Suppose that a full-face Sculptra session is planned but during the session it becomes apparent that the patient will need more than the maximum number of vials (i.e. 3) that can safely be applied in 1 session. So the doctor basically runs out of Sculptra and says to come back in some weeks (i.e. 2wks) to finish up the untreated area. Right side is 100% done, the other side is only 50% done. How does the doctor know where to resume without overfilling?