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Is There a Difference in Stability After Intraoral Vertical Ramus Osteotomy Between Vertically High-Angle and
Sung-Hwan Choi1, Da-Young Kang2, Jung-Yul Cha3
1Fellow, Department of Orthodontics, The Institute of Cranial-Facial Deformity, College of Dentistry, Yonsei University, Seoul, Republic of Korea.
Summary
Intraoral vertical ramus osteotomy (IVRO) effectively corrects mandibular prognathism in patients with high-angle facial types. This study found no significant difference in relapse rates between high-angle and normal-angle groups after IVRO surgery.
Area of Science:
- Orthognathic surgery
- Craniofacial surgery
- Maxillofacial surgery
Background:
- Mandibular prognathism is a common skeletal discrepancy.
- Intraoral vertical ramus osteotomy (IVRO) is a surgical technique used for correction.
- Vertical facial types, characterized by mandibular plane angle, may influence surgical outcomes.
Purpose of the Study:
- To evaluate the relapse patterns following IVRO for mandibular prognathism.
- To compare relapse rates between patients with high-angle and normal-angle vertical facial types.
- To determine the stability of IVRO in managing mandibular prognathism across different facial morphologies.
Main Methods:
- A retrospective cohort study involving skeletal Class III patients undergoing IVRO.
- Patients were categorized into normal-angle (SN-MP 27°-37°) and high-angle (SN-MP >37°) groups.
- Lateral cephalograms were analyzed pre-surgery, 7 days post-surgery, and 12 months post-surgery.
Main Results:
- The high-angle group experienced greater initial superior mandibular repositioning (2.5 mm more) and overbite correction (2 mm more) compared to the normal-angle group.
- Despite initial differences, no statistically significant difference in maxillary or mandibular relapse was observed between the groups at 12 months post-surgery.
- Both groups showed minimal superior mandibular movement (approx. 0.7 mm) during the retention period.
Conclusions:
- Intraoral vertical ramus osteotomy (IVRO) is a stable and clinically acceptable treatment for mandibular prognathism, even in patients with high-angle facial types.
- Vertical facial type does not appear to significantly impact the long-term skeletal stability after IVRO for mandibular prognathism.
- IVRO offers predictable outcomes for a wide range of vertical facial morphologies.
