A case of delayed differentiation and/or calcification, that is, devel
opment, followed by accelerated growth of the maxillary second premola
rs is presented. This condition was accompanied by the congenital abse
nce of mandibular second premolars even though maxillary and mandibula
r third molar germs were present. The case was followed over a five-ye
ar period. It seems that agenesis of any tooth might be found in conju
nction with delay in development of any other tooth. Moreover, full de
velopment of a tooth germ (followed by an accelerated growth) as well
as pathological changes may occur, despite an initial marked delay in
tooth development.