Why did my subnasal lip lift fail? Do you have suggestions for revision?

Without knowing the specifics of their individual technique, its difficult to know exactly what was done, and therefore my answer will be a little vague.  That being said, I have talked about this in the past extensively (differences in measurements, anchoring points, etc) if you are interested. In general, with most traditional lip lifts will drop 20% about 6 months after.  So if you were at ~1.8, and finished at ~1.3, then being at around 1.5 afterwards sounds about right. This happens due to the skin suffering from "biological creep" - the tension of the weight from the upper lip slowly pulls on the incision over time and the entire tissue lengthens.  Its the same idea behind using tissue expanders.  At first it looks really tight, and after some time the skin relaxes to accommodate for the changes.  The best way to avoid this from happening again is to account for it and anchoring deeply.  May cause a little more swelling, but there are ways to avoid that.  Remember that its important too to also look at how much tooth show you may have.  We can talk numbers all day, but if we were to take out another 5 or so mm to bring you to ~1cm with a final outcome of 1.15cm...and you get a rabbit looking smile with excessive tooth show, thats not good either! So it really depends on your facial features such that you get something natural that looks good for you.  I hope some of this helps! Best of luck.