Narrow MaxillaMARPE_1NCT06449014
Efficacy of Mini-implant Assisted Maxillary Expansion in Adolescents and Adults
A study testing Mini-implants assisted maxillary expansion in people with Narrow Maxilla, run by Erasme University Hospital at 2 sites in Belgium.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 16 years and olderHealthy volunteers can take part
- Conditions the study is for
- Narrow Maxilla
- What is being tested?
- Mini-implants assisted maxillary expansion
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 2 sitesBelgium
- Study dates
- 2 Oct 2024to Sep 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 16 years and older
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Who may be able to join
- from the age of 16 onwards
- who presented with transverse maxillary discrepancy (unilateral, bilateral, anticipated, or constriction without crossbite).
Who cannot join
- 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
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Belgium2 sites, 2 recruiting
- Not yet recruiting
Route de Lennik 900
Anderlecht, Brussels Capital, 1070
Fairouz BEN ABDELOUAHED, Dr, +32487262857, f.benabdelouahed@hubruxelles.be
- Recruiting
service dentaire et d'orthodontie de l'hopital université de bruxelles (HUB)
Anderlecht, Brussels Capital, 1070
Fairouz BEN ABDELOUAHED, Dr, +32 487262857, f.benabdelouahed@hubruxelles.be
About this study
Official title: 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.
Read the 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:
- Continuous rapid activation protocol: Patients received one activation of 0.17 mm per day until reaching the clinical goal.
- 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).
- 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.
- Conditions
- Narrow Maxilla
- Being tested
- Mini-implants assisted maxillary expansion
- Keywords
- MARPE, Endognathia, rhinomanometry
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Mini-implants assisted maxillary expansionDevice
Also called Mini-screws assisted maxillary expansion, Mini-implants assisted rapid 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.
| Study group | Role | What they receive |
|---|---|---|
| CRAP | Experimental | 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 Receives: Device: Mini-implants assisted maxillary expansion |
| SCAP | Experimental | 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). Receives: Device: Mini-implants assisted maxillary expansion |
| FCPC | Experimental | 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) Receives: Device: Mini-implants assisted maxillary expansion |
What is being measured
The primary outcome is the main question the study is designed to answer.
MPSM: mid-palatal suture middle molars
the width of the mid-palatal suture measure in millimeters at the level of the first molars
Measured: 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
Measured: 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
Measured: 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.
Measured: 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.
Measured: 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
Measured: up to 6 months
NCW: nasal cavity width
Transverse distance in millimeters between the left and right most lateral point of the nasal cavity
Measured: 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
Measured: up to 6 months
IMW: intermolar width
Transverse distance in millimeters between the left and right maxillary M1 mesiocentral fossae
Measured: up to 6 months
IPW: interpremolar width
Transverse distance in millimeters between the left and right maxillary P1 mesial fossae
Measured: up to 6 months
ICW: intercanine width
Transverse distance in millimeters between the left and right maxillary canine buccal cusp tips
Measured: 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
Measured: 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
Measured: up to 6 months
Secondary outcomes (8)
RT resistance total
Total bilateral nasal resistance in Pa.s.cm³
Measured: up to 6 months
NCV: nasal cavity volume
nasal cavity volume in mm3
Measured: up to 6 months
RMSV : right maxillary sinus volume
Right maxillary sinus volume in mm3
Measured: up to 6 months
LMSV : left maxillary sinus volume
left maxillary sinus volume in mm3
Measured: up to 6 months
NPV nasopharynx volume
nasopharynx volume in mm3
Measured: up to 6 months
OPV oropharynx volume
OPV oropharynx volume in mm3
Measured: up to 6 months
OMCSA: oropharynx minimum cross-sectional area
oropharynx minimum cross-sectional area in mm2
Measured: 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
Measured: up to 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Jun 2024
- Study start2 Oct 2024
- Primary completionJul 2027 (estimated)
- Study completionSep 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Narrow MaxillaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Erasme University Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06449014
- Sponsor's protocol ID
- Erasme_MARPE_1
- Acronym
- MARPE_1
- Status last verified
- Dec 2024
- First submitted
- 23 May 2024
- Last updated
- 11 Aug 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 11 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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)
- ClinicalTrials.gov ID
- NCT06449014
- Acronym / sponsor ID
- MARPE_1 / Erasme_MARPE_1
- Conditions
- Narrow Maxilla
- Keywords
- MARPE, Endognathia, rhinomanometry
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Erasme University HospitalUniversity, hospital or other
- Study start
- 2 Oct 2024 (actual)
- Primary completion
- Jul 2027 (estimated)
- Study completion
- Sep 2027 (estimated)
- First posted
- 7 Jun 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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:
- Continuous rapid activation protocol: Patients received one activation of 0.17 mm per day until reaching the clinical goal.
