The findings appear in JAMA Facial Plastic Surgery.
Kofi Boahene, MD, a facial plastic and reconstructive surgeon in the Department of Otolaryngology-Head and Neck Surgery at the Johns Hopkins University School of Medicine in Baltimore, 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.
Study author Kofi Boahene, MD, discusses the new findings in this video clip.
To test the procedure, Boahene and his collaborators recruited 22 patients (14 women and eight men) 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.
Baseline measures of lip tone were performed 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 three patients with muscular dystrophy suffered from uniform weakness across the lips, while the rest of the patients had lost control on one side only.) The researchers then identified the weakest points by having participants blow air with pursed lips. At points where air escaped, the researchers injected the Hyaluronic acid.
The findings were striking, with the greatest improvement seen in the three patients with muscular dystrophy, whose lip strength increased six- to sevenfold over the original reading, Boahene reports. 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.
Next Steps Outlined
If the initial 25 patients continue to show improvement without any marked side effects, Boahene might pursue tests of longer-lasting solutions, such as removing fat from elsewhere in the body and injecting it around the mouth.
Plans are now under way to confirm the benefits in a larger study with about 100 patients. If validated by further study, the procedure may also help patients whose facial nerves have been repaired but who need temporary lip help while full healing from such repairs occurs.