teething or gas?

the boy who is usually smiley and sing-songy has metamorphosized into a drooling, cranky mess. we tossed around the idea that maybe he may be teething, and popped one of these under his tongue:

as we are lying here on the couch (the boy is asleep- in his own room), c just dropped the bomb... she had a fiber one bar. so either he is gassy or he really is teething. time will tell.