When can I start giving my baby chewing gum?

Never. Bad enough when they pick up the habit on their own; if you start them on it, that's more time for them to develop TMJ -- a painful condition in which an apparent earache is actually a sign of damage to the joint that moves the lower jaw.
No not ever. Besides the dental hazards of increasing the risk of toothy decay, the risk of choking is ridculously high.Never in a baby. And not really healthy for any age child.
I wouldn't!!! There is not a good reason to give a baby chewing gum, think tiny stomach....Hunk of material that does not digest well....Not good!
Not for awhile. Chewing gum is essentially a cavity causing choking hazard. There is really no reason to give an infant or small child chewing gum since it has the easy potential to be inhaled and block airways. This goes with hard candy and other such food items. Generally these shouldn't be given to children until they can be thoroughly trusted, perhaps by 5 or 6 years old depending on the child.