A Study on Bone-Contact to Inter-Segmental Length Ratio of Rigid Fixation Screws used in Bssro for Mandibular Setback.
- Author:
Sung Min CHO
1
;
Seong Hun KIM
;
Je Uk PARK
Author Information
1. Division of Oral & maxillofacial Surgery, Department of Dentistry, College of medicine, The Catholic University, Korea. jupark@catholic.ac.kr
- Publication Type:Original Article
- Keywords:
Screw length and ratios;
Rigid fixation;
Bilateral sagittal split ramus osteotomy
- MeSH:
Cone-Beam Computed Tomography;
Humans;
Malocclusion;
Mandibular Nerve;
Osteotomy;
Osteotomy, Sagittal Split Ramus
- From:Journal of the Korean Association of Oral and Maxillofacial Surgeons
2009;35(5):329-334
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
OBJECTIVE: To evaluate the ratio between bone-contact length and inter-segmental length of the rigid fixation screw used in bilateral sagittal split ramus osteotomy (BSSRO) for mandibular setback. MATERIAL AND METHODS: Records of 40 patients with Class III malocclusion were selected. 20 of them had BSSRO, while the other 20 had BSSRO with maxillary LeFort I osteotomy. All of the patients had three noncompressive bicortical screws inserted at the gonial angle through transcutaneous approach. Two screws were inserted antero-posteriorly above inferior alveolar nerve and one screw was inserted below. The lengths of bone-contact and that of inter-segmental part were measured using cone-beam computed tomography. Ratio between these two measured lengths was calculated. RESULTS: Both bone-contact and inter-segmental lengths were longer in BSSRO group than in BSSRO with maxillary LeFort I osteotomy group. Ratio of bone-contact to inter-segmental length was lower in BSSRO group than in BSSRO with Lefort I group. Both bone-contact and inter-segmental lengths were longer at the antero-superior position than at the inferior position. However, their ratio showed little difference. CONCLUSION: This study suggest that stability of screws in BSSRO group was greater than in BSSRO with Lefort I group. Stability of screws at the antero-superior position was greater than at the inferior position. Ratio of bone-contact to inter- segmental lengths was 0.2 in average.
