Surgical incisions can result in scar tissue that will not produce hair (the hair follicles on the scalp are destroyed and this results in permanent bald patches).
Have you considered semi-permanent attachment methods or hair transplant?
What was the reason for mole removal, cosmetic or suspected cancer potential?

it was suspected to be cancerous.

Usually, if there is no regrowth of hair within 6 months after the trauma (cutting off the moles), transplantation is considered.
Were the moles proved cancerous?