Non-Cochrane · intervention · PM42060239
Effectiveness of clear aligners for maxillary expansion in growing patients: a systematic review and meta-analysis.
Fonseca Planells Lucía, Bellot-Arcís Carlos, Montiel-Company José María, et al. · Progress in orthodontics · 2026 · PubMed · doi:10.1186/s40510-026-00620-7
Findings
Population Growing patients (mixed or early permanent dentition) requiring maxillary expansion
10 findings
| Clear aligners (Invisalign First) | Conventional maxillary expanders (RME/Hyrax, leaf, removable acrylic, slow expansion) | Second primary molar distance (E-E) Change from baseline to end of treatment | MD -0.38 [-1.16, 0.40] GRADE not reported 3 studies · 180 participants |
| Clear aligners (Invisalign First) | Conventional maxillary expanders (RME/Hyrax, leaf, removable acrylic, slow expansion) | Total palatal volume Change from baseline to end of treatment | MD -460.63 [-738.32, -182.94] -460.63 [-738.32, -182.94] mm3 Moderate Downgraded: risk of bias 2 studies · 85 participants |
| Clear aligners (Invisalign First) | Conventional maxillary expanders (RME/Hyrax, leaf, removable acrylic, slow expansion) | First primary molar distance (D-D) Change from baseline to end of treatment | MD 0.14 [-1.08, 1.37] GRADE not reported 3 studies · 180 participants |
| Clear aligners (Invisalign First) | Conventional maxillary expanders (RME/Hyrax, leaf, removable acrylic, slow expansion) | Total palatal area Change from baseline to end of treatment | MD -48.15 [-104.07, 7.76] -48.15 [-104.07, 7.76] mm2 Low Downgraded: risk of bias, imprecision 2 studies · 85 participants |
| Clear aligners (Invisalign First) | Conventional maxillary expanders (RME/Hyrax, leaf, removable acrylic, slow expansion) | Arch depth Change from baseline to end of treatment | MD -0.14 [-0.66, 0.38] -0.14 [-0.66, 0.38] mm Low Downgraded: risk of bias 2 studies · 68 participants |
| Clear aligners (Invisalign First) | Conventional maxillary expanders (RME/Hyrax, Haas/slow, removable acrylic, Leaf expander) | Predictability of expansion (achieved vs planned) End of aligner or expander treatment (T0 to T1) · Orthodontic clinics | Not estimable (Supplementary Table V); 10 observational studies, n = 487 Moderate Downgraded: risk of bias 10 studies · 487 participants |
| Clear aligners (Invisalign First) | Conventional maxillary expanders (RME/Hyrax, leaf, removable acrylic, slow expansion) | Arch perimeter Change from baseline to end of treatment | MD -1.75 [-2.71, -0.80] -1.75 [-2.71, -0.80] mm Low Downgraded: risk of bias 2 studies · 102 participants |
| Clear aligners (Invisalign First) | Conventional maxillary expanders (RME/Hyrax, leaf, removable acrylic, slow expansion) | Quantity of expansion: intermolar distance (6-6) Change from baseline to end of treatment | MD -1.77 [-2.57, -0.97] -1.77 [-2.57, -0.97] mm Moderate Downgraded: risk of bias 7 studies · 333 participants |
| Clear aligners (Invisalign First) | Conventional maxillary expanders (RME/Hyrax, leaf, removable acrylic, slow expansion) | Intercanine distance (C-C) Change from baseline to end of treatment | MD -0.74 [-1.68, 0.20] GRADE not reported 7 studies · 333 participants |
| Clear aligners (Invisalign First) | Conventional maxillary expanders (RME/Hyrax, leaf, removable acrylic, slow expansion) | Intercanine distance (C-C) Change from baseline to end of treatment · Trim-and-fill adjusted (1 study imputed) | MD -0.507 [-1.44, 0.426] GRADE not reported 7 studies · 333 participants |
Included primary studies 26
Open in Studies| Study | Year | Also included by | Outcomes it informs here | Trial data |
|---|---|---|---|---|
| Bruni 2024 Efficacy of clear aligners vs rapid palatal expanders on palatal volume and surface area in mixed dentition patients: A randomized… PMID:39066746 | 2024 | 1 other review | Intercanine distance (C-C); Quantity of expansion: intermolar distance (6-6); Total palatal area; Total palatal volume | not extracted yet |
| Cretella Lombardo 2022 Evaluation of the Upper Arch Morphological Changes after Two Different Protocols of Expansion in Early Mixed Dentition: Rapid Maxillary… PMID:36143360 | 2022 | 1 other review | Intercanine distance (C-C); Quantity of expansion: intermolar distance (6-6); First primary molar distance (D-D); Second primary molar distance (E-E) | not extracted yet |
