Stable,dynamic,elastic miniplate osteosynthesis in cranio-maxillofacial surgery:evolution of concepts,biomechanical study and applications

An osteosynthesis of the mandible should be called stable when this type of treatment does not need to be supported by intermaxillary fixation,without disturbing the healing process.In that intention,many techniques of osteosynthesis based on different concepts were proposed during the last century.A classification of these concepts was formulated.The adaptive osteosynthesis which is pragmatically i.e.empirical,wherein the goal is immobilizing the fracture by bringing the fragments together and fixing them with rigid screwed plates.The rigid compressive osteosynthesis which is an extrapolation of the ideas of Lane proposed in 1912.The stable dynamic elastic osteosynthesis whose principles,equipment and technique as their applications were developed exclusively through biomechanical studies.The basic principle was the recovery of mobility by neutralization of detrimental distraction stresses,and reestablishment of favorable compressive stresses providing dynamic physiological stimulations.The biomechanical characteristics of the plates and the screws made possible the use of the fixation of all types of fractures or orthognathic procedures in mandibular surgery.With the application of mini or microplates in other facial bones and the skull,the art of fracture treatment and of reconstructive surgery of the craniomaxillofacial skeleton,including orthognathic and reconstructive surgery with or without bone grafting,has profoundly changed.At the present time,metal plates are sometimes superseded by resorbable plates and screws.Nevertheless,the fundamental biomechanical principles of osteosynthesis and bone healing remain unchanged.

An osteosynthesis of the mandible should be called stable when this type of treatment does not need to be supported by intermaxillary fixation, without disturbing the healing process. In that intention, many techniques of osteosynthesis based on different concepts were proposed during the last century. A classification of these concepts was formulated. The adaptive osteosynthesis which is pragmatically i.e. empirical, wherein the goal is immobilizing the fracture by bringing the fragments together and fixing them with rigid screwed plates. The rigid compressive osteosynthesis which is an extrapolation of the ideas of Lane proposed in 1912. The stable dynamic elastic osteosynthesis whose principles, equipment and technique as their applications were developed exclusively through biomeehanical studies. The basic principle was the recovery of mobility by neutralization of detrimental distraction stresses, and reestablishment of favorable compressive stresses providing dynamic physiological stimulations. The biomechanical characteristics of the plates and the screws made possible the use of the fixation of all types of fractures or orthognathic procedures in mandibular surgery. With the application of mini or microplates in other facial bones and the skull, the art of fracture treatment and of reconstructive surgery of the craniomaxillofacial skeleton, including orthognathic and reconstructive surgery with or without bone grafting, has profoundly changed. At the present time, metal plates are sometimes superseded by resorbable plates and screws. Nevertheless, the fundamental biomechanical principles of osteosynthesis and bone healing remain unchanged.