Lower doses of botulinum toxin type A delivered more frequently yield better results in certain areas of the face, according to Dr. Joel L. Cohen.
While crow's feet and the glabella still do better with a higher dose and a 3- to 4-month dosing interval, there are several areas that do better with half the typical dose and half the dosing interval.
Dr. Joel L. Cohen
The forehead is one such area. "We use lighter doses in the forehead because we really want things to be more natural in terms of still having movement," Dr. Cohen said at a cosmetic dermatology seminar sponsored by Skin Disease Education Foundation in Santa Monica, Calif. "Sometimes these patients need to be dosed in the forehead every 8-10 weeks, whereas in the glabella and the crow's feet, if you're using regular doses, you might only need to inject them every 3.5 or 4 months. Sometimes they're in a cycle where they come in for Botox or Dysport in the forehead every 8 or 10 weeks and every 16 weeks or 18 weeks for the glabella and the crow's feet."
Brow lifts also do better with lower doses at shorter intervals. But Dr. Cohen, director of AboutSkin Dermatology and DermSurgery, Englewood, Colo., cautioned that brow lifts with botulinum toxin should not be attempted in patients who have a lot of sagging in the lateral brow. These patients require surgery; botulinum toxin should be reserved for patients with mild redundancy between the brow and the eyelid. Occasionally, patients with moderate sagging can benefit as well.
Around the mouth, Dr. Cohen uses 5-7 units of botulinum toxin to treat the vertical muscle columns of the upper lip and to prevent etched-in lines. At the same time, he uses 2-3 units in the lower lip, "so it doesn't feel funny." Once again, this needs to be repeated every 8-10 weeks, he said.
There is another class of patients in which low doses of perioral botulinum toxin may be beneficial. Studies have shown that healing after resurfacing procedures tends to be better after the area has previously been immobilized with botulinum toxin.
"There's decreasing contraction across the wound, so you're not imprinting lines where you already have lines," Dr. Cohen said. "And the second thing is there is decreased inflammation because there's less mobility of the area."
For one-time erbium or CO2 laser resurfacing, Dr. Cohen recommends the patient be treated with botulinum toxin a week to 10 days before. "Or you can do pretreatment a week or two before you do a fractionated ablative laser where the plan is to do three, four, or five treatments. By treating the patient with the fractionated laser every 3 weeks, you may really be able to get a session of three treatments in for every one pretreatment with Botox. The overall goal is less movement across what you're trying to heal."
Dr. Cohen acknowledged participating in clinical trials and serving as a consultant for Allergan, Medicis, Johnson and Johnson/Mentor, and Merz. SDEF and this news organization are owned by Elsevier.