Sousaphones, mellophones, euphoniums, trumpets, French horns, trombones…how do the musicians playing these instruments in marching bands avoid having the heavy brass mouthpiece strike their teeth? Do they use special mouthpieces (smilar to boxers’ mouthpieces, for example)?
(And players of single- and double-reed woodwinds perhaps have to use special attachments so the angled mouthpiece doesn’t skewer the back of their throat…?") 
I played trombone in a marching band for a few years. Basically, the mouthpieces don’t hit teeth because there are lips in the way.
If you’re asking why the sudden movement of putting the horn to the lips doesn’t do damage, it’s because the mouth/mouthpiece area is pretty much at the center of rotation, so there’s not much velocity involved right there.
How do they play them without them hitting their teeth?
Carefully.
I spent four years in the high school marching band, playing trombone. Trombones are heavy and awkward. As TheNerd said, there are lips in the way, so there is a buffer. But if you stumble, you certainly can whack the mouthpiece into your teeth, and yes, it hurts.
A lot of it is balance, though, especially with a trombone. With a trombone, you don’t just hold it & press keys. You have to march, balance the instrument with one hand, and move the slide with the other. Oh yeah–you have to be sure not to whack the people in front of you with your slide, too, which can be tricky when you’ve got close, tight formations, like the ones done on a football field. Parade marching is easier, where there’s usually a little more space between you and the line in front of you, and all you’re doing is marching with no fancy formations.
On behalf of clarinetists and oboists everywhere, allow me to reassure you, Dougie, that the mouthpiece with the reeds doesn’t go any further into your mouth than just behind your lips. If you know an oboist who’s skewering himself in his soft palate with his reed, then you know an oboist with more serious problems than his music teacher can help him with. 
Okay? Feel better now? Thaaaaat’s good. Thank you for worrying about us.
I marched bass trombone for two years, baritone for one, and euphonium for my senior year. (And euphonium in drum corps.) Like someone else said, the mouthpiece doesn’t move very far. Also, when you bring a horn up, you don’t bring the mouthpiece quite into contact with your face. That would cause painful bruising. You just get it fairly close. When you’re marching, the movement shouldn’t cause a problem then either. If you’re moving your head/upper body around that much when marching, you’re probably doing something wrong.
-Neil
…and basically echoing previous answers. No special equipment is needed. About the only thing that one has to do is learn to walk without bouncing, and this was only an issue for me when marching pretty fast.
This may be more of an issue with something like a sousaphone, which rests directly on the left shoulder - any upper-body bounce will get transmitted directly to the horn. Smaller instruments, in my limited experience with them, have some shock-absorbing benefit from the player’s arms.
A proper marching-band “march” is much more of a smooth glide (Big 12 schools excepted :)) than your average military clomp-step. Done correctly, upper-body bounce is minimized, and the mouthpiece-moving-every-which-way problem (which makes it damn near impossible to play well) isn’t really an issue.
This is off topic, but since we’re talking about teeth and musical instruments:
My spouse (the musicologist) has done some reading on orchestral musicians in the 18th century and relates that apparently tooth loss was a serious problem for brass and wind players at the time – not necessarily because the playing caused the tooth loss (although there were cases of this – remember dental hygiene wasn’t great then so pressing on your teeth could move your teeth around a lot over time) but rather because loss of teeth affected one’s ability to play.
Just thought you might like to know.
Thank you Ducky! As Clarinetist turned SaxMan, I applaud you for defend our soft palates!
On another note, the oboist with their reed way to far into their mouth reminds me of one time at bandcamp…
:lol
Former marching band trumpeter here, echoing what everyone else said, with an addition. One thing you do want to be careful of is that your mouthpiece is tight enough in the bore, so that it doesn’t fly out and hit you in the face when you bring your horn up.
Adding to what Strainger said, you don’t want the mouthpiece coming loose and hitting someone else when you bring your horn down. Most of the people I’ve hit weren’t too appreciative.
I spent three years in a high school marching band playing sousaphone, and never worried too much about my choppers. The mouthpiece is too big to really pose a problem, aside from dislocating your jaw.
