Condylar Position Changes and TMJ Functions After BSSO Mandibular Setback, Low Medial Cut.

Not Applicable

Active, not recruiting

• Conditions: Skeletal Malocclusion; Mandible Prognathism; Maxillofacial Abnormalities
• Interventions: Other: mandibular setback using BSSRO

• Registration Number: NCT05713084
• Lead Sponsor: Cairo University

Brief Summary

This study hypotheses that using low medial cut osteotomy BSSO in mandibular setback can be an efficient and effective method to limit the bony segment interferences , decreasing muscles stripping during osteotomy ,decrease condylar torque and so securing preoperative condylar position during BSSO in comparison with using high medial cut BSSO.

Detailed Description

Research question:

Description of research question:

P: Population: Patients with facial skeletal deformity and need for mandibular setback using bilateral sagittal split osteotomy (BSSRO) alone or combined with lefort osteotomy.

I: Intervention: Patients with facial skeletal deformity and need and for mandibular setback using low medial cut osteotomy as modification of bilateral sagittal split ramus osteotomy (BSSRO).

C: Comparator: Patients with facial skeletal deformity and need and for mandibular setback using traditional high medial cut osteotomy bilateral sagittal split ramus osteotomy (BSSRO).

O: Outcome: Comparing the post-operative condylar positions changes and TMJ functions of two osteotomies.

Research question:

Is using low medial cut osteotomy modification in BSSRO in mandibular setback will provide more control over proximal segment position than traditional high medial cut through:

1. limit the segments interference and so maximizes the passive bony contact across the osteotomy site after surgically repositioning the distal segment

2. Passively positioned the proximal segment without displacement of the condyle from its normal position.

Study Timeline

• Study Start: 2022-09-28
• Study First Submitted: 2023-01-21
• Status Verified: 2023-02
• Study First Submitted QC: 2023-02-02
• Last Update Submitted: 2023-02-02
• Study First Posted: 2023-02-06
• Last Update Posted: 2023-02-06
• Primary Completion: 2023-04
• Study Completion: 2023-09

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 24

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
mandibular setback using low medial cut ostetomy	mandibular setback using BSSRO	mandibular setback using low medial cut ostetomy by keeping the cut ''low'' or close to the mandibular occlusal plane and ''short'' or terminating anterior to the lingula.
mandibular setback using high medial cut ostetomy	mandibular setback using BSSRO	mandibular setback by placement of the medial ramus osteotomy cut 'high', just a few millimeters above the lingula, superior and lateral to the entrance point of the inferior alveolar nerve (IAN) into the mandibular foramen ,

Primary Outcome Measures

Name	Time	Method
3D mandibular condylar position changes	Preoperative- 1-month postoperative - 6 months post operative	assessment of condylar position changes in millimetre using C.T.(axial ,coronal and sagital cut. ).; 1. Axial condylar head long-axis angle (AHA): angle between the sagittal plane and the axial condylar head axis line; 2. Axial condylar head position (AHP): perpendicular distance between the sagittal plane and the most medial point of the condylar head; 3. Frontal condylar head long-axis angle (FHA): angle between the axial plane and the frontal condylar head long-axis line; 4. Frontal condylar head position (FHP): perpendicular distance between the axial plane and most superior point of the condylar head; 5. Sagittal condylar head long-axis angle (SHA): angle between the coronal plane and the sagittal condylar head long-axis line; 6. Sagital condylar head position (SHP): perpendicular distance between the coronal plane and the most superior point of the condylar head

Secondary Outcome Measures

Name	Time	Method
Assessment of changes in articular disc position	Preoperative , 6month postoperative	In order to trace the position of the TMJ disc, a line was drawn from the uppermost point of the articular fossa (UAF, marked as 10) to the lowermost point of the articular tubercle (LAT, marked as 0).; This line was continued anteriorly and inferiorly. If the anterior border of the disc was anterior to this line, it was considered negative. These two points were chosen because they did not change with remodelling .; Perpendicular lines to this line were drawn in the anterior and posterior borders of the disc. Finally, disc position was determined by averaging anterior (point A) and posterior (point P) disc limits.

Trial Locations

Locations (1)

Faculty of Dentistry Cairo University; 🇪🇬 Cairo, Egypt