Caroline--you clearly seem worried and not fully reassured by the care and responses you have received so far. ENTs are the experts in this area and tend to have MUCH more experience than dentists in sorting out cancer from other issues. A second opinion by an ENT would give you more definitive information and help you be more at ease, as otherwise this may nag at you for many months more. A quick biopsy in the office, and the more thorough exam than an ENT can perform, can make all the difference.