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

Condition(s) studied

Investigational drug(s) / intervention(s)

Tooth-Borne Maxillary Expansion Appliance: 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.

Hybrid Tooth-Bone-Borne Maxillary Expansion Appliance: 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.

Study 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.

Eligibility

Primary outcome measure(s)

• Transverse Skeletal Relapse in External Maxillary Width — From the end of the distraction phase to 6 months after completion of expansion
  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.

Trial sites (2)