Don't know but DT sure increases sensation; especially when mixed with other teasing techniques.  BTW, I am a willing volunteer for any provider who wants to improve their technique.  LOL

DT exposes the throat to much more vigorous activity then a simple blow job,  When a lady gives a bj the penis typically stays in the mouth which is protected by the teeth and the hard palate.  This can not be said when deep throating,  a provider opens her throat allowing the penis to reach soft tissues.  Theses tissue are not protected as well as those of the mouth and are therefore more subject to injury.  If an injury occurs in the throat a increased risk of infection would be no different then a fresh cut in the mouth or bleeding gums,  It's is important to remember that deep throating should be done safely for just such reasons.
Doc