Kofi Boahene says he stumbled across a possible role for hyaluronic acid injection while working with a patient with a then-undiagnosed case of muscular dystrophy.
Each year, thousands of cosmetic surgery patients across the country receive lip augmentation injections with products containing hyaluronic acid. Recent research led by Johns Hopkins facial plastic and reconstructive surgeon Kofi Boahene
suggests that these injections could serve a purpose far beyond enhancing form—they can also significantly enhance function for people with facial paralysis.
Facial paralysis from tumor, stroke, Bell’s palsy, muscular dystrophy, trauma or birth defects can cause both physical and psychological problems, Boahene explains. Without lip control, patients struggle with eating and drinking without spillage, and making sounds that require fully closing the lips, such as words containing the letters “b” and “p.” Many individuals with facial paralysis also become self-conscious about how they look.
Boahene says he stumbled across a possible role for hyaluronic acid injection while working with a patient with a then-undiagnosed case of muscular dystrophy. Her face was weak, and she had trouble speaking. To improve her lip muscle tone, he tried the injection and says the effects were immediate. Her face appeared stronger, and her articulation markedly improved.
To see if this procedure might be useful for a wider audience, Boahene and his colleagues recruited 22 patients with facial paralysis on one side of the mouth along with three patients with muscular dystrophy who had lost control of both sides of the mouth.
They performed baseline measures of lip tone by having participants place their lips around an instrument that measured pressure and took readings from the left, middle and right sides of the mouth. The researchers then identified the weakest points by having participants blow air with pursed lips. At points where air escaped, the researchers injected hyaluronic acid.
Results showed the greatest improvement in the three patients with muscular dystrophy, whose lip strength increased six- to sevenfold over the original reading. For participants with paralysis on only one side of the mouth, lip strength increased an average of 1.4-fold on the paralyzed side and 0.4-fold on the unaffected side.
To see how well those improvements carried over to daily life needs, a speech therapist conducted a before-and-after assessment of the patients’ ability to speak and to eat and drink without spilling. All 25 patients showed marked improvement, Boahene says. After publishing these results in the June 18, 2015, JAMA Facial Plastic Surgery, plans are underway to confirm the benefits in a larger study with about 100 patients.
“To maintain structure, plants fill their leaves and stems with water,” Boahene says. “It’s a crude analogy, but injecting the lips with hyaluronic acid works in much the same way. It tones the tissue surrounding the muscle.”
Boahene says that if the 25 patients continue to show improvement without any marked side effects, he might pursue tests of longer-lasting solutions, such as removing fat from elsewhere in the body and injecting it around the mouth.