Speech, except in the case of a total glossectomy is not often mentioned as a serious issue with the people I routinely talk to in hospitals etc. Seems like it would be different, but most end up with minor impediments like lisps etc. For some speech therapy is useful, others just charge right through this. The biggest issue I hear of is controlling what is left to move to bolus of chewed food to the back of the mouth for swallowing, which takes a little practice to master, along with some slower eating habits which wouldn