Anatomical Proposal for Botulinum Neurotoxin Injection for Horizontal Forehead Lines.

SUMMARY: The frontalis muscle is situated across the forehead and is a representative target muscle for botulinum neurotoxin (BoNT) injections aimed at treating horizontal wrinkles in this region. However, a lack of anatomical information regarding the shape and thickness of the frontalis may lead to unexpected adverse effects, such as ptosis and samurai eyebrows, caused by the lack of detail on anatomical variation. Achieving the maximum effect using the minimal amount of BoNT requires a precise injection into the frontalis muscle. The anatomical factors associated with BoNT injection into the frontalis muscle have been reviewed in the current study. Up-to-date understanding of the localization of the BoNT injection point according to an updated understanding of the anatomy leads to more accurate localization of the injection point into the frontalis muscle. Optimal injection sites have been provided for the frontalis muscle, and the injection method has been recommended. The authors suggest optimal injection sites according to the external anatomical landmarks of the forehead. Furthermore, these proposals could aid in a more precise procedure that avoids the deleterious effects of BoNT.

Guidelines for Botulinum Neurotoxin Injection for Facial Contouring.

SUMMARY: The hypertrophied temporalis and masseter muscles give a muscular shaped and bulky contour to the face. Botulinum neurotoxin injection methods are commonly used for facial contouring; however, adverse effects have been reported owing to a lack of delicate anatomical information. The anatomical considerations when injecting botulinum neurotoxin into the temporalis and masseter muscles were reviewed in the present study. Current knowledge on the localization of the botulinum neurotoxin injection point with more recent anatomical dissection and modified Sihler staining procedures was assessed. The authors found that, for the muscles, the injection point can be more precisely demarcated. Optimal injection sites are presented for the temporalis and masseter muscles, and the injection technique is suggested. The authors propose the optimal injection sites in relation to external anatomical landmarks for the frequently injected muscles of the face to facilitate the efficiency of botulinum neurotoxin injections. In addition, these guidelines would aid in more precise practice without the adverse effects of botulinum neurotoxin.

A novel needle-free microjet drug injector using Er:YAG LASER: A completely new concept of transdermal drug delivery system.

The skin barrier effectively inhibits the penetration of substances; therefore, drug delivery, especially the delivery of drugs that are hydrophilic, through the skin, is challenging. Objectives: Physicians in the esthetic field now use the transdermal drug delivery system to attempt to deliver esthetic materials, such as hyaluronic acid and poly-DL-lactic acid into the skin. Conventionally, esthetic physicians manually injected these materials using needle syringes into the dermis layer. However, the injection is often irregular, imprecise, slow, and painful. Injector devices have been developed to overcome these limitations. A total of five Korean cadavers (that of three men and two women with a mean age of 69.2 years; range, 60-73 years) underwent laser injection. We used a device called Er:YAG LASER to create the pressure needed for microjet delivery to the skin of the cadaver. Discussion: In this study, the first LASER pressure-based, needle-free microjet injector was used to deliver drugs effectively into the dermis of a cadaver. This study showed that a novel needle-free microjet injector using Er:YAG LASER can introduce beneficial, liquid, esthetic drugs into the papillary dermal layer (depth of 300um) with minimal epidermal damage.

Intramuscular Neural Arborization of the Latissimus Dorsi Muscle: Application of Botulinum Neurotoxin Injection in Flap Reconstruction.

Postoperative pain after breast reconstruction surgery with the latissimus dorsi flap is a common occurrence. Botulinum neurotoxin (BoNT) injection during surgery is effective in reducing postoperative pain. This study aimed to determine the most appropriate locations for BoNT injection. A modified Sihler's method was performed on the latissimus dorsi muscles in 16 specimens. Intramuscular nerve arborization was noted under the landmark of the medial side surgical neck of the humerus to the line crossing the spinous process of T5 and the middle of the iliac crest. The latissimus dorsi muscles were divided into medial, middle, and lateral segments with 10 transverse divisions to give 10 sections (each 10%). Intramuscular nerve arborization of the latissimus dorsi muscle was the largest from the medial and lateral part of the muscle ranging from 40 to 60%, middle part from 30 to 60% and medial, middle and lateral part from 70 to 90%. The nerve entry points were at the medial and lateral part with 20-40% regarding the medial side of surgical neck of the humerus to the line crossing spinous process of T5 to the middle of iliac crest. These outcomes propose that an injection of BoNT into the latissimus dorsi muscles should be administered into specific zones.

