Should the treatment cycle for Botox be varied even for the same area?

If you plan to get repeated Botox injections, I believe the follow-up care schedule is just as important as the effect of the first treatment.

Since the degree of muscle usage and the duration of the effects can vary depending on the body part, it seems difficult to set a uniform schedule.

I would like to know how the recommended treatment interval varies by body part and what criteria are used to determine the timing for re-treatment.