Tooth-Borne (TBA) Versus Hybrid Expanders (HA) in Surgically Assisted Rapid Maxillary Expansion (SARME)

NCT07849855 | Not Yet Recruiting

• 1 other identifier: SARME-AAL-2026
• Study Type: interventional
• Target: 32
• Locations: 2 countries
• Sites: 2

Brief Summary

This randomized clinical trial will compare two types of expansion appliances used with surgically assisted rapid maxillary expansion (SARME) in adults with a narrow upper jaw. SARME is a surgical and orthodontic treatment used to widen the upper jaw when orthodontic expansion alone is not sufficient. The study will investigate whether a tooth-borne appliance, which is supported by the teeth, and a hybrid appliance, which is supported by both the teeth and two small screws placed in the palate, produce different treatment outcomes. A total of 32 adults scheduled for SARME at Aalborg University Hospital in Denmark and Lund University Hospital in Sweden will be randomly assigned to treatment with either the tooth-borne appliance or the hybrid appliance. Participants will be examined before surgery, after completion of the expansion phase, and six months after completion of expansion. Assessments will include cone-beam computed tomography (CBCT), digital dental scans, facial imaging, periodontal examinations, recording of complications, and questionnaires about pain, recovery, oral health-related quality of life, general quality of life, and treatment experience. The main outcome of the study is skeletal relapse, meaning how much of the widening of the upper jaw is lost between the end of expansion and the six-month follow-up. Other outcomes include the amount of skeletal and dental expansion, tooth tipping, changes in the supporting bone and gums around the teeth, facial soft-tissue changes, complications, recovery, and patient-reported quality of life. The study aims to determine whether one appliance provides better stability or fewer unwanted effects and thereby improve future treatment recommendations for adults undergoing SARME.

Conditions

Maxillary Transverse Deficiency

Keywords

Surgically Assisted Rapid Maxillary Expansion; SARME; Surgically Assisted Rapid Palatal Expansion; SARPE; Tooth-Borne Appliance; Hybrid Appliance; Skeletal Anchorage; Maxillary Expansion; Skeletal Relapse; Dentoalveolar Expansion; Cone-Beam Computed Tomography; CBCT

Outcome Measures

Primary Outcomes (1)

• Transverse Skeletal Relapse in External Maxillary Width

  Transverse skeletal relapse will be assessed as the reduction in external maxillary width (EMW) from the end of the distraction phase (T1) to the six-month follow-up (T2). EMW will be measured in millimetres on CBCT images at the maxillary first premolar and first molar levels, using the hard palate as the skeletal reference. Skeletal relapse will be calculated as the T1 EMW minus the T2 EMW; a larger positive value indicates greater skeletal relapse.

  From the end of the distraction phase to 6 months after completion of expansion

Secondary Outcomes (17)

• Change in External Maxillary Width During Expansion

  From baseline before surgery to the end of the distraction phase, approximately 15-30 days after surgery

• Change in Maxillary Dental Arch Width

  Baseline before surgery, end of the distraction phase approximately 15-30 days after surgery, and 6 months after completion of expansion

• Change in Maxillary Tooth Inclination

  Baseline before surgery, end of the distraction phase approximately 15-30 days after surgery, and 6 months after completion of expansion

• Plaque Index

  Baseline before surgery, end of the distraction phase approximately 15-30 days after surgery, and 6 months after completion of expansion

• Change in Gingival Index

  Baseline before surgery, end of the distraction phase approximately 15-30 days after surgery, and 6 months after completion of expansion

Other Outcomes (2)

• Change in Midpalatal Sutural Expansion Width

  Baseline before surgery, end of the distraction phase approximately 15-30 days after surgery, and 6 months after completion of expansion

• Change in Maxillary Midline Diastema Width

  Baseline before surgery, end of the distraction phase approximately 15-30 days after surgery, and 6 months after completion of expansion

Study Arms (2)

Tooth-Borne Appliance (TBA)

ACTIVE COMPARATOR

Participants allocated to this arm will undergo surgically assisted rapid maxillary expansion (SARME) using a tooth-borne appliance (TBA). The computer-aided design/computer-aided manufacturing (CAD/CAM)-fabricated appliance consists of four printed metal bands cemented to the maxillary first premolars and first molars and connected to a palatal expansion mechanism. No palatal mini-implants are used. The appliance is cemented before surgery. Following SARME, expansion is initiated after a latency period of 5-7 days at approximately 0.5 mm/day until the planned expansion or overcorrection is achieved. The appliance is then maintained passively during a six-month consolidation period.