Anatomical locations of the motor endplates of sartorius muscle for botulinum toxin injections in treatment of muscle spasticity.

PURPOSE: This study aimed to detect the idyllic locations for botulinum neurotoxin injection by analyzing the intramuscular neural distributions of the sartorius muscles. METHODS: An altered Sihler's staining was conducted on sartorius muscles (15 specimens). The nerve entry points and intramuscular arborization areas were measured as a percentage of the total distance from the most prominent point of the anterior superior iliac spine (0%) to the medial femoral epicondyle (100%). RESULTS: Intramuscular neural distribution were densely detected at 20-40% and 60-80% for the sartorius muscles. The result suggests that the treatment of sartorius muscle spasticity requires botulinum neurotoxin injections in particular locations. CONCLUSIONS: These locations, corresponding to the locations of maximum arborization, are suggested as the most suggestive points for botulinum neurotoxin injection.

Application of Botulinum Neurotoxin Injections in TRAM Flap for Breast Reconstruction: Intramuscular Neural Arborization of the Rectus Abdominis Muscle.

Breast reconstruction after mastectomy is commonly performed using transverse rectus abdominis myocutaneous (TRAM) flap. Previous studies have demonstrated that botulinum neurotoxin injections in TRAM flap surgeries lower the risk of necrosis and allow further expansion of arterial cross-sectional diameters. The study was designed to determine the ideal injection points for botulinum neurotoxin injection by exploring the arborization patterns of the intramuscular nerves of the rectus abdominis muscle. A modified Sihler's method was performed on 16 rectus abdominis muscle specimens. Arborization of the intramuscular nerves was determined based on the most prominent point of the xyphoid process to the pubic crest. All 16 rectus abdominis muscle specimens were divided into four muscle bellies by the tendinous portion. The arborized portions of the muscles were located on the 5-15%, 25-35%, 45-55%, and 70-80% sections of the 1st, 2nd, 3rd, and 4th muscle bellies, respectively. The tendinous portion was located at the 15-20%, 35-40%, 55-60%, and 90-100% sections. These results suggest that botulinum neurotoxin injections into the rectus abdominis muscles should be performed in specific sections.

Guidelines for botulinum neurotoxin injections in piriformis syndrome.

BACKGROUND: The piriformis muscle is normally involved in piriformis syndrome and can be treated with botulinum neurotoxin using several different injection methods. However, definitive injection guidelines for the muscle have not been reported previously. AIMS: This study aimed to determine the ideal area for injections based on the intramuscular nerve distribution as obtained using a modified Sihler's staining technique. MATERIALS AND METHODS: A modified Sihler's method was applied to the piriformis muscle in 15 specimens. The intramuscular arborization areas were identified based on two anatomical landmarks: (a) the lateral border of the sacrum bone and (b) the greater trochanter. RESULTS: The nerve entry point for both piriformis muscles was found in the area between the lateral border of the sacrum and one-fifth of the distance toward the greater trochanter. The intramuscular nerve distribution for the piriformis muscle had the largest arborization patterns between one-fifth and two-fifths of the distance from the sacrum to the greater trochanter. The piriformis muscle was tendinous from two-fifths of the distance to the greater trochanter. DISCUSSION: This study has yielded suggested optimal injection locations for the piriformis muscle relative to external anatomical landmarks. CONCLUSION: Clinicians can use these guidelines to ensure the effectiveness of not only botulinum neurotoxin injections but also other agents such as steroids, anesthetics, and normal saline. These guidelines will also help to avoid adverse outcomes of injection treatments.

Comparison between Conventional Blind Injections and Ultrasound-Guided Injections of Botulinum Toxin Type A into the Masseter: A Clinical Trial.