Something like facing into a high wind only serves to set your embouchre all the more firmly.
What would be bad would be having a trombone player do a garamonde-left right in front of you and slam his slide into the bell of your trumpet. THAT would smart.
Played trumpet in high school marching band. I agree with all the above. One of the first things you learn in Band Camp is how to march eight-to-the-bar while keeping your upper body relatively fixed. There’s a little movement, but not much, and you can absorb that small amount with your lips. As Neil said, if it’s moving around so much that you hurt your lips, you’re doing something wrong.
A trumpet player’s teeth NEVER touch the mouthpiece.
This is probably why there aren’t any marching Jaw Harp bands.
'Nother trumpet player checking in. I always found the cold was a bigger problem than anything else. Think about it. People always tell ya don’t lick the flagpole, but then you stick your lips on that frozen sonofabitch. Chapped lips were a perennial problem, too. Lip balm and mouthpieces just never got along in my opinion.
Tuba/sousaphone player, here. Braces were a much bigger problem than getting hit with the mouthpiece.
Hear, hear, Ethilrist! I had years of peeling my lips off my braces after a long toot. Sucked when you had band after being smacked in the face with a basketball, shredding the insides of your lips. Oh, the horror, the HORROR!
(whisper) Keep your mouthpiece in your POCKET until it’s time to play! Like a charm, it works. (/whisper)
TubaDiva was telling me at one point about plastic mouthpieces. I can only conjecture in morbid fashion about what effect this sort of thing would have on one’s tone.
Trust me, the pocket thing. It’s simple, it’s easy, it’s obvious, it works good.
[marching band/drum corp anecdote]
For those who are not familiar – if you are in marching band, or especially drum and bugle corp, you do not let anything, short of nuclear weapons and earthquakes, get in the way of your precision and execution during competition.
That being said, when I was in high school we had a marching instructor who marched in the Blue Devils drum and bugle corp who related the following incident:
Once, during a competition, this instrutor noticed an on-field judge standing right where he was going to be placing his bell in about 2 seconds after a sudden right (Or left. It’s been a while.) pivot. Sensing this, my instructor called out to the judge to warn him, but because of the corp playing and the judge’s own preoccupation with recording his comments in the tape recorder, the judge didn’t hear him. Sure enough, 2 seconds later – pivot…SMACK!!
Later, the corp gathered to listen to the judges’ tapes. While listening to that particular judge , they were treated to something along the lines of, “Formation is looking good through here. Contras need to watch the intervals at OW!! SON OF A BITCH!!”
[/marching band/drum corp anecdote]
YANATrombone checks in:
Mouthpiece-tooth interaction was never a problem unless someone hit the instrument somehow. As others have pointed out, lip fatigue and damage were bigger problems. I was in our All-Stars band for several years (all right, get the “Once, at band camp” laughs outof your systems), and quickly learned to hit my dentist up for a little topical anaesthetic before I went. When you practice marching and playing from 8 AM to 11:30 PM, your lips tend to get sore (at least for the first day or two). Most of the brass players used some kind of balm at least the first night. As for the folks with braces, <shudder> I don’t know how you stood it. At least cold mouthpieces weren’t a problem–the average daily high temp during the practices was around 101 F; dehydration and heat exhaustion always cost us at least one or two performers by the end of the week.
Generally that’s true Persephone, but in competition parades we did use rather fancy drills and formations. One of my least favorite marching memories is of marching down a steep hill on a ice-covered brick street in Natchitoches while performing a track drill (each line “rolls”, with the front member turning and leading the line to the back of the formation). It was especially exciting for the trombones because the street was narrow and we were packed 8-abreast during the drill–not much room for a slide! That was also the parade during which someone chucked a full can of beer at the bell of one of the tubas–not so unusual, except the tuba player fielded, pegged it back, and knocked the thrower flat with it.
Hey, we tuba players are NATURAL athletes. Not to mention loaded with sex appeal.
I have only one thing to say:
After reading some of these horror stories, I am so glad I play a string instrument.
<d+r>
LL