Device: Tooth-Borne Maxillary Expansion Appliance

Hybrid Appliance (HA)

EXPERIMENTAL

Participants allocated to this arm will undergo surgically assisted rapid maxillary expansion (SARME) using a hybrid appliance (HA). The appliance uses the same CAD/CAM design as the tooth-borne appliance, with four printed metal bands on the maxillary first premolars and first molars connected to a palatal expansion mechanism. In addition, skeletal anchorage is provided by two palatal mini-implants (BENEfit® DIRECT screws, 2.0 mm diameter, 9 mm length), inserted immediately before surgery under general anaesthesia and connected to the expander. Following SARME, expansion is initiated after a latency period of 5-7 days at approximately 0.5 mm/day until the planned expansion or overcorrection is achieved. The appliance is then maintained passively during a six-month consolidation period.

Device: Hybrid Tooth-Bone-Borne Maxillary Expansion Appliance

Interventions

Tooth-Borne Maxillary Expansion Appliance DEVICE

A CAD/CAM-fabricated tooth-borne maxillary expansion appliance used during surgically assisted rapid maxillary expansion (SARME). The appliance consists of four printed metal bands cemented to the maxillary first premolars and first molars and connected to a palatal expansion mechanism. Anchorage is provided exclusively by the teeth, with no palatal mini-implants. The appliance is cemented before surgery. Following a postoperative latency period of 5-7 days, the appliance is activated at approximately 0.5 mm per day until the planned expansion or clinical overcorrection is achieved. The appliance is subsequently maintained passively during the six-month consolidation period.

Also known as: Tooth-Borne Appliance, TBA

Tooth-Borne Appliance (TBA)

Hybrid Tooth-Bone-Borne Maxillary Expansion Appliance DEVICE

A CAD/CAM-fabricated hybrid tooth-bone-borne maxillary expansion appliance used during surgically assisted rapid maxillary expansion (SARME). The appliance consists of four printed metal bands on the maxillary first premolars and first molars connected to a palatal expansion mechanism. In addition to dental anchorage, skeletal anchorage is provided by two palatal mini-implants (BENEfit® DIRECT screws, 2.0 mm diameter and 9 mm length) inserted immediately before surgery and connected to the expander. Following a postoperative latency period of 5-7 days, the appliance is activated at approximately 0.5 mm per day until the planned expansion or clinical overcorrection is achieved, followed by a six-month passive consolidation period.

Also known as: Hybrid Appliance, HA

Hybrid Appliance (HA)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Moderate or severe maxillary transverse deficiency (MTD).
• Healthy adults aged 18 years or older.
• Completed craniofacial growth.
• Presence of the maxillary first premolars and first molars.
• Healthy periodontal status.

You may not qualify if:

• Previous surgical treatment of facial trauma or dentofacial deformities.
• Systemic disease, medication, genetic disease, or developmental condition expected to affect craniofacial morphology, bone turnover, or healing.
• Pregnancy.
• Inability to understand the study information or provide written informed consent.

Sponsors & Collaborators

• Lund University Hospital: collaborator
• Aalborg University Hospital: lead

Study Sites (2)

Department of Oral and Maxillofacial Surgery, Aalborg University Hospital

Aalborg, 9000, Denmark

Location

Skåne University Hospital

Lund, Skåne County, 22242, Sweden

Location

Study Officials

• Thomas Starch-Jensen, Professor

  Aalborg University Hospital

  STUDY DIRECTOR

• Hanna Hejlesen, PhD, Head of department

  Aalborg University Hospital

  STUDY CHAIR

• Martin Bengtsson, Associate Professor

  Skane University Hospital

  STUDY CHAIR

Central Study Contacts

Osman Khachab, DDs, MSc

CONTACT

+46 720441061; osmankhachab@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: Participants, surgeons, orthodontists, and outcome assessors cannot be masked because the two expansion appliances are visibly different. However, all measurements will be performed using coded datasets according to a standardized measurement protocol, and the statistical analysis will be conducted by a statistician who is unaware of treatment allocation.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Specialist Orthodontist

Model Details: Two-arm, parallel-group randomized controlled trial with 1:1 allocation to either a tooth-borne appliance (TBA) or a hybrid appliance (HA). Randomization is stratified by study centre using computer-generated block randomization.

Study Record Dates

• First Submitted: September 16, 2026
• First Posted: September 30, 2026
• Study Start (Estimated): January 1, 2027
• Primary Completion (Estimated): December 1, 2031
• Study Completion (Estimated): December 1, 2031
• Last Updated: September 30, 2026

Record last verified: 2026-09

Data Sharing

• IPD Sharing: Will not share

Locations

DK (1); SE (1)