1 If X is a topological (or metric) space and M is a metric space, then the set of all bounded continuous functions from X to M forms a metric space if we define the metric as above: d (f, g) = sup x in X d (f (x), g (x)) for any bounded continuous functions f and g.
Invisalign is orthodontic appliance, so since orthodontic treatment is allowed as an FSA expense, Invisalign is covered. Different companies have different rules concerning amounts set aside and the timing of how funds are used for orthodontics.
Becoming an orthodontic assitant requires a dental assitant school certificate. Hopefully, you get experience in orthodontic proceedures. In many instances, you can gain more experience by working in an orthodontic office as an intern. I know i enjoy training dental assistants in orthodontics in my own office.