Orthognathic Surgical ProceduresNCT07758725
Effect of Proximal Segment Positioning on Condylar Remodeling
A study testing Proximal Segment Rotation and Inferior Border Osteotomy Without Proximal Segment Rotation in people with Orthognathic Surgical Procedures, run by Bezmialem Vakif University at 1 site in Turkey (Türkiye).
Trial summary
This study aims to evaluate postoperative condylar remodeling in patients undergoing bimaxillary orthognathic surgery by comparing two different proximal segment positioning techniques used during mandibular osteotomy. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Orthognathic Surgical Procedures
- What is being tested?
- Proximal Segment Rotation and Inferior Border Osteotomy Without Proximal Segment Rotation
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Jan 2026to 28 Dec 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Patients with skeletal Class III dentofacial deformity scheduled to undergo bimaxillary orthognathic surgery.
- Age between 18 and 65 years.
- Patients who have completed preoperative orthodontic treatment.
- Patients in whom the mandibular distal segment demonstrates a maximum counterclockwise rotation of 4° after bilateral sagittal split osteotomy (BSSO) when positioned in the final planned occlusion.
Who cannot join
- History of temporomandibular joint surgery, orthognathic surgery, or tumor resection.
- Presence of facial asymmetry.
- Patients with cleft lip and/or palate, craniofacial syndromes, or a history of maxillofacial trauma.
- Patients in whom the mandibular distal segment requires more than 4° of counterclockwise rotation after BSSO to achieve the final planned position, as the amount of inferior border (basal) resection required would exceed the clinically acceptable limit.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site, 1 recruiting
- Recruiting
Bezmialem Vakif University
Istanbul, Fatih, 34093
Taha Pergel, Assit. Prof, +905316350088, tahapergel_05@hotmail.com
About this study
Official title: The Effect Of Different Proximal Segment Positioning Methods On Postoperative Condylar Remodeling in Patients Undergoing Bimaxillary Orthognathic Surgery
This study aims to evaluate postoperative condylar remodeling in patients undergoing bimaxillary orthognathic surgery by comparing two different proximal segment positioning techniques used during mandibular osteotomy. Condylar remodeling will be assessed using preoperative, immediate postoperative, and 6-month postoperative computed tomography (CT) scans together with clinical findings.
Read the detailed description
Bilateral sagittal split ramus osteotomy (BSSO), performed as part of bimaxillary orthognathic surgery, requires accurate positioning of the proximal mandibular segment to achieve postoperative skeletal stability and preserve temporomandibular joint function. During mandibular repositioning, discrepancies at the inferior border of the mandibular segments may be managed either by rotating the proximal segment to achieve inferior border alignment or by leveling the inferior border without rotating the proximal segment. The influence of these different positioning strategies on postoperative condylar remodeling has not been fully elucidated.
The aim of this study is to compare postoperative condylar remodeling between patients treated with proximal segment rotation for inferior border alignment and those treated with inferior border leveling without proximal segment rotation.
Condylar remodeling will be evaluated using computed tomography (CT) images obtained preoperatively, immediately after surgery, and at the 6-month postoperative follow-up. Radiological findings will be analyzed together with clinical outcomes to assess changes in condylar morphology and postoperative adaptation. The results of this study are expected to provide evidence regarding the effect of different proximal segment positioning methods on condylar remodeling and may contribute to optimizing surgical techniques in orthognathic surgery.
- Conditions
- Orthognathic Surgical Procedures
- Being tested
- Proximal Segment Rotation, Inferior Border Osteotomy Without Proximal Segment Rotation
- Keywords
- Condylar Remodeling, orthognathic surgery, Proximal Segment Position
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Proximal Segment RotationProcedure or surgery
During bimaxillary orthognathic surgery, after bilateral sagittal split osteotomy (BSSO), the proximal mandibular segment is rotated to achieve alignment of the inferior border of the proximal and distal mandibular segments before rigid fixation.
Inferior Border Osteotomy Without Proximal Segment RotationProcedure or surgery
During bimaxillary orthognathic surgery, after bilateral sagittal split osteotomy (BSSO), the proximal mandibular segment is maintained in its preoperative position. Alignment of the mandibular inferior border is achieved by performing an additional osteotomy at the inferior border of the proximal segment without rotating the proximal segment before rigid fixation.
| Study group | Role | What they receive |
|---|---|---|
| Proximal Segment Rotation | Active comparator | Patients underwent mandibular osteotomy followed by repositioning of the proximal segment. Alignment of the inferior border of the proximal segment with the mandibular inferior border was achieved by rotating the proximal segment before fixation. Receives: Procedure: Proximal Segment Rotation |
| Inferior Border Osteotomy Without Proximal Segment Rotation | Experimental | Patients underwent mandibular osteotomy with the proximal segment maintained in its preoperative position. Alignment of the mandibular inferior border was achieved by performing an additional osteotomy at the inferior border of the proximal segment without rotating the proximal segment before fixation. Receives: Procedure: Inferior Border Osteotomy Without Proximal Segment Rotation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Three-dimensional condylar axis angular changes
Changes in condylar axis orientation will be assessed using computed tomography (CT) by measuring the condylar axis angle in the axial, coronal, and sagittal planes relative to standardized reference planes. In the axial plane, the angle between the condylar axis and the midsagittal reference plane (MSR) will be measured. In the coronal and sagittal planes, the angle between the condylar axis and the Frankfort Horizontal Plane (FHP) will be measured. Preoperative, immediate postoperative, and 6-month postoperative measurements will be compared to evaluate postoperative condylar remodeling and positional changes.
