Cobblestoning on hairline - how this can develop if all tha grafts on hairline includes 1 hair only?

Cobblestoning is an error of graft placement. The properly placed graft rises minimally usually about 1 mm above the scalp surface. This maximizes the proper alignment with the surrounding scalp producing growth of the transplanted grafts that are leveled with the surrounding scalp.When the transplanted grafts are placed protruding too much above the surrounding scalp plane then the graft grows elevated above the surrounding scalp. This often produces shadows when light hits it at a certain angle, or outright bumps. Often times this issue will become less evident if enough hair is growing in the area, as it will cover up the issue. If these bumps are significant and you desire to style your hair short, the proper repair can necessitate treating the area with a little dermabrasion.

If you have issues with your scalp and believe you have cobble stoning, go back to see your doctor.  Get an examination before considering your options or treatment.

Cobelstonning can occur even with excellent technique when you have coarse hair.  It occurs due to volumetric increase locally.  If you drop a rock in a glass of water, the water will rise.  If you place a coarse hair in the skin, it can make the skin rise.  What you have may or may not be cobblestonning.  Have your physician evaluate it first.  If you have cobbelstonning, you can try dermabrasion to make the skin flat.  True cobbelstonning from coarse hair is the only complication that is unavoidable in some individuals.  It can also arise when too much tissue is left on the graft during placement.  This is avoidable and is poor technique.  

Sure, this phenomenon may occur even if only single hair follicular units are used. Just depends on how aggressively your skin heals. But if you're a six months there is still "re-modeling" of the skin occurring so you may find what is obvious now may not be so much in the future. Let your transplants heal and then make a determination at the 16 month mark. I'll bet it will look better and feel better than it does now at only 6 months. Come back to Real Self and update us. Heal well and grow well.

should do is go in for a follow up. You want to make sure you know all your options and how the healing is going before you progress down any path.  Sometimes this goes away on its own once you hit the 12 month mark but it depends on things like skin type and case size.

This is a condition of the recipient area skin that is common when the skin disc from the transplanted grafts are not trimmed. This leaves a small area of skin that appears different in both color and texture from the skin around it. I trim all of our grafts and use slits to place them, minimizing any transplanted skin. We have see cobblestonning.