Do Lack Of Forehead Movement And Soft Tissue Swelling Post Head Injury Need Medical Attention?
Doesn't look like a medical emergency.
Detailed Answer:
I read your question carefully and I understand your concern.
Judging from the description you provide I do not think that it is a medical emergency either.
First must precise that movement of facial muscles including forehead is done by facial nerve, the trigeminal nerve is responsible for sensation (which you say to be intact). I do not think this is a case of facial nerve involvement either because it would affect the lower part of the face.
There are two types of facial paresis central one due to brain involvement and peripheral due to damage to peripheral nerve itself. Clinically the difference is that the central one usually involves the lower two thirds of the face sparing the forehead (so the contrary of what you describe) while the peripheral one involves the whole half of the face. So in both scenarios lower part should be included.
For that reason I suggest you check again for movement in the lower part of the face, doing in front of the mirror actions like smiling and showing your teeth, puffing your cheeks etc in order to check for weakness in the lower part of your face. Only if there is weakness or asymmetry there can a facial palsy be suspected and should check in ED.
Otherwise if there is no such weakness, no other symptoms such as vision abnormalities, double vision, weakness of the limbs on one side, confusion or abnormal behavior noted by others I would say there is no indication of a traumatic brain damage which would constitute an emergency, probably issue is due to soft tissue damage and will subside with time.
I hope to have been of help.
You're welcome
Detailed Answer:
I hope you will be back to normal very soon.