Quantification of skin elasticity changes associated with pulsed carbon dioxide laser skin resurfacing

A Randomized, Placebo-Controlled Trial Evaluating the Single and Combined Efficacy of Radiofrequency and Hybrid Fractional Laser for Nonsurgical Aesthetic Genital Procedures in Post-Menopausal Women

BACKGROUND

The efficacy of interventions that provide long-term relief of genitourinary symptoms of menopause has not been determined.

OBJECTIVES

The authors sought to evaluate radiofrequency and hybrid fractional laser (HFL) treatments for menopausal vulvovaginal symptoms.

METHODS

Thirty-one postmenopausal women completed all treatments and at least 1 follow-up. Outcomes included the Vulvovaginal Symptom Questionnaire (VSQ), Vaginal Laxity Questionnaire (VLQ), Urogenital Distress Short Form, Incontinence Impact Questionnaire (IIQ), Female Sexual Function Index (FSFI), laxity measurements via a vaginal biometric analyzer probe, and gene expression studies.

RESULTS

Mean VSQ score decreased 2.93 (P = 0.0162), 4.07 (P = 0.0035), and 4.78 (P = 0.0089) among placebo, dual, and HFL groups 3 months posttreatment and decreased to 3.3 (P = 0.0215) for dual patients at 6 months. FSFI scores increased in the desire domain for placebo and dual groups and in arousal, lubrication, orgasm, satisfaction, and pain domains for the HFL group 3 and 6 months posttreatment. An increase of 1.14 in VLQ score (P = 0.0294) was noted 3 months and 2.2 (P = 0.002) 6 months following dual treatment. There was also a mean decrease of 15.3 (P = 0.0069) in IIQ score for HFL patients at 3 months. Dual, HFL, and RF treatments resulted in statistically significant decreases in collagen I, elastin, and lysyl oxidase expression.

CONCLUSIONS

Several self-reported improvements were noted, particularly among HFL, dual, and placebo groups 3 and 6 months posttreatment. Objective biopsy analysis illustrated decreased gene expression, suggesting that treatments did not stimulate new extracellular matrix production.

LEVEL OF EVIDENCE: 2

Photoprotective and Antiaging Effects of a Standardized Red Orange (Citrus sinensis (L.) Osbeck) Extract in Asian and Caucasian Subjects: A Randomized, Double-Blind, Controlled Study

The increase in solar ultraviolet radiation (UVR) that reaches the Earth’s surface should make us reflect on the need to develop new approaches in protecting the skin from UVR exposure. The present study aims to evaluate the photoprotective and antiaging efficacy of a red orange extract (100 mg/day) in both Asian and Caucasian subjects. A randomized, double-blind, controlled study was carried out in 110 Asian and Caucasian subjects. Product efficacy was measured as follows: (1) the photoprotective effect was measured by the minimal erythema dose (MED) assessment; (2) the efficacy in decreasing the UVA+B-induced skin redness was measured by colorimetry; (3) the antioxidant efficacy was measured by the ferric-reducing antioxidant power (FRAP) and the malondialdehyde (MDA) assay; and (4) skin moisturization, skin elasticity, skin radiance, the intensity of melanin staining, transepidermal water loss (TEWL), and wrinkles were measured to assess the antiaging efficacy. The intake of the product for 56 days was effective in improving the skin reaction to UV exposure; in increasing the skin antioxidant capacity as well as in decreasing UVA-induced lipid peroxidation; in increasing the skin moisturization, skin elasticity, and skin radiance; and in decreasing TEWL, the intensity of melanin staining inside dark spots, and wrinkle depth. Our results suggest that the test product is effective in counteracting both the harmful effects of UVR exposure and aging signs.

A novel approach to the proximal interphalangeal joint: The volar oblique incision - a retrospective cohort study

BACKGROUND

The surgical approach to the volar structures in the digits must be designed to provide adequate exposure of tendons, vessels and nerves but also in a way that prevents flexion contracture of the digit as the scar contracts. This is traditionally done using a zigzag 'Bruner' incision, first described by Dr Julian M Bruner in 1967. In this paper, we describe an alternative approach, the Volar Oblique incision, and present a single institutional cohort of patients who have undergone procedures beginning with this approach.

