  While many properties of the vector charmonium first excitations are yet to
be measured, enhancements at unexpected energies are intriguing, alias the $Y$
states. In order to understand the naturally unquenched mesonic line-shapes,
the influence of the most relevant hadronic decay channels must be taken into
account. Within an unitary effective approach we present results where mesonic
loops are included in an equivalent manner to coupled-channels. We show results
for the $\psi(3770)$ and $\psi(4160)$ systems, where we find the
nonperturbative effects of dynamical generation of poles and line-shape
distortion.
