Before laryngeal theory was widely accepted, how did Indo-Europeanists explain stuff like what we now recognize as the Greek triple reflex?

Without out it, you get stuff like some Greek words having random vowels attached missing in other branches (e.g. Greek ὀδών (odon) versus Latin dens "tooth"), without any obvious correspondences. Nowadays we know them to be reflexes of PIE *h₃dónts, but among past linguists who didn't accept laryngeal theory, how did they explain it?