The modified Michelet's (1973) technique of mandibular osteosynthesis, which consists of monocortical juxta-alveolar and sub-apical osteosynthesis, without compression and without inter-maxillary fixation, is described. This technique can be used in many types of mandibular fracture, single or multiple, associated or isolated, except in the case of a fracture of the condylar neck and in the presence of pre-existing infection. Infected fractures are treated by orthopaedic methods. Materials used (plates and screws) and particulars of the method have been tested by multi-disciplinary experimentation, particularly by anatomical verification and biomechanical studies. The ideal line of osteosynthesis is described. For the author, this technique is a routine treatment of any type of mandibular fracture.