I am revisiting this site  after three years.  Originally, my dentist discovered a white spot on the underside of my tongue.  It was removed and biopsied and the result was mild epithelial dysplasia.  I have continued to perform weekly self exams.  I visited my dentist on 2-2-16 and he did a full exam, but did not notice anything unusual.  On 2-24-16, during my weekly self-exam, I noticed a very small white spot on the gum below my front teeth.   I was away for a three week trip and called the oral surgeon upon my return.  He could not believe I discovered the spot as it is very small and suggested we wait a month before removal.  I returned yesterday and had it removed and sent for a biopsy.  
What I am wondering is if this is a common occurrence?  I am in good health, non-smoker, non-drinker, age 61.  I don't have any risk factors of which I am aware.  Any suggestions or comments are welcome.  Thanks in advance.