A Prospective, Split-Face, Randomized, Double-Blind Study Comparing OnabotulinumtoxinA to IncobotulinumtoxinA for Upper Face Wrinkles.

BACKGROUND: The authors sought to compare the newest U.S. Food and Drug Administration-approved botulinum toxin type A product, incobotulinumtoxinA, to onabotulinumtoxinA for upper face wrinkles. This is the first prospective, split-face, randomized, double-blind study addressing three types of facial wrinkles using a 1:1 dose ratio. METHODS: The study was designed, institutional review board approval was obtained, and 45 patients were enrolled. A three-judge independent reviewer panel compared photographs of patients to the upper face validated assessment scales, selecting a grade ranging from 0 (no lines) to 4 (very severe) for the degree of glabellar lines, crow's feet, and forehead lines for each side of the face for photographs taken before treatment and 3 days, 2 weeks, 3 months, and 4 months after treatment. For toxin comparison, the difference in the magnitude of the degree of wrinkle scale at each period compared to before treatment was calculated and statistical analysis performed. Individual wrinkle types and all three wrinkle types combined were analyzed. RESULTS: Both products offered significant reduction in individual and combined wrinkles at comparable time points; however, onabotulinumtoxinA had significantly greater combined dynamic wrinkle reduction at 3 days (p < 0.010), 2 weeks (p < 0.008), 3 months (p < 0.013), and 4 months (p < 0.045). CONCLUSIONS: For identical dosage, both onabotulinumtoxinA and incobotulinumtoxinA are safe and effective in reducing dynamic wrinkles in the upper face; however, for the authors' dosages, onabotulinumtoxinA had statistically greater efficacy at 3 days, 2 weeks, 3 months, and 4 months. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

Exposure to low concentrations of nicotine during cranial nerve development inhibits apoptosis and causes cellular hypertrophy in the ventral oculomotor nuclei of the chick embryo.

Maternal cigarette use during pregnancy is associated with increased incidence of neural impairments in offspring, but nicotine's unique contribution to any neuropathology remains unclear, and nicotine's neurodevelopmental effects assessed in animal models vary with concentration. During ontogenesis, the chick oculomotor complex (OMN) is regulated by central nervous system (CNS) afferent-derived and target-derived trophic factors, allowing assessment of nicotine's potential interference in receptor-mediated CNS trophic phenomena, unconfounded by myriad other compounds in cigarette smoke. In the current study, 100 ng nicotine applied daily in ovo to yolk during embryonic days (E) 1-7 mimicked maternal plasma nicotine concentrations during fetal cranial nerve development. Nicotine-treated embryos exhibited a 15% decrease in whole body weight and 7% decrease in brain weight at E16. However, at E16, nicotine-treated embryos had 37% and 15% increases in the combined ventromedial+lateral (v) OMN motoneuron density and soma area, respectively, effects not observed in the optic tectum, in which nicotine cholinergic receptor expression is delayed until E8-12. Incorporation of tritiated thymidine into whole brain DNA demonstrated that the nicotine treatment did not cause increased rates of whole brain mitosis, suggesting that the dosage regimen did not elicit a cytotoxic, wound-healing, response of differentiating cells. As determined by DNA fragment-labeling assay during the normal period of cell death, vOMN apoptosis occurs maximally on E11 during a normal period of declining cell density, and a dose-response study demonstrated 78% E11 vOMN apoptotic suppression at approximately 0.30 microM cumulative yolk nicotine with an inhibition threshold between 0.10 and 0.20 microM. These results suggest that plasma nicotine concentrations resulting from tobacco use or nicotine replacement therapy (NRT) are sufficient to inhibit motoneuron apoptosis and enhance neuronal growth.