METHODS

A retrospective cohort study was performed on eight cases that involved a Bruner incision and eight similar cases that involved a volar oblique incision. Charts were reviewed for demographic data. Patients were asked to return to clinic postoperatively for scar assessment using the Patient and Observer Scar Assessment Scale (POSAS), where lower scores correspond to more favourable scar characteristics. The average follow-up period was 22 months. While in clinic, standard joint measurements were taken to assess for any proximal interphalangeal joint contracture. Demographics and questionnaire data were analysed using the Mann-Whitney U test for non-parametric data and quantitative joint measurements were analysed using Student's t-test.

RESULTS

There was no difference in flexion contracture between the two groups. The POSAS patient score for scar irregularity was lower in the volar oblique group compared to the Bruner group, but there was no difference in any of the other subcategories, the total patient score, nor the overall patient opinion. The total POSAS observer score was lower in the volar oblique group compared to the Bruner group, with lower scores in the scar thickness, observed relief and observed pliability subcategories as well as the overall observer opinion.

CONCLUSION

The volar oblique incision appears to be satisfactory alternative to the classic Bruner incision in hand surgery that requires volar exposure of the digits. Future studies are needed to assess the validity of these findings on a larger scale.

LAY SUMMARY

There are various types of incisions that surgeons use when they operate on fingers. When choosing an incision, it is important that the incision provides good exposure to the deeper structures but does not form a tight scar that limits movement of the finger (contracture).A commonly used incision for the palmar side of the finger is the zig-zag or 'Bruner' incision. Some people, however, find this zig-zag scar unappealing. We started using a single diagonal incision, which we have called the volar oblique, instead of the zig-zag Bruner for access to the middle joint of the finger. We wanted to describe the volar oblique technique and then compare the quality of these two scars and also assess if one limits movement of the finger more than the other.Our research found no differences in finger contracture between groups. We did, however, find that patients reported scar irregularity more favourably in the volar oblique group and that surgeons rated scar thickness, relief (roughness) and pliability of the volar oblique scar higher than that of the zig-zag Bruner scar.This research presents a novel surgical technique and compares its results with respect to scar quality and finger contracture to the more traditional zig-zag Bruner approach.

Treating Excess Lower Eyelid Skin Without Incisions

INTRODUCTION

Periocular rhytids and dermatochalasis are common and striking signs of facial aging. The CO₂ laser technique described herein addresses Hester classification type I, aging at the level of the lower eyelid, focus on the treatment of the dermatochalasis.

MATERIALS AND METHODS

In this retrospective study of patients undergoing treatment at our clinic between 2000 and 2018, 263 were classified as Hester I and CO₂ laser therapy was the treatment to improve the local rhytids.

RESULTS

Improvement in dermatochalasis was found in all patients, resulting in better rejuvenation of the target area while eliminating visible scarring from a suture through the skin.

DISCUSSION

In our experience, CO₂ laser functions as a substitute for transcutaneous lower blepharoplasty, due to the fact that the contracture of the skin renders resection of that skin unnecessarily, thus avoiding the tell-tale scalpel incisions under the lashes.

CONCLUSION

The quality of the results of this retrospective study allows us to offer this laser therapy to treat lower eyelids classified as Hester I.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Use of formulations for sensitive skin improves the visible signs of aging, including wrinkle size and elasticity

Background: Sensitive skin affects an increasingly large proportion of the population and is less tolerant to frequent and prolonged use of cosmetics. This study investigates the antiaging effects of a skin care system developed for use on sensitive skin. Methods: A total of 30 healthy Caucasian females, aged 32-72, were enrolled in this double-blind randomized placebo-controlled split-face study. A routine consisting of twice daily topical applications of the test cleanser and test moisturizer or placebo or positive control products was followed for 28 days, with parameters measured at baseline and at 7-day intervals. Objective skin assessments for hydration, transepidermal water loss (TEWL), skin surface topography, elasticity and safety assessment were conducted. Results: Wrinkle surface, length and depth significantly improved by 34.8±4.7% (P<0.001), 19.0±3.2% (P<0.05) and 24.3±3.5% (P<0.05), respectively, after 28 days of skin care treatment with the test cleanser and test moisturizer. R2 (gross elasticity), R5 (net elasticity) and R7 (biological elasticity) significantly increased by 32.8±6.5% (P<0.001), 47.3±8.6% (P<0.001) and 50.6±5.1% (P<0.001), respectively, while R6 (viscoelastic portion) significantly decreased by 33.4±4.6% (P<0.001) after 28 days. Skin hydration was also found to increase significantly after 28 days by 42.2±8.5% (P<0.01), but there was no change in TEWL. No adverse events were reported. Conclusions: A novel skin care routine developed for use on sensitive skin significantly improves the signs of aging including hydration, wrinkle size and elasticity without significant adverse effects.

