How "Dangerous" is It to Have my Overlarge 2 Front Teeth Filed Down?

Most teeth have 1.5 millimeters of enamel over the underlying layer, dentin.  This is the layer that may have some nerve sensitivity. When we adjust to recontour teeth, we may reduce .5 millimeters at most. Usually microns.  Not a big deal.

You would certainly be fine having your dentist shorten your front teeth, but it is hard to tell you exactly how much without a picture or exam.  Each individuals enamel and bite is different and these both determine how much enamel can be removed safely.  Find a local dentist and have them discuss your options with you.  Good luck. 

Without seeing a photo, it's hard to give you advice on your exact situation but in general, I never recommend that patients just file down teeth (especially front teeth). The reason being is that most people think that their front teeth should be all the same length, however, in an ideal/esthetic smile, the front 2 central incisors are usually 1mm longer than the 2 lateral incisors next to them. The reason for this is the teeth are meant to fit in the frame of the smile, and our lower lip, when smiling, is a curve. So, to fit in the curve of the lower lip, the teeth are slightly different lengths.