How to make a 3d-printed fursuit head base wearable

First I attach the lower jaw to the head base with hand-molded pegs (made with Polymorph or Blackmorph). Then I set the distance between my face and the front of the mask by gluing foam sheets in the head base (in front of my forehead). With this distance set, I can add a strip of webbing in the lower jaw that will push against my chin.