The Structure of Human Sebaceous Glands and Its Relation to Skin Viscoelasticity

High-frequency ultrasound has realized high-resolution observation of deep part of the dermis in vivo. The size of sebaceous glands was evaluated by three-dimensional ultrasound microscopy with the ultrasonic frequency of 120 MHz. The viscoelasticity of the same regions was measured by well-established biomechanical equipment. There was no significant difference between the size of sebaceous glands in cheek and forearm. The skin's ability to recover to its initial position after deformation was significantly higher in forearm than in cheek. Both sizes of sebaceous glands in cheek and forearm were positively correlated with the parameter of viscoelasticity. The size of the sebaceous glands in the deep part of the dermis can be a parameter of skin viscoelasticity. High-frequency ultrasound imaging contributes to the evaluation of human skin morphology as well as functions.

Quantitative and qualitative dermal change with microfat grafting of facial scars

Objective

To evaluate changes in dermal characteristics with subdermal fat grafting of cutaneous scars.

DESIGN

Prospective cohort.

METHODS

Fourteen patients with various scar types were treated with subdermal fat grafting over 30 months. Dermal elasticity, vascularity, pigmentation, patient perception and satisfaction, and observer assessment of scar characteristics were evaluated preoperatively and 1 year after treatment with validated objective and subjective measures.

RESULTS

Significant improvements were observed in dermal elasticity, patient and observer perception of scar thickness, patient perception of stiffness, and observer perception of relief and pliability ( P < 0.05). A trend toward significance was seen in observer assessment of height as evaluated by the Vancouver Scar Scale ( P < 0.1). No significant differences were seen in quantitatively and qualitatively measured vascularity and pigmentation ( P > 0.1). No significant difference in pain, pruritis, and irregularity were reported ( P > 0.1).

CONCLUSION

Although fat grafting represents a subdermal process, it appears to improve certain quantitative and qualitative dermal characteristics. Fat grafting does not appear to affect skin color, vascularity, or patient symptoms.

An antiaging skin care system containing alpha hydroxy acids and vitamins improves the biomechanical parameters of facial skin

Background

The demand for antiaging products has dramatically increased in recent years, driven by an aging population seeking to maintain the appearance of youth. This study investigates the effects of an antiaging skin care system containing alpha hydroxy acids (AHAs) in conjunction with vitamins B₃, C, and E on the biomechanical parameters of facial skin.

Methods

Fifty two volunteers followed an antiaging skin care regimen comprising of cleanser, eye cream, day moisturizer, and night moisturizer for 21 days. Wrinkle depth (R_y) and skin roughness (R_a) were measured by skin surface profilometry of the crow’s feet area, and skin elasticity parameters R2 (gross elasticity), R5 (net elasticity), R6 (viscoelastic portion), and R7 (recovery after deformation) were determined for facial skin by cutometer, preapplication and after 7, 14, and 21 days. Volunteers also completed a self-assessment questionnaire.

Results

Compared to baseline, R_y and R_a significantly improved by 32.5% (P<0.0001) and 42.9% (P<0.0001), respectively, after 21 days of antiaging skin care treatment. These results were observed by the volunteers with 9 out of 10 discerning an improvement in skin texture and smoothness. Compared to baseline, R2 and R5 significantly increased by 15.2% (P<0.0001) and 12.5% (P=0.0449), respectively, while R6 significantly decreased by 17.7% (P<0.0001) after 21 days. R7 increased by 9.7% after 21 days compared to baseline but this was not significant over this time period.

Conclusion

An antiaging skin care system containing AHAs and vitamins significantly improves the biomechanical parameters of the skin including wrinkles and skin texture, as well as elasticity without significant adverse effects.

