All veins of the face are connected. Knowing the anatomy allows for safe treatment. We never use a laser for these dilated 2-3 mm veins, since multiple treatments may be necessary and the failure rate is high.
Foam sclerotherapy is usually a one-time treatment. % of concentration depends on vessel size but, Sotradecol 0.5% or Polidocanol 1% 1% is the most commonly used concentrations