Review of Laser Treatments for Post-Inflammatory Hyperpigmentation in Skin of Color.

Post-inflammatory hyperpigmentation is an extremely common disorder of pigmentation in skin of color. It most frequently and severely affects phototypes that are rich in melanin and often has a chronic and unpredictable course. It presents significant treatment challenges and often requires a multi-factorial approach. We review the literature available for the optimal use of laser-based devices in the treatment of post-inflammatory hyperpigmentation, particularly for Fitzpatrick skin phototypes III-VI. For the treatment of post-inflammatory hyperpigmentation in skin of color, lasers remain second line to topical agents based on the variable response, cost, and risk of complications with laser use. For post-inflammatory hyperpigmentation resistant to topicals, laser devices, particularly neodymium:yttrium-aluminum-garnet and fractional photothermolysis systems, can provide adjunctive treatment in skin of color patients when appropriate parameters are used. Future studies would benefit from an objective and consistent assessment to assist with a systematic analysis.

CO2 Laser Treatment of Multiple Oral Hamartomas in Cowden's Syndrome: A Review and Case Study.

Background: Cowden's syndrome is a genetic disorder characterized by multiple oral hamartomas and an increased risk of internal malignancy. These mucocutaneous lesions can be physically disfiguring and psychologically distressing. As a result, patients frequently seek treatment for their destruction. Removal of oral hamartomas is often a challenge due to their sensitive location and high risk of recurrence. Objective: To review the clinical use, effectiveness, and safety of a fractional ablative laser to treat multiple oral hamartomas in a patient with Cowden's syndrome. Materials and Methods: A thorough literature review pertaining to treatment of oral hamartomas and a discussion of an illustrative case showcasing successful lesional destruction with a fractional ablative carbon dioxide (CO2) laser in a 33-year-old man with Cowden's syndrome. Results: Multiple oral hamartomas were effectively removed with fractional CO2 laser vaporization. No infection, scarring, dermatitis, nor lesional recurrence were observed 6 months post-treatment. Conclusion: Fractional CO2 laser vaporization can be used effectively to treat multiple oral hamartomas associated with Cowden's syndrome.

Alternative Cosmetic and Medical Applications of Injectable Deoxycholic Acid: A Systematic Review.

BACKGROUND: Beyond submental fat reduction, injectable deoxycholic acid (DCA) has gained popularity in recent years for various minimally invasive lipolysis applications. OBJECTIVE: To summarize and evaluate the evidence of off-label uses of injectable DCA. METHODS: MEDLINE, Embase, CINAHL, Web of Science, and CENTRAL were searched. The outcomes measured included applications of DCA, treatment regimen, and its efficacy. An overall success rate for each condition was calculated based on the improvement defined in the included studies. RESULTS: Eleven studies evaluated the cosmetic use of DCA for excess adipose tissue on various anatomical locations. The outcomes were evaluated at time points ranging from 1 to 21 months post-treatment, with overall success rates over 85%. Eight case reports and series reported the success of using DCA treating lipomas, xanthelasmas, paradoxical adipose hyperplasia, fibrofatty residue of infantile hemangioma, piezogenic pedal papules, and HIV-associated lipohypertrophy. Although the preliminary efficacies were high, the overall recommendations for off-label uses are weak because of the lack of high-level studies. CONCLUSION: The review emphasizes the diversity of injectable DCA as a minimally invasive technique for lipolysis. Further high-level studies demonstrating consistent treatment regimens and methods of evaluation are warranted to make more definitive recommendations regarding off-label DCA use.

Alternative Clinical Indications of Botulinum Toxin.

Botulinum toxin type A (BoNTA) is a powerful neurotoxin that inhibits acetylcholine release from presynaptic vesicles. The potency and safety profile of BoNTA grant the toxin vast therapeutic potential. It has been used off-label for a variety of dermatologic conditions. This review aims to analyze published literature regarding the benefits and risks of the off-label use of BoNTA beyond facial lines, including eccrine hidrocystomas, enlarged pores, keloids and hypertrophic scars, hidradenitis suppurativa, hyperhidrosis, masseter muscle hypertrophy, and salivary gland hypertrophy, among others. A MEDLINE search from January 2000 to December 2019 was conducted on the off-label uses of botulinum toxin in dermatology.

