Maxillary Expansion: Leaf Expander Versus Hyrax Expander (LEAF)

Leaf Expander Versus Hyrax Expander. A Multicenter, Prospective, Randomized Trial

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.

Study Overview

• Status: Not yet recruiting
• Conditions: Maxillary Deficiency
• Intervention / Treatment: Device: orthodontic - rapid maxillary expansion; Device: orthodontic - slow maxillary expansion with leaf expander; Device: orthodontic - slow maxillary expansion with self leaf expander

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.

• Study Type: Interventional
• Enrollment (Anticipated): 200
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Alessandro Ugolini, DDS, Phd; Phone Number: +390103537309; Email: alessandro.ugolini@unige.it

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 5 years to 12 years (Child)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: 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.	Device: 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.; Other Names: orthodontic - rapid palatal expansion
Experimental: 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.	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.; Other Names: orthodontic - slow palatal expansion with leaf expander
Experimental: 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	Device: orthodontic - slow maxillary expansion with self leaf expander; Leaf self expander: similar to Leaf expander with no need for reactivation or patient compliance.; Other Names: orthodontic - slow palatal expansion with self leaf expander
Experimental: 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.	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.; Other Names: orthodontic - slow palatal expansion with leaf expander
Experimental: 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	Device: orthodontic - slow maxillary expansion with self leaf expander; Leaf self expander: similar to Leaf expander with no need for reactivation or patient compliance.; Other Names: orthodontic - slow palatal expansion with self leaf expander

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Crossbite and/or traversal maxillary deficiency correction	Crossbite and/or traversal maxillary deficiency correction	6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Crossbite correction stability	Crossbite correction stability	1 year
Crossbite correction stability	Crossbite correction stability	2 years
Canine and molar expansion (upper and lower arch)	Canine and molar millimetres of expansion (upper and lower arch)	6 months
Canine and molar angulation (upper and lower arch)	Canine and molar degrees of angulation (upper and lower arch)	6 months
Canine and molar expansion (upper and lower arch)	Canine and molar millimetres of expansion (upper and lower arch)	1 year
Canine and molar angulation (upper and lower arch)	Canine and molar degrees of angulation (upper and lower arch)	1 year
Upper and lower dental arch perimeter modifications	Upper and lower dental arch perimeter modifications (millimetres)	6 months
Upper and lower dental arch perimeter modifications	Upper and lower dental arch perimeter modifications (millimetres)	1 year
Pain during active expansion phase (VAS scale)	Pain during active expansion phase (VAS scale)	1 month
Appliance breakages and detachments	Appliance breakages and detachments	6 months
Number of in-office appointments	Number of in-office appointments	6 months
Time needed to correct the malocclusion	Time needed to correct the malocclusion	6 months

Collaborators and Investigators

• Sponsor: University of Genova
• Collaborators: University of Milan; Università degli Studi di Brescia
• Investigators: Principal Investigator: Valentina Lanteri, DDS, Phd, University of Milan; Principal Investigator: Domenico Dalessandri, DDS, Phd, Università degli Studi di Brescia; Principal Investigator: Alessandro Ugolini, Università degli Studi di Genova

Study record dates

Study Major Dates

• Study Start (Anticipated): December 1, 2021
• Primary Completion (Anticipated): December 1, 2022
• Study Completion (Anticipated): November 1, 2023

Study Registration Dates

• First Submitted: October 4, 2021
• First Submitted That Met QC Criteria: November 15, 2021
• First Posted (Actual): November 26, 2021

Study Record Updates

• Last Update Posted (Actual): November 26, 2021
• Last Update Submitted That Met QC Criteria: November 15, 2021
• Last Verified: November 1, 2021

More Information

Terms related to this study

• Keywords: maxillary expansion; slow expansion; rapid expansion; leaf expander
• Other Study ID Numbers: Leaf Expander mRCT

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No