Matrix WaveTM System for Mandibulo-Maxillary-Fixation – Just Another Variation on the MMF Theme? – Part II: In Context to Self-Made Hybrid Erich Arch Bars and Commercial Hybrid MMF Systems – Literature Review and Analysis of Design Features

Study design: Trends in utilization of MMF types are shifting nowadays from tooth-borne devices over specialized screws to hybrid MMF devices. Hybrid MMF devices come in self-made Erich arch bar modifications and commercial hybrid MMF systems (CHMMFSs). Objective: Survey on available technical/clinical data. Hypothetically the risk of tooth root damage by transalveolar screws is diminished by a targeting function of the screw holes/slots. Methods: Literature review; graphic displays to disclose parallels and dissimilarities of design and functionality with an in-depth look at the targeting properties. Results: Self-made hybrid arch bars have limitations to meet low-risk interradicular screw insertion sites. Technical/clinical information on CHMMFSs is unevenly distributed in favor of the SMARTLock System: positive outcome variables are increased speed of application/removal, possibility to eliminate wiring and stick injuries, screw fixation with standoff of the embodiment along the attached gingiva. Inferred from the SMARTLock System all four CHMMFs possess potential to effectively prevent tooth root injuries but are subject to their design features and targeting with the screw receiving holes. The height profile and geometry shape of a CHMMFS may restrict 3-dimensional spatial orientation and reach during placement. To bridge between interradicular spaces and tooth equators, where hooks or cleats for intermaxillary cerclages should be ideally positioned under biomechanical aspects, can be problematic. The movability of their screw receiving holes according to all six degrees of freedom, differs. Conclusion: CHMMFSs allow simple immobilization of facial fractures involving dental occlusion. The performance to avoid tooth root damage is a matter of design subtleties.