Can chewing on one side of your mouth cause facial asymmetry?

Yes, it's possible: If you only lifted with your right arm, would it become more muscular than your left? Would its bones be stronger, too? Of course. And your face is no different. If you only chew on one side, you are exercising that side much more and so your chewing muscles and bones on that side get bigger. This leads to asymmetry. It can also cause joint (TMJ) problems.

Rarely: First of all the 2 sides of everyone's face are somewhat asymmetric, and have been since birth. An Orthodontist or Orel Surgeon can point out the differences for you. Second, we are all primarily one sided chewers, just like we are either right or left handed. Your body will allow you some leeway as it functions. Most of the time the difference between the 2 sides is very small.