Had 4000 hair transplant 7 months ago and I didn't get density. Did wearing bandana 20 days after surgery effect graft? (photo)

It can take 6 to 12 months after surgery to see results.  If you are concerned it is best to contact your doctor.Wearing a bandana does not affect your results unless it was really tight.

Wearing a bandana 20 days after a transplant should have no effect on the grafts.You still have another 4-5 months to go for full results so be patient.If at one year you are still questioning the density I would suggest following up with your surgeon.

Wearing bandana 20 days after HT would not effect the result. Regrowing hair is thin, undersized and not bright untill 4-5 th months of hair transplant. İt's normal for new growing hair starting to get native characteristics, waviness, curl in first 4-5 months..This actually takes 10-13 months for hair to become full mature , as thick and bright  as native hair. 

It is difficult to say that your results were a failure to grow since I have not seen how much hair you had there prior to the surgery. If you are unhappy with the results, go back to your doctor. I would wait another 3 months and see what still will grow out