  We study quantum corrections to an extra dimensional Yukawa theory where a
single flat extra spatial dimension is compactified on an interval. At a UV
scale this theory can be made equivalent to a 5D theory with a bulk
four-fermion operator by choosing appropriate boundary conditions for the
running of the low-energy theory. Using the fermion bubble approximation we
find vacuum solutions which break the chiral symmetries that arise from
compactification. Of particular interest are the form of brane localized terms
which arise from fermion loops. For example, quadratically divergent
contributions to the scalar mass are absent at one loop due to a remnant of 5D
Lorentz invariance that is only lost after introducing fermion bulk masses. The
model is interpreted as an implementation of top condensation in extra
dimensions with an automatic seesaw mechanism.
