Sometimes the muscles in your back can tighten up more on one side then the other causing the hip to hike up, so making it seem like the leg is shorter on that side. Loosen the muscles and do some traction and it usually balances out.

True leg length discrepancy is structural, so it is actually the bones, not muscles, which are causing the difference. Usually they say it's not a worry until you have about an inch difference and then you can be fitted for a wedge in your shoe.

To measure for true leg length discrepancy, have someone measure from your ASIS (the bony prominence at the front of your hip--being accurate in placement side to side) and your lateral or medial malleolus at the ankle.

If the xrays are right, 1.4 cm is not a huge difference for true leg length. However you may definitely have some muscular issues that are worsening functional movements for you by causing a non-true shortening of the one leg as evidenced by your chiro being able to change it. Wedging would only worsen the problem. Massage may be helpful.