Dermatologic Laser Side Effects and Complications: Prevention and Management.

The evolution of modern laser and light-based systems has mirrored the demand for clinically effective treatments and the need for safer technologies with reduced postoperative recovery, side effects, and complications. With each new generation of lasers, more selective tissue destruction can be achieved with reduced unwanted sequelae. Patient selection and preparation, operator technique, and expeditious recognition and management of post-treatment side effects are paramount in avoiding complications and patient dissatisfaction. An overview of important variables to consider for dermatologic laser treatments are presented in order to provide a framework to reduce the severity and duration of possible post-treatment side effects and complications.

Microneedling of Scars: A Large Prospective Study with Long-Term Follow-Up.

BACKGROUND: In recent years, microneedling has been increasingly used to treat a number of dermatologic conditions, including scars. Although initial studies demonstrated improvement of (mostly) atrophic scars with microneedling, the number of patients evaluated was relatively small, and the devices and treatment protocols used and posttreatment follow-up varied widely. Through this prospective observational study, the results of microneedling on 120 patients with a variety of scars are described. METHODS: One hundred twenty consecutive patients (skin phototypes I through VI) with facial and nonfacial scars from a variety of etiologic sources (acne, trauma, surgery) were treated using a mechanical microneedling device. No additional treatments (topical or intralesional) were applied. Two assessors blinded to treatment protocol rated clinical improvement of scars 1, 3, 6, and 12 months after treatment on a five-point scale. Side effects were monitored and tabulated. RESULTS: Patients received one to six consecutive monthly microneedling treatments. All scars improved at least 50 percent after an average of 2.5 treatments. Over 80 percent of patients had 50 to 75 percent improvement, and 65 percent of patients demonstrated over 75 percent improvement. No significant clinical differences were observed in treatment responses of facial scars versus nonfacial scars nor between responses of atrophic acne scars and traumatic or surgical scars. CONCLUSIONS: This study supports the use of microneedling for various facial and nonfacial scars across a broad range of skin phototypes with minimal risk of adverse effects. Further studies will help to establish standardized protocols to optimize treatment outcomes for different scar types. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Microneedling Treatment of Striae Distensae in Light and Dark Skin With Long-Term Follow-Up.

BACKGROUND: Striae distensae have notoriously been difficult to treat due to their extensive involvement of nonfacial skin. Microneedling with its lack of thermal injury during microneedling treatment renders it a viable treatment option in darker skin tones and nonfacial regions due to the reduced risk of postinflammatory hyperpigmentation. OBJECTIVE: To describe the clinical results and side effects of microneedling in a series of 25 individuals with striae distensae. MATERIALS AND METHODS: Twenty-five consecutive adults (SPT I-V) with striae distensae involving the trunk and extremities were treated using a microneedling device. No additional treatments (topical or intralesional) were applied. Two assessors blinded to treatment protocol rated clinical improvement of striae on a 5-point scale. Side effects were monitored and tabulated. RESULTS: Patients received 1 to 3 consecutive monthly treatments. All striae improved at least 50% after an average of 1.8 treatments, and 28% of patients demonstrated more than 75% clinical improvement. Striae in thicker skin regions (e.g., buttocks/thighs) showed comparable clinical improvement than those in thinner skin areas (e.g., breasts) and did not require additional treatment sessions. Side effects were limited to transient erythema in all skin phototypes. No infections or dyspigmentation were observed. CONCLUSION: The clinical results obtained in this study support the safe and effective treatment of striae distensae with microneedling in light and dark skin tones in various body locations. Standardization of treatment protocols are anticipated with further (ongoing) studies.

An Observational Study of the Safety and Efficacy of Tissue Stabilized-Guided Subcision.

BACKGROUND: Cellulite is a common female cosmetic concern for which there are few treatment options with long-term effectiveness data. The aim of this multisite prospective registry study was to collect observational data on the real-life clinical use of a tissue stabilized-guided subcision (TS-GS) system for long-term improvement of cellulite appearance. METHODS: Fifty-three subjects were enrolled and received a single treatment using the TS-GS system. Physicians treated the subjects according to their standard of care. Global Aesthetic Improvement Scale (GAIS) was completed by the patient and clinician assessing overall aesthetic improvement after 180 days. Treatment parameters, pain scores, quality of life data, and expected treatment effects and adverse events were also recorded throughout the study. RESULTS: The patient and physician GAIS scores at Day 180 revealed an overall improvement in 91% and 96% of patients, respectively. Quality of life and self-confidence scores also improved through 180 days. No serious adverse events were reported. Expected treatment effects were similar to those reported in the pivotal trial supporting FDA clearance. CONCLUSION: This study demonstrated significant improvement in the appearance of cellulite after a single treatment session in patients with moderate-to-severe cellulite. These results are consistent with the previously published the pivotal study data.

