Efficacy of Mini-implant Assisted Maxillary Expansion in Adolescents and Adults (MARPE_1)

Efficacy of Mini-Implant-Assisted Maxillary Expansion on Late Adolescents and Adults and Its Effects on Nasal Permeability and Airway Volume Using Three Different Activation Protocols: A Randomized Controlled Trial (MARPE_1)

Transverse maxillary deficiency is a common orthodontic issue, affecting around 10% of adults. Late adolescents and adults often require more force to expand the midpalatal suture due to its increased interdigitation. This study aims to assess the effectiveness of MARPE in this demographic and determine the best activation protocol for non-surgical maxillary expansion using mini-screw-supported appliances. Additionally, the study will evaluate the effectiveness of MARPE on nasal permeability and airway volume.

Study Overview

• Status: Recruiting
• Conditions: Narrow Maxilla
• Intervention / Treatment: Device: Mini-implants assisted maxillary expansion

Detailed Description

The study design comprised a three-arm, parallel-group randomized controlled trial (RCT) conducted at the Orthodontics clinic of Brussels University Hospital. Patients were randomly allocated into one of three groups:

1. Continuous rapid activation protocol: Patients received one activation of 0.17 mm per day until reaching the clinical goal.
2. Continuous slow activation protocol: Patients underwent two activations (0.33 mm) per day for the first 7 days, followed by one turn forward every third day (0.17 mm / 3 days).
3. Force-controlled polycyclic protocol: Patients underwent two activations (0.33 mm) per day for the first 7 days. Then, the hex nut was turned 6 sides backward, followed by 6 sides forward after 15 minutes. Additionally, the device was activated by 0.17 mm every third day.

Intervention:

All patients underwent maxillary expansion with MARPE. Four orthodontic mini-screws were inserted under local anesthesia using a surgical guide and motor. Surgical incision was not required, and predrilling was performed if necessary. The MARPE remained in place for 12 months after expansion to allow bone remodeling in the midpalatal suture. Fixed straight-wire treatment commenced 2 months after expansion termination. Patients underwent retention check-ups at 6 and 12 months post-expansion, and expansion screws and mini-screws were removed after 12 months or before orthognathic surgery, if applicable.

The specific aims of the study were to evaluate the success rate of nonsurgical maxillary expansion, compare the efficacy of the three activation protocols, assess and compare complications, analyze the correlation between success rate and Midpalatal Suture Maturation Stage (MPS), age, and sex, and measure nasal permeability variation using anterior rhinomanometry.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: arnel NANA, Dr; Phone Number: +32460952160; Email: narnelredon@gmail.com

Study Locations

• Belgium
  • Bruxelles
    • Anderlecht, Bruxelles, Belgium, 1070
      • Not yet recruiting
      • Route de Lennik 900
      • Contact: Fairouz BEN ABDELOUAHED, Dr; Phone Number: +32487262857; Email: f.benabdelouahed@hubruxelles.be
    • Anderlecht, Bruxelles, Belgium, 1070
      • Recruiting
      • service dentaire et d'orthodontie de l'hopital université de bruxelles (HUB)
      • Contact: Fairouz BEN ABDELOUAHED, Dr; Phone Number: +32 487262857; Email: f.benabdelouahed@hubruxelles.be

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• from the age of 16 onwards
• who presented with transverse maxillary discrepancy (unilateral, bilateral, anticipated, or constriction without crossbite).

Exclusion Criteria:

• history or presence of maxillofacial surgery, cleft lip and palate, craniofacial anomalies or syndromes, congenital tooth anomalies, and periodontal disease.
• Patients who had previously palatal expansion were excluded also.
• Presence of anatomic or pathological obstacle of the palatal mini-screw insertion (impacted tooth, tumor.)
• refusal of study participation