Measured: From enrollment to the end of treatment at 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Aug 2026
- Study start1 Jan 2026
- Primary completion15 Dec 2026 (estimated)
- Study completion28 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Orthognathic Surgical ProceduresStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Bezmialem Vakif University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07758725
- Sponsor's protocol ID
- E.185561
- Status last verified
- Aug 2026
- First submitted
- 6 Aug 2026
- Last updated
- 11 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 11 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect Of Different Proximal Segment Positioning Methods On Postoperative Condylar Remodeling in Patients Undergoing Bimaxillary Orthognathic Surgery
- ClinicalTrials.gov ID
- NCT07758725
- Acronym / sponsor ID
- E.185561
- Conditions
- Orthognathic Surgical Procedures
- Keywords
- Condylar Remodeling, orthognathic surgery, Proximal Segment Position
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- Bezmialem Vakif UniversityUniversity, hospital or other
- Study start
- 1 Jan 2026 (actual)
- Primary completion
- 15 Dec 2026 (estimated)
- Study completion
- 28 Dec 2026 (estimated)
- First posted
- 11 Aug 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study aims to evaluate postoperative condylar remodeling in patients undergoing bimaxillary orthognathic surgery by comparing two different proximal segment positioning techniques used during mandibular osteotomy. Condylar remodeling will be assessed using preoperative, immediate postoperative, and 6-month postoperative computed tomography (CT) scans together with clinical findings.
Detailed description
Bilateral sagittal split ramus osteotomy (BSSO), performed as part of bimaxillary orthognathic surgery, requires accurate positioning of the proximal mandibular segment to achieve postoperative skeletal stability and preserve temporomandibular joint function. During mandibular repositioning, discrepancies at the inferior border of the mandibular segments may be managed either by rotating the proximal segment to achieve inferior border alignment or by leveling the inferior border without rotating the proximal segment. The influence of these different positioning strategies on postoperative condylar remodeling has not been fully elucidated.
The aim of this study is to compare postoperative condylar remodeling between patients treated with proximal segment rotation for inferior border alignment and those treated with inferior border leveling without proximal segment rotation.
Condylar remodeling will be evaluated using computed tomography (CT) images obtained preoperatively, immediately after surgery, and at the 6-month postoperative follow-up. Radiological findings will be analyzed together with clinical outcomes to assess changes in condylar morphology and postoperative adaptation. The results of this study are expected to provide evidence regarding the effect of different proximal segment positioning methods on condylar remodeling and may contribute to optimizing surgical techniques in orthognathic surgery.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Proximal Segment Rotation | Active comparator | Procedure: Proximal Segment RotationPatients underwent mandibular osteotomy followed by repositioning of the proximal segment. Alignment of the inferior border of the proximal segment with the mandibular inferior border was achieved by rotating the proximal segment before fixation. |
| Inferior Border Osteotomy Without Proximal Segment Rotation | Experimental | Procedure: Inferior Border Osteotomy Without Proximal Segment RotationPatients underwent mandibular osteotomy with the proximal segment maintained in its preoperative position. Alignment of the mandibular inferior border was achieved by performing an additional osteotomy at the inferior border of the proximal segment without rotating the proximal segment before fixation. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Patients with skeletal Class III dentofacial deformity scheduled to undergo bimaxillary orthognathic surgery.
- Age between 18 and 65 years.
- Patients who have completed preoperative orthodontic treatment.
- Patients in whom the mandibular distal segment demonstrates a maximum counterclockwise rotation of 4° after bilateral sagittal split osteotomy (BSSO) when positioned in the final planned occlusion.
Key exclusion criteria (4 listed)
- History of temporomandibular joint surgery, orthognathic surgery, or tumor resection.
- Presence of facial asymmetry.
- Patients with cleft lip and/or palate, craniofacial syndromes, or a history of maxillofacial trauma.
- Patients in whom the mandibular distal segment requires more than 4° of counterclockwise rotation after BSSO to achieve the final planned position, as the amount of inferior border (basal) resection required would exceed the clinically acceptable limit.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Proximal Segment RotationDuring bimaxillary orthognathic surgery, after bilateral sagittal split osteotomy (BSSO), the proximal mandibular segment is rotated to achieve alignment of the inferior border of the proximal and distal mandibular segments before rigid fixation. | Procedure or surgery | Proximal Segment Rotation |
| Inferior Border Osteotomy Without Proximal Segment RotationDuring bimaxillary orthognathic surgery, after bilateral sagittal split osteotomy (BSSO), the proximal mandibular segment is maintained in its preoperative position. Alignment of the mandibular inferior border is achieved by performing an additional osteotomy at the inferior border of the proximal segment without rotating the proximal segment before rigid fixation. | Procedure or surgery | Inferior Border Osteotomy Without Proximal Segment Rotation |
Primary outcome
Three-dimensional condylar axis angular changes
Time frame: From enrollment to the end of treatment at 6 months
Changes in condylar axis orientation will be assessed using computed tomography (CT) by measuring the condylar axis angle in the axial, coronal, and sagittal planes relative to standardized reference planes. In the axial plane, the angle between the condylar axis and the midsagittal reference plane (MSR) will be measured. In the coronal and sagittal planes, the angle between the condylar axis and the Frankfort Horizontal Plane (FHP) will be measured. Preoperative, immediate postoperative, and 6-month postoperative measurements will be compared to evaluate postoperative condylar remodeling and positional changes.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Aug 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Proximal Segment Rotation and Inferior Border Osteotomy Without Proximal Segment Rotation in people with Orthognathic Surgical Procedures, run by Bezmialem Vakif University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 11 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Taha Pergel, Asist Prof (+905316350088, tahapergel_05@hotmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Three-dimensional condylar axis angular changes (time frame: From enrollment to the end of treatment at 6 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Aug 2026.