Treatment of Cosmetic Tattoos: A Review and Case Analysis.

BACKGROUND: Cosmetic tattoos such as eyeliner, brow liner, and lip liner have become increasingly popular in the United States and throughout the world. For a variety of reasons, patients frequently regret their tattoos and request their removal; however, removal is often complicated by the aesthetically sensitive location of these specialized tattoos and the fact that they often contain white metallic compounds that darken on pigment-specific laser irradiation. OBJECTIVE: To review the clinical use, effectiveness, and safety of an ablative laser technique for cosmetic tattoos. MATERIALS AND METHODS: A thorough literature review pertaining to laser treatment of cosmetic tattoos and a discussion of illustrative patient cases showcasing the successful use of ablative carbon dioxide (CO2) laser to treat cosmetic tattoos is presented. RESULTS: Cosmetic eyeliner and lip liner tattoos were significantly improved after CO2 laser vaporization. Side effects were limited to erythema, edema, and serosanguinous drainage. No infection, scarring, nor tattoo ink darkening was observed. CONCLUSION: Because ablative lasers do not target specific tattoo inks, they do not pose a risk of paradoxical tattoo ink darkening and, thus, can be applied successfully in the treatment of iron oxide- or titanium dioxide-containing cosmetic tattoos.

Safety and Efficacy of a 1550nm/1927nm Dual Wavelength Laser for the Treatment of Photodamaged Skin.

BACKGROUND: Fractional photothermolysis (FP) is a popular treatment option for photodamaged skin and addresses shortcomings of ablative skin resurfacing and nonablative dermal remodeling. Previous studies have demonstrated that FP using the 1550nm wavelength has led to improvement of ultrastructural changes and clinical effects associated with photodamaged skin in the deeper dermal structures, while treatment with the 1927nm wavelength has shown clinical effects in the superficial dermis. Both wavelengths produce precise microscopic treatment zones (MTZs) in the skin. The two wavelengths used in combination may optimize the delivery of fractional nonablative resurfacing intended for dermal and epidermal coagulation of photodamage skin.

OBJECTIVES: To evaluate the safety and efficacy of a 1550/1927 Laser System (Fraxel Dual, Solta), using both 1550nm and 1927nm wavelengths in combination for treatment of facial and non-facial photodamage.

METHODS: Prospective, multi-center, post-market study in subjects with clinically identifiable photodamage (N=35) (Fitzpatrick skin types I-IV). Both 1550nm and 1927nm wavelengths were used at each treatment visit. Investigator assessment of the affected area(s) occurred at one week, one month and 3 months after a series of up to four treatments. Severity of adverse events (AEs) were assessed using a 4-point scale (where 0=none and 3=marked). Assessments included erythema, edema, hyperkeratosis, hyper- and hypo-pigmentation, scarring, itchiness, dryness, and flaking. Severity of photoaging, fine and coarse wrinkling, mottled hyperpigmentation, sallowness, and tactile roughness at baseline was assessed using the same scale. Investigators and subjects assessed overall appearance of photodamage and pigmentation based on a 5-point quartile improvement scale at all follow-up visits (where 0=no improvement and 4=very significant improvement [76%-100%]).

RESULTS: There was a positive treatment effect at all study visits, with moderate improvement (average reduction in severity of 21%-43%) observed 3-months after final treatment. Greatest reduction in severity of other benefit areas was at the 3-month follow-up visit, with a 21% and 30% decrease in severity in fine wrinkling and tactile roughness. No AEs or serious AEs were reported. Pain sensation during treatment was tolerable. Anticipated moderate erythema (mean score 1.6±0.5) and mild edema (mean score 0.8±0.7) were transient and resolved within 7-10 days. Anticipated and transient mild dryness (52% of subjects) and flaking (30%) were reported at the 1-week follow-up. There were no incidences of hyperkeratosis, scarring, or itchiness.

