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Updated: May 21, 2026
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A Postoperative Evaluation Guideline for Computer-Assisted Reconstruction of the Mandible
Published on: January 28, 2020
Evaluation of intersegmental displacement according to osteosynthesis method for mandibular setback sagittal split
Yong-Il Kim1, Soo-Byung Park, Yun-Hoa Jung
1Department of Orthodontics, Biomedical Research Institute, Pusan National University Hospital, Busan. kimyongil@pusan.ac.kr
Summary
The study found that using bicortical screws for mandibular setback surgery resulted in the most significant intersegmental displacement. Surgeons should carefully select fixation methods to minimize unwanted bone movement.
Area of Science:
- Oral and Maxillofacial Surgery
- Orthognathic Surgery
- Biomaterials Engineering
Background:
- Mandibular setback surgery is a common procedure in orthognathic surgery.
- Fixation methods play a crucial role in stabilizing bone segments after osteotomy.
- Minimizing intersegmental displacement is essential for predictable surgical outcomes.
Purpose of the Study:
- To compare intersegmental displacements following mandibular setback sagittal split ramus osteotomy.
- To evaluate the influence of different fixation systems on postoperative stability.
Main Methods:
- A comparative study involving 42 subjects undergoing mandibular setback surgery.
- Three groups were analyzed based on fixation: miniplate with monocortical screw, 3 bicortical screws, and 1 bicortical screw with 2 resorbable screws.
- Cone-beam computed tomography (CBCT) was used to measure intersegmental displacements at immediate postoperative (T0) and 6-month follow-up (T1).
Main Results:
- The group using 3 bicortical screws exhibited significantly greater condylion (Cd) and coronoid process (Cp) displacements compared to other groups.
- Specific patterns of anterior, inferior, and lateral displacements were observed for Cd and Cp in each fixation group.
- The bicortical screw group showed the most pronounced postoperative instability.
Conclusions:
- Fixation with 3 bicortical screws led to the highest degree of intersegmental displacement after mandibular setback surgery.
- The choice of osteosynthesis method significantly impacts postoperative stability.
- Surgeons must carefully consider fixation techniques to reduce unwanted bone segment movement and improve treatment predictability.