Evaluation of a combined laser‐radio frequency device (Polaris WR) for the nonablative treatment of facial wrinkles

Nonablative wrinkle reduction or skin tightening is desired by individuals who, ideally, hope to have the skin improvement associated with chemical or laser ablative techniques but without the undesirable recovery process. Electro-optical synergy (ELOS) technology that combines radio frequency (RF) and diode laser energy (900 nm) was used to treat 15 patients in this IRB sanctioned study. Energy settings were based on the depth of wrinkles (the greater the depth and concentration of wrinkles, the higher the RF setting) and ranged from 50-100 J/cm2 RF and 15 J/cm2 for the optical, laser component. Patients received three full-face treatments, and results were evaluated by comparison of standardized photographs and patient questionnaire given prior to each treatment and one month after the third treatment. The primary investigator and three other "blinded" physicians evaluated these photographs using Fitzpatrick's wrinkle classification to assess the improvement, if any, between the initial and final visit. Eight patients completed the study. Explanation for the exclusion of the remaining six patients were: one decided to have surgery, two felt the treatment was too painful, and three moved out of the area. Following treatment, all patients had mild swelling (resolved <48 hours) and skin hyperemia (resolved <24 hours). Results observed one month after the last treatment in eight patients demonstrated an average of 25% reduction in skin wrinkles (range 14%-32%). There were no adverse side effects. The major concern of the patients was the discomfort associated with the treatment. As part of an FDA investigation to assess efficacy, long-term follow-up was not a part of this study protocol.

Lasers and optical technologies in facial plastic surgery

Lasers and optical technologies play a significant role in aesthetic and reconstructive surgery. The unique ability of optical technologies to target specific structures and layers in tissues to effect chemical, mechanical, or thermal changes makes them a powerful tool in cutaneous rejuvenation, hair removal, fat removal, and treatment of vascular lesions such as port-wine stains, among many other procedures. With the development of adjunct techniques such as epidermal cooling, lasers and optical technologies have become more versatile and safe. The constant improvement of existing applications and the emergence of novel applications such as photodynamic therapy, nanoparticles, spectroscopy, and noninvasive imaging continue to revolutionize aesthetic medicine by offering a minimally invasive alternative to traditional surgery. In the future, therapies will be based on individualized, maximum, safe radiant exposure to deliver optimal dosimetry. Lasers and optical technologies are headed toward safer, easier, more quantifiable, and more individualized therapy.

Ablative versus non-ablative treatment of perioral rhytides. A randomized controlled trial with long-term blinded clinical evaluations and non-invasive measurements

BACKGROUND AND OBJECTIVE

To compare efficacy and side effects of CO(2) laser resurfacing and intense pulsed light (IPL) rejuvenation for treatment of perioral rhytides.

METHODS

Twenty-seven female subjects with perioral rhytides (class I-III) were randomly treated with either CO(2) laser or IPL (three monthly treatments). Efficacy was evaluated by patient self-assessments and blinded photographs up to 12 months postoperatively. Side effects were assessed clinically. Non-invasive measurements included: trans epidermal water loss (TEWL), skin reflectance, skin elasticity, and ultrasound.

RESULTS

CO(2) laser resurfacing resulted in higher degrees of patient satisfaction and clinical rhytide reduction compared to IPL rejuvenation up to 12 months postoperatively (patient evaluations, P < 0.05) (observer evaluations, P < 0.008). Laser-induced side effects included erythema, dyspigmentation, and milia whereas no side effects were observed after IPL rejuvenation. Non-invasive measurements showed a significant higher reduction of the subepidermal low-echogenic band in CO(2) laser treated areas versus IPL treated areas (12 months postoperatively, P < 0.001). Skin elasticity (expressed as Young's modulus) increased in both groups (P = ns). One month postoperatively a significant increase in TEWL values (P < 0.009) and skin redness% (P < 0.02) was found in CO(2) laser treated patients versus IPL treated patients. No significant differences were seen in skin pigmentation% during the observation period.

CONCLUSION

CO(2) laser resurfacing induces a significantly higher degree of clinical rhytide reduction followed by considerably more side effects compared to IPL rejuvenation in a homogeneous group of patients.

Effects and side-effects of 2% progesterone cream on the skin of peri- and postmenopausal women: results from a double-blind, vehicle-controlled, randomized study

BACKGROUND

For many years topical progesterone has been prescribed by gynaecologists as an antiageing and skin-firming treatment, without any clinical scientific evidence of its effects, tolerability and safety when applied to skin.

