Final answer:
To avoid brow ptosis when injecting botox into the frontalis, you should inject at least 1-2 cm above the brow.
Step-by-step explanation:
When injecting botox into the frontalis muscle, it is important to consider the anatomy to avoid brow ptosis. To prevent brow ptosis, the injections should be placed at least 1-2 cm above the brow. Injecting too low can lead to relaxation of the muscles that elevates the brow, resulting in brow ptosis.
By injecting at a higher point on the frontalis muscle, the muscle can still contract and lift the brow without causing it to droop. This allows for a more natural appearance and reduces the risk of brow ptosis.