What happens if you use an 18 mm distance gauge when the laser was set to 15 mm?

Typically lasers will not fire if the gauge is not set properly.  Otherwise it typically has very little effect on the delivery of the device. More information is needed.  Best, Dr. Emer.

I'm not sure your question makes complete sense.  Most of the lasers I have used do not allow you to use an 18 mm distance gauge erroneously.  Once the gauge is put in place, the laser defaults to the most common 18 mm settings.  Other factors are involved in the outcome, such as energy and pulse duration, so it's impossible to completely answer your question.Laser is a science, and not an easy one to learn.  My suggestion to you is see a board-certified physician with experience in laser.  If you are worried about the settings your practitioner used, you may not be seeing the right person, or do not have full trust in their abilities.  Best of luck to you!

The beam was set to 15mm and a 18 gauge was used .This will not affect the laser beam delivery ,The energy was delivered over a wider area however some of the hair will be missed since the laser beam did not cover 18 mm spit site.