Possible nerve injury after Browlift
Basically there is only one muscle that spans your total forehead -it is called the frontalis muscle and is innervated by the frontal branch of the facial nerve. This can get temporarily injured during fat transfer in the forehead and temples as well as after a brow lift. When this is injured, your ability to raise your eyebrows is diminished. Most of the time, fortunately, this fully recovers within 4 to 8 weeks. If it is completely cut, however, the situation is more serious. You should follow up with your surgeon to ascertain if this would be a possibility.
Forehead weakness after browlift
The frontal branch of the facial nerve controls the movement of the forehead muscle (frontalis). Sometimes this tiny, delicate nerve can be bruised or stretched during browlift. It is rarely cut, as the dissection is typically done with blunt instruments. Recovery can be slow -- sometimes it takes weeks or even months. But most patients recover function. Please stay in touch with your surgeon.
It sounds like the temporal branch of the facial nerve is not working now. This can occur after a temporal lift from damage to the nerve - either cutting it, stretching it, or even just a lot of swelling around the nerve. Until it comes back, the brow may appear low. It can take up to 6-12 months for it to come back completely.