CONCLUSION: Treatments using both wavelengths associated with the combined 1550/1927 Laser System were well tolerated with limited, transient anticipated side effects and no serious AEs. Clinical efficacy in the appearance of photodamage and pigmentation was greatest following a series of up to 3 treatments.

J Drugs Dermatol. 2018;17(1):41-46.

Microneedling: A Review and Practical Guide.

BACKGROUND: Microneedling is a relatively new treatment option in dermatology and has been touted for a broad range of applications including skin rejuvenation, acne scarring, rhytides, surgical scars, dyschromia, melasma, enlarged pores, and transdermal drug delivery. The significant increase in minimally invasive procedures that has been reported over the past several years suggest that microneedling may occupy a specific niche for patients who desire measurable clinical results from treatments with little to no recovery. OBJECTIVE: To review the published medical literature relating to microneedling in dermatology and provide a practical guide for its use in clinical practice. MATERIALS AND METHODS: A thorough literature search of microneedling in dermatology using PubMed was conducted, and all references pertaining to skin scarring and rejuvenation were reviewed. Based on the information presented in these publications and the authors' clinical experience, a microneedling technique is outlined for clinical practice. Pretreatment recommendations, intraoperative technique and treatment end points, and postoperative considerations are outlined. RESULTS: Microneedling produces substantial clinical improvement of scars, striae, and rhytides with expedient recovery and limited side effects. Controlled dermal wounding and stimulation of the wound healing cascade enhances collagen production and is likely responsible for the clinical results obtained. CONCLUSION: Microneedling is a safe, minimally invasive, and effective esthetic treatment for several different dermatologic conditions including acne and other scars, rhytides, and striae. Given its expedient post-treatment recovery, limited side effect profile, and significant clinical results, microneedling is a valuable alternative to more invasive procedures such as laser skin resurfacing and deep chemical peeling.

Laser Treatment of Professional Tattoos With a 1064/532-nm Dual-Wavelength Picosecond Laser.

BACKGROUND: Picosecond-domain laser pulses improve the photomechanical disruption of tattoos. OBJECTIVE: This study evaluates the efficacy and safety of a novel, dual-wavelength, 1,064/532-nm, picosecond-domain laser for tattoo clearance. MATERIALS AND METHODS: This was a prospective, self-controlled, clinical study of 34 subjects with 39 tattoos treated at 2 sites with an interval of 4.8 ± 1.6 weeks and up to 10 treatments (mean, 7.5). Blinded evaluation and investigator assessment of serial digital images was performed to evaluate treatment efficacy in the 36 tattoos that received at least 3 treatments. Investigators also assessed efficacy before each treatment visit up to 10 treatments. Safety and tolerability was evaluated for all 39 tattoos that underwent at least 1 treatment. RESULTS: Blinded evaluation demonstrated that lightening of tattoos was achieved in all subjects, with 86% (31 of 36 tattoos) showing at least a 50% clearance after 3 treatments. Adverse events were few and transient in nature. Patient satisfaction and treatment tolerability were high. CONCLUSION: Treatment of single-colored and multicolored tattoos with this novel 1,064/532-nm picosecond laser is highly safe and effective.

Laser Tattoo Removal: An Update.

Tattoo art has been around for thousands of years in every culture and is currently flourishing in all age groups, social classes, and occupations. Despite the rising popularity of tattoos, demand for their removal has also increased. While various treatments, including surgical excision, dermabrasion, and chemical destruction have historically been applied, over the past 2 decades, lasers have revolutionized the way tattoos are treated and have become the gold standard of treatment. To achieve optimal cosmetic outcome of treatment, lasers emitting high energies and short pulses are required to adequately destroy tattoo ink. We review the history of laser tattoo removal, outlining the challenges inherent in developing lasers that can most effectively remove tattoo particles while safely protecting skin from unwanted injury.

The role of lasers and intense pulsed light technology in dermatology.

The role of light-based technologies in dermatology has expanded dramatically in recent years. Lasers and intense pulsed light have been used to safely and effectively treat a diverse array of cutaneous conditions, including vascular and pigmented lesions, tattoos, scars, and undesired hair, while also providing extensive therapeutic options for cosmetic rejuvenation and other dermatologic conditions. Dermatologic laser procedures are becoming increasingly popular worldwide, and demand for them has fueled new innovations and clinical applications. These systems continue to evolve and provide enhanced therapeutic outcomes with improved safety profiles. This review highlights the important roles and varied clinical applications that lasers and intense pulsed light play in the dermatologic practice.

