Splintless Versus Conventional Maxillomandibular Advancement Surgery for Obstructive Sleep Apnea (SvCMAS)

Splintless Versus Conventional Maxillomandibular Advancement Surgery for Obstructive Sleep Apnea: a Randomized Controlled Trial

The goal of this clinical trial is to find out whether using a splintless surgical approach improves the accuracy of maxillomandibular advancement (MMA) surgery for treating obstructive sleep apnea (OSA) in adults. The study will also look at the safety, functional outcomes, and cost-effectiveness of the splintless approach. The main questions it aims to answer are:

Does the splintless approach lead to more accurate surgical movements of the jaws compared to the conventional splint-based method? What are the safety profile, functional outcomes, and cost-effectiveness of the splintless approach?

Researchers will compare splintless MMA to conventional MMA.

Patients will:

Undergo MMA surgery using either the splintless or splint-based method; Attend regular follow-up visits as part of routine care; Complete questionnaires and undergo assessments at various time points; Receive one additional CT scan (24 months after surgery) and one overnight sleep study (60 months after surgery).

Bedpartners of patients will:

Complete questionnaires at various time points.

This trial will help determine whether the splintless approach is a better, safer, and more effective alternative for treating OSA with MMA surgery.

Study Overview

• Status: Not yet recruiting
• Conditions: Sleep Apnea Syndrome (OSAS); Sleep Apnea - Obstructive; Orthognathic Surgical Procedures
• Intervention / Treatment: Procedure: Splintless MMA surgery; Procedure: Splint MMA surgery

• Study Type: Interventional
• Enrollment (Estimated): 66
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Ho; Phone Number: 020-5663898; Email: j.p.ho@amsterdamumc.nl

Study Locations

• Netherlands
  • North Holland
    • Amsterdam, North Holland, Netherlands, 1105 AZ
      • Department of Oral and Maxillofacial Surgery, Amsterdam UMC
      • Contact: Ho; Phone Number: 020-5663898; Email: j.p.ho@amsterdamumc.nl

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

For OSA patients:

• Adults aged 18 years or older;
• Moderate to severe OSA (apnea hypopnea index (AHI) ≥ 15 events/hour) as determined by an overnight polysomnography (PSG) preoperatively;
• Continunous positive airway pressure failure or intolerance;
• General good health for surgery;
• MMA surgery indicated for OSA treatment.

For bedpartners of patients:

• Sharing a bed ⩾2 nights/week with patient.

Exclusion Criteria:

For OSA patients:

• Other adjunctive procedures indicated at the time of MMA (e.g., multi-piece Le Fort I osteotomy, temporomandibular joint reconstruction);
• Previous history of orthognathic surgery;
• Cleft palate and syndromic patients;
• Refusal to participate.

For bedpartners of patients:

• Refusal to participate.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Splintless group; In the splintless group, MMA using patient-specific osteotomy guides and fixation implants (i.e., splintless MMA) will be executed.	Procedure: Splintless MMA surgery; Splintless orthognathic surgery is a more recent technical innovation in Oral and Maxillofacial surgery, in which patient-specific computer-aided design and manufacturing (CAD/CAM) surgical cutting guides and fixation implants are used to improve surgical precision. Splintless MMA sugery involves virtual surgical planning, surgical procedures, and postoperative monitoring.
Active Comparator: Splint group; In the splint group, conventioanl MMA using surgical splints (i.e., splint MMA) will be executed.	Procedure: Splint MMA surgery; In splint MMA surgery, surgical procedure is virtually planned in three dimensions (3D) and the surgical planning is transfered to the operating room with 3D-printed intermediate and final splints. These splints are used during surgery to place and fixate the maxilla and mandible in the planned position.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Surgical accuracy	Because the main objective of MMA for OSA is achieving the planned advancement and counter-clockwise rotation to relieve the upper airway collapse, anteroposterior translation of the maxilla and mandible, and pitch of the maxilla and mandible are the main study parameters. The postoperative CT scan is superimposed on the preoperative virtual planning. The absolute difference between the planned value for a parameter and the postoperative acquired value will be calculated, which provides an intuitive accuracy measurement of MMA surgery.	1 week after MMA