OBJECTIVES

To evaluate the influence of 2% progesterone cream on function and texture of the skin in peri- and postmenopausal women.

METHODS

A double-blind, randomized, vehicle-controlled study was conducted in 40 subjects. Objective methods for measuring skin elasticity, epidermal hydration and skin surface lipids, clinical monitoring and self-assessment, and determination of blood hormone levels (luteinizing hormone, follicle-stimulating hormone, oestrogen and progesterone) were used to determine effects and side-effects of this treatment at four visits over a 16-week period.

RESULTS

The study demonstrated a significant (P < or = 0.05) increase of the elastic skin properties in the treatment group, as demonstrated by objective measurements of three skin elasticity parameters, whereas in the control group no such effect was observed. This effect in the treatment group was further paralleled by the results of the clinical monitoring, where the 2% progesterone cream yielded consistent superiority over vehicle in counteracting different signs of ageing in the skin of peri- and postmenopausal women. Clinical monitoring showed a greater reduction in wrinkle counts (29.10% vs. 16.50%) and wrinkle depth (9.72% vs. 7.35%) around the right eye, a greater decrease in nasolabial wrinkle depth (9.72% vs. 6.62%) and a significantly higher (P < 0.05) increase in skin firmness (23.61% vs. 13.24%) in the treatment group. Epidermal hydration and skin surface lipids did not change significantly in either group during the study. Progesterone was well absorbed in the systemic circulation: mean blood levels rose minimally, but statistically significantly (P = 0.001), by 0.53 ng mL(-1). No serious side-effects of the treatment were observed.

CONCLUSIONS

The results of this study demonstrate that topical 2% progesterone acts primarily in increasing elasticity and firmness in the skin of peri- and postmenopausal women. These effects in combination with good tolerability make progesterone a possible treatment agent for slowing down the ageing process of female skin after onset of the menopause.

Improvement of Dermatochalasis and Periorbital Rhytides With a High-Energy Pulsed CO2 Laser: A Retrospective Study

BACKGROUND

Upper eyelid dermatochalasis is typically treated with excisional blepharoplasty. The role of the CO2 laser previously had been confined to that of a vaporizing, incisional, or hemostatic tool. Over the past several years, however, ablative CO2 laser skin resurfacing has been popularized as an adjunctive treatment to blepharoplasty to minimize periorbital rhytides through its vaporizing as well as skin-tightening action.

OBJECTIVE

To evaluate the safety and efficacy of a high-energy pulsed CO2 laser as a stand-alone treatment for dermatochalasis and periorbital rhytides.

METHODS

Sixty-seven patients (skin phototypes I-IV) with mild-to-severe upper eyelid dermatochalasis and periorbital rhytides received periocular CO2 laser skin treatment. Global assessment scores of dermatochalasis and rhytides were determined by a side-by-side comparison of periocular photographs preoperatively and 1, 3, and 6 months postoperatively. In addition, caliper measurements of upper eyelids before and 1, 3, and 6 months after treatment were obtained.

RESULTS

Both dermatochalasis and periorbital rhytides were significantly improved after periocular CO2 laser skin resurfacing. Patients with more severe dermatochalasis and rhytides showed greater improvement after CO2 laser treatment than did those with mild or moderate involvement. Side effects were limited to erythema and transient hyperpigmentation. No scarring, hypopigmentation, or ectropion were observed.

CONCLUSIONS

Periocular skin resurfacing with a CO2 laser can safely and effectively improve upper eyelid dermatochalasis and periorbital rhytides.

Minimally Invasive Laser Contraction Myringoplasty for Tympanic Membrane Atelectasis*

OBJECTIVE: We sought to develop a minimally invasive surgical technique using the CO2 laser to reduce or eliminate tympanic membrane atelectasis in a select group of patients.

STUDY DESIGN: Thirty-seven ears with varying degrees of tympanic membrane atelectasis underwent CO2 laser myringoplasty with the patients under intravenous sedation in the operating room setting. Atelectasis severity was graded for each patient and documented before and after laser myringoplasty through photodocumentation. Patients were followed for 1 year with comparison tympanic membrane photography.

SETTING: The study was conducted in a tertiary care private otology-neurotology practice.

RESULTS: Laser myringoplasty significantly reduced retraction pocket severity in most patients. No patients required resection of the retraction pocket or tympanoplasty. The most favorable outcomes were observed in patients with atelectasis addressed early rather than later in its more advanced stages.

