This study evaluates a new, individualized treatment for adolescents with temporomandibular joint disorders (TMD) caused by bilateral, reducible disc displacement. Participants will undergo clinical and imaging examinations, including cone-beam CT (CBCT), MRI, and intraoral digital scanning to create three-dimensional models of the teeth and jaw. Based on these data, the study team will design and fabricate a personalized repositioning digital occlusal splint for each participant. Patients will be instructed on how to wear the splint and will return for regular follow-up visits to monitor symptoms and adjust the splint as needed. The study aims to improve pain, chewing function, and overall quality of life. All research-related imaging, digital scans, splint fabrication, and follow-up visits will be provided at no cost to participants. Possible risks include temporary discomfort or pressure when first wearing the splint, and the possibility that symptoms may not improve as expected. Participant safety, privacy, and data confidentiality will be strictly protected, and participants may withdraw from the study at any time without affecting their future medical care.
Detailed Description This study evaluates four different methods for mandibular repositioning in patients with bilateral reducible temporomandibular joint (TMJ) disc displacement requiring occlusal reconstruction. Methods of Mandibular Repositioning: 1. Intraoral Direct Positioning Group: The therapeutic jaw position is determined clinically using the clicking elimination method, where patients open wide until clicking occurs, then gradually retract the mandible while performing opening-closing movements to find the minimal protrusion position without clicking. 2. Articulator Positioning Group: Uses mechanical facebow transfer and semi-adjustable articulator (Artex CR) with condylar guidance parameters obtained from protrusive and lateral excursion records. The therapeutic position is determined by analyzing CBCT joint space measurements and MRI disc displacement data. 3. Digital Anatomical Positioning Group: Combines intraoral scanning data with CBCT-reconstructed 3D jaw models. The therapeutic position is determined by referencing MRI disc reduction phase, optimal joint space ratios, and anatomical landmarks using CAD software (Exocad). 4. Digital Jaw Motion Tracking Group: Integrates 3D jaw models with electronic jaw tracking data (Zebris). The therapeutic position is determined by analyzing condylar movement trajectories (identifying the "figure-8" pattern crossover points indicating disc displacement) combined with dynamic MRI and optimal joint space parameters. Treatment Protocol: All groups receive digitally designed and manufactured repositioning splints. Patients wear splints 24 hours daily (except during meals) for 3 months, with follow-up adjustments at 2 weeks, 1 month, 2 months, and 3 months. Imaging Protocol: * CBCT (I-CAT FLX): 120 kV, 5 mA, 0.2 mm resolution * MRI (GE Discovery MR750w 3.0T): Bilateral TMJ surface coils, oblique sagittal and coronal views in closed-mouth position, oblique sagittal in maximum opening Assessment Methods: * Joint space measurements using Ikeda's method on registered pre- and post-treatment CBCT images * Condyle position analysis using Gelb 4/7 position criteria * Disc-condyle angle measurement on MRI (\>15° defined as disc displacement)
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
48
A custom-fabricated hard acrylic repositioning splint based on manual intraoral mandibular positioning. The splint is created by: 1. Clinically identifying the optimal jaw position through clicking elimination technique 2. Taking alginate impressions of maxillary and mandibular arches 3. Pouring stone models and manually adjusting mandibular model to the determined position 4. Fabricating a hard acrylic splint with 1-2 mm occlusal clearance 5. Finishing and polishing the splint Patients wear the splint 24 hours daily (except during meals) for 3 months, with adjustments at 2 weeks, 1 month, 2 months, and 3 months.
A custom-fabricated hard acrylic repositioning splint using adjustable articulator (Artex CR) methodology: 1. Performing mechanical facebow transfer 2. Recording condylar guidance parameters in protrusive and lateral excursions 3. Analyzing CBCT joint space measurements and MRI disc displacement data 4. Mounting study models on Artex CR articulator with precise condylar settings 5. Manually adjusting splint to achieve optimal mandibular position 6. Fabricating hard acrylic splint with 1-2 mm occlusal clearance Patients wear the splint 24 hours daily (except during meals) for 3 months, with adjustments at 2 weeks, 1 month, 2 months, and 3 months.
A digitally designed and 3D-printed repositioning splint using advanced digital workflow: 1. Performing intraoral digital scanning (iTero Element) 2. Acquiring CBCT scan (I-CAT FLX) 3. Importing MRI disc displacement data 4. Using CAD software (Exocad) to: * Overlay intraoral scan with CBCT 3D model * Reference MRI disc reduction phase * Calculate optimal joint space ratios 5. Digitally designing splint with precise mandibular positioning 6. Fabricating hard acrylic splint with 1-2 mm occlusal clearance Patients wear the splint 24 hours daily (except during meals) for 3 months, with adjustments at 2 weeks, 1 month, 2 months, and 3 months.
A digitally designed repositioning splint using electronic jaw motion tracking: 1. Performing 3D jaw motion tracking (Zebris JMA system) 2. Capturing mandibular movement trajectories 3. Identifying "figure-8" pattern crossover points indicating disc displacement 4. Integrating dynamic MRI data 5. Analyzing optimal joint space parameters 6. Using CAD software to design precise mandibular positioning splint 7. Fabricating hard acrylic splint with 1-2 mm occlusal clearance Patients wear the splint 24 hours daily (except during meals) for 3 months, with adjustments at 2 weeks, 1 month, 2 months, and 3 months.
School and Hospital of Stomatology, Fujian Medical University,
Fuzhou, Fujian, China
Change in Temporomandibular Joint Space Ratio
Quantitative assessment of changes in temporomandibular joint space using Cone Beam Computed Tomography (CBCT) with Ikeda's method.
Time frame: Baseline and 3 months post-treatment
Change in Disc-Condyle Relationship Angle
Quantitative assessment of disc displacement using Magnetic Resonance Imaging (MRI) with angle measurement technique.
Time frame: Baseline and 3 months post-treatment
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.