Related Experiment Video
Updated: Sep 29, 2025
Treatment of Facial Deformities using 3D Planning and Printing of Patient-Specific Implants
Published on: May 23, 2020
Three-dimensional analysis of mandible ramus morphology and transverse stability after intraoral vertical ramus
Luo Huang1, Shan Tang2, Jing Yan1
1Guangzhou Key Laboratory of Basic and Applied Research of Oral Regenerative Medicine, Key Laboratory of Oral Medicine, Department of Oral and Maxillofacial Surgery, Guangzhou Institute of Oral Disease, Affiliated Stomatology Hospital of Guangzhou Medical University, No. 39 Huangsha Avenue, Guangzhou, 510150, China.
Objectives:
The purpose of this study was to investigate short- and long-term postoperative changes of both morphology and transverse stability in mandibular ramus after intraoral vertical ramus osteotomy (IVRO) in patients with jaw deformity using three-dimensional (3D) orthognathic surgery planning treatment software for measurement of distances and angles.
Study Design:
This retrospective study included consecutive patients with skeletal Class III malocclusion who had undergone intraoral vertical ramus osteotomy and computed tomography images before (T0), immediately after (T1), and 1 year after (T2) surgery. Reference points, reference lines and evaluation items were designated on the reconstructed 3D surface models to measure distances, angles and volume. The average values at T0, T1, T2 and time-dependent changes in variables were obtained.
Results:
After surgery, the condylar length, ramal height, mandibular body length and mandibular ramus volume were significantly decreased (P < 0.01), while clinically insignificant change was observed from T1 to T2. The angular length was increased immediately after surgery (P < 0.05), but it was decreased 1 year after surgery (P < 0.05). Lateral ramal inclination showed significant increase after surgery (P < 0.05) and maintained at T2.
Conclusion:
Changes in the morphology of the mandibular ramus caused by IVRO do not obviously bring negative effect on facial appearance. Furthermore, despite position and angle of mandibular ramus changed after IVRO, good transverse stability was observed postoperatively. Therefore, IVRO technique can be safely used without compromising esthetic results.
