Why don't my upper teeth show when I open my mouth or when I talk? (Photos)

Actually, your question is readily answered.  As we get older, and sometimes genetically, our upper lips get longer. When this happens you won't be able to see your upper teeth (or see them very little).  Five or more times many weeks I do a lip lift to improve that.  It looks like in your case your nose may be pushing out very strongly and it would possibly be beneficial to help that at the same time.

Thanks for your question! 
I can't fully see your upper lip quite like I'd like to but it does appear that your upper white lip is long- the ideal upper lip length is around 19mm for you. Longer than this can cover the upper teeth and not show your beautiful teeth!
Seek advice and counsel from an experienced surgeon who you communicate with and trust!
Hope this helps and God Bless!
Dr. Robb

Thank you for sharing your question and photographs.  Unfortunately without an in-person examination it is difficult to offer definite advice as your pictures offer limited views.  Your complaints may be due to a natural variation of genetics or due to a dental/bony issue.  I would either see an ASPS board certified plastic surgeon in consultation or discuss your concerns with your dentist who may be able to make an appropriate referral.  Hope this helps.

Your larger upper lip and a low vermilion edge masks your upper teeth. While a smile line reduction can be done to show more upper teeth, this comes at the price of a smaller upper lip size.