DS7 has gone through phases where he sucks or chews on things (usually his sleeves, gloves, etc) and his OT gave him gum to chew during the sessions. It was never a constant thing, seemed to come and go and it was hard to see if it was related to anything else. I always suspected his teeth, but now he has three teeth coming in and hasn't been doing it for months. It always struck me as odd how he never showed any interest in sucking a pacifier or his thumb as a toddler, then all of a sudden he was sucking his fingers, clothes, at age 4+