Reconstruction accuracy of four different angular-stable mandibular reconstruction plate systems. Results of an in-vitro study.

Objectives: For mandibular reconstruction after continuity resection locking reconstruction plates are mostly used. Aim of the study was the investigation of reconstruction accuracy (RA) of 4 different mandibular reconstruction plate systems. Methods: The systems (1) Medartis Modus Reco 2.5, (2) Synthes Compact 2.4 UniLock, (3) Synthes MatrixMANDIBLE Recon 2.4 and (4) Stryker Leibinger Universal Mandible Recon were compared. Per system 10 mandibular models were provided. Each model was marked with 4 measuring points (MP) on both sides of the condyles and mandibular rami. For evaluation of the RA the distances between the 4 MP were measured before and after the simulation of the reconstruction. Results: The absolute values of system (1) showed with 0.78mm the largest deviation from the initial value. The other systems showed nearly identical deviations ((2)=0.57mm, (3)=0.48mm, (4)=0.52mm). The difference between system (1) and the others is significant. Between the other systems there are no significant differences. Concerning the signed values, system (2) showed a distance reduction of -0.57mm, which indicates a narrowing between the rami and condyles. The other systems showed an increase of the distances ((1)=+0.42mm, (3)=+0.27mm, (4)=+0.40mm), which implies an enlargement in the rami- and condyle region. Only the difference between system (2) and the others is significant. Conclusion: The tested systems are showing differences concerning their reconstruction accuracy, which are partially statistically significant. However, with median deviations below 1 mm, it can be assumed, that all investigated systems have a high RA. No relevant differences can be expected concerning the clinical outcome. Keywords: mandibular reconstruction, mandibular reconstruction plates, mandibular models, rapid prototyping, mandible reconstruction plates, locking plates, mandibular reconstruction accuracy, angular-stable mandibular reconstruction plates