Comparative study of skeletal stability between bicortical resorbable and titanium screw fixation after sagittal split ramus osteotomy for mandibular prognathism.
BACKGROUND
Resorbable screw fixation for orthognathic surgery is widely used in oral and maxillofacial surgery and has several advantages. However, surgeons are concerned about using resorbable screws in orthognathic surgery because of possible postoperative complications such as relapse, screw fracture, and infection. The purpose of this study was to evaluate the skeletal stability of bicortical resorbable screw fixation after sagittal split ramus osteotomies for mandibular prognathism.


METHODS
This study included 25 patients who underwent mandibular setback surgery fixed with resorbable screws after sagittal split osteotomy at the Department of Oral and Maxillofacial Surgery at Seoul National University Dental Hospital. Five resorbable screws (Inion CPS(®), Inion Ltd., Finland) were applied bicortically at each osteotomy site via a transbuccal approach. No rigid intermaxillary fixation was applied on the first postoperative day. Passive mouth opening exercises were allowed, using two light, rubber elastics for guidance. The control group was 25 patients fixed with four titanium screws. The follow-up period was 12-22 months (mean 17.8 months). Postoperative skeletal changes on lateral cephalometric radiographs were analyzed and compared between the two groups preoperatively, immediately postoperatively, and 6 months postoperatively.


RESULTS
The average setback was 6.9 mm and no major intraoperative complications occurred. One patient experienced infection immediately after surgery that was controlled uneventfully. The data did not demonstrate any significant difference in postoperative skeletal stability between the two groups. Differences between the immediate postoperative state and 6 months after surgery were not significant. In earlier cases, especially for patients with severe mandibular prognathism, immediate postoperative elastic traction was needed for stable occlusal guidance.


CONCLUSIONS
The results of this study indicate that bicortical resorbable screws offer a clinically stable outcome for the fixation of mandibular sagittal split osteotomies in mandibular prognathism. However the resorbable screws showed less stable results vertically than the titanium screws.
Department of Oral and Maxillofacial Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. jypaeng@gmail.com
Jun-Young
JY
Paeng
Jongrak
J
Hong
Chang-Soo
CS
Kim
Myung-Jin
MJ
Kim
D020341:Absorbable Implants; D000293:Adolescent; D000328:Adult; D001672:Biocompatible Materials / Q000737:chemistry; D001863:Bone Screws; D002508:Cephalometry / Q000379:methods; D004868:Equipment Failure; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008313:Malocclusion, Angle Class III / Q000473:pathology / Q000601:surgery; D008334:Mandible / Q000473:pathology / Q000601:surgery*; D008437:Maxilla / Q000473:pathology; D009295:Nasal Bone / Q000473:pathology; D009967:Orthodontic Appliances; D056948:Orthognathic Surgical Procedures / Q000295:instrumentation* / Q000379:methods; D059229:Osteotomy, Sagittal Split Ramus / Q000295:instrumentation* / Q000379:methods; D011378:Prognathism / Q000601:surgery*; D012658:Sella Turcica / Q000473:pathology; D013530:Surgical Wound Infection / Q000209:etiology; D014025:Titanium / Q000737:chemistry; D016896:Treatment Outcome; D014716:Vertical Dimension; D055815:Young Adult
D001672:Biocompatible Materials; D014025:Titanium