SORG History

In 1989, Maxime Champy (Strasbourg, France), Dieter Pape, Klaus Gerlach (Cologne, Germany) and Leen de Zeeuw (Tuttlingen, Germany) founded the now reputable Strasbourg Osteosynthesis Research Group to advocate a new rationale in the treatment of fractures of the mandible. SORG promoted stable dynamic osteosynthesis using so-called miniplates positioned along the ideal osteosynthesis line.

Prior to this, fixation of mandibular fractures was based on the empirical concept of the absolute need for a rigid osteosynthesis with a rigid plate. Spiessl and Luhr had emphasized the value of axial compression. The difficulty of such treatment and the requirement for a cutaneous approach (and associated risk of facial nerve injury and scarring) presented problems for both patients and surgeons.  In addition, the difficulty in adapting a rigid plate to the requirements of the occlusion became clear.

The first truly scientific and biomechanical study of fractured mandible treatment developed from research was carried out by M. Champy from 1971 to 1973 at the Faculty of Medicine of Strasbourg in association with the ENSAIS (High School of Arts and Industry). The new principles established by this study were neutralization of traction forces, reestablishment of normal compression forces, and consequent neutralization of shearing and torsion forces.                                                                                                                                                    

The various stages of the study were:

• Measurement of the bite forces that induces strain in the mandibular bone
• Measurement of the thickness of the cortical bone
• Photoelastic stress analysis of an acrylic bar determining harmful traction strains along the upper border and compression strains on the lower border
• Confirmation that fixation on the upper border neutralizes traction stains and that within the  mandible, the dental roots and adjacent cortical bone make that zone unsuitable for fixation, but below the apex of the teeth, a narrow zone where traction strains exist  is still useful
• Resistance of the cortical bone to tearing stresses                            
• Precise determination of the position of the teeth apices regarding the alveolar canal and the cortical bone     
• Analysis of the of the traction strains beneath the dental roots
• Computer Assisted Reckoning of the strains below teeth (based on the Theory of the Right Beam and the Theory of the Curved Beam by Galileo, Leonardo da Vinci, Bernoully)
• Description of the ideal line of osteosynthesis       
• Demonstration that small, solid and shapeable plates are able to resist the strains existing in the mandible, and are in conformity with Young’s Modulus, anatomical, biological, mechanical and surgical requirements              
• Confirmation that perfectly appropriated screws comply with the mechanical characteristics of the cortical bone
• The holographic analysis of a synthesized model of the mandible confirming axial micro motion generates mechanical stimulations between the contact surfaces of the model in keeping with physiological norms, further confirmed by post-operative measurements using extensometric gauges.   

A new rationale in the surgical treatment of mandibular fractures was derived from these biomechanical studies, an intraoral approach with specific plates providing stable fixation on the ideal line of osteosynthesis. The correct naming of this technique is stable dynamic miniplate osteosynthesis.   

Later Champy demonstrated that bone healing of the mandible is periosteal and not a primary bone healing providing further evidence for less invasive intraoral approaches.

The use of small adaptable plates is now common practice and routinely used in traumatology, orthognathic and reconstructive mandibular, facial and cranial bone surgery.

SORG has developed into a well-established increasing community of respected CMF surgeons, active in all aspects of research and education.  Above all, they are a group of esteemed presenters teaching within SORG Academy in which Maxime Champy’s principles of miniplate osteosynthesis are still one of the cornerstones of evidence-based practice.