We restrict our computation in the mean field approximation which could lead to a clear critical behavior. analyze scaling behavior with different shape of interaction kernel by considering dressed-gluon models. The exponent we obtained is consistent that $3D$ $\textrm{O}(4)$ universality class. size region up $m_{0}^{} \le 2\sim 4\;$MeV this sets naturally an upper bound since fluctuations bey...