Comparison of 532 nm Potassium Titanyl Phosphate Laser and 595 nm Pulsed Dye Laser in the Treatment of Erythematous Surgical Scars: A Randomized, Controlled, Open-Label Study.

BACKGROUND: The pulsed dye laser (PDL) has long been used for treatment of erythematous and hypertrophic scars. Its effectiveness has been attributed in large part to its vascular-specificity. The vascular-specific potassium titanyl phosphate (KTP) laser has also been reported to be clinically effective for scars, but has not been compared to the PDL. OBJECTIVE: To compare the safety and clinical efficacy of a 532-nm KTP laser versus a 595-nm PDL in improving the appearance of erythematous surgical scars. METHODS: Twenty patients with matched bilateral erythematous surgical scars or a single linear erythematous scar measuring longer than 5 cm were enrolled in the study. Single scars were divided into equal halves with each half randomized to receive 3 successive treatments at 6-week intervals with either a 532-nm KTP laser (Excel V; Brisbane, CA) or a 595-nm PDL (Cynergy; Cynosure Inc., Chelmsford, MA) at equivalent laser parameters. Bilateral matched scars were similarly randomized to receive three 532-nm KTP or 595-nm PDL treatments. Clinical efficacy was evaluated 12 weeks after the third (final) laser treatment by independent, blinded photographic scar assessments. Secondary evaluations included final investigator and subject treatment/satisfaction assessments, Vancouver scar scale (VSS) scores, subject scar symptoms, intraoperative pain scores, and incidence of side effects. RESULTS: Clinical improvement of erythematous surgical scars was observed with both 532-nm KTP and 595-nm PDL systems. No statistically significant differences between the 2 treatment arms were noted in the independent, blinded photographic scar assessments, investigator and subject treatment/satisfaction assessments, subject scar symptoms, and intraoperative pain scores. The KTP arm produced statistically significant improvement for the vascularity component of the VSS only. Side effects were limited to mild treatment discomfort and minimal transient post-treatment erythema and purpura. No vesiculation, infection, scarring or other adverse events were experienced. Subject satisfaction surveys mirrored the observed clinical effects. CONCLUSION: The-532 nm KTP laser is comparable in efficacy and safety to the 595-nm PDL laser in the treatment of erythematous surgical scars.

A Randomized, Double-Blind Trial to Investigate the Equivalence of IncobotulinumtoxinA and OnabotulinumtoxinA for Glabellar Frown Lines.

BACKGROUND: IncobotulinumtoxinA and onabotulinumtoxinA are indicated for the temporary improvement in the appearance of glabellar frown lines (GFL). This is the first randomized direct comparator study to date, at the Food and Drug Administration-recommended dose of 20 units (U), for the treatment of GFL. OBJECTIVE: To investigate the dose equivalence of incobotulinumtoxinA (20 U) and onabotulinumtoxinA (20 U) for the treatment of moderate-to-severe GFL. MATERIALS AND METHODS: Prospective, randomized (1:1), double-blinded, parallel-group study in 250 females (18-50 years), employing a single treatment with incobotulinumtoxinA or onabotulinumtoxinA, followed by a 4-month observational period. RESULTS: At the primary efficacy endpoint (1 month after treatment), incobotulinumtoxinA was equivalent to onabotulinumtoxinA in the treatment of GFL at the 20 U dose within the prespecified ± 15% margin of equivalence. Efficacy remained similar between treatment groups through 4 months after treatment as assessed by the independent masked panel and the masked treating physicians. Patient satisfaction ratings were similar between groups and favorable (>90%) throughout. Both treatments were well tolerated. CONCLUSION: Equivalence was demonstrated at the primary endpoint between incobotulinumtoxinA and onabotulinumtoxinA in the treatment of GFL at the 20 U dose at 1 month. Similar efficacy and tolerability profiles were observed through 4 months after treatment.

Delayed Onset Pain Associated With Cryolipolysis Treatment: A Retrospective Study With Treatment Recommendations.

