Hair Characteristics Research Articles

Shock Waves for Hair Growth and Regeneration in Patients With Female Pattern Hair Loss.

Female pattern hair loss (FPHL) is women's most common form of alopecia. The study aimed to evaluate the efficacy of extracorporeal shock waves for hair growth and regeneration in women with FPHL. A prospective single-center noncontrolled study was conducted in patients with FPHL who underwent eight treatment sessions with C-Actor, a shock wave applicator. Outcome measures included total hair count, number of follicular units (FUs)-single FUs, double FUs, triple and bigger FUs-the average thickness, cumulative hair thickness, and changes in the Derived Sinclair scale, assessed with Tricholab (Fotofinder System). Patients completed a survey to assess their subjective perceptions of hair improvement regarding softness, hair loss, quality, and volume. Twenty women were included with a mean age of 43 (SD = 5.65). The mean increase in total hair count was 8.9% (p<0.00001), in number of FUs 4.6% (p = 0.00031), in number of triple and bigger FUs 18.4% (p = 0.0004), in cumulative hair thickness 8.0% (p<0.00001), with a decrease of 5.7% in mean Derived Sinclair scale value by 2.2-2.1 (p<0.0001). After 3 months, 85% of patients perceived improvement in hair volume. Extracorporeal shock waves for hair growth and capillary regeneration in women with FPHL showed statistically significant outcomes, and all patients reported an improvement in hair characteristics.

An Optimization Design of Piezoelectric Hair Sensor for Oscillatory Flow Detection

Abstract Biological hair is widely found in nature, and they are responsible for sensing and responding to environmental stimuli in living organisms. By simulating biological hair characteristics, they develop hair flow sensor to achieve high sensitivity detection of environmental factors such as small motion and fluid flow field. Output signal is the key indicator of hair flow sensor, and the improvement of output signal is important to the design of hair flow sensor. The existing hair flow sensor sensing structure is generally straight hair, and the output signal is limited by the structure, and the response is small. Using the direct piezoelectric fiber as the initial configuration, we form a new piezoelectric curved fiber by modeling the secondary spline curve and control point. We propose an optimization model for piezoelectric functional hair design using axial strain as a target function. At 100Hz and 500Hz, the output voltage of the optimized model is much higher than that of straight, 10 times and 7 times that of straight, respectively; An optimized curved hair configuration is obtained in a specific frequency band from 1 Hz to 500 Hz, whose average voltage magnitude of 3.1×10−3 V is 4 times greater than that of the straight hair of 7.8×10−4 V with the same size. The curved hair flow sensor breaks the output limitation of traditional straight hair configuration.

The comparison of metabolic syndrome parameters, trichoscopic and trichoscan characteristics in androgenetic alopecia (AGA) and early-onset androgenetic alopecia (early-onset AGA).

Androgenetic alopecia (AGA), the most common cause of hair loss, is influenced by various risk factors. Metabolic syndrome constitutes a collection of risk factors elevating the risk of cardiovascular disease. The presence of early-onset AGA could serve as an indicator of the emergence of metabolic syndrome, yet to date, no research has examined these parameters in AGA. This is a cross-sectional study comparing two groups; early onset versus normal onset AGA. Forty participants were enlisted and evenly distributed into the two groups. Subsequently, participants underwent examinations utilizing trichoscopy, trichoscan, and laboratory assessments. Apart from waist circumference, BMI, and age of alopecia onset, there were no notable differences concerning sociodemographic and clinical features. In terms of hair growth parameters, the telogen hair rate stands out as the sole indicator exhibiting a significant difference between both groups, while trichoscopy data also revealed varying hair characteristics. Lastly, metabolic parameters namely triglyceride, fasting blood glucose, HbA1c and HDL differ significantly, with the normal onset group demonstrating a higher prevalence of metabolic abnormality. This suggests a potential association between AGA and metabolic syndrome. However, the exact nature of this relationship remains uncertain, necessitating further research with larger samples, specific age groups and diverse study designs.

