No abstract

Background: Microbotulinum refers to the systematic injection of tiny blebs of diluted botulinum toxin at repeated intervals into the skin. This targets the superficial fibers of the facial muscles, and weakens their insertion into the undersurface of the skin, which is responsible for the fine lines and wrinkles on the face. The authors present a pilot study based on quantitative evaluation, by means of a skin-scanning technology, of the aesthetic improvement of skin texture, microroughness, and enlarged pore size in a patient group treated with microbotulinum injections for cosmetic purposes. Methods: The treatment was performed using a 32-gauge needle to deliver injections on a regular 1-cm grid from the forehead to the cheek and down to the jawline. Results: Sixty of the 62 patients completed the study. All analyzed parameters improved significantly (p < 0.0001) at 90 days with respect to the pretreatment time point (skin texture, −1.93 ± 0.51; microroughness, −2.48 ± 0.79; and pore diameter, 2.1 ± 0.43). Best results have been obtained in patients aged between 42.7 and 46.8 years, and standard deviation calculation allows us to recommend it in patients aged between 36.5 and 53 years. Conclusions: The results of this pilot study suggest that intradermal botulinum toxin injection, or so-called microbotulinum, is a safe and effective method to treat skin flaws. Because of the high satisfaction rate among both physicians and patients, further studies are indeed mandatory to determine the optimal number of units needed for a longer and lasting effect with this particular novel dilution. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

There are several areas commonly treated for aesthetic purposes in the upper face (glabella, forehead, and brow), mid face (bunny lines and Crow's feet), and lower face (gummy smile, masseter, mentalis, and neck). [5][6][7][8][9][10][11][12] In addition to that, the smooth lustrous appearance of the skin due to decreased sweat and sebaceous gland activity secondary to the neuro-chemically induced bulk atrophy of the glands is an aesthetic bonus. 13 To achieve more natural and less dramatic results, clinicians started to experiment with reducing the dose and increasing the dilution to obtain optimum results in small aesthetic flaws and dermatological conditions. 8,9 There is in fact growing evidence that botulinum toxins exhibit biological effects on various human cell types with plenty of associated clinical implications: their receptors and intracellular targets are not unique for neurotransmission. 14,15 The skin, in fact, interacts with the nervous system, and there is evidence that the neurological system directly participates in cutaneous inflammation and wound healing. Botulinum Toxin type A can elicit specific biological effects in dermal fibroblasts, mast cells, sebocytes, and vascular endothelial cells