kelly Lemke, DDS, MS |
| Faculty mentor/Co-author e-mail |
lemkek@uthscsa.edu |
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?) |
post a rationale |
| None available | |
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Comments and Evidence-Based Updates on the CAT
(FOR PRACTICING DENTISTS', FACULTY, RESIDENTS and/or STUDENTS COMMENTS ON PUBLISHED CATs) |
post a comment |
| None available | |
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