curved and small areas such as the nasal ala and the periocular and perioral areas. Most devices have a rechargeable battery that operates in two modes: high speed mode (700 cycles/minute) and low speed mode (412 cycles/minute) in a vibrating stamplike manner [17].
Figure 1.3 Pen: Single‐use cartridge with adjustable frequency and needle length.
Source: Sakurra/Shutterstock.
The devices contain multiple fine needles, ranging from 0.5 to 1.5 mm in length, that are rolled onto the skin. Needles between 1.5 and 3.0 mm are available but are preferred for the use of scars and damaged skin. The roller device is a drum‐shaped tool with a cylindrical head that is rolled back and forth to induce thousands of tiny pores in the stratum corneum and papillary dermis.
The length of needle selected for an individual patient depends upon the indication for microneedling and on the thickness of epidermis and dermis of the skin being treated. For treating acne and other scars, on average a needle length of 1.5–2 mm is utilized. When microneedling is used as a procedure to treat skin aging and wrinkles, a needle length of 0.5 mm or 1.0 mm is recommended [18]. The frequency interval for microneedling depends upon the indication for which the procedure is being done as well as the needle length of the dermaroller device used. Microneedling generally requires more than one session and a series of treatments is usually recommended.
Five basic types of medical dermarollers, which are registered with the FDA, have been described in the dermaroller series by Anastassakis and most dermarolling devices are adopted from these elementary types [19].
Stamps
Stamps were popular in the late 1990s and have made a resurgence recently. The stamps currently offered have attached microchambers which have the ability to directly administer a form of mesotherapy using the stamping device. Stamps have different needle lengths (0.2–3 mm) and a diameter of 0.12 mm These are useful in the administration of treatment to scars and anatomically small surface areas such as the perioral, periocular, and nasal regions where greater control is beneficial, and may be used on isolated scars and wrinkles (see Figure 1.4) [3, 20–22].
Figure 1.4 Microneedling stamp: fixed needle length with customizable vial for needling infusion.
Source: Aquavit Pharmaceuticals, Inc.
Rollers
Rollers have many fine‐gauged needles that are on a cylindrical surface that pierces the skin on an angle. The rollers are fixed; the parameters are uniform for each device that you use. Unlike pens, you can not mechanically adjust rollers. The quality of rollers is also critical. Patients are seeking at‐home rollers but the quality of the needles is paramount. Needles that are dull or loose may cause tears in the skin and foreign body reactions, including but not limited to granulomas.
The most important factor is needle length. A high ratio of tip length to diameter (13:1) is an important property of good needles [9]. The length of needle selected for an individual patient depends upon the indication for microneedling. For treating acne and other scars as a routine, a needle length of 1.5–2 mm is usually used. When microneedling is used as a procedure to treat aging skin and wrinkles, a needle length of 0.5 mm or 1.0 mm is usually recommended [19]. The needle length to use will also depend on the thickness of the epidermis and dermis of the skin for optimal results.
Given their design and mechanics, rollers are able to pierce the skin deeper when at a 90‐degree angle or perpendicular to the skin. Fernandes showed that with the use of rollers you have an intact epidermis with microchannels spaced out with about a four‐cell width distribution [4]. The provider’s technique with these devices is critical. Tearing of the epidermis may occur if performed incorrectly, with too much pressure, or at an increased speed. The needle rollers themselves are variable based on the materials used, needle length and diameter, and total number of needles. The quality of the rollers is also critical to evaluate.
Needle length is generally 0.2–3.00 mm, with a diameter of > 0.25mm and the materials are variable: stainless steel, titanium, or silver and gold. Stainless steel is the most common type of needle, silver and gold offer antimicrobial properties and carry less of a risk of allergic reactions, and titanium needles usually stay sharper longer (see Figure 1.5).
Figure 1.5 Current rollers with fixed needle length; some current models are autoclavable.
Source: marcinm111/Shutterstock.
DermaFrac
DermaFrac treatment is a newer modification of microneedling combining microdermabrasion, microneedling, simultaneous deep tissue serum infusion, and light emitting diode (LED) therapy. DermaFrac treatments target aging and sun damaged skin, acne, enlarged pores, uneven skin tone, wrinkles, fine lines, hyperpigmentation, and superficial scars. It takes approximately 45 minutes to complete a full face treatment when all four modalities are used. This noninvasive, cost‐effective treatment carries the advantage of having no downtime, with individualized selection of serums for infusion (see Figure 1.6) [22].
Figure 1.6 DermaFrac™: Microneedling device combining simultaneous customized infusion followed by LED light therapy.
Source: Genesis Biosystems, Inc.
Clinical considerations
Microneedling is not only used for rejuvenation of the skin. Its use in dermatology and aesthetic medicine has expanded to include the treatment of acne scars, alopecia, dyspigmentation, alopecia, striae, and for many other indications. It can be utilized alone or in combination with other treatment modalities, such as chemical peels, platelet‐rich plasma, radiofrequency, subcision, punch elevation, and lasers. It is often used in conjunction with a topical formulation to enhance its penetration and action.
Microneedling is safely used for enhanced drug delivery to the deeper epidermis and dermis by bypassing the stratum corneum. This strategy has been utilized for burn patients and for rejuvenation, allowing cosmeceuticals to be delivered more deeply. Caution is necessary in deciding which topicals to use during delivery, as inflammation may occur and granulomas have been noted.
Conclusion
Microneedling
