Hear the word “laser,” and you probably think about a device that cuts. Depending on your age, you might think of sci fi weapons or industrial cutting tools or medical procedures that involve removing tissue with extreme precision. Even in dentistry, lasers are used largely for cutting, shaping, or vaporizing tissue.
Of course, lasers are light. Highly focused, highly concentrated light — like that used in the light shows that were popular for a time in planetariums and concert venues alike.
In our everyday lives, though, light can seem almost passive. It helps us see. It brightens a room. It makes colors visible. It can provide warmth. Yet life has always responded to light in more complex ways than that.
Long before anyone invented or even imagined a laser, people noticed that sunlight seemed to influence health in unexpected ways. Laundry hung outdoors smelled fresher. Certain skin conditions were found to be improved by exposure to sunlight. During the 19th and early 20th centuries, “heliotherapy” — the therapeutic use of sunlight — was a thing, used to treat conditions ranging from tuberculosis to chronic wounds.
Nobody understood all the mechanisms involved. They simply observed what light seemed capable of doing. Then attention shifted toward other uses of light: — until a happy accident happened in the late 1960s.
That was when a Hungarian physician named Endre Mester began investigating whether lasers — only recently invented — might cause cancer. As part of his experiment, lab mice were shaved and exposed to a low-powered ruby laser.
No cancer developed. Something else happened. Hair growth around the shaved area was significantly improved.
Suffice it to say that this finding was quite unexpected. The laser wasn’t powerful enough to cut tissue. It wasn’t generating significant heat. Yet something about the light appeared to be influencing a biological process. It was the first demonstration of what would come to be called photobiomodulation or low-level laser (light) therapy, or LLLT.
Today, LLLT has many uses, including the treatment of temporomandibular disorders (TMD), a group of conditions that can contribute to jaw pain, muscle tension, headaches, limited jaw movement, and other symptoms. It’s one of the tools we have available for helping patients here in our Laguna Hills office.
How can light accomplish such a thing?
Scientists have long known that different wavelengths of light can produce different effects in the body. Ultraviolet wavelengths from the sun can damage skin and cause sunburn. Yet other wavelengths of sunlight help regulate sleep/wake cycles and other biological rhythms. Still others can be used therapeutically to treat conditions ranging from seasonal affective disorder to certain skin problems.
In other words, the body doesn’t respond to all light in the same way. With respect to LLLT, scientists now believe that specific wavelengths of light interact directly with cells and tissues.
“Conversations” among cells are constantly happening as they send and receive signals. Those signals help regulate inflammation, tissue repair, energy production, and countless other processes throughout the body. Current theories suggest that photobiomodulation may influence some of those conversations. The “how” is still being studied, but evidence suggests that certain wavelengths can influence cellular activity in ways that may support healing and recovery.
Instead of acting like a surgical instrument, the light used for LLLT seems to act as a signal. And for improving TMJ conditions, an effective one at that. As the authors of one recent systematic review put it,
Photobiomodulation is an effective adjunct for the treatment of temporomandibular disorders, being a less invasive approach, safe, low-cost, and without side effects.
Another recent review of the literature since 2018 similarly concluded that “LLLT appears to be a safe, noninvasive, and effective adjunctive therapy” in a combined therapy approach to treating TMD — more effective, in fact, than some earlier guidelines suggested.
That word “adjunct” is worth emphasizing. TMD can have many contributing factors, including joint problems, muscle tension, airway issues, bite imbalances, and habits such as clenching or grinding. This is why, as we noted before, TMD treatment often involves more than one single approach.
Photobiomodulation isn’t intended to replace any other therapy. Rather, it gives us another tool for helping patients reduce pain, improve function, and support the healing process.
Not bad for an observation that began with a few unexpectedly hairy mice in a Hungarian laboratory!