[Basics of esthetic and functional cephalometric analysis of the profile]

We report a new cephalometric method for profile analysis, which uses strictly exobasicranial landmarks: 13 anatomic points, 9 bone points and 4 skin points. The analysis is based on phylogenetic, ontogenetic, anatomic and biomechanical data. Phylogenetic analysis reveals that the occipital plate belongs more to the cranial vault than the base of the skull. Embryology shows that on the midline the facial skull base ends at the spheno-occipital suture and that the overall skull base ends at the basion. The pre-maxillary fuses rapidly to the maxillary, while the pterygoid processes, which belong to the face and not the skull base, fusion very rapidly to the skull base. Revisiting the anatomy of the facial skull base shows that it is prolonged posteriorly medially to meast the synostosic creast and latterally to the glenoid fossae. Further anatomic analysis shows that the dentate and muscular part of the superior level of the facial mass correspond to equivalent parts of the inferior mandibular level. The biomechanical analysis reveals that the anterior pillar passes through the pre-maxillary, ending on the supra-orbital border and the glabella and as such belongs to the face. The posterior pillar follows the pterygoid process ending in the sphenoid. The glabella and these two pillars are taken into account in this new analysis technique.