Hi, Thanks for writing in. The nerve supply to the face is through divisions of the same nerve. Therefore getting injury in one area can cause tingling in another part. That is why the injury near the temple can be cause for tingling in forehead. The nerves originate in the brain and divide in to 3 branches, they supply the skin over face and forehead region. An injury in one region will cause build up of chemical transmitters which carry information on pain and strange sensations like numbness and tingling. When the wound is healing and the nerves also heal then the tingling like sensations appear. Since the nerve branches come together in the brain therefore the sensations from one nerve branch might appear as coming from another branch.