Springer Science and Business Media LLC Acta Medica Okayama 1865-1569 30 1 2026 Three-dimensional virtual planning reduces operative time in orthognathic surgery: a procedure-specific retrospective study incorporating additive manufacturing 94 EN Yuki Kunisada Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Norie Yoshioka Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Akiyoshi Nishiyama Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Masanori Masui Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Koichi Kadoya Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hiroaki Takakura Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Kyoichi Obata Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Kisho Ono Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Koki Umemori Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Soichiro Ibaragi Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Purpose Three-dimensional virtual surgical planning (3D-VSP) is increasingly used in orthognathic surgery; however, procedure-specific evidence regarding its real-world impact on operative efficiency and intraoperative blood loss remains limited. This study evaluated the association between 3D-VSP implementation and operative time, and intraoperative blood loss across different orthognathic procedures.<br> Methods This retrospective cohort study included consecutive patients who underwent orthognathic surgery at a single academic institution before (2019–2020) and after (2023–2024) the full implementation of 3D-VSP integrated with in-house additive manufacturing (n = 344). Procedure-specific multivariable linear regression analyses were performed, adjusting for age, sex, and surgeon experience.<br> Results After 3D-VSP implementation, operative time was reduced by approximately 36 min in sagittal split ramus osteotomy (SSRO), 50 min in Le Fort I (LF1) combined with SSRO, and 42 min in segmental LF1 combined with SSRO, representing a 15–20% reduction in total operative time. No meaningful reduction was observed in intraoral vertical ramus osteotomy (IVRO)-based procedures. A statistically significant, but modest, reduction in intraoperative blood loss was observed only in SSRO. The time-saving effect was independent of surgeon experience.<br> Conclusion The clinical benefit of 3D-VSP in orthognathic surgery is procedure-dependent and most evident in geometrically complex SSRO-based operations. These findings support the targeted implementation of digital planning and additive manufacturing workflows to improve operative efficiency in routine practice. No potential conflict of interest relevant to this article was reported.

BMC Acta Medica Okayama 1746-160X 16 1 2020 Occlusal reconstruction of a patient with ameloblastoma ablation using alveolar distraction osteogenesis: a case report 12 EN Yoshihito Ishihara Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hikaru Arakawa Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine,Dentistry and Pharmaceutical Sciences Akiyoshi Nishiyama Department of Oral and Maxillofacial Surgery, Okayama University Graduate School of Medicine Dentistry, and Pharmaceutical Sciences Hiroshi Kamioka Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Background Ameloblastoma is one of the most common benign odontogenic neoplasms. Its surgical excision has the potential to lead to postoperative malocclusion. In this case report, we describe the successful interdisciplinary orthodontic treatment of a patient with ameloblastoma who underwent marginal mandibulectomy. Case presentation A woman of 20-year-old was diagnosed with ameloblastoma, and underwent marginal mandibulectomy when she was 8 years of age. She had an excessive overjet (11.5 mm) and a mild open bite (- 1.5 mm) with a severely resorbed atrophic edentulous ridge in the area around the mandibular left lateral incisor, canine and first premolar. An alveolar bone defect associated with tumor resection was regenerated by vertical distraction osteogenesis (DO). Subsequently, 3 dental implants were placed into the reconstructed mandible. Orthodontic treatment using implant-anchored mechanics provided a proper facial profile with significantly improved occlusal function. The occlusion appeared stable for a 7-year retention period. Conclusions These results suggest that surgically assisted and implant anchored-orthodontic approaches might be effective for the correction of such malocclusions. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 67 1 2013 Severe Gummy Smile with Class II Malocclusion Treated with LeFort I Osteotomy Combined with Horseshoe Osteotomy and Intraoral Vertical Ramus Osteotomy 55 60 EN Tsuyoshi Shimo Akiyoshi Nishiyama Tokiari Jinno Akira Sasaki Case Report 10.18926/AMO/49257 In this article, we report the successful surgical treatment of a patient, 34 years of age, who had a severe gummy smile and a class II malocclusion. The patient had an 11-mm gingival exposure during full smile and a convex profile. A LeFort I osteotomy combined with a horseshoe osteotomy was used for the superior repositioning of the maxilla;then, an intraoral vertical ramus osteotomy (IVRO) and genioplasty were performed for mandibular advancement. The maxilla was acceptably impacted 8mm at the first incisor and 5mm at the first molar. Both the occlusion and facial appearance were significantly improved by this surgical-orthodontic treatment. Our results suggest that the combination of a horseshoe osteotomy with a LeFort I osteotomy is a useful technique for reliable superior repositioning of the maxilla. No potential conflict of interest relevant to this article was reported.