Can Botox help to give eyebrows more of an arched shape?

Thank you for your question. An in person consultation would be beneficial to answer your question accurately. There are injection techniques that can lift the arc of your eyebrow. Schedule a consultation with an expert injector to discuss your options. Best,  

Without photos, I can only comment in the most general terms. The short answer to your question is yes, a small droplet of Botox (or other
neuromodulator, such as Dysport or Xeomin) placed at
the tail of each eyebrow may promote  a  the lift to the outer third of the eyebrows. A longer answer would include the following: if there is loss of volume
within the region immediately below the eyebrows, leading to lack of
projection and support, and to early descent of the eyebrows volumizing fillers could prove additionally helpful. A simple
procedure, known as The Nonsurgical 3D Vectoring Browlift might be worth
discussing with your aesthetic physician if this is indeed the case. The latter procedure takes
about ten to fifteen minutes to perform and requires the use of a
volumizing filler to help to restore support and projection to the
region immediately below the outer (lateral) third of the eyebrows and
to provide lift and a more youthful upward and outward flare to this
significant aesthetic unit.