Maxillary Patient Specific Implants in Bimaxillary Orthognathic Surgery

Maxillary Patient Specific Implants in Bimaxillary Orthognathic Surgery: A Quality Assessment by Novel Automated Virtual Methods

Orthognathic surgery is a type of jaw surgery where a surgeon cuts the bones of the upper and lower jaw and places them better. There are two ways they can put the bones in the correct place and keep them in place after the surgery. One way, called the "conventional method", is to use a 3D-printed guide called a splint to set the bones in the right place and then screw the bones together using metal plates that the surgeon bends into shape to fit during the surgery. Another way is to use a patient-specific implants (PSI) that has been 3D-printed in titanium beforehand that because of its unique shape both places and keeps all the bones in the correct place after they are screwed in. Both ways of doing it are golden standards, meaning they are already approved.

Measuring the accuracy of the surgery is done by comparing the positions of the bones after the surgery with the intended positions of those bones, according to the surgical plan. The closer the achieved position of each bone is to the intended position, the more accurate the result.

Measuring the stability of the surgery is done by comparing the positions of the bones after the surgery with the positions of the bones two years later. The less the position is changed, the more stable the result.

The goal of this clinical trial is to see how accurate and stable PSIs are in orthognathic surgery when the maxilla is split in 3 pieces, and to compare them with the conventional method in patients with overjet or overbite. The main questions it aims to answer are:

• Does using PSIs provide accurate movements of the maxilla pieces?
• Does using PSIs provide more accurate movements of the maxilla pieces than the conventional method?
• Does using PSIs provide stable movements of the maxilla pieces after 2 years?
• Does using PSIs provide more stable movements of the maxilla pieces than the conventional method?

Participants will get orthognathic surgery as part of their normal orthodontic treatment.

Investigators will compare the PSI and conventional groups to see if the PSIs are more accurate than the conventional method.

Study Overview

• Status: Active, not recruiting
• Conditions: Malocclusion, Angle Class II; Retrognathia
• Intervention / Treatment: Device: Patient-specific implants; Device: Conventional mini-plates

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

Contacts and Locations

Study Locations

• Denmark
  • Esbjerg, Denmark, 6700
    • University Hospital of Southern Denmark

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Mandibular retrognathia
• Occlusion class II
• Three-piece Le Fort I osteotomy, as part of bimaxillary orthognathic surgery with or without genioplasty

Exclusion Criteria:

• Cleft lip
• Craniofacial syndromes
• Former trauma
• Obstructive sleep apnea

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Intervention; Participants treated with patient-specific implants for Le Fort I osteotomy and genioplasty in bimaxillary orthognathic surgery.	Device: Patient-specific implants; Application of patient-specific implants for Le Fort I osteotomy and genioplasty in bimaxillary orthognathic surgery.
Active Comparator: Control; Participants treated with conventional mini-plates for Le Fort I osteotomy and genioplasty in bimaxillary orthognathic surgery.	Device: Conventional mini-plates; Application of conventional mini-plates for Le Fort I osteotomy and genioplasty in bimaxillary orthognathic surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The accuracy of segmental Le Fort I bone movements	The three-dimensional linear and angular accuracy are measured as differences between the planned and postoperative positions of all repositioned bone segments. Measurements are performed on pre- and two weeks postoperative cone-beam computed tomography scans using the Mimics Innovation Suite software (Materialise NV, Leuven, Belgium). An error measure above 2 mm and/or 4 degrees is categorized as inaccurate.	Two weeks postoperative
The stability of segmental Le Fort I bone movements	The three-dimensional linear and angular stability are measured as differences between the short- and long-term postoperative positions of all repositioned bone segments. Measurements are performed on two weeks and two years postoperative cone-beam computed tomography scans using the Mimics Innovation Suite software (Materialise NV, Leuven, Belgium). An error measure above 2 mm and/or 4 degrees is categorized as unstable.	Two years postoperative
The stability of the upper airway	The stability of the upper airway space is measured as voluminal and cross-sectional area differences between the short- and long-term postoperative airway in mm3 and mm2, respectively. Measurements are performed on two weeks and two years postoperative cone-beam computed tomography scans using the Mimics Innovation Suite software (Materialise NV, Leuven, Belgium).	Two years postoperative

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Diagnostic Criteria for Temporomandibular Disorders Symptom questionnaire	Has Yes/No questions for the patient, used by the clinician to diagnose according to specific diagnostic criteria. See: Schiffman E, Ohrbach R, Truelove E, Look J, Anderson G, Goulet JP, List T, Svensson P, Gonzalez Y, Lobbezoo F, Michelotti A. Diagnostic criteria for temporomandibular disorders (DC/TMD) for clinical and research applications: recommendations of the International RDC/TMD Consortium Network and Orofacial Pain Special Interest Group. Journal of oral & facial pain and headache. 2014;28(1):6.	Preoperative and two years postoperative
The Jaw Functional Limitation Scale	JFLS-8 measures global functional limitation of the jaw. It has 8 questions scored 0-10, where 10 is the most severe level jaw limitation in the last month.	Preoperative and two years postoperative
The STOP-BANG - Snorting, Tiredness, Observed apnea, blood Pressure, BMI, Age, Neck circumference, Gender questionnaire	It assesses risk/likelihood of obstructive sleep apnea (OSA). It has 8 yes/no questions, and the number of yes answers are counted towards the score as follows: 0-2: low risk of OSA. 3-4: moderate risk of OSA. 5-8: high risk of OSA.	Preoperative and two years postoperative
The Epworth Sleepiness Scale questionnaire	Is scored by the sum of the responses to eight questions, on a scale 0-24 where 24 is the highest sleepiness. A score above 10 is considered as significant daytime sleepiness and is considered abnormal.	Preoperative and two years postoperative
The occlusion including horizontal/vertical overlap	The horizontal/vertical dental overlap is measured using a ruler in millimeters.	Preoperative, two weeks postoperative and two years postoperative

Collaborators and Investigators

• Sponsor: Esbjerg Hospital - University Hospital of Southern Denmark
• Collaborators: University of Southern Denmark
• Investigators: Study Chair: Else M Pinholt, dr.odont., University Hospital of Southern Denmark, Esbjerg; Principal Investigator: Alexandru Diaconu, m.sc., University Hospital of Southern Denmark, Esbjerg; Study Director: Michael B Holte, ph.d., University Hospital of Southern Denmark, Esbjerg

Study record dates

Study Major Dates

• Study Start (Actual): September 12, 2023
• Primary Completion (Estimated): August 31, 2027
• Study Completion (Estimated): August 31, 2027

Study Registration Dates

• First Submitted: January 17, 2024
• First Submitted That Met QC Criteria: March 4, 2024
• First Posted (Actual): March 7, 2024

Study Record Updates

• Last Update Posted (Actual): January 27, 2026
• Last Update Submitted That Met QC Criteria: January 25, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: Cone-Beam Computed Tomography; Accuracy; Stability; Orthognathic Surgery; Mandibular Osteotomy; Computer-Assisted Surgery; Genioplasty; Three-dimensional Imaging; Virtual Surgical Planning; Maxillary Osteotomy; Osteotomy, Le Fort; Patient-Specific Implants
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Stomatognathic Diseases; Jaw Diseases; Tooth Diseases; Jaw Abnormalities; Maxillofacial Abnormalities; Craniofacial Abnormalities; Musculoskeletal Abnormalities; Mandibular Diseases; Stomatognathic System Abnormalities; Congenital Abnormalities; Malocclusion; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Retrognathia; Malocclusion, Angle Class II
• Other Study ID Numbers: S-20230033

Drug and device information, study documents

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