Hi there,
i would like to share my experience on flying to london with headgear attached.
First of all, there is no metal detection sound when passing the metal detector.
on the airport everything went good, all the people were friendly, no one stared at me and no one told me to remove headgear for some kind of special control.
Even in the plane everything went unspectacular and so i decided to wear it all the time during my stay in London.
my advice for anyone who is willing to try that too. Do it - it´s not a big deal. 

Well thats funny. I have been doing this twice now.
ones on a flight to Amsterdam, and ones to Paris.

I noticed the same nobody mind.
Only problem with me is that i cannot really talk so i had to write on my phone i wanted a beer in the plane

hi blue_bio
i'm wearing metal brackets on upper and lower jaw ... and as i said a headgear with a blue cervical strap !

now a few weeks later i look forward planning the next trip with headgear. But at the moment there´s no
time unfortunately