Maxillary Expansion: Leaf Expander Versus Hyrax Expander

NCT ID: NCT05135962

Last Updated: 2021-11-26

Basic Information

• Recruitment Status: UNKNOWN
• Clinical Phase: NA
• Total Enrollment: 200 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2021-12-01
• Study Completion Date: 2023-11-01

Brief Summary

The aim of the current study was to evaluate maxillary and mandibular arch widths' response to five different appliances and clinical protocols (Rapid maxillary expander RME, Leaf Expander 450g, Leaf Expander 900g, Self-expander 450g, Self-expander 900g) for the correction of the maxillary deficiency.

Detailed Description

Maxillary expansion with fixed appliance is a well-known and consolidated practice in clinical orthodontics but current findings of "evidence-based dentistry" have not yet identified a better clinical expansion protocol. This issue is due both to the several expansion screws available on the market and to the different screw activation protocols, which could be grouped in rapid and slow, with several customizations. The comparison between slow and rapid expansion is a hotly debated topic in the literature and a recent systematic review have shown that both rapid and slow expansion protocols are clinically effective on the primary outcome (the resolution of the maxillary deficiency and crossbite with a significant increase of skeletal transversal maxillary dimension). Based on these results, the choice of appliance based on its ability to solve the maxillary constriction may not be any more the main selection criteria. The choice of the orthodontist should also be based on the timing and on a "patient-oriented" device, that minimizes the side effects, such as e.g. appliance breakages, functional impairments, and pain perception.

The aim of the present study is to investigate and analyze five different maxillary expansion appliances to identify an effective and efficient clinical protocol for the maxillary expansion.

Conditions

Maxillary Deficiency

Keywords

maxillary expansion; slow expansion; rapid expansion; leaf expander

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: TRIPLE

Study Groups

RME (rapid expansion)

Intervention orthodontic - maxillary expansion:

maxillary expansion with RME expander anchored on second deciduous molars. Activation: 1/turn day. RME was kept on teeth as a passive retainer and removed after one year from its application.

Group Type: ACTIVE_COMPARATOR

orthodontic - rapid maxillary expansion

Intervention Type: DEVICE

Rapid expansion: when RME was in situ, patients started the screw activation of one-quarter turn a day until overcorrection was achieved and RME was kept on teeth as a passive retainer and removed after one year from its application.

Leaf expander 450g (slow expansion)

Intervention orthodontic - maxillary expansion: maxillary expansion with Leaf Expander appliance anchored on second deciduous molars Activation: The leaves are preactivated in the laboratory to deliver 3mm of expansion. Reactivation is performed in the office by 10 quarter-turns of the screw per month until expansion has been completed. After active expansion, the Leaf Expander was kept on teeth as a passive retainer and removed after one year from its application.

Group Type: EXPERIMENTAL

orthodontic - slow maxillary expansion with leaf expander

Intervention Type: DEVICE

Leaf expander: The screw delivers a maximum expansion of 6 or 9 mm by activating (compressing) the spring, which generates a light (450g or 900g) and constant force. The leaves are preactivated in the laboratory to deliver 3mm of expansion. Reactivation is performed in the office by 10 quarter-turns (leaf 450g) or 15 quarter-turns (leaf 900g) of the screw per month until expansion has been completed. After active expansion the Leaf Expander is maintained passively in place for retention period. Leaf expander was kept on teeth as a passive retainer and removed after one year from its application.

Leaf self-expander 450g (slow expansion)

Intervention orthodontic - maxillary expansion: maxillary expansion with Leaf self Expander appliance anchored on second deciduous molars.

Activation: self activation (preactivated). After active expansion the Leaf self expander was kept on teeth as a passive retainer and removed after one year from its application

Group Type: EXPERIMENTAL

orthodontic - slow maxillary expansion with self leaf expander

Intervention Type: DEVICE

Leaf self expander: similar to Leaf expander with no need for reactivation or patient compliance.

Leaf expander 900g (slow expansion)

Intervention orthodontic - maxillary expansion: maxillary expansion with Leaf Leaf Expander appliance anchored on second deciduous molars.

Activation: The leaves are preactivated in the laboratory to deliver 3mm of expansion. Reactivation is performed in the office by 15 quarter-turns of the screw per month until expansion has been completed. After active expansion the Leaf Expander was kept on teeth as a passive retainer and removed after one year from its application.

Group Type: EXPERIMENTAL

orthodontic - slow maxillary expansion with leaf expander

Intervention Type: DEVICE

Leaf expander: The screw delivers a maximum expansion of 6 or 9 mm by activating (compressing) the spring, which generates a light (450g or 900g) and constant force. The leaves are preactivated in the laboratory to deliver 3mm of expansion. Reactivation is performed in the office by 10 quarter-turns (leaf 450g) or 15 quarter-turns (leaf 900g) of the screw per month until expansion has been completed. After active expansion the Leaf Expander is maintained passively in place for retention period. Leaf expander was kept on teeth as a passive retainer and removed after one year from its application.

