I have burnt my forehead with curler iron and how long will it take to go back to normal . now i have a open wound?

Curling irons are very hot (as you know), and may cause severe burns. The most at-risk areas are those with thin skin and little fat padding (like the forehead). If the "wound" part does not hurt when touched, it may be a 3rd-degree burn and might require a skin graft to close and heal. It is important that your Dr or a Plastic Surgeon examine the wound to guide you best.