To evaluate intersegmental displacement during long-term follow-up after bilateral sagittal split osteotomy (BSSO) by mandibular body area superimposition.

Materials and Methods

Cone-beam computed tomography (CBCT) images of 23 patients ages 18−37 years with class III malocclusion before orthognathic surgery were obtained. A three-dimensional (3D) CBCT examination was performed at four stages: surgery (T0), 6 months after surgery (T1), 1 year after surgery (T2), and long-term follow-up (6.1 ± 2.1 years, T3). The CBCT datasets were superimposed on the symphyseal area and the lower part of the distal segment of the mandible between T0 and the other time points (T1, T2, and T3). The reference points (both condyle, coronoid, and sigmoid) were estimated by the CBCT analyzed program.


The coronoid, condylion, and sigmoid showed changes within 6 months after surgery, but there was no significant change in the intersegmental displacement between 6 months and 6 years after surgery. The distances between the left and right coronoid, condylion, and sigmoid from T0 to T3 were noted.


The change in intersegmental displacement between T0 and T3 affecting relapse after orthognathic surgery was not significantly different. This suggests that the mandible itself may have a stable morphology during the follow-up period.

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Author notes


Associate Professor, Department of Oral and Maxillofacial Surgery, Pusan National University Dental Hospital, Yangsan, South Korea.


Resident, Department of Orthodontics, Dental Research Institute, Pusan National University Dental Hospital, Yangsan, South Korea.


Clinical Assistant Professor, Department of Orthodontics, Pusan National University Dental Hospital, Yangsan, South Korea.


Associate Professor, Dental and Life Science Institute, School of Dentistry, Pusan National University, Busan, South Korea.


The first two authors contributed equally to this work.