Looking to solve issue where temples tend to bulge when I chew or when jaw is lowered. Temporalis Hypertrophy? Botox? (Photo)

From the photos and description that you have provided it appears that you indeed have temporalis muscle hyperactivity and hypertrophy and what sounds like masseter muscle hypertrophy.  Botox (and other neuromodulators) are very effective in treating these issues.  The solution is only temporary however, relaxing these muscles even temporarily may have a long lasting effect on the size of the muscle over time.

Thankyou for your question .It would be useful to know if this is associated with masseter hypertrophy ie do you grind your teeth or have a square jaw? If this is the case I would start with botox treatment to the masseters  as bilateral  temple muscle hypertrophy is usually in reaction to  increased chewing  muscle action. If you have temporalis hypertrophy in isolation I would be looking for a cause in the area of the skull/jaw/dentition . Temporalis muscle can be injected but this would be off label use

Botox is a fabulous way to freeze the muscle on a temporary basis and that is the way that it works to reduce wrinkles. I use a great deal of Botox for the masseter muscle to freeze the muscle for slimming the face as well.  Please consult an expert in Botox to assess the situation.  Best, Dr. Green