Photobiomodulation or low‐level laser therapy

It is not often that the globally accepted name of a scientific field has changed between the time at which a journal commissions a special issue and the time at which the actual issue goes to press. Such has been the case here. Low-level laser (light) therapy (formerly abbreviated as LLLT) is approaching its 50th anniversary. LLLT was discovered in 1967 by Endre Mester at the Semmelweis Medical University in Hungary. Mester was trying to repeat an experiment first conducted by Paul McGuff in Boston USA, who had successfully used the newly discovered ruby laser to cure malignant tumors in rats [1]. However, Mester’s custom-made ruby laser possessed only a very small fraction of the power possessed by McGuff’s laser. Despite not curing any tumors with his low-power laser beam, he did observe a heightened rate of hair growth and better wound healing in the rats in which he had surgically implanted tumors. This was the first indication that low-level laser light (rather than high power thermal lasers) could have its own beneficial applications in medicine [2, 3].