4 KudoZ points awarded for this answer. Comment: "I THOUGHT I'd asked a similar question to this - but about freipräparieren! Thanks to Armaat for spotting that! Well, this time, just to be consistent, I'm going to use ... expose! In fact, looking back at the freipräparieren question, I have a feeling I maybe should have used expose there as well, although the context was different (knee surgery as opposed to sinus floor surgery). "Exposed" does seem a little better than "dissected", especially if the removal of the bone lid is temporary. It also makes better sense in a surgical context (which is why I think I maybe should have used it for freipräparieren as well). Both auspräparieren and freipräparieren are singularly horrible words, but hopefully, I've finally come closer to solving them for good! So thanks and well done Gisela, but thanks also to the others who also offered a suggestion."