| Lu 2023 Treatment effects after maxillary expansion using invisalign first system vs. acrylic splint expander in mixed dentition: a prospective… PMID:37635237 | 2023 | 1 other review | Intercanine distance (C-C); Quantity of expansion: intermolar distance (6-6); Arch perimeter; Arch depth | not extracted yet |
| Moravedje Torbaty 2024 Vertical and transverse treatment effects of Invisalign First system compared to Hyrax maxillary expanders with fixed appliances in mixed… PMID:39230021 | 2024 | 1 other review | Intercanine distance (C-C); Quantity of expansion: intermolar distance (6-6); First primary molar distance (D-D); Second primary molar distance (E-E) | not extracted yet |
| Pamukcu 2024 Evaluation of maxillary dimensional changes in the mixed dentition: clear aligners vs acrylic expanders. PMID:39229950 | 2024 | 1 other review | Intercanine distance (C-C); Quantity of expansion: intermolar distance (6-6); Arch depth | not extracted yet |
| Wang 2023 Dimensional changes in the palate associated with Invisalign First System: a pilot study. PMID:37052464 | 2023 | 1 other review | Intercanine distance (C-C); Quantity of expansion: intermolar distance (6-6); Total palatal area; Total palatal volume | not extracted yet |
| Bruni 2024 Efficacy of clear aligners vs rapid palatal expanders on palatal volume and surface area in mixed dentition patients: A randomized… DOI:10.1016/j.ajodo.2024.04.006 | 2024 | this review only | not stated | not extracted yet |
| Goncalves 2023 DOI:10.23804/ejpd.2023.1754 | NR | this review only | not stated | not extracted yet |
| Goncalves 2023 Efficiency of Invisalign First® to promote expansion movement in mixed dentition: a retrospective study and systematic review. PMID:37038757 | 2023 | this review only | not stated | not extracted yet |
| Kai 2024 An evaluation of maxillary expansion after Phase I orthodontic treatment with clear aligners using model analysis and cone-beam computed… DOI:10.25259/apos_168_2022 | 2023 | this review only | not stated | not extracted yet |
| Kim 2024 The predictability of arch expansion with the Invisalign First system in children with mixed dentition: a retrospective study DOI:10.22514/jocpd.2024.012 | 2024 | this review only | not stated | not extracted yet |
| Kim 2024 The predictability of arch expansion with the Invisalign First system in children with mixed dentition: a retrospective study. PMID:38239161 | 2024 | this review only | not stated | not extracted yet |
| Levrini 2021 DOI:10.23804/ejpd.2021.22.02.7 | NR | this review only | not stated | not extracted yet |
| Levrini 2021 Maxillary expansion with clear aligners in the mixed dentition: A preliminary study with Invisalign® First system. PMID:34238002 | 2021 | this review only | not stated | not extracted yet |
| Levrini 2024 Predictability of Maxillary Expansion with Invisalign® First: Treatment Planning vs. Outcome DOI:10.3390/app14219871 | 2024 | this review only | not stated | not extracted yet |
| Lin 2024 Impact of Invisalign® first system on molar width and incisor torque in malocclusion during the mixed dentition period DOI:10.1097/md.0000000000038742 | 2024 | this review only | not stated | not extracted yet |
| Lin 2024 Impact of Invisalign® first system on molar width and incisor torque in malocclusion during the mixed dentition period. PMID:38968482 | 2024 | this review only | not stated | not extracted yet |
| Lione 2023 Upper arch dimensional changes with clear aligners in the early mixed dentition DOI:10.1007/s00056-021-00332-z | 2021 | this review only | not stated | not extracted yet |
| Lione 2023 Upper arch dimensional changes with clear aligners in the early mixed dentition : A prospective study. PMID:34477905 | 2023 | this review only | not stated | not extracted yet |
| Loberto 2024 Predictability of expansion movements performed by clear aligners in mixed dentition in both arches: a retrospective study on digital casts DOI:10.1186/s12903-024-04435-y | 2024 | this review only | not stated | not extracted yet |
| Loberto 2024 Predictability of expansion movements performed by clear aligners in mixed dentition in both arches: a retrospective study on digital casts. PMID:38879479 | 2024 | this review only | not stated | not extracted yet |
