The extra contribution − − i [ n ^ ^ × × ∂ ∂ n ^ ^ ] in the light-front angular momentum operator increases the number of spin components in the light-front wave function. For example, the non-relativistic deuteron wave function is determined by two components ( S - and D -waves). Whereas, the relativistic light-front deuteron wave function is determined by six components. These components were calculated in the one-boson exchange model.