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: CRAP; Continuous Rapid Activation Protocol: 1 activation of the expansion screw per day which is equal to 0,17 mm expansion of the maxilla per day till reaching the clinical goal	Device: Mini-implants assisted maxillary expansion; The intervention involved the placement of orthodontic mini-screws in the patient's palate, varying in diameter from 2 to 2.3 mm and in length from 11 to 15 mm. After mini-screw insertion, another intraoral scan was taken for the fabrication of the appliance. Approximately three weeks later, the expander was placed in the patient's palate, and maxillary expansion was initiated immediately afterward according to the chosen protocol.; Other Names: Mini-screws assisted maxillary expansion; Mini-implants assisted rapid maxillary expansion
Experimental: SCAP; Continuous Slow Activation Protocol: 2 activations of the expansion screw which is equal to 0,33 mm expansion of the maxilla per day during the first 7 days. After that first week, then each third day 1 activation (0,17 mm / 3 days).	Device: Mini-implants assisted maxillary expansion; The intervention involved the placement of orthodontic mini-screws in the patient's palate, varying in diameter from 2 to 2.3 mm and in length from 11 to 15 mm. After mini-screw insertion, another intraoral scan was taken for the fabrication of the appliance. Approximately three weeks later, the expander was placed in the patient's palate, and maxillary expansion was initiated immediately afterward according to the chosen protocol.; Other Names: Mini-screws assisted maxillary expansion; Mini-implants assisted rapid maxillary expansion
Experimental: FCPC; force-controlled polycyclic protocol: 2 activations of the expansion screw which is equal to 0,33 mm expansion of the maxilla per day during the first 7 days. Then the expansion screw will be turned 6 sides backward, and after 15 min, the expansion screw will be turned forward 6 sides again. And every third day, the device will be additionally activated by 0.17mm (0,17 mm / 3 days)	Device: Mini-implants assisted maxillary expansion; The intervention involved the placement of orthodontic mini-screws in the patient's palate, varying in diameter from 2 to 2.3 mm and in length from 11 to 15 mm. After mini-screw insertion, another intraoral scan was taken for the fabrication of the appliance. Approximately three weeks later, the expander was placed in the patient's palate, and maxillary expansion was initiated immediately afterward according to the chosen protocol.; Other Names: Mini-screws assisted maxillary expansion; Mini-implants assisted rapid maxillary expansion

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
MPSM: mid-palatal suture middle molars	the width of the mid-palatal suture measure in millimeters at the level of the first molars	up to 6 months
ANS-ANS	the distance in millimeters between the right anterior nasal spine and the left anterior nasal spine after the maxillary expansion	up to 6 months
PNS-PNS	distance in millimeters between the right posterior nasal spine and the left posterior nasal spine after the maxillary expansion	up to 6 months
UID	distance in millimeters from the most external point of the right frontozygomatic suture to the most external point of the left frontozygomatic suture.	up to 6 months
ZMA	width in millimeters between the right and left zygomatic arches at its widest point at the most inferior level of the orbits.	up to 6 months
LID:	distance in millimeters from the most external point of the right zygomaticomaxillary suture to the most external point of the left zygomaticomaxillary suture	up to 6 months
NCW: nasal cavity width	Transverse distance in millimeters between the left and right most lateral point of the nasal cavity	up to 6 months
MSW: midpalatal suture width	Transverse distance in millimeters between the medial limits of the left and right palatal process at the palatal floor	up to 6 months
IMW: intermolar width	Transverse distance in millimeters between the left and right maxillary M1 mesiocentral fossae	up to 6 months
IPW: interpremolar width	Transverse distance in millimeters between the left and right maxillary P1 mesial fossae	up to 6 months
ICW: intercanine width	Transverse distance in millimeters between the left and right maxillary canine buccal cusp tips	up to 6 months
PAW: palatal alveolar width	Transverse distance between in millimeters the left and right most cervical medial limits of the palatal alveolar process	up to 6 months
TI : tooth inclination	2D inner angle (in degrees) between the palatal plane and the left and right line running through the palatal apex and the mesiobuccal fossa or the mesial fossa	up to 6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
RT resistance total	Total bilateral nasal resistance in Pa.s.cm³	up to 6 months
NCV: nasal cavity volume	nasal cavity volume in mm3	up to 6 months
RMSV : right maxillary sinus volume	Right maxillary sinus volume in mm3	up to 6 months
LMSV : left maxillary sinus volume	left maxillary sinus volume in mm3	up to 6 months
NPV nasopharynx volume	nasopharynx volume in mm3	up to 6 months
OPV oropharynx volume	OPV oropharynx volume in mm3	up to 6 months
OMCSA: oropharynx minimum cross-sectional area	oropharynx minimum cross-sectional area in mm2	up to 6 months
AV: Accumulated volume	which represents the total volume in mm3, is calculated using the sum of the NCV, RMSV, LMSV, NPV, and OPV	up to 6 months

Collaborators and Investigators

• Sponsor: Erasme University Hospital

Study record dates

Study Major Dates

• Study Start (Actual): October 2, 2024
• Primary Completion (Estimated): July 1, 2027
• Study Completion (Estimated): September 1, 2027

Study Registration Dates

• First Submitted: May 23, 2024
• First Submitted That Met QC Criteria: June 3, 2024
• First Posted (Actual): June 7, 2024

Study Record Updates

• Last Update Posted (Actual): August 11, 2025
• Last Update Submitted That Met QC Criteria: August 8, 2025
• Last Verified: December 1, 2024

More Information

Terms related to this study

• Keywords: rhinomanometry; MARPE; Endognathia
• Other Study ID Numbers: Erasme_MARPE_1

Drug and device information, study documents

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