I just stck my hand in there and feel for sharp edges along the cheek. I also float my horse's teeth myself so I have a speculum that I can use to get a good look in their if I need to. But I wouldn't really recommend sticking your hand in your horse's mouth if you aren't comfortable. If she's never had it done, then it's safe to assume she needs it. At her age it's also very possible that she has wolf teeth that need to come out. I think you should just go ahead get the equine dentist out there.
It's not fair ro you horse to make her carry a bit if her teeth have sharp edges or if she has wolf teeth. So if i were you I would ask your barn owner if he will check her mouth for you so you know if uou need to hold off on making her pack a bit.
As for the bridling issues. I would recommend you practice putting in on over her halter, with the lead rope tied to the fence so that she can't get away from you.
First, before even messing with the bridle I would teach her to drop her head as someone else already mentioned. Place your hand on her poll (top of her head just behind her ears) then use your fingers to press and apply pressure to her poll. Keep increasing pressure until you get some sort of response. Her first response is likely to be to push against you and raise her head. DO NOT REMOVE ANY PRESSURE if she does that. But as soon as you feel her move away from the pressure and drop her head even the slightest tiniest bit, remove your hand completely and give her a pet. Then repeat over and over again until you can get her to drop her head low. Always starting with just placing your hand gently on her poll first, then adding finger pressure. That way, eventually she'll drop her head just from you placing your hand on her poll bc she knows what's coming next.
Then I would work on teaching her the cue to open her mouth without having the bit in your hand first. That way if she has issues/anxiety about having the bit put in you don't have to deal with it yet. Stick your thumb in her mouth right there on the side where she has no teeth and wiggle it a little. If she opens her mouth remove all pressure then pet and repeat. If she doesn't open stick your thumbnail into her gum with increasing pressure until she opens, then immediately release and pet. Do this enough times until she'll open with slight pressure from your thumb on the side of her mouth. With this, the cue to lower her head and having her haltered and tied you have some tools to help you be successful.
I know your instructor told you to reach your right hand under her throat, but i think you'll find it easier to hold your right arm up at her poll, especially after teaching her that is the cue to drop her head. Like in this picture
The part you would be holding onto is called the crown piece. (The part that goes across her forehead is called the browband and the part that buckles under her throat is called the throatlatch) Gentle bring the bit to her mouth. If she doesnt readily open her mouth, use the cue you taught her with your thumb. When she opens very nicely slide the bit in without banging her teeth, then gently slide the crown piece over her ears and pet her. You want the bit sitting on top of her tongue. Occasionally they will get their tongue over the bit and you want to be sure to notice if that happens soyou can fix it. Many horses will react badly if you miss it and try to ride like that.
Once you can bridle her with no issues with the halter on, then try it without the halter. With the leadrope still tied to the fence, remove the halter from her face and fasten it around her neck, like the gal in this photo has done
, tight enough that she can't get out of it if she pulls back. And practice putting the bridle on the same way.
Hope I explained that well enough that it makes sense. Posted via Mobile Device