The aim of the study was to propose a more efficient and safer botulinum toxin type A (BoNT-A) injection method for the masseter by comparing the conventional blind injection and a novel ultrasonography (US)-guided injection technique in a clinical trial. The 40 masseters from 20 healthy young Korean volunteers (10 males and 10 females with a mean age of 25.6 years) were included in this prospective clinical trial. The BoNT-A (24 U) was injected into the masseter of each volunteer using the conventional blind and US-guided injection techniques on the left and right sides, respectively, and analyzed by US and three-dimensional (3D) facial scanning. One case of PMB (paradoxical masseteric bulging) was observed on the side where a conventional blind injection was performed, which disappeared after the compensational injection. The reduction in the thickness of the masseter in the resting state differed significantly at 1 month after the injection between the conventional blind injection group and the US-guided injection group by 12.38 ± 7.59% and 17.98 ± 9.65%, respectively (t(19) = 3.059, p = 0.007). The reduction in the facial contour also differed significantly at 1 month after the injection between the conventional blind injection group and the US-guided injection group by 1.95 ± 0.74 mm and 2.22 ± 0.84 mm, respectively (t(19) = 2.908, p = 0.009). The results of the study showed that the US-guided injection method that considers the deep inferior tendon by visualizing the masseter can prevent the PMB that can occur during a blind injection, and is also more effective.

PAN-ASIAN CONSENSUS-Key Recommendations for Adapting the World Congress of Dermatology Consensus on Combination Treatment with Injectable Fillers, Toxins, and Ultrasound Devices in Asian Patients.

BACKGROUND. The demand for minimally invasive aesthetic procedures has driven requests by physicians for guidance on their use in Asian patients, who have unique cultural preferences, social trends, and anatomy. However, few guidelines exist, particularly on combination treatment strategies for different facial shapes or indications such as the modification of face shapes to the "oval ideal."Physicians must, therefore, apply Caucasian patient-optimized guidelines to their Asian patients. METHODS. Eleven specialists developed a consensus on the use of botulinum toxin A (BoNT-A), calcium hydroxylapatite (CaHA) and hyaluronic acid (HA) fillers, and microfocused ultrasound with visualization (MFU-V) devices in Asian patients on upper-, middle-, and lower-face indications, including strategies to modify different facial shapes to the oval shape. Approval from 70 to 90 percent of all participants led to moderate consensus, while 90 percent agreement denoted a strong consensus. RESULTS. For early intervention/enhancement and restoration, most combination strategies are similar between Asian and Caucasian patients. Compared to Caucasian patients, however, beautification is a more common focus in Asian patients. The "ideal" oval facial shape can be created using different interventions depending on the patient's baseline characteristics. CONCLUSIONS. Although treatments and treatment sequences for early intervention/enhancement and restoration for beautification in Asian patients are similar to those in Caucasian patients, different treatment strategies may be required.

Filler Rhinoplasty Evaluated by Anthropometric Analysis.

BACKGROUND: There are no reports of objectively evaluating the efficacy of filler rhinoplasty by anthropometric techniques. OBJECTIVE: To objectively demonstrate the effectiveness of filler rhinoplasty by anthropometric analysis. MATERIALS AND METHODS: A total of 242 patients who revisited the clinic within 2 months of undergoing hyaluronic acid filler rhinoplasty were analyzed based on the injection site, injected volume, and the change in anthropometry. RESULTS: Among the 242 patients, 112 (46.3%) were in the nasal dorsum augmentation group, 8 (3.3%) were in the tip rotation group, and 122 (50.4%) were in the whole nose augmentation group. Average injection volume was 1 ± 0.4 mL for nasal dorsum and 0.9 ± 0.3 mL for tip rotation, whereas 1.6 ± 0.5 mL was used for whole nose augmentation. On follow-up, the radix height, nasofrontal angle, and nasolabial angle (NLA) had increased by 78.3%, 5.7 ± 4.1°, and 9.4 ± 4.5°, respectively, whereas the modified nasofacial angle had decreased by 1.9 ± 2.9°. Three cases (1.2%) of vascular complications were encountered. CONCLUSION: Filler rhinoplasty is a simple and effective treatment modality producing outcomes comparable with surgical augmentation rhinoplasty. Among various anthropometric measurements, the nasal radix height was the most useful for evaluating dorsum augmentation, whereas the NLA was the best for nasal tip rotation.

