Sorry I've not been able to unearth that answer rocky, but have learnt the following useless facts whilst looking .... it takes 17 muscles to smile, 42 muscles to frown and the tongue is apparently the strongest muscle in the human body !! .......... So it looks as if it's much less of an effort to be happy!!! ;0)
There are four pairs of intrinsic muscle within the tongue that help to control shape.
There are several extrinsic muscles:
styloglossus : which is the smallest and shortest and helps to bring the tongue back into the mouth and to raise it
genioglossus : is the main muscle of the tongue and helps to make it concave from side to side
hyoglossus which brings tongue back into the mouth and depresses it.
There are also palatoglossus and pharyngoglossus muscles..
Got to twenty -five (without the intrinsic and extrinsic tongue muscles), then lost the will.
Best muscle so far ..Palatopharyngeus.
Key word Deglutition.
Also number will probably be different for liquids and solids.
Sorry rocky999, no definitive answer yet.