TL072 supply voltage +-4.5 V vs. +-9 V
The datasheet I have for TI's TL07x series tells me that the minimum supply voltage is 10V(+-5V).
That, combined with the common-mode input range and max output swing, means that you're lucky your existing circuit works at all (and might not work if you drop in a different TL072 from a different production batch).

If you have 18V(+-9V) available I would definitely make use of it.