Kopexil vs minoxidil: In vivo comparative study on hair growth, hair growth promoting factors and toxicity

Introduction: This study aimed to investigate the impact of a hydro-alcoholic solution containing kopexil on hair growth, and growth factors, and to evaluate its skin penetration, as well as its potential toxic effects on the liver and kidneys in animal models. Methods: Animal studies were conducted on mice over 28 days, involving minoxidil (positive control), kopexil (test), and negative control groups. Morphological characteristics of skin and hair were assessed. Levels of hair growth-promoting markers (HGF and VEGF) were determined through western blot analysis. Toxic effects were examined by isolating and weighing the kidneys and livers, followed by histological examination. Results: The kopexil group demonstrated significant increases in hair weight, follicle count, percentage of anagen hair, and hair growth compared to the minoxidil. Western blot analysis revealed higher expression levels of hair growth-promoting factors in the kopexil-treated group. No statistically significant differences in liver and kidney weights or noticeable morphological variations were observed in the toxicity tests across the groups. Conclusion: The 5% (w/v) hydro-alcoholic solution containing kopexil proved to be an effective hair growth stimulator, influencing various factors. Its daily use can be considered a suitable treatment method for stimulating hair growth, given its improved effectiveness and ease of use for patients.

Clinic Analysis and Effective Improvement Tips for Poor Eyebrow Transplantation.

Follicular unit hair transplantation has greatly elevated the results of eyebrow restoration. However, unnatural and unbeautiful-looking results are still often seen after the surgery. This study focused on poor eyebrow transplantation, discussed its possible reasons, and offered refined proposals. A retrospective analysis was performed on 100 patients who were dissatisfied with the results of eyebrow grafting and came to our department from 2011 to 2021. Demographic characteristics, primary disease, and clinical data were objectively summarized and analyzed for these patients. The patients' medical charts and photographs were analyzed and summarized into the following outcomes: Thirty-six patients (36%) had sparse eyebrows. Forty-one patients (41%) had eyebrows with inhomogeneous density and disordered growth direction. Eleven patients (11%) did not have single-hair grafting. Seven reconstructed eyebrows (7%) had a poor connection with the remaining eyebrows. Five new eyebrows (5%) had inconsistent hair characteristics with the original eyebrows. Lower hair survival rates, insufficient understanding of naturally beautiful eyebrows, and inadequate communication with patients were the main reasons for poor outcomes. Good reconstructed eyebrows should have a high hair survival rate, and hair growth direction and characteristics should also be consistent with the natural eyebrow to achieve ideal surgical effects. 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 .

Clinical Signs and Laboratory Tests for the Differential Diagnosis ofAndrogenic and Post-COVID-19 Alopecia in Women

Background: Pathological hair loss in women has emerged as a prevalent cause for seeking specialized dermatological and cosmetic services. The most common type of this condition is androgenetic alopecia, which arises due to hormonal and micronutrient imbalances.Furthermore, during the COVID-19 epidemic, there has been a notable increase in the number of female patients with pathological hair loss as a complication of the disease, with some individualsexperiencing alopecia the sole indication of asymptomatic COVID-19. Aims: The aim of the study wassearch for objective criteria for the differential diagnosis of androgenetic alopecia and post-COVID alopecia in women based on informative trichological and laboratory markers. Materials and methods: The including criteria for androgenetic alopecia (AGA) group were elevated dihydrotestosterone (DHT) levels, clinical indications of alopecia corresponding to initial stages of the condition, and a past experience of continuous observation untilFebruary 2020. For the post-COVID alopecia (COVID) group, inclusion criteria were a confirmed diagnosis of COVID-19 using RT-PCR and the presence of alopecia symptoms emerging within a year post-infection. Evaluation of quantitative characteristics of hairs was conducted was carried out based on trichogram and phototrichogram data, followed by image processing using a computer diagnostic program. Key indicators for hair growth were identified in patients' plasma, including DHT, vitamins B9 (folic acid), B12, D (25(OH)-D3 form), E, as well as calcium (Ca), iron (Fe), magnesium (Mg), selenium (Se), copper (Cu), and zinc (Zn). CART algorithm (Classification and Regression Trees) based on recursive partitioning of available data with selection of informative predictors and formation of a tree-like hierarchical structurewas applied to determine criteria to differentiate between patients with androgenetic and post-COVID alopecia. Results: Analysis of trichograms and phototrichograms revealed that unlike androgenetic alopecia, which primarily impacts hair follicles in the telogen and anagen phases in the androgen-dependent zone, post-COVID hair loss presents as a diffuse telogen effluvium pattern, involving the androgen-dependent (parietal) area of the scalp. Notably, patients with post-COVID alopecia exhibited elevated dihydrotestosterone levels compared to reference values, with no significant differencein comparison to AGA. While there were no variations in vitamin and certain trace element levels (Fe, Ca, Mg, Zn), individuals in COVID group have demonstrated a statistically significant reduction in copper content (46.4% lower than AGA; p=0.006) alongside an increase in selenium levels (24.7% higher than AGA; p=0.003). Conclusions: The performed study for the first time presents objective criteria for the differential diagnosis of androgenetic and post-COVID alopecia in women. The data obtained show a diffuse pattern of telogen effluvium after recovering from COVID-19, linked to an imbalance in trace elements - specifically, a decrease in copper (Cu) and an increase in selenium (Se). Based on this fact, the algorithm CART used allows for a highly effective differentiation of the compared variants of pathological hair loss in studied patients and forms the basis for pathogenetically justified conservative therapy.

