Hi Lois-
Just thought I'd say "welcome" to our little club. Six months ago, I didn't even know such a thing as an acoustic neuroma existed! Scary stuff, but take your time, find the right doctors and try learn as much as you can about treatment options. Ask as many questions of all of us as you'd like and definitely ask your doctors many questions.
On the subject of dental exrays as a possible cause of AN's - I lived in remote parts of Alaska growing up and had almost zero exposure to exrays of any type until I was an adult. I then developed a ridiculous fear of dentists which kept me away from the dental chairs for more years than I'd be willing to admit. So, in my case ... definitely NOT exrays! I have also used a headset for both cell phones and cordless phones for years, so can't blame those either. I just think the AN, in my case, was "one of those things..."
Keep us posted, and try not to stress too much.
Debbi