What can be done If three of my top teeth are not fitting into my trays properly for the last 5 sets of trays?

there is a gap between the bottom of the teeth and the tray even with the use of chewies and acceledent, what can be done? Should attachments be put on those teeth? New trays made up? Im on tray 9 and have had this problem the last five sets of my trays. My orthodontist doesn't seem concerned as he says bands can be used later but I am worried that that means there will be more bands at the front of my teeth. Currently Initial treatment of 30 trays should be completed by end of sept.

No doctor answers yet