Discrimination of slight thermal damage to hair for arson investigation

To determine whether a suspect was in close contact with the fire source at a fire site through slight thermal damage to hair, a cone calorimeter was employed to simulate fire scene conditions as a standard radiant source. The research focused on analyzing the thermal behavior of black hair and delving into the morphological characteristics of hair exhibiting slight thermal damage. At temperatures exceeding 240 °C, the proteins within the hair began to degrade. This degradation, in conjunction with tension along the hair shaft resulting from water loss, led to the formation of microcracks that could be detected through scanning electron microscopy (SEM) but eluded observation with an optical microscope (OM). It is noteworthy that the initial slight thermal damage was regularly located at the hair shaft but not the hair tip, which should be the key parts when exanimating hairs without obvious thermal damage. Additionally, during very short exposure, the appearance of typical slight thermal damage on fire is probabilistic events. Along with the increase of temperature, the organic compounds in hair were thermally degraded into NH3, SCO and carbon CO2, resulting in the typical traces of discoloration, expansion, blistering, and cracking presented at hair shafts and tips. The probability of encountering both slight and obvious thermal damage on hair increased with rising temperatures. By observing the traces on the easily overlooked part of the hair shaft, the research established a method to analyze and discriminate the slight thermal damage to hair at fire scene, which provide valuable references for confirming arson suspects.

Characterization and Theoretical Analysis of the Venus Flytrap Trigger Hair

The Venus flytrap, which possesses a number of mechano-sensitive trigger hairs, is a typical carnivorous plant that effectively senses and catches insects to survive in nutrient-poor habitats. When insects touch the trigger hairs on a leaf, once they reach the threshold, the Venus flytrap induces an action potential and sharply closes to capture the prey. In this paper, the trigger hairs obtain a special cantilever beam structure with a stiff hair lever and a flexible basal podium, and there is a noticeable notched structure at the basal podium, which differs from a common homogeneous hair. Based on the characteristics of the Venus flytrap trigger hairs, we established a three-dimensional model and conducted theoretical and finite element analysis. The results show that the unique hollow heterogeneous cantilever structure of the Venus flytrap trigger hair can achieve high sensitivity and optimal tactile perception. Overall, the morphology, structure and mechanical characteristics of Venus flytrap trigger hairs were characterized in detail, which may provide a deeper understanding of the trigger hairs’ tactile perception mechanism. And the mechanical simulation and optimization analysis of Venus flytrap trigger hairs had an important theoretical basis and parameter support for the further design of state-of-the-art tactile sensors with high sensitivity inspired by Venus flytrap trigger hairs.

Towards a taxonomy for assessing and classifying the needs of curly hair: A mixed method, ethnographic and quantitative data study.