- 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).
- 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 design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| CRAP | Experimental | Device: Mini-implants assisted maxillary expansionContinuous 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 |
| SCAP | Experimental | Device: Mini-implants assisted maxillary expansionContinuous 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). |
| FCPC | Experimental | Device: Mini-implants assisted maxillary expansionforce-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) |
Who may qualify
- Ages
- 16 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (2 listed)
- from the age of 16 onwards
- who presented with transverse maxillary discrepancy (unilateral, bilateral, anticipated, or constriction without crossbite).
Key exclusion criteria (4 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Mini-implants assisted maxillary expansionAlso: Mini-screws assisted maxillary expansion, Mini-implants assisted rapid maxillary expansionThe 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. | Device | CRAP, FCPC, SCAP |
Primary outcome
MPSM: mid-palatal suture middle molars
Time frame: up to 6 months
the width of the mid-palatal suture measure in millimeters at the level of the first molars
ANS-ANS
Time frame: up to 6 months
the distance in millimeters between the right anterior nasal spine and the left anterior nasal spine after the maxillary expansion
PNS-PNS
Time frame: up to 6 months
distance in millimeters between the right posterior nasal spine and the left posterior nasal spine after the maxillary expansion
UID
Time frame: up to 6 months
distance in millimeters from the most external point of the right frontozygomatic suture to the most external point of the left frontozygomatic suture.
ZMA
Time frame: up to 6 months
width in millimeters between the right and left zygomatic arches at its widest point at the most inferior level of the orbits.
LID:
Time frame: up to 6 months
distance in millimeters from the most external point of the right zygomaticomaxillary suture to the most external point of the left zygomaticomaxillary suture
NCW: nasal cavity width
Time frame: up to 6 months
Transverse distance in millimeters between the left and right most lateral point of the nasal cavity
MSW: midpalatal suture width
Time frame: up to 6 months
Transverse distance in millimeters between the medial limits of the left and right palatal process at the palatal floor
IMW: intermolar width
Time frame: up to 6 months
Transverse distance in millimeters between the left and right maxillary M1 mesiocentral fossae
IPW: interpremolar width
Time frame: up to 6 months
Transverse distance in millimeters between the left and right maxillary P1 mesial fossae
ICW: intercanine width
Time frame: up to 6 months
Transverse distance in millimeters between the left and right maxillary canine buccal cusp tips
PAW: palatal alveolar width
Time frame: up to 6 months
Transverse distance between in millimeters the left and right most cervical medial limits of the palatal alveolar process
TI : tooth inclination
Time frame: up to 6 months
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
8 secondary outcomes
RT resistance total
Time frame: up to 6 months
NCV: nasal cavity volume
Time frame: up to 6 months
RMSV : right maxillary sinus volume
Time frame: up to 6 months
LMSV : left maxillary sinus volume
Time frame: up to 6 months
NPV nasopharynx volume
Time frame: up to 6 months
OPV oropharynx volume
Time frame: up to 6 months
OMCSA: oropharynx minimum cross-sectional area
Time frame: up to 6 months
AV: Accumulated volume
Time frame: up to 6 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Aug 2025.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Mini-implants assisted maxillary expansion in people with Narrow Maxilla, run by Erasme University Hospital at 2 sites in Belgium.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 11 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact arnel NANA, Dr (+32460952160, narnelredon@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
MPSM: mid-palatal suture middle molars (time frame: up to 6 months). The study lists 13 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Aug 2025.