s/l "endotracheal tube 70 at 24 of the teeth" - ConfusedinAustin

Here's an excerpt to put the confusing line in context:

"The airway was initially assessed by Dr. _____, who stated that it was not in the trachea.  After an airway was placed, endotracheal tube 70 at 24 of the teeth was placed.  He visualized it going through the trachea."

I tried reading up on endotracheal tube placement procedures and whatnot to try to figure this out (seems like too many things are being placed in addition to the teeth thing), but perhaps my brain is too addled with too much information to hear what the physician is saying.

Please pardon any gaffes I've made in my post, as this is my first time posting here. ("Long-time listener, first-time caller....")

Many, many thanks!