The Anatomical Basis of Paradoxical Masseteric Bulging after Botulinum Neurotoxin Type A Injection.

The aim of this study was to determine the detailed anatomical structures of the superficial part of the masseter and to elucidate the boundaries and locations of the deep tendon structure within the superficial part of the masseter. Forty-four hemifaces from Korean and Thai embalmed cadavers were used in this study. The deep tendon structure was located deep in the lower third of the superficial part of the masseter. It was observed in all specimens and was designated as a deep inferior tendon (DIT). The relationship between the masseter and DIT could be classified into three types according to the coverage pattern: Type A, in which areas IV and V were covered by the DIT (27%, 12/44); Type B, in which areas V and VI were covered by the DIT (23%, 10/44); and Type C, in which areas IV, V, and VI were covered by the DIT (50%, 22/44). The superficial part of the masseter consists of not only the muscle belly but also the deep tendon structure. Based on the results obtained in this morphological study, we recommend performing layer-by-layer retrograde injections into the superficial and deep muscle bellies of the masseter.

Comparison of onabotulinumtoxinA and rimabotulinumtoxinB for the treatment of axillary hyperhidrosis.

BACKGROUND: Recently, rimabotulinumtoxinB has been increasingly used as an off-label treatment of primary axillary hyperhidrosis (PAH). However, the optimal conversion ratios for onabotulinumtoxinA and rimabotulinumtoxinB remain to be determined. OBJECTIVE: To compare effectiveness, satisfaction level, and safety of rimabotulinumtoxinB with onabotulinumtoxinA at a conversion ratio of 1:30 for the treatment of PAH. METHODS: Adults with PAH were enrolled in this bilaterally paired single-subject study. Each patient was randomly treated with 1,500 U rimabotulinumtoxinB on 1 axilla and 50 U onabotulinumtoxinA contralaterally. Hyperhidrosis Disease Severity Scale was assessed before and after treatment up to 20 weeks. A 10-cm visual analog scale representing improvement of hidrotic symptom and starch-iodine test were also used to assess therapeutic efficacy. RESULTS: Twenty-four patients completed the study. Both groups showed comparable and efficacious anhidrotic effects through 20 weeks for any variable. There were no significant differences in terms of the onset of action or mean duration of action between the 2 groups. Overall satisfaction with the treatment was equally high in both groups. CONCLUSION: Both toxins showed comparable anhidrotic effect for the treatment of axillary hyperhidrosis at a conversion ratio of 1:30.

Alternative method for creating fine hairs with hair removal laser in hair transplantation for hairline correction.

BACKGROUND: Foremost fine hairs in the frontal hairline region are critical in hair transplantation for hairline correction (HTHC) in women. However, there are few studies on a nonsurgical revisionary method for improving an unnatural foremost hairline with thick donor hairs resulting from a previous HTHC. OBJECTIVE: To investigate the efficacy and safety of using a hair removal laser (HRL) system to create fine hairs in Asian women with thick donor hairs. METHODS: Through a retrospective chart review, the HRL parameters, hair diameter (measured with a micrometer before and after the procedures), subjective results after the procedures, adverse effects, and the number of procedures were investigated. The reduction rate of the hair diameter was calculated. RESULTS: Twenty-four women who received long-pulse Neodymium-Doped:Yttrium Aluminum Garnet therapy after HTHC were included. The parameters were as follows: delivered laser energy, 35~36 J/cm(2); pulse duration, 6 ms; and spot size, 10 mm. The mean number of laser sessions was 2.6. The mean hair diameter significantly decreased from 80.0±11.5 µm to 58.4±13.2 µm (p=0.00). The mean rate of hair diameter reduction was -25.7% (range, -44.6% to 5.7%). The number of laser sessions and the hair diameter after the procedures showed a negative correlation (r=-0.410, p=0.046). Most of the patients (87.5%) reported subjective improvement of their hairlines. Most complications were transient and mild. CONCLUSION: HRL can be an alternative method for creating fine hairs and revising foremost hairline in Asian women with thick donor hairs.

