J. Verhulst et P. Onghena, CRANIAL SUTURE CLOSING IN HOMO-SAPIENS - EVIDENCE FOR CIRCASEPTENNIANPERIODICITY, Annals of human biology, 24(2), 1997, pp. 141-156
In their classical study on cranial suture closing, Todd and Lyon (192
4-25) expressed their belief that suture closure proceeds according to
some periodic pattern. Spectral analysis applied to their data corrob
orates the opinion of Todd and Lyon. Closure of the cranial sutures in
humans is pervaded by a circaseptennian periodicity. Pulses of accele
rated closure occur at intervals of about 7 years, and are separated b
y periods of relative quiescence.