BACKGROUND: Cryolipolysis has become a popular treatment for noninvasive destruction of unwanted subcutaneous fat. It is a generally well-tolerated treatment with mild transient side effects. Delayed posttreatment pain has been sporadically reported, but its incidence, etiology, and treatment have not been elucidated in a large series of patients. METHODS: A retrospective review of 125 patients who received 554 cryolipolysis procedures over a 1-year period was conducted. Demographic data were obtained to determine specific variables that influenced development of delayed posttreatment pain. RESULTS: Young women (mean age, 39 years) undergoing abdominal cryolipolysis were at greatest risk of experiencing delayed posttreatment pain. The pain was self-limited (duration, 3-11 days) and resolved completely without long-term sequelae. The number of treatment cycles did not impact the development of this side effect. CONCLUSION: Delayed posttreatment pain is a not uncommon adverse effect after cryolipolysis. Patients should be counseled on the possibility of its occurrence, and timely intervention should be instituted to reduce its impact.

Multicenter prospective cohort study of the incidence of adverse events associated with cosmetic dermatologic procedures: lasers, energy devices, and injectable neurotoxins and fillers.

IMPORTANCE: Common noninvasive to minimally invasive cosmetic dermatologic procedures are widely believed to be safe given the low incidence of reported adverse events, but reliable incidence data regarding adverse event rates are unavailable to date. OBJECTIVE: To assess the incidence of adverse events associated with noninvasive to minimally invasive cosmetic dermatologic procedures, including those involving laser and energy devices, as well as injectable neurotoxins and fillers. DESIGN, SETTING, AND PARTICIPANTS: A multicenter prospective cohort study (March 28, 2011, to December 30, 2011) of procedures performed using laser and energy devices, as well as injectable neurotoxins and soft-tissue augmentation materials, among 8 geographically dispersed US private and institutional dermatology outpatient clinical practices focused on cosmetic dermatology, with a total of 23 dermatologists. Participants represented a consecutive sample of 20 399 cosmetic procedures. Data acquisition was for 3 months (13 weeks) per center, with staggered start dates to account for seasonal variation. EXPOSURES: Web-based data collection daily at each center to record relevant procedures, by category type and subtype. Adverse events were detected by (1) initial observation by participating physicians or staff; (2) active ascertainment from patients, who were encouraged to self-report after their procedure; and (3) follow-up postprocedural phone calls to patients by staff, if appropriate. When adverse events were not observed by physicians but were suspected, follow-up visits were scheduled within 24 hours to characterize these events. Detailed information regarding each adverse event was entered into an online form. MAIN OUTCOMES AND MEASURES: The main outcome was the total incidence of procedure-related adverse events (total adverse events divided by total procedures performed), as verified by clinical examination. RESULTS: Forty-eight adverse events were reported, for a rate of 0.24% (95% CI, 0.18%-0.31%). Overall, 36 procedures resulted in at least 1 adverse event, for a rate of 0.18% (95% CI, 0.13%-0.25%). No serious adverse events were reported. Adverse events were infrequently associated with known risk factors. CONCLUSIONS AND RELEVANCE: Noninvasive to minimally invasive cosmetic dermatologic procedures, including energy, neurotoxin, and filler procedures, are safe when performed by experienced board-certified dermatologists. Adverse events occur in less than 1% of patients, and most of these are minor and transient.

Safety and efficacy of combining microfocused ultrasound with fractional CO2 laser resurfacing for lifting and tightening the face and neck.

BACKGROUND: Microfocused ultrasound (MFU) and ablative fractionated laser (AFL) resurfacing techniques have been used separately to noninvasively improve skin laxity and rhytides on the face and neck. Simultaneous combination treatment would be anticipated to provide further improvement but has not previously studied. METHODS: A retrospective analysis of 100 combination face and neck treatments from 3 centers was performed, including collective treatment protocols, postoperative recovery, side effect profile, and clinical results. RESULTS: Skin laxity and photodamage (rhytides and texture) showed significant improvement with combination MFU + AFL treatment. Except for increased facial swelling in a small percentage of patients, postoperative recovery and side effects were comparable with those obtained after application of individual treatments. CONCLUSION: Combination MFU-AFL on the face and neck is a safe and effective method for targeting multiple facets of facial and neck skin aging and can be safely performed in a single treatment session.