Origin of the calvaria and its sutures
D. W. Smith and G. Tondury
Studies indicate that the dura is the guiding tissue in the morphogenesis
of the calvaria and its major sutures, which develop from ten to 16 weeks
of fetal life. Overlying the central zones between the dural reflections
ossification takes place, whereas none occurs over the reflections of dura,
these being the suture sites. Strong evidence for the role of the dural
reflections in determining the suture sites was obtained from the
evaluation of instances of major brain malformations that must have
antedated calvarial morphogenesis. These included holoprosencephaly,
craniopagus, and dicephaly. The altered dural reflections, which related to
the aberrant form of the brain, coincided with the position of the unusual
sutures. Furthermore, a lack of a dural reflection was accompanied by a
lack of development of a suture at that site.
