To John’s point, if this inside the sculpt and not hurting the exterior appearance, there’s no dire reason to fix it. But it can be fixed if need be.
In short, I would retesselate that area with big polygons by touching the area with a very low-strength brush (like Inflate) and subdivide collapse as the method. The retesselation should get rid of the artifact. Once gone, you can go back to smaller polygons and polish up the area.
If that didn’t make sense, please link me to your .blend and I’ll download it to demo the fix during next week’s stream.
