How Long Does It Take for (High Doses) Botox Can Completely Gone?

I am not aware of the effect of Botox lasting longer than six months in terms of muscular contraction. botox used for cosmetic uses will not persist after six months and usually around 12 to 16 weeks.  Some patients retain their relaxation state as they learn not to make the expressions of muscular contraction. Treatment of hyperhidrosis, or increased sweating, also disappears around six months at the latest. 

However, there is not much information in the literature as to the muscle mass of those muscles treated with larger doses than used in cosmetic treatment, to reduce the size of enlarged cheeks. If the muscles atrophy,  how long does it take for the muscle to become larger after the Botox wears off? the muscle is expected to regain its size with renewed activity but the length of time may vary from individual to individual.

The effects of Botox typically last anywhere from 3 to 4 months. If you had treatment over a year and a half ago, the Botox is definitely gone. It's unclear what you mean by high doses, but if you were having treatment for facial contouring (injections to your masseter muscles), a one-time treatment won't change the shape of your face indefinitely.

There is individual variation, but you can expect that most of the effects will be gone between 4-6 months.  I have had some patients that last a bit over 6 months, but usually they are established patients that have had Botox injections for many years.  Since you noted that the injections were performed a year and a half ago, you should be back to your normal muscle activity.