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.
It's a good idea to get an orthodontic evaluation by the time a child is 7 years old. An orthodontist is a dentist with additional training, who specializes in aligning and straightening teeth. The best time for your child to get dental braces depends on the severity and the cause of the misalignment of your child's teeth.