This question pisses us off every time we encounter it. We always compare trying to train your jaw muscle with gum as trying to grow your biceps by doing curls with 2kg dumbbells. Yes, you will eventually get there, but it will take you years. So, the two main differences between using gum or CHISELL are:1) CHISELL is more efficient by providing a MUCH higher resistance level 2) CHISELL guarantees equal results on both sides. Many gum exercisers eventually develop a muscle imbalance by chewing gum more on one side than on the other. Masseter muscles are the second toughest muscles on your body after your heart, and are able to take up to 80kg (176lb). To challenge this muscle and produce enough strain to actually grow it in size, you need a lot of resistance. CHISELL provides that.