CONCLUSION: Laser contraction myringoplasty can reduce or eliminate atelectatic areas of the tympanic membrane through immediate contraction and “tightening” of the tympanic membrane tissues. Clinicians should use a standardized tympanic membrane atelectasis grading format.

SIGNIFICANCE: A minimally invasive surgical technique for addressing tympanic membrane atelectasis is described, and a tympanic membrane at-electasis grading system is presented based on size, location, and depth of the atelectatic region.

Laser skin resurfacing

Laser skin resurfacing has become an important component of rejuvenation surgery. The laser allows for precise control of ablation depth and permits the surgeon to vary these depths as needed. The two wavelengths in common use are pulsed carbon dioxide and erbium:yttrium aluminum garnet. The principles and techniques of using these lasers for resurfacing and the practice of combining these wavelengths in sequence are described. Preprocedure and postprocedure measures also are discussed.

In vivo model of histologic changes after treatment with the superpulsed CO(2) laser, erbium:YAG laser, and blended lasers: a 4- to 6-month prospective histologic and clinical study

BACKGROUND AND OBJECTIVE

To compare the in vivo histologic effects of the pulsed carbon dioxide (CO(2)) and erbium:ytrium aluminum garnet (Er:YAG) lasers and to assess the effects of combining CO(2) and Er:YAG laser modalities during a single treatment session. We previously reported 10 patients treated with four laser regimens: CO(2) alone, CO(2)/Er:YAG, Er:YAG alone, Er:YAG/CO(2) with time points at 1 hour and 7 days between laser treatment and histologic analysis. This study found that the optimal treatment consisted of limited CO(2) laser passes followed by Er:YAG. This treatment produced less collagen injury, less thermal necrosis, and more robust epithelial and dermal fibrous tissue regeneration in the acute phase of healing. The present study examines the histologic changes resulting from the host healing response to laser treatment on long-term follow-up of 4-6 months.

STUDY DESIGN/MATERIALS AND METHODS

The Stanford University Committee on Human Subjects in Medical Research approved this study. Nine patients with actinic damage and indications for rhytidectomy volunteered for this interventional study in which each patient served as both experimental and control. The right preauricular area was treated at five sites with the following: (1) CO(2), (2) CO(2) followed by Er:YAG, (3) Er:YAG, (4) blended CO(2)/Er:YAG (Derma-Ktrade mark), (5) phenol. Each was subjected to full-face or sub-unit treatment. Each patient was followed up initially daily then weekly for healing of the full-face laser and for differences in healing of the five treatment areas. Five patients were selected for histologic evaluation. At 4-6 months, these patients underwent rhytidectomy with immediate removal of laser-treated skin, which was evaluated histologically by the study dermatopathologist, who was blinded to the treatment at each site.

RESULTS

CO(2) laser treatment produced the greatest thickness of neocollagen (0.27 mm; P < 0.05), the highest neocollagen density (P < 0.05), the greatest decrease in elastosis (27%), but took the longest time for healing and resolution of erythema and inflammation (up to 6 months). Er:YAG used alone produced the least collagen density, with the thinnest band of neocollagen (0.08 mm), but the most rapid resolution of erythema and inflammation (within 10 days). Combined CO(2)/Er:YAG treatments, including Derma-Ktrade mark and CO(2) followed by Er:YAG produced histologic changes that were intermediate, as well as recovery that was intermediate (resolution of erythema within 1 month); the development of neocollagen was greater in CO(2)-containing modalities than Er:YAG used alone by a statistically significant margin (P = 0.001). These histologic findings were corroborated by clinical correlation by examination of the five treatment spots in nine patients and in full-face treatments in 100 patients.

CONCLUSION

Collagenesis is greatest with CO(2) and least with Er:YAG. Elastosis decreased to the greatest degree with CO(2), least with erbium, and to an intermediate extent with blended CO(2)/Er:YAG regimens (sequential and Derma-K). These changes from control are statistically significant with all regimens (P < 0.05). Blended CO(2)/Er:YAG treatments provide an optimal combination of the benefits of CO(2) but with lesser erythema and healing delay. Clinical and histologic findings change over time for different treatments. Thus, long-term histology is critical for predicting results of treatment.