Evidence map›Paper›PMID 42429959›Full record

ReviewJournal of orofacial orthopedics = Fortschritte der Kieferorthopadie : Organ/official journal Deutsche Gesellschaft fur Kieferorthopadie2026

Three-dimensional skeletal and dental effects of the Haas vs. hyrax type expanders in adolescent rapid maxillary expansion : Systematic review and meta-analysis.

Yuhong Wang, Yi Yang, Qi Li, Shuxi Xu, Zhouxing Zhou, Renming Tan, Wenjie Zhong, Xiang Gao

Abstract readReview
PubMed Publisher
In one paragraph

Review in Journal of orofacial orthopedics = Fortschritte der Kieferorthopadie : Organ/official journal Deutsche Gesellschaft fur Kieferorthopadie, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors.

Yuhong WangCollege of Stomatology, Chongqing Medical University, Chongqing, China.
Yi YangCollege of Stomatology, Chongqing Medical University, Chongqing, China.
Qi LiCollege of Stomatology, Chongqing Medical University, Chongqing, China.
Shuxi XuCollege of Stomatology, Chongqing Medical University, Chongqing, China.
Zhouxing ZhouCollege of Stomatology, Chongqing Medical University, Chongqing, China.
Renming TanCollege of Stomatology, Chongqing Medical University, Chongqing, China.
Wenjie ZhongCollege of Stomatology, Chongqing Medical University, Chongqing, China.
Xiang GaoCollege of Stomatology, Chongqing Medical University, Chongqing, China. xiangg@hospital.cqmu.edu.cn.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeThe three-dimensional dentoskeletal effects of Haas versus hyrax rapid maxillary expanders (RMEs) in adolescents with maxillary transverse deficiency remain uncertain. We conducted a systematic review and meta-analysis to compare their short-term skeletal and dental outcomes using three-dimensional measurements. Additionally, uncontrolled Haas studies were descriptively synthesized to contextualize within-group changes.

methodsElectronic searches (PubMed, Embase, Web of Science, Cochrane, China National Knowledge Infrastructure) up to January 2025 identified eligible clinical studies in adolescents reporting three-dimensional outcomes. Comparative studies that directly evaluated the Haas versus hyrax appliances were incorporated into the quantitative synthesis, while single-arm or self-controlled studies applying the Haas appliance were included solely in the qualitative synthesis. Primary outcomes included midpalatal suture width, first molar and premolar interdental distances, buccal and lingual alveolar bone thickness at first molars, and first molar inclination.

resultsNine studies met inclusion criteria: seven comparative studies (Haas vs. hyrax; meta-analysis), two Haas-only (narrative synthesis). Across all six evaluated outcomes, pooled analyses revealed no statistically significant differences between the Haas and hyrax expanders. Substantial heterogeneity was observed for midpalatal suture width, first molar distance, and lingual alveolar bone thickness.

conclusionCurrent comparative evidence does not reveal statistically significant short-term differences between the Haas and hyrax expanders concerning the evaluated three-dimensional skeletal and dental outcomes. These findings suggest that the existing evidence does not substantiate clear superiority or inferiority of the Haas appliance compared to the hyrax appliance for the assessed outcomes.

Indexed as

Maxillary expansion effectMaxillary transverse deficiencyMeta-analysisSystematic reviewsThree-dimensional treatment outcomes

Identifiers

PMID42429959

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.