Long pulsed 1064 nm Nd:YAG laser treatment for wrinkle reduction and skin laxity: evaluation of new parameters.

INTRODUCTION: Among non-ablative devices for wrinkle reduction and skin laxity, long pulsed 1064 nm Nd:YAG laser (LPND) has considerable effectiveness. It can penetrate to deep dermis due to its longer wavelength. This study assesses the efficacy and safety of LPND applying new parameters for skin rejuvenation in Korean subjects. METHODS: A prospective randomized split-faced study was done (n = 20). Half of the face was treated with three passes of LPND at a spot size of 12 mm, 20-24 J/cm(2) fluence, 12 ms width, and frequency of 2 Hz, for three sessions, every four weeks. Outcomes were measured by wrinkle evaluation of blinded investigators, subjects' self-assessment, objective measurements of elasticity, and skin biopsy. RESULTS: Four weeks after the final treatment sessions, the average wrinkle grades of the treated side were reduced by 45.1%. Skin elasticity was significantly increased. The increment of collagen and elastic fiber in papillary dermis was confirmed histologically. No adverse reaction was reported. Pain on the treated side was mild without needing anesthesia. DISCUSSION: The authors studied new parameters for LPND for improvement of wrinkles and skin laxity with fewer treatment sessions without serious complications. Histologic findings corresponded to clinical improvement. CONCLUSION: New parameters of LPND can achieve wrinkle improvement with few side effects.

The risorius muscle: anatomic considerations with reference to botulinum neurotoxin injection for masseteric hypertrophy.

BACKGROUND: The botulinum neurotoxin Type A (BTX) injection into the masseter muscle often causes a change in the facial expression. There is as yet no precise anatomic evidence to support this etiologic factor of constrained facial expressions. OBJECTIVE: The aim of this study was to clarify the location and boundaries of the risorius muscle and its topographical relationship with the surrounding structures. MATERIALS AND METHODS: This study involved the dissection of 48 hemifaces. The locations of origin and insertion points of the risorius muscle were measured, and the masseter muscle was divided into 6 equally sized rectangular areas. RESULTS: Cases where the masseter muscle was covered by the risorius muscle were classified into the following 4 types: in Type A, Area III was partially covered by the risorius (17.8%); in Type B, Area VI was partially covered (20.0%); in Type C, Areas III and VI were partially covered (53.3%); and in Type D, Areas II, III, and VI were covered (6.7%). CONCLUSION: These findings suggest that the medial part of the masseter muscle represents a hazard zone into which the injection of BTX may affect the risorius muscle, potentially resulting in iatrogenic unnatural facial expressions.

Paracrine effects of adipose-derived stem cells on keratinocytes and dermal fibroblasts.

BACKGROUND: Adipose-derived stem cells (ASCs) are mesenchymal stem cells that have recently been applied to tissue repair and regeneration. Keratinocytes and dermal fibroblasts play key roles in cutaneous wound healing. OBJECTIVE: We investigated the paracrine effects of ASCs on HaCaT cells (i.e., immortalized human keratinocytes) and human dermal fibroblasts to explore the mechanism of the effects of ASCs on cutaneous wound healing. METHODS: HaCaT cells and primary cultured human dermal fibroblasts were treated with 50% conditioned medium of ASCs (ASC-CM). Viability, in vitro wound healing, and fibroblast-populated collagen lattice contraction assays were conducted, and reverse transcription-polymerase chain reaction (RT-PCR) for the type I procollagen α1 chain gene was performed. RESULTS: The proliferation of HaCaT cells and fibroblasts was increased by ASC-CM in the viability assay. ASC-CM promoted in vitro wound healing of HaCaT cells and increased the contraction of the fibroblast-populated collagen lattice. RT-PCR showed that the transcription of the type I procollagen α1 chain gene in fibroblasts was upregulated by ASC-CM. CONCLUSION: The stimulatory effect of ASC on cutaneous wound healing may be partially mediated by paracrine effects of ASCs on other skin cells. Application of ASCs or ASC-derived molecules could be an innovative therapeutic approach in the treatment of chronic wounds and other conditions.