  The formation of hole pairs in the planar t-J model is studied in the
presence of independent {\it dynamic} vibrations of the in-plane oxygen atoms.
In-plane (breathing modes) and out-of-plane (buckling modes) displacements are
considered. We find strong evidences in favor of a stabilization of the two
hole bound pair by out-of-plane vibrations of the in-plane oxygens. On the
contrary, the breathing modes weaken the binding energy of the hole pair. These
results are discussed in the context of the superconducting cuprates.
