Mandibular Medial Osteotomy Modifications and Postoperative Stability

August 24, 2026 updated by: Bezmialem Vakif University

The Effect of Mandibular Medial Osteotomy Modifications on Postoperative Stability Following Orthognathic Surgery

This study aims to compare the effects of the Hunsuck and Posnick modifications of medial mandibular osteotomy on postoperative skeletal stability and relapse in patients undergoing orthognathic surgery. The study will evaluate whether the choice of medial osteotomy technique influences postoperative mandibular relapse.

Study Overview

Detailed Description

This study aims to evaluate and compare the effects of two different medial mandibular osteotomy modifications, namely the Hunsuck and Posnick techniques, on postoperative skeletal stability and relapse in patients undergoing orthognathic surgery.

Patients who meet the study eligibility criteria and are scheduled to undergo bilateral sagittal split ramus osteotomy (BSSO) as part of orthognathic surgery will be included. Depending on the medial mandibular osteotomy technique used, patients will be evaluated in two groups: those undergoing the Hunsuck modification and those undergoing the Posnick modification.

Preoperative and postoperative radiographic records will be evaluated to assess skeletal changes associated with each osteotomy technique. Postoperative skeletal stability will be assessed by comparing relevant mandibular and skeletal reference points and angular measurements between the preoperative, immediate postoperative, and follow-up imaging records. The amount and direction of postoperative skeletal relapse will be determined based on changes occurring during the follow-up period.

The primary objective is to determine whether the Hunsuck and Posnick modifications differ in terms of postoperative skeletal stability and relapse following orthognathic surgery. Secondary evaluations may include assessment of the magnitude and direction of mandibular positional changes and comparison of the radiographic outcomes between the two techniques.

The findings of this study may provide clinically relevant information regarding the influence of medial mandibular osteotomy design on postoperative skeletal stability and may help guide the selection of an appropriate osteotomy technique in orthognathic surgery.

Study Type

Interventional

Enrollment (Estimated)

34

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  1. Patients with an indication for orthognathic surgery who are planned to undergo bimaxillary orthognathic surgery.
  2. Patients who have undergone preoperative orthodontic treatment.
  3. Patients aged 18-65 years.

Exclusion Criteria:

  1. Patients who develop an unfavorable split (bad split) during surgery.
  2. Patients with cleft lip and palate, craniofacial syndromes, or a history of facial trauma.
  3. Patients who have previously undergone orthognathic surgery and require revision surgery.
  4. Patients whose computed tomography (CT) records are inadequate for the required measurements.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Hunsuck Modification Group
Patients undergoing orthognathic surgery with bilateral sagittal split ramus osteotomy (BSSO) will undergo medial mandibular osteotomy using the Hunsuck modification. The osteotomy will be performed according to the Hunsuck technique, with the medial horizontal osteotomy terminating at the level of the lingula and extending posteriorly to facilitate the sagittal split. Postoperative skeletal stability and relapse will be evaluated during the follow-up period.
Bilateral sagittal split ramus osteotomy will be performed as part of orthognathic surgery to correct the planned mandibular skeletal deformity. The mandibular ramus and body will be divided using the assigned medial osteotomy modification (Hunsuck or Posnick), followed by sagittal splitting of the mandible. The distal mandibular segment will then be repositioned according to the preoperative surgical plan and stabilized using appropriate osteosynthesis. Postoperative skeletal stability and mandibular relapse will be evaluated during the follow-up period.
The Hunsuck modification of the medial mandibular osteotomy will be performed during bilateral sagittal split ramus osteotomy (BSSO). The medial horizontal osteotomy will be initiated at the lingula and extended posteriorly for a short distance, according to the Hunsuck modification. The remaining steps of the BSSO will be performed using the standard surgical technique. Postoperative skeletal stability and relapse will be assessed using preoperative, immediate postoperative, and follow-up radiographic evaluations
Active Comparator: Posnick Modification Group
Patients undergoing orthognathic surgery with bilateral sagittal split ramus osteotomy (BSSO) will undergo medial mandibular osteotomy using the Posnick modification. The osteotomy will be performed according to the Posnick technique, with the modified medial osteotomy design extending posteriorly in accordance with the technique. Postoperative skeletal stability and relapse will be evaluated during the follow-up period.
Bilateral sagittal split ramus osteotomy will be performed as part of orthognathic surgery to correct the planned mandibular skeletal deformity. The mandibular ramus and body will be divided using the assigned medial osteotomy modification (Hunsuck or Posnick), followed by sagittal splitting of the mandible. The distal mandibular segment will then be repositioned according to the preoperative surgical plan and stabilized using appropriate osteosynthesis. Postoperative skeletal stability and mandibular relapse will be evaluated during the follow-up period.
The Posnick modification of the medial mandibular osteotomy will be performed during bilateral sagittal split ramus osteotomy (BSSO). The medial horizontal osteotomy will be performed according to the Posnick modification, with the osteotomy design extending posteriorly along the medial aspect of the mandibular ramus as described for this technique. The remaining steps of the BSSO will be performed using the standard surgical technique. Postoperative skeletal stability and relapse will be assessed using preoperative, immediate postoperative, and follow-up radiographic evaluations.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postoperative Skeletal Relapse
Time Frame: 1 year
The primary outcome will be the amount and percentage of skeletal relapse between 1 month and 12 months after orthognathic surgery (T3-T1), assessed using three-dimensional cephalometric and skeletal measurements.
1 year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 1, 2026

Primary Completion (Estimated)

December 28, 2026

Study Completion (Estimated)

April 25, 2027

Study Registration Dates

First Submitted

August 24, 2026

First Submitted That Met QC Criteria

August 24, 2026

First Posted (Actual)

August 27, 2026

Study Record Updates

Last Update Posted (Actual)

August 27, 2026

Last Update Submitted That Met QC Criteria

August 24, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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