Which of 51 Plate Designs Can Most Stably Fixate the Fragments in a Fracture of the Mandibular Condyle Base?

Abstract

In the surgical treatment of the most common fracture of the mandible, which is a fracture of the condylar base, a great choice of different plate shapes is observed. The aim of this study was to determine which shape gives the greatest fixation stiffness. To ensure homogeneity in comparison, tests were performed on polyurethane models divided at the level of the condylar base fracture and each were fixed with 51 plates. The plates were cut from a 1 mm thick grade 23 titanium sheet. The models were then loaded and the force required for 1 mm of fracture displacement was recorded. It was noted that in addition to osteosynthesis from two simple plates, there were also two dedicated single plates with similar rigidity. Among the large number of described designs of plates, there is considerable variation in terms of the stability of the fixation performed with them. The proposed Mechanical Excellence Factor allows a pre-evaluation of the expected rigidity of fixation with a given plate shape without the need for a loading experiment. The authors expect this to be helpful for surgeons in the application of relevant plates, as well for inventors of new plates for the osteosynthesis of basal fractures in mandibular condyle.

Which of the 37 Plates Is the Most Mechanically Appropriate for a Low-Neck Fracture of the Mandibular Condyle? A Strength Testing

“…Evaluation of the influence of oval holes showed that they have an adverse effect on the rigidity of the fixation, which can be seen in the delta plate (plate 2 vs. plate 37) or XCP (plate 19 vs. plate 40). The best plates are those fixed with seven, eight, or nine screws [21].…”

“…These polyurethane mandibular models were standardized and featured a uniform internal structure, closely mimicking the properties of human spongy bone. Polyurethane mandibles from Sawbones (Vashon, WA, USA; density 0.16 g/cc, compression modulus 58 Mpa) served as the testing models [9,[17][18][19][20][21].…”

“…The maximum force required to displace the condyle by 1 mm in the entire study group was 15.23 ± 3.53 N. The PDF (Plate Desing Factor) [23] and MEF (Mechanical Excellence Facto previously proposed by the authors were calculated for each plate (Table 1). PD coefficient, for which four plate variables are used to calculate it: Height, Width The PDF (Plate Desing Factor) [23] and MEF (Mechanical Excellence Factor) [21] previously proposed by the authors were calculated for each plate (Table 1). PDF is a coefficient, for which four plate variables are used to calculate it: Height, Width, Plate surface area, and Total fixing screws number.…”

Optimal Plate Choice for High-Neck Mandibular Condyle Fracture: A Mechanistic Analysis of 16 Options

“…These models are made of a material that mimics the properties of spongy bone in humans. Specifically, for strength assessments, we employed polyurethane mandibles (Sawbones, Vashon, WA, USA: density 0.16 g/cc, compression modulus 58 MPa) [13][14][15][16][17].…”

“…The PDF (Plate Desing Factor) [19] and MEF (Mechanical Excellence Factor) [17] already recommended by the authors were determined for each plate (Table 1). The PDF (Plate Desing Factor) [19] and MEF (Mechanical Excellence Factor) [17] already recommended by the authors were determined for each plate (Table 1).…”