Biomechanical Evaluation of Different Types of Rigid Internal Fixation Techniques for Subcondylar Fractures

• Published in: Journal of oral and maxillofacial surgery Vol. 64; no. 10; pp. 1510 - 1516
• Main Authors: Tominaga, Kazuhiro, Habu, Manabu, Khanal, Amit, Mimori, Yasuhiro, Yoshioka, Izumi, Fukuda, Jinichi
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.10.2006; Elsevier
• Subjects: Biological and medical sciences; Biomechanical Phenomena; Biomechanics. Biorheology; Bone Plates; Bone Screws; Dental Stress Analysis - methods; Dentistry; Equipment Design; Equipment Failure; Fracture Fixation, Internal - instrumentation; Fundamental and applied biological sciences. Psychology; Humans; Injuries of the limb. Injuries of the spine; Jaw Fixation Techniques - instrumentation; Lactic Acid; Mandibular Fractures - surgery; Medical sciences; Miniaturization; Models, Anatomic; Otorhinolaryngology. Stomatology; Polyesters; Polymers; Tissues, organs and organisms biophysics; Traumas. Diseases due to physical agents; Biomechanics; Evaluation; Internal fixation; Treatment; Stomatology; Surgery; Diseases of the osteoarticular system; Osteosynthesis; Fracture; Technique; Trauma
• ISSN: 0278-2391; 1531-5053
• DOI: 10.1016/j.joms.2006.03.038

The aim of this study was to evaluate the biomechanical stability of various internal fixation systems for subcondylar fractures. Eighteen identical synthetic mandibles were used. Left condylar processes were cut to mimic perpendicular subcondylar fracture and right sides were mimicked oblique subcondylar fracture. The fixation systems used included single 4-hole mini adaptation plate, double fixation with the same plates, single 4-hole mini dynamic compression plate (DCP), Eckelt lag screw system, Wurzburg lag screw plate system and double 4-hole biodegradable miniplates made of poly L-lactide (PLLA). In oblique fractures, one of the screws fixing plates was used bicortically through bone fragments. The loading vector simulated physiologic forces to the condyle on biting with servohydraulic testing machine until failure was reached. Load-displacement curve, maximum load for failure, and stiffness were measured. In perpendicular fracture, double adaptation plate showed the highest level of tolerance load followed by Eckelt lag and double PLLA plate. In stiffness, double adaptation plate and Eckelt lag screw showed higher level of stiffness, whereas double PLLA was almost at the same level of single DCP. In oblique fracture, double adaptation plate showed the highest strength. In this laboratory setting, double adaptation plates fixation proved to have superior biomechanical stability in both fracture conditions. Eckelt lag screw showed good stability in the perpendicular fracture, however, it was weak in the oblique fracture.