A biomechanical evaluation of mandibular condyle fracture plating techniques

Objectives: The purpose of this investigation was to evaluate the biomechanical behavior of various rigid internal fixation techniques for mandibular condylar process fractures. Materials and Methods: Synthetic mandible replicas (Synbone, Landquart, Switzerland) were used to evaluate a control, and four monocortical mandibular condyle plating techniques. Each group was subjected to linear loading in lateral to medial, medial to lateral and posterior to anterior directions by an Instron 1331 (Instron, Canton, MA) servohydraulic mechanical testing unit. Yield load, yield displacement, and stiffness were measured. In addition, each group was subjected to torsional loading using an Instron 8521 (Instron), Yield torque, yield rotation, and stiffness were measured. Five samples were tested for each group and method of loading (n = 100). Means and standard deviations were derived and compared for statistical significance using a I-way analysis variance (P < .05). Third-order polynomial best-fit curves were also created for each group to further evaluate and compare the mechanical behavior. Results: Statistically significant differences were noted between fixation groups for the different mechanical measures evaluated under the different conditions of linear loading. Statistically significant differences were noted between groups for yield rotation during torsional loading. Although different in magnitude, similar patterns of mechanical behavior were observed in the third-order polynomial best-fit curves for lateral to medial loading, medial to lateral loading and torsional loading. For posterior to anterior loading, different patterns of mechanical behavior were noted between the experimental groups, but similar behavior was noted between the control and mini dynamic compression plate Conclusions: While differences were noted between each of the fixation systems in their abilities to resist loads under the conditions tested, the mini dynamic compression plate provided the most favorable mechanical behavior. Based on the presumed clinical parameters, we can suggest that none of the systems evaluated were ideal for the treatment of mandibular condyle fractures, but that the mini dynamic compression plate is the closest to an effective means for reconstruction. (C) 2002 American Association of Oral and Maxillofacial Surgeons.