Fig. 4.

Spatial requirements of tooth crypts and scaling of superior transverse torus during ontogeny. (a) Superior transverse torus length plotted against mandibular length for the ontogenetic sample (r= 0.91, P< 0.01). Specimens with unerupted mandibular incisors are plotted in grey; specimens with erupted mandibular incisors are plotted in black. (b) Parasagittal CT scans of the mandibular symphysis during ontogeny. The specimens are of increasing age from left to right. On the left, the crypt of the developing permanent central incisor can be seen occupying the majority of the superior transverse torus. This relationship is maintained as both structures increase in size with age. As the permanent incisor erupts it occupies less of the torus, which then begins to fill with trabecular bone.