Is It Common for the Scar on the Forehead from Mohs Surgery to Be Depressed? How To Fix?

It is not unusual to have a depressed scar in the forehead after Mohs.  Scar revision is possible with surgery or nonsurgical approaches (ie  injecting filler to fill the depressed area).

It is not unusual to have a depressed scar in the forehead after Mohs. Scar revision is possible with surgery or nonsurgical approaches such as injecting filler to fill the depressed area.
 

It is not unusual to have a scar depression after Mohs.  In some cases a depressed scar may be treated by removing the scar and bringing the edges of the wound together at the same level. 

The purpose of Mohs is to take as little tissue as possible, get clear margins, and close it with as minimal a scar as possible. That being said, cancerous tissue was removed and you should expect some scarring post-procedure. I usually request my patients wait a minimum of 6 months post surgery to evaluate how to treat any scar. But there are possible revision surgeries or cosmetic fillers to add to depressed areas. But first let your body heal its best.