  Dirac has predicted that the $g$ factor of an electron is strictly equal to 2
in the framework of relativistic quantum mechanics. However, later physicists
have found that this factor can be slightly deviated from 2 (i.e., the problem
of anomalous magnetic moments of leptons) when they consider quantum filed
theory. This fact thus renders the $g$ factors of free leptons serving as
precision tests for quantum electrodynamics, the standard model and beyond. In
this work, we re-examine the problem of $g$ factor within the framework of
relativistic quantum mechanics. We propose a possible mechanism called the
``electron-braidon mixing'', such that the $g$ factor of an electron can be
visibly altered. Our results are hopeful to be verified in experiments and also
shed new light to the problem of the anomalous magnetic moments of leptons.
