Well, that's an interesting question. Smoking, in general, has a very detrimental effect on healing in its broadest sense. It's not so much the THC that's a detrimental chemical but there's also nicotine. There's also carbon monoxide. The offending agent in cigarette smoke is carbon monoxide because healing is dependent upon oxygen flow. Oxygen is carried to all wounds by the hemoglobin molecule. Hemoglobin molecule picks up the oxygen and takes it to the wound and helps heal it. The oxygen molecule is removed by carbon monoxide. Carbon monoxide will compete with the oxygen molecule on the hemoglobin to displace it so it can actually can stop healing to some degree.

Smoking After Surgery: "It Can Stop Healing"

Dr. Thomas Trevisani explains the chemical reaction that takes place in a smoker's body and how it can impair healing after surgery.