INTRODUCTION
Microneedling was first described in 1995 by Orentreich and Orentreich for the treatment of atrophic scars and wrinkles.1 The local injury induced by dermal penetration of microneedling causes release of growth factors such as transforming growth factor (TGF)-α, TGF-β, and platelet-derived growth factor (PDGF). This stimulates collagen and elastin fiber production as well as capillary formation, ultimately leading to tissue remodeling.2 Since its initial description in the literature, microneedling has been expanded to effectively treat a variety of cosmetic and dermatological conditions, including rhytides, scars, dyspigmentation, and hair pathology.2 It should be noted that several of these studies were split face in nature. However, none directly compared microneedling devices to each other. A benefit of microneedling is that an intact epidermis is maintained, leading to minimal side effects, most commonly erythema and pinpoint bleeding. Tram-track scarring3 and granuloma formation when used in conjunction with topical applications4 have been observed rarely. Since its inception, microneedling technology has evolved from manual roller devices to automated devices, some of which have radiofrequency technology. Here, we aim to provide a brief review of the cost and technology, particularly of the newer microneedling electric and RF pen devices. No comparisons of efficacy are possible with current published research.
DISCUSSION
There are currently multiple microneedling devices being utilized in clinical practice. Three broad categories include the traditional manual rollers (eg, Dermaroller®, Cynergy®), automated pens, and automated pens with combined RF technology. The Dermaroller is a hand-held device with 192 needles of fixed length, varying in depth from 0.5-3 mm with a diameter of 0.1-0.25 mm, loaded on a cylindrical roller. The ultimate penetration depth achieved with a Dermaroller is variable and dependent on pressure application by the user. In contrast, automated pens utilize a disposable tip with varying numbers of needles hidden inside a guide, which can be set to cycle at different frequencies. The guide allows for safer application and disposable needles allow for pen reusability. An advantage of automated pens is that needle lengths are adjustable and the depth of penetration is not user-dependent. The relatively small tip size allows for treatment of anatomically challenging areas,such as the nose and skin adjacent to the lips and eyes.2 The addition of radiofrequency technology to automated pens has the advantage of utilizing insulated needles to deliver thermal energy localized to a targeted depth. These devices are believed to be safer in darker skin types as there is minimal to no damage to the epidermis.2Commercially available automated microneedling device brands include Réjuvapen™ (Refine USA, LLC), InnoPen™ (Clinical Resolution Laboratory, Inc.), Collagen P.I.N.™ (Induction Therapies™), and Eclipse MicroPen® (Salient Medical Solutions). Considerations when choosing a brand include cost of the pen and needle replacements, number of needles per device tip, and range of depths and speeds available (Table 1). The Réjuvapen, retailing at $2,495, is a corded device containing a tip with 3, 5, or 9 needles, varying in depth from 0.2-2.5 mm and functioning at four different speeds of up to 11,000 RPM. The InnoPen is also a corded device, similarly priced at $2,499, and contains a 13-needled tip with depth variation between 0-2 mm and five speed settings. The Collagen P.I.N., priced at $2,995, can function as a cordless device with a single speed setting or while corded with seven speeds up to 23,750 RPM, and is available with either 12 or 36 needles in depths varying between 0-3 mm. The Eclipse MicroPen, retailing at $3,500, is a cordless device that utilizes 12 needles functioning at a set speed of 6,900 RPM with fixed depth of 2 mm. It is worthwhile noting that while needle penetration up to 1mm is accurate, actual achieved depths past this threshold can be more variable.5Radiofrequency microneedling devices are more costly than traditional electric microneedling pens. Currently available devices include the Infini™ (Lutronic), which has 49 bipolar needles functioning at depths of 1-3.5 mm and three separate intensities. The Infini retails for $60,000, a cost that includes 10 needles, with a price of $95 per needle tip replacement. The Profound® (Syneron Medical Ltd.) is the most expensive device at $114,900 and is the only one to combine fractionated radiofrequency with traditional microneedling. It includes two separate sets of bipolar needles for both dermal and sub-cutaneous penetration. To target the dermis, the device uses 5 pairs of needles at a depth range of 1-2 mm, with a cost $2,100 for a set of 6. For sub-cutaneous penetration, the device utilizes a set
