caa a22 4500 445851139 CHVBK 20180317145413.0 cr unu---uuuuu 170323e20110901xx s 000 0 eng 10.1007/s10006-011-0266-9 doi (NATIONALLICENCE)springer-10.1007/s10006-011-0266-9 In vitro biomechanical evaluation of the effect of an additional L-shaped plate on straight or box plate fixation in sagittal split ramus osteotomy using a bioabsorbable plate system [Elektronische Daten] [Kazuhiro Matsushita, Nobuo Inoue, Yasunori Totsuka] Purpose: Relapse caused by clockwise (opening) rotation of the distal segment (dentate segment) in the sagittal plane is one of the postoperative complications sometimes seen after sagittal split ramus osteotomy. The force involved in this movement is primarily exerted by the masticatory and suprahyoid muscles. For postoperative stability, we have used two plates on each side: a straight plate placed over the vertical osteotomy line at the buccal surface of the first molar and an L-shaped plate placed at the distal or lateral part of the last molar over the osteotomy line, just crossing over the upper-lateral edge of the buccal shelf, to prevent the tail of the distal segment from moving upward. Although postoperative stability was clinically fine, experimental evaluations have not previously been performed. To clarify the effects of the L-shaped plate, we performed an experimental study using a bioabsorbable plate system. Methods: A custom-fabricated jig was made to simulate rotational movement of the segments. Two segments made from polyoxymethylene resin were fixed with a four-hole straight or four-hole box poly-l-lactate bioabsorbable plate. An L-shaped plated was then added for rigidity, and mechanical testing was performed. Results: The yield load exerted by the four-hole straight plate alone was 152.4 ± 11.0N. This increased significantly to 273.8 ± 43.7N with addition of an L-shaped plate (P < 0.05). Conclusion: Addition of an L-shaped plate significant improves the rigidity of four-hole straight plate fixation in a bioabsorbable plate system. Springer-Verlag, 2011 Sagittal split ramus osteotomy (SSRO) nationallicence Stability nationallicence Rigidity nationallicence Bioabsorbable plate nationallicence Relapse nationallicence Matsushita Kazuhiro Department of Oral and Maxillofacial Surgery, Division of Oral Pathobiological Science, Graduate School of Dental Medicine, Hokkaido University, N13W7, Kita-ku, 060-8586, Sapporo, Hokkaido, Japan aut Inoue Nobuo Department of Gerodontology, Division of Oral Health Science, Graduate School of Dental Medicine, Hokkaido University, N13W7, Kita-ku, 060-8586, Sapporo, Hokkaido, Japan aut Totsuka Yasunori Department of Oral and Maxillofacial Surgery, Division of Oral Pathobiological Science, Graduate School of Dental Medicine, Hokkaido University, N13W7, Kita-ku, 060-8586, Sapporo, Hokkaido, Japan aut Oral and Maxillofacial Surgery Springer-Verlag 15/3(2011-09-01), 139-146 1865-1550 15:3<139 2011 15 10006 https://doi.org/10.1007/s10006-011-0266-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10006-011-0266-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Matsushita Kazuhiro Department of Oral and Maxillofacial Surgery, Division of Oral Pathobiological Science, Graduate School of Dental Medicine, Hokkaido University, N13W7, Kita-ku, 060-8586, Sapporo, Hokkaido, Japan aut NATIONALLICENCE 700 1- Inoue Nobuo Department of Gerodontology, Division of Oral Health Science, Graduate School of Dental Medicine, Hokkaido University, N13W7, Kita-ku, 060-8586, Sapporo, Hokkaido, Japan aut NATIONALLICENCE 700 1- Totsuka Yasunori Department of Oral and Maxillofacial Surgery, Division of Oral Pathobiological Science, Graduate School of Dental Medicine, Hokkaido University, N13W7, Kita-ku, 060-8586, Sapporo, Hokkaido, Japan aut NATIONALLICENCE 773 0- Oral and Maxillofacial Surgery Springer-Verlag 15/3(2011-09-01), 139-146 1865-1550 15:3<139 2011 15 10006 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer