Forces Causing One-Millimeter Displacement of Bone Fragments of Condylar Base Fractures of the Mandible after Fixation by All Available Plate Designs

Abstract

Background: There has been no direct comparison of all existing plates dedicated for fracture osteosynthesis of mandibular condyle base until now. The aim of the study was to test mechanically all available designs of titanium plates on the market on polyurethane mandibles using an individually designed clamping system. Methods: Forces required for a 1 mm displacement of fixed fracture and incidents of screw loosening were recorded. Results indicated the best mechanical plates among all existing designs available. Results: It has occured that some of osseofixation plates should not be used any more, whereas some shape of the single plates are similar shape to two single plates shape are regarded as the best osseofixation method for condyle base fracture. Conclusion: General observation is the bigger plate and more screws, the better rigid stable osteosynthesis of mandibular condyle base. 4 plates of current designs of total 30 tested series can be recommended for open rigid internal fixation of fractures of the base of the mandibular condyle. The rest of 26 existing plates should not be used in condylar base fractures.

Mechanical Evaluation of Titanium Plates for Osteoesynthesis High Neck Condylar Fracture of Mandible

“…[4][5][6][7][8][9][10][11][12][13][14] Recently, 30 plates design have been compared in basal condylar fracture osseosynthesis. [22] Four plates' designs among 30 have been concluded as those that could withstand screw pull-out and displacing force.…”

“…Among all available for rigid fixation of condylar process of mandible plates, only four designs can be applied for high-neck condylar fixation due to anatomical structure of head of condylar process. Some of the other plates [22] could be used, however, manual bending would be necesary and it would change physical properties the osteosynthesis. That is why only four plates were included into this study ( Figure 2, Table 1).…”

“…According to the previous study [22] the Plate Design Factor was calculated: Plate Design Factor = 0.850954 x Height (mm) + 0.846751 × Width (mm)+ 0.936732 × Plate (mm 2 ) + 0.848039 × Total fixing screws.…”

“…According to the previous study [22] the Plate Design Factor was calculated: Plate Design Factor = 0.850954 x Height (mm) + 0.846751 × Width (mm)+ 0.936732 × Plate (mm 2 ) + 0.848039 × Total fixing screws. Irreversible change of shape was described as the start point that the load-displacement relationship became non-linear.…”

“…In the paper, double plates (plate design 20] has been proved as osseosynthesis material thanks to which excellent stability might be achieved. These plates have been well known [22,33] and derived from combination of biomechanical plates location and up to 4-screw fixation in the proximal fragment i.e. upper fragment [34].…”