Review Article

Year : 2026 | Volume : 17 | Issue : 2 | Page : 114-127

A Comparative Evaluation of Efficiency of Orthodontic Treatment with Different Palatal Expanders: Hyrax Type and Haas Type — A Systematic Review

Soumya Ranjan Padhi- 1, Shashank Gaikwad- 2, Parag V. Gangurde- 3, Pritam Mohanty- 4, Debapreeti Mohanty- 5

1- Assistant Professor, Department of Orthodontics and Dentofacial Orthopaedics, Institute of Dental Sciences, SOA, Bhubaneswar, Odisha, India, 2- Professor, 3- Professor and Head, Department of Orthodontics and Dentofacial Orthopaedics, Bharati Vidyapeeth (Deemed to be University) Dental College and Hospital, Navi Mumbai, Maharashtra, India, 4- Professor and Head, Department of Orthodontics and Dentofacial Orthopaedics, 5- Associate Professor, Department of Conservative Dentistry and Endodontics, Institute of Dental Sciences, SOA, Bhubaneswar, Odisha, India.

Address for Correspondence:

Dr. Soumya Ranjan Padhi,

Assistant Professor, Department of Orthodontics and Dentofacial Orthopaedics,

Institute of Dental Sciences, SOA, Bhubaneswar, Odisha, India- 751029,

Email ID- drsoumyaranjanpadhi@gmail.com

ABSTRACT

AIM: To compare the efficiency of Hyrax-type and Haas-type rapid maxillary expanders (RME) in growing patients with transverse maxillary deficiency, with respect to dentoskeletal effects, root resorption, and periodontal outcomes.

METHODS: Electronic databases (PubMed/MEDLINE, Embase, Cochrane Library, Web of Science, Scopus) were searched from inception to November 2022 for English-language studies on growing patients (7–18 years) receiving rapid maxillary expansion (RME). Risk of bias was assessed using ROB 2 (Cochrane Risk of Bias tool, version 2) for RCTs and ROBINS-I (Risk of Bias in Non-randomized Studies of Interventions) for non-randomized studies. Findings were synthesized narratively across three outcome domains: skeletal/dental expansion, root resorption, and periodontal effects. PROSPERO Registration: CRD42022336910

RESULTS: Nine studies (N=719 patients; 7 RCTs, 2 non-randomized studies) met inclusion criteria. Both appliances effectively corrected transverse maxillary deficiency, with Hyrax favoring dento-alveolar expansion and Haas favoring skeletal movement, though between-group differences were small. Both produced comparable, non-significant root resorption and similar periodontal bone changes (decreased buccal and increased lingual bone plate thickness). Risk of bias was low to moderate in most studies; two RCTs were high risk.

CONCLUSION: Both Hyrax- and Haas-type expanders are effective for correcting transverse maxillary deficiency, with comparable root resorption and periodontal effects. However, confidence in these findings is limited by the predominantly low-to-moderate, and in two RCTs high, risk of bias among included studies, and definitive conclusions await better-quality evidence.

Substantial clinical and methodological heterogeneity across studies precluded meta-analysis; well-designed RCTs with standardized outcome reporting are needed.
KEYWORDS: Rapid maxillary expansion; RME; Hyrax expander; Haas expander; palatal expansion; systematic review.

CONFLICT OF INTEREST AND FUNDING

Nil

How to cite this article: Soumya Ranjan Padhi, Shashank Gaikwad, Parag V. Gangurde, Pritam Mohanty, Debapreeti Mohanty. A Comparative Evaluation of Efficiency of Orthodontic Treatment with Different Palatal Expanders: Hyrax Type and Haas Type — A Systematic Review.

Int JOrthod Rehabil 2026; 17 (2): 114-127.

Doi: 10.56501/Intjorthodrehabil.172.ijor0048