Cocaine can be detected in the system anywhere from 12 hours to 4 days after use. The length of time cocaine stays in your system depends on the dosage amount ingested, the route of administration and frequency of use. When cocaine is metabolized, the liver turns it into benzoylecgonine, which is then excreted in urine.
BUT, if you chew gum a lot, especially if you have a lot of tension in the muscles of mastication anyways, you're going to have problems... The muscles that make the motion/act of chewing/clenching include the masseter, lateral/medial pterygoids, and the temporalis.
The facial muscles detailed below are the main muscles used in facial reconstruction. The facial muscles can be divided into two groups: the muscles of mastication and the muscles of facial expression. The muscles of mastication are the ones we use when we chew.