Near the top of my list is the 'head-tilt'. (The top spot being reserved for my favourite personal mantra ~"shut up, shut up, shut up..." yes, I talk to much and am trying to recite this internally BEFORE I actually say something ~ still working on it).
Allow me to demonstrate:
The grin stays the same, yet by merely changing the angle of my head I go from looking like I have an underbite (though portraying a strong, confident exterior ) to being able to mask it quite well (this gets you called 'cute' once in a blue moon, which is the risk one takes...)
I've noticed some references to how people are perceived on first meeting based purely on initial response. It's been found that irregardless of actual personality or other characteristics, those with underbites are frequently viewed as strong, stubborn, confident, even grouchy. I plead the 5th on all above.
Obviously this is not an exact science, and varies a bit between the sexes. (severity of the bite has to play in as well). I find interesting that chin implants are a frequent request of men visiting their plastic surgeons ~ it's felt they look weak and overlooked, and want a stronger look assuming it will serve them well with the ladies & in the workplace.
I'm not going to draw many conclusions on this and would have to think if you spend much time with a person the truth will out. However, on aesthetics I wouldn't mind a happy medium. Less bull dog, no pushover, just, just..... hmmm.
Sharing time, folks. What's in your bag?