| Lu 2023 Treatment effects after maxillary expansion using invisalign first system vs. acrylic splint expander in mixed dentition: a prospective… DOI:10.1186/s12903-023-03312-4 | 2023 | this review only | not stated | not extracted yet |
| Moravedje Torbatya 2024 Vertical and transverse treatment effects of Invisalign First system compared to Hyrax maxillary expanders with fixed appliances in mixed… DOI:10.2319/121023-818.1 | 2024 | this review only | not stated | not extracted yet |
| Pamukcu 2024 Evaluation of maxillary dimensional changes in the mixed dentition: clear aligners vs acrylic expanders DOI:10.2319/121523-833.1 | 2024 | this review only | not stated | not extracted yet |
| Silvestrini-Biavati 2024 Three-Dimensional Analysis of Maxillary Expansion during Mixed Dentition: Comparison between Leaf Expander and Aligners—A Case-Control Study DOI:10.3390/app14198700 | 2024 | this review only | Intercanine distance (C-C); Quantity of expansion: intermolar distance (6-6); First primary molar distance (D-D); Second primary molar distance (E-E); Arch perimeter | not extracted yet |
| Wang 2023 Dimensional changes in the palate associated with Invisalign First System: a pilot study DOI:10.2319/110422-755.1 | 2023 | this review only | not stated | not extracted yet |
Overlap with other reviews
Reviews that include the same primary studies are not independent evidence. Shared counts match studies by PMID, DOI or NCT, and otherwise by author and year (a probable match). Only the non-Cochrane dental reviews have study lists, so overlap with Cochrane reviews is not counted yet.
| Review | Shared studies | Jaccard |
|---|---|---|
| Comparative Evaluation of Transverse Maxillary Arch Changes in Mixed Dentition with Clear Aligners vs Conventional Maxillary Expanders: A… (2026) | 6 | 0.21 |
Review question
| Element | Planned (methods) | Found (results) |
|---|---|---|
| Population | Growing patients with mixed dentition or early permanent dentition requiring maxillary expansion | Growing patients aged 6 to 12 years in mixed dentition (n=776 analyzed across 15 studies) |
| Intervention | Treatment with clear aligners | Invisalign First clear aligners (15 studies) |
| Comparison | Conventional maxillary expanders (removable or fixed) | Rapid maxillary expander/Hyrax, Haas slow expander, removable acrylic expander, Leaf expander, or no comparator (7 studies in meta-analysis) |
| Outcomes | Predictability and effectiveness of maxillary expansion measured as transverse changes in the maxillary arch (C-C, D-D, E-E, 6-6, palatal area, palatal volume, arch perimeter, arch depth) | C-C, 6-6, D-D, E-E distances; total palatal area; total palatal volume; arch perimeter; arch depth; predictability |
| Study designs | Retrospective and prospective studies and randomized clinical trials; excluded reviews, case series, case reports and in vitro studies | 1 RCT, 12 retrospective studies, 2 prospective studies (n=15) |
| Timing | Not specified | Treatment duration about 6 to 18 months |
AMSTAR 2 items
Two independent extractors rated each item. Their ratings are shown side by side because they have not been reconciled yet. The overall rating follows Shea et al. 2017: one critical flaw gives Low, more than one gives Critically Low.
| Item | Extractor A | Extractor B | Agree |
|---|---|---|---|
| 1Research question includes PICO components | Yes | Yes | yes |
| 2Protocol established before the reviewcritical | Partial Yes | Partial Yes | yes |
| 3Choice of study designs explained | No | No | yes |
| 4Comprehensive literature searchcritical | Partial Yes | Partial Yes | yes |
| 5Study selection in duplicate | Yes | Yes | yes |
| 6Data extraction in duplicate | No | No | yes |
| 7List of excluded studies with reasonscritical | Yes | Yes | yes |
| 8Included studies described in detail | Yes | Yes | yes |
| 9Risk of bias assessed satisfactorilycritical | RCT: Yes · NRSI: Yes | RCT: Yes · NRSI: Yes | yes |
| 10Funding of included studies reported | No | No | yes |
| 11Appropriate meta-analysis methodscritical | RCT: Yes · NRSI: No | NRSI: No · RCT: N/A | no |
| 12Impact of risk of bias on the pooled results | No | No | yes |
| 13Risk of bias accounted for in interpretationcritical | Yes | Yes | yes |
| 14Heterogeneity explained | Yes | Yes | yes |
| 15Publication bias investigatedcritical | Yes | Yes | yes |
| 16Conflicts of interest reported | Yes | Yes | yes |
| Overall | Low | Low | yes |