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Other translational surgical movement parameters	Mediolateral and superoinferior movement of the maxilla and mandible in millimeters measured by CT scan	1 week after MMA
Other rotational surgical movement parameters	Roll and yaw of the maxilla and mandible in degrees measured by CT scan	1 week after MMA
Duration of surgery	The time between the start of incision and the suture of the incisions.	During MMA surgery
Blood loss	Blood loss during surgery	During MMA surgery
Adverse events/complications	Intra- and post-operative adverse events/complications	During MMA surgery and follow-Ups (up to 60 months postoperatively)
Apnea hypopnea index	The average number of apnea and hypopnea events per hour of sleep during a sleep study (polysomnography)	Preoperatively, six months postoperatively, and 60 months postoperatively
3% oxygen desaturation index	Number of times per hour of sleep that blood oxygen saturation drops by ≥3% from baseline during a sleep study	Preoperatively, six months postoperatively, and 60 months postoperatively
Lowest oxygen saturation	The minimum blood oxygen level (%) reached during a sleep study	Preoperatively, six months postoperatively, and 60 months postoperatively
Percentage of sleep time spent with oxygen saturation < 90%	Percentage of sleep time spent with blood oxygen saturation < 90% during a sleep study	Preoperatively, six months postoperatively, and 60 months postoperatively
Epworth sleep scale (ESS) total score	Daytime sleepiness as assessed with Epworth sleep scale total score (range 0-24; higher scores indicate greater daytime sleepiness / worse outcome)	Preoperatively, and 3 months, 6 months, 12 months, 24 months, 36 months, 48 months, and 60 months after MMA
Functional Outcomes of Sleep Questionnaire (FOSQ) total score	Functional status as assessed with Functional Outcomes of Sleep Questionnaire total score (range 5-20; higher scores indicate better functional status / less impairment due to sleepiness)	Preoperatively, and 3 months, 6 months, 12 months, 24 months, 36 months, 48 months, and 60 months after MMA
Pittsburgh Sleep Quality Index (PSQI) global score	Sleep quality as assessed with Pittsburgh Sleep Quality Index global score (range 0-21; higher scores indicate worse sleep quality)	Preoperatively, and 3 months, 6 months, 12 months, 24 months, 36 months, 48 months, and 60 months after MMA
EuroQol 5-Dimension 5-Level (EQ-5D-5L) utility index	Patient's health status as assessed with EuroQol 5-Dimension 5-Level utility index (utility index ranges from <0 to 1; higher scores indicate better health-related quality of life)	Preoperatively, and 3 months, 6 months, 12 months, 24 months, 36 months, 48 months, and 60 months after MMA
EuroQol 5-Dimension 5-Level (EQ-5D-5L) visual analogue scale (VAS) score	Patient's health status as assessed with EuroQol 5-Dimension 5-Level visual analogue scale (VAS) score (VAS ranges 0-100, higher scores indicate better health status)	Preoperatively, and 3 months, 6 months, 12 months, 24 months, 36 months, 48 months, and 60 months after MMA
36-Item Short Form Health Survey (SF-36) domain and summary scores	Quality of life as assessed with 36-Item Short Form Health Survey domain and summary scores (range 0-100; higher scores indicate better health-related quality of life)	Preoperatively, and 3 months, 6 months, 12 months, 24 months, 36 months, 48 months, and 60 months after MMA
FACE-Q satisfaction with facial appearance score	Patient satisfaction with facial appearance as assessed using the FACE-Q questionnaire (range 0-100; higher scores indicate greater satisfaction with facial appearance / better outcome)	Preoperatively, and 3 months, 6 months, 12 months, 24 months, 36 months, 48 months, and 60 months after MMA
Patient satisfaction with facial appearance and surgical outcome	Patient's satisfaction with surgery outcomes as assessed with customized patient satisfaction questionnaire (5-point Likert scales; higher ratings indicate greater satisfaction)	Preoperatively, and 3 months, 6 months, 12 months, 24 months, 36 months, 48 months, and 60 months after MMA
Partner-reported snoring severity, snoring disturbance, and satisfaction with postoperative facial appearance (5- to 6-point Likert scales）	Partner-reported assessment of snoring severity, snoring-related disturbance, and perceived postoperative facial appearance changes using a study-specific questionnaire completed by the participant's partner (higher ratings indicate greater snoring severity/disturbance or more positive perceived facial change, depending on the item).	Preoperatively and 6 months after MMA
Postsurgical relapse measures	Postsurgical relapse measures in translation parameters (anteroposterior, mediolateral, superoinferior) and rotation parameters (roll, pitch, yaw) of the maxilla and mandible. The discrepancy between immediately post-operation (1 week after MMA) and 2 years after surgery will be used to define the amount of relapse.	2 years after MMA
Facial soft tissue changes	Facial soft tissue changes following MMA at various soft-tissue points. These are determined by the difference in 3D coordinates of soft tissue landmarks between baseline and 6 months after MMA;	6 months after MMA
Upper airway volume	Upper airway volume (mm³) measured using three-dimensional imaging analysis	Preoperatively and 6 months after MMA
Upper airway length	Upper airway length measured using three-dimensional imaging analysis (mm)	Preoperatively and 6 months after MMA
Upper airway surface area	Upper airway surface area (mm²) measured using three-dimensional imaging analysis	Preoperatively and 6 months after MMA
Upper airway minimum cross-sectional area (minCSA)	Minimum cross-sectional area (mm²) of the upper airway measured using three-dimensional imaging analysis	Preoperatively and 6 months after MMA
Lateral dimension of the minimum cross-sectional area of the upper airway	Lateral dimension of the upper airway minimum cross-sectional area (mm) measured using three-dimensional imaging analysis.	Preoperatively and 6 months after MMA
Anteroposterior dimension of the minimum cross-sectional area of the upper airway	Anteroposterior dimension of the upper airway minimum cross-sectional area (mm) measured using three-dimensional imaging analysis.	Preoperatively and 6 months after MMA
Blood pressure	Systolic and diastolic blood pressure	Preoperatively, and 3 months, 6 months, 12 months, 24 months, 36 months, 48 months, and 60 months after MMA
Cost-effectiveness	Incremental cost-effectiveness ratio (ICER) and incremental cost-utility ratio (ICUR).	6, 12, 24, 36, 48, and 60 months after MMA

Collaborators and Investigators

• Sponsor: Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)
• Collaborators: Materialise

Study record dates

Study Major Dates

• Study Start (Estimated): December 1, 2026
• Primary Completion (Estimated): June 30, 2028
• Study Completion (Estimated): February 28, 2033

Study Registration Dates

• First Submitted: May 6, 2026
• First Submitted That Met QC Criteria: May 13, 2026
• First Posted (Actual): May 20, 2026

Study Record Updates

• Last Update Posted (Actual): May 20, 2026
• Last Update Submitted That Met QC Criteria: May 13, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: OSA; MMA; Patient-specific implants; Maxilomandibular advancement surgery; Splintless orthognathic
• Additional Relevant MeSH Terms: Nervous System Diseases; Respiratory Tract Diseases; Respiration Disorders; Sleep Wake Disorders; Apnea; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Apnea Syndromes; Sleep Apnea, Obstructive
• Other Study ID Numbers: 2024.0736

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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