Leaf self-expander 900g (slow expansion)

Intervention orthodontic - maxillary expansion: maxillary expansion with Leaf self Expander appliance anchored on second deciduous molars.

Activation: self activation (preactivated). After active expansion the Leaf self expander was kept on teeth as a passive retainer and removed after one year from its application

Group Type: EXPERIMENTAL

orthodontic - slow maxillary expansion with self leaf expander

Intervention Type: DEVICE

Leaf self expander: similar to Leaf expander with no need for reactivation or patient compliance.

Interventions

orthodontic - rapid maxillary expansion

Rapid expansion: when RME was in situ, patients started the screw activation of one-quarter turn a day until overcorrection was achieved and RME was kept on teeth as a passive retainer and removed after one year from its application.

Intervention Type: DEVICE

orthodontic - slow maxillary expansion with leaf expander

Leaf expander: The screw delivers a maximum expansion of 6 or 9 mm by activating (compressing) the spring, which generates a light (450g or 900g) and constant force. The leaves are preactivated in the laboratory to deliver 3mm of expansion. Reactivation is performed in the office by 10 quarter-turns (leaf 450g) or 15 quarter-turns (leaf 900g) of the screw per month until expansion has been completed. After active expansion the Leaf Expander is maintained passively in place for retention period. Leaf expander was kept on teeth as a passive retainer and removed after one year from its application.

Intervention Type: DEVICE

orthodontic - slow maxillary expansion with self leaf expander

Leaf self expander: similar to Leaf expander with no need for reactivation or patient compliance.

Intervention Type: DEVICE

Other Intervention Names

orthodontic - rapid palatal expansion; orthodontic - slow palatal expansion with leaf expander; orthodontic - slow palatal expansion with self leaf expander

Eligibility Criteria

Inclusion Criteria

• prepubertal phase of development (cervical stage CS1 or 2 in cervical vertebral maturation or corresponding stage of third Finger middle phalanx maturation index).
• early or intermediate mixed dentition stage with fully erupted upper and lower first permanent molars.
• presence of the second upper deciduous molars available as an anchoring tooth. The second deciduous molar was considered available as anchoring tooth when the root had the same length as the clinical crown at the radiographic examination (Quinzi V, Federici Canova F, Rizzo FA, Marzo G, Rosa M, Primozic J. Factors related to maxillary expander loss due to anchoring deciduous molars exfoliation during treatment in the mixed dentition phase. Eur J Orthod. 2021 Jun 8;43(3):332-337. doi: 10.1093/ejo/cjaa061)
• Posterior transverse interarch discrepancy (PTID) of at least 3 mm. PTID was calculated on dental casts with a caliper as the difference between the maxillary intermolar width (distance between the central fossae of right and left permanent first maxillary molars) and the mandibular intermolar width (distance between the tips of the distobuccal cusps of right and left permanent first mandibular molars) (Tollaro, I., Baccetti, T., Franchi, L. and Tanasescu, C.D. 1996 Role of posterior transverse interarch discrepancy in Class II, Division 1 malocclusion during the mixed dentition phase. AJODO, 110, 417-422).

Exclusion Criteria

• age older than 12 years,
• pubertal or postpubertal stage of development (CS 3-6),
• late deciduous or late mixed dentition, 4. agenesis of upper second premolars (assessed on initial panoramic radiograph),
• Class III malocclusion,
• cleft lip and/or palate and craniofacial syndromes

• Minimum Eligible Age: 5 Years
• Maximum Eligible Age: 12 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University of Milan

OTHER

Sponsor Role: collaborator

Università degli Studi di Brescia

OTHER

Sponsor Role: collaborator

University of Genova

OTHER

Sponsor Role: lead

Responsible Party

ALESSANDRO UGOLINI

Assistant Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Valentina Lanteri, DDS, Phd

Role: PRINCIPAL_INVESTIGATOR

University of Milan

Domenico Dalessandri, DDS, Phd

Role: PRINCIPAL_INVESTIGATOR

Università degli Studi di Brescia

Alessandro Ugolini

Role: PRINCIPAL_INVESTIGATOR

Universita degli Studi di Genova

Central Contacts

Alessandro Ugolini, DDS, Phd

Role: CONTACT

Phone: +390103537309

Email: alessandro.ugolini@unige.it

References

Abate A, Ugolini A, Bruni A, Quinzi V, Lanteri V. Three-dimensional assessment on digital cast of spontaneous upper first molar distorotation after Ni-ti leaf springs expander and rapid maxillary expander: A two-centre randomized controlled trial. Orthod Craniofac Res. 2025 Feb;28(1):104-115. doi: 10.1111/ocr.12849. Epub 2024 Sep 8.

Reference Type: DERIVED

PMID: 39244736 (View on PubMed)

Other Identifiers

Leaf Expander mRCT

Identifier Type: -

Identifier Source: org_study_id