Others on this string have given you some good advice regarding root resorption as it relates to too much time in braces. As to tooth loss 'being no big deal', well I guess that would depend on whether or not you had $$$$$$ burning a hole in your pocket to invest in new modalities and/or dental implants. So, here, I'll focus on another possibility for you to explore WITH your perio.
As to the LOOSE TEETH, another possible culprit could be periodontal pathogens housed in the tartar on the roots of the teeth below the gum line. So, be sure to ask your perio to either RULE OUT that possibility OR to perform a DEEP cleaning which is when they scale the roots of the teeth to remove the tartar from there that houses the pathogenic bacteria. There is a time frame to have this before a surgery and it CAN'T be too soon before it. I think it's approx one month before. So, definitely put the discussion on the table about possible periodontal pathogens and getting a DEEP CLEANING.