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Enrolling by Invitation

NCT Number: NCT07090772

The Effectiveness of Different Therapeutic Jaw Position Determining Methods in Repositioning Splint Therapy for Temporomandibular Joint Disk Displacement Without Reduction：A Randomized Controlled Clinical Trial

The goal of this clinical trial is to learn if different therapeutic jaw position determining methods influence the efficacy of repositioning splint therapy for temporomandibular joint disk displacement without reduction. The main questions it aims to answer are:

Does different therapeutic jaw position determining methods influence the efficacy of repositioning splint therapy for temporomandibular joint disk displacement without reduction? Researchers will compare the efficacy of repositioning splint therapy made with different therapeutic jaw position determining methods for temporomandibular joint disk displacement without reduction.

Participants will:

Take repositioning splint made with different therapeutic jaw position determining methods every day for 3-6 months.

Visit the clinic once every 3 weeks for checkups and tests.

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Key information

Conditions

Temporomandibular Disorder (TMD) Craniomandibular Disorders Jaw Diseases Joint Diseases Mandibular Diseases Muscular Diseases Musculoskeletal Diseases Stomatognathic Diseases Temporomandibular Joint Disorders

Age range

13 year–50 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Fujian Medical University

Fuzhou, Fujian, China

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Aged 13-50 years, with permanent dentition, possessing full autonomy in behavior and expression;
  • Meeting the 2014 Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) diagnostic standards for irreducible temporomandibular joint disc displacement;
  • MRI-confirmed unilateral irreducible disc displacement: At maximum intercuspation: Posterior band of disc located anterior to the 11:30 position, intermediate zone anterior to condyle; At maximum mouth opening: Intermediate zone remains anterior to condyle.

Exclusion criteria

  • Systemic diseases, psychiatric disorders, or impaired consciousness;
  • Pain-only disorders without articular pathology signs;
  • Mandibular hypoplasia, TMJ tumors, or prior TMJ trauma;
  • History of definitive TMJ disorder treatment.

Treatment and study plan

Repositioning splint therapy with jaw position determined by mechanical articulator

Procedure

The therapeutic jaw position will be determined by the following steps:

  • Pre-treatment Jaw Position Recording Participants were seated upright with relaxed posture, eyes facing forward, and the Frankfort plane parallel to the floor. Intercuspal position (ICP) was recorded using silicone registration material. Edge-to-edge position of central incisors was recorded for protrusive position. Left/right lateral positions were recorded with opposing canines aligned.
  • Transfer of Jaw Positions Following the manufacturer's protocol for the Artex CR mechanical facebow (Amann Girrbach, Austria) to transfer Participants' jaw positions.
  • Determination of Therapeutic Position The Glenoid fossa was divided into 7 grids in the oblique-sagittal plane using Gelb's method, identifying grid 4 (Gelb 4/7) as the target condylar position.Condylar displacement knobs were set per VTO analysis.

Incisal pin height was increased to establish vertical dimension.

Repositioning splint therapy with jaw position determined by ai-assisted virtual articulator

Procedure

The jaw position was determined by the following steps:

  • AI-Based Segmentation and Reconstruction of Jaw Models CBCT DICOM data was imported into an ai-based craniomaxillofacial bone segmentation system to reconstruct 3D models of the jaws and dentition. The mandibular/maxillary bone models and dental arches were exported as .ply files. These .ply files were then imported into Exocad software.
  • Virtual Transfer of Jaw Positions Bilateral AI-segmented medial pole points of the condyles and the right infraorbital point were annotated in cross-sectional views.A virtual articulator was added and registered to the facebow's reference planes and hinge axis. (3)Determination of Therapeutic Position Sagittal joint spaces (anterior/superior/posterior) were measured on cross-sectional views. The composite mandibular model was repositioned to the target occlusion using the "Move Mesh" function based on: Optimal mean joint space measurements and physiological condylar position.

Repositioning splint therapy with jaw position determined by ai-assisted virtual patient

Procedure

The jaw position was determined by the following steps:

  • AI-Based Segmentation and Reconstruction of Virtual Patients:

CBCT DICOM data was imported into an ai-based craniomaxillofacial bone segmentation system to reconstruct 3D models of the jaws and dentition. The trajectory of mandibular movement was recorded by an electronic facebow.

  • Virtual Transfer of Jaw Positions Bilateral AI-segmented medial pole points of the condyles and the right infraorbital point were annotated in cross-sectional views.A virtual articulator was added and registered to the facebow's reference planes and hinge axis. (3)Determination of Therapeutic Position Sagittal joint spaces (anterior/superior/posterior) were measured on cross-sectional views. The therapeutic position was determined based on: Optimal mean joint space measurements, physiological condylar position and optimal trajectory of mandibular movement.

Primary outcomes

  1. Condylar position as assessed by CBCT measurements

    Time frame: 3-6 months

    Condylar position of the three groups will be assessed after each treatment based on the measurements of sagittal joint spaces (anterior/superior/posterior) on CBCT's cross-sectional views.

  2. Condylar repositioning rate as assessed by CBCT measurements

    Time frame: 3-6 months

    Using Mimics software, post-treatment condylar positions were analyzed and measured. The proportions of affected-side condyles reposition to the Gelb 4/7 position were compared across the three therapeutic jaw position determination methods.

Secondary outcomes

  1. Fricton index as assessed by comprehensive physical examination to participants

    Time frame: 3-6 months

    Fricton index consists of dysfunction index and palpation index, which can quantify mandibular function and movement, palpation of muscles and other indicators, and is widely used to evaluate the clinical efficacy of temporomandibular disorders.

  2. Dysfunction index as assessed by by comprehensive physical examination to participants

    Time frame: 3-6 months

    Dysfunction index refers to the comprehensive Index that reflect temporomandibular joint tenderness and functioning problems.

  3. Palpation index as assessed by by comprehensive physical examination to participants

    Time frame: 3-6 months

    Palpation index refers to the comprehensive index that reflect muscle tenderness problems.

Sponsors and collaborators

Lead sponsor

Fujian Medical University

Other

Registry information

Important dates

Study start
2025
Primary completion
2026
Study completion
2026
First posted
Jul 29, 2025
Registry last updated
Jul 29, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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