I have done over 30 dental missions in many countries and was in practice for 26 years. There is zero reason to use a face shield when you are not performing aerosolizing procedures and a plastic shield does not help with odors at all. 

 i have studied medicine and most of my friends are dentists.

no one would ever wear a dog muzzler.
some wear a face shield, some protect their eyes.
i was in third world countries. they do all kind of shocking nonsense 

 You have not studied medicine or have
dentist friends in the US then. It is against OSHA requirements to work on patients without a mask or protective eyewear. Offices can and have been shut down by violating these standards. 

 usa is occupied by satanists
i do not care.
also i do not care what you think or in what cult you are

you are an imposter 

 usa is a third world country
masses of unemployed homless people live in every city everywhere
it does not have any public transport
the infrastructure is the worst in the world

why should i go there?