hello there, thanks for consulting hcm. how old r u,since u havnt mentioned ur symptms also ,,, r u feeling pain bfr meals, and is thre pooling of saliva?? if so may be it is salivary gland stone,, but either wise i think u shd consult a oral maxillofacial surgeon or nearest dentist..to have a look at u..if ur have dryness of the mouth then it is side effect of radiation therapy..there r various investigation like sialography,, and even ultrasound can be done,,u can take lemon peppermints to increase ur saliva flow if is mild it will flush out the debris.. hope it helps,,,if problem persists plz consult a local dentist..