Indentations after botox. Is this normal?

The dent in your forehead is not likely to be due to the Botox itself but rather due to the effect of Botox on the underlying muscles. Indentations may occur because of some muscle pulling, but they most often occur because of loss of tissue.

Depending on the dosage that was used for Botox, meaning if the muscle was frozen versus there is still some minimal movement in there can affect how the skin overlays the muscle overtime. In my experience, patients who have been getting higher doses of Botox with no movement in their muscle over time will see thinning of their skin to a greater degree and less resilience in the skin. I typically will reduce the dose to allow minimal movement and work on improving and restoring skin texture, with laser/peels/or collagen bio stimulators.

Thank you for sharing your questions. As we age, theses lines do persist longer upon awakening and can become permanent. They are not related to your getting Botox. You can try sleeping on your back. There are pillows which keep your head straight.
Good luck!