Christophe Meyer

The anatomical feature of the ascending branches of the mandible is of great importance for the osteosynthesis of fractures of the condylar region. In the frontal plane, the ascending branch has a more or less pronounced S-shape, and the amount of spongy bone lying between the inner and outer cortices is very variable (Härle, 1980; Schneider et al., 2005), depending on the age and gender of the patient and on anatomical variation among individuals. This may sometimes hinder the insertion of an intramedullar axial lag screw. At the level of a typical condylar neck fracture, which is at the level of the sigmoid notch, cross-sections show that the thickest cortical bone is located dorsally and laterally at the outer cortex of the condylar neck (Härle, 1980; Tillmann et al., 1983; Krenkel, 1994). Ventrally, the outer and inner cortices merge in a thin blade-shaped ridge at the level of the sigmoid notch. This may explain why, historically, osteosynthesis plates have been placed vertically in the axis of the condylar neck.