Hair defined as curly has an elliptical cross sectional area and unique 3D form. While the chemical, morphological and mechanical characteristics of such hair are being explored using a range of analytical techniques, hair assembly (head of hair) characteristics and individual behaviour are difficult to determine via tress-based instrumental and sensory testing. Since the demand for more efficacious and personalized products is expected to gain pace, this project sets the groundwork for developing a taxonomy for exploring and classifying curly hair needs from an individual's perspective. A mixed-method exploratory sequential design was used to gather information from people with curly hair starting with a novel in the field of cosmetics qualitative research method, Subjective Evidence-Based Ethnography (SEBE) (n = 14) and followed by an online survey (n = 212). The SEBE data analysis identified four common hair goals (aesthetic, haptic, practical and emotive) and a group of perceptions related to hair management routines. The survey explored the relationship of these hair goals with hair perceptions, hair esteem, hair characteristics and demographic variables. The findings suggest that hair goals and perceptions are stronger predictors of hair esteem than other characteristics such as hair length or curl type. Hence, a taxonomy for classifying curly hair should facilitate the development of more appropriate products, and product testing methods should incorporate such personal information in addition to objective fibre and hair assembly data. The focus of this study is on curly hair due to the lack of established methods for its objective evaluation and the personal challenges faced by people with curly and textured hair; however, the approach could be adopted to include straighter hair types.

헤어바이나이트 디자인 분석에 의한 작품 제작 연구

This study attempted to examine the formative characteristics of hair-by-night styles from the Korean beauty skills competition and analyze its meaning. The formative analysis of hair-by-night styles from the Korean beauty skills competition is a must-have tool in understanding the value and meaning of hairstyles through the analysis of visual elements. It is a field to be studied and developed continuously to obtain better results in aesthetics and design. It is anticipated that emphasis on the importance of such formative analysis would be available as basic data needed to increase and further develop applicability to diverse fields. This study analyzed shape, texture, color and direction flows, and the results found the followings: In terms of the formative characteristics of hair by night, symmetric forms were observed. In addition, triangular structure was designed at the front in an elegant and stable form. They can be defined as a dinner-party style which maximizes brilliance, using at least two different hairpieces, maintaining their creative style and uniformity. Hair directions and shapes at the front, side and nape varied depending on the position of a hairpiece. This study examined hairstyles from the beauty skills competition only so that it is limited in generalizing the formative characteristics of hairstyles. It is hoped that Korean hairstyles would evolve in a more creative fashion, gradually going beyond the formality and limit of conventional design.

Retrospective evaluation of Penguin Cold Caps for chemotherapy-induced alopecia

BackgroundScalp cooling is an increasingly recognized non-pharmacologic approach to minimize chemotherapy-induced alopecia (CIA). Several commercially available machine-based and manual scalp cooling systems are available; however, literature reports of effectiveness are highly variable. The purpose of this study was to determine real-world tolerability and subjective effectiveness of a manual cold capping system in minimizing CIA across a variety of patient race and hair types. This study was a single-institution review of outcomes from manual cold capping.MethodsWe identified retrospective cohort of adult patients who presented to discuss cold capping between January 14, 2019, and March 31, 2022. Data collected from medical records included demographics, decision to pursue/continue cold capping, diagnoses, chemotherapy regimens, hair characteristics (length, thickness, coarseness, type), and subjective perception of percentage of hair retained. Those with successful vs. unsuccessful cold capping (≥ 50% vs. < 50% of hair retained) were compared based on the patient-level factors of interest.FindingsA total of 100 patients initiated cold capping during the study period, and 95% of them completed cold capping. The majority of patients who started cold capping completed it. The median-reported percentage of hair maintained was 75%, and 82/89 (92.1% of patients) had favorable results, defined as ≥ 50% of hair retained. The only patient-level factor associated with favorable response was chemotherapy regimen, with fewer patients receiving doxorubicin-containing regimens having successful hair retention compared to other chemotherapy types (71.4% successful results vs. 95.7% for those receiving paclitaxel-containing regimens and 96.6% for those receiving docetaxel-containing regimens (p = 0.018). There was no difference in success based on patient race/ethnicity or hair characteristics.InterpretationThe overall effectiveness (92.1%) in this study is consistent to higher than many literature reports. One possible reason for the high success in our cohort is compliance with cold capping protocols, meaning applying the cap in the appropriate manner and wearing the cap for the prescribed durations, which may impact effectiveness.

Begonia tripurensis (Begoniaceae, sect. Platycentrum), a new species from Tripura, Northeast India

A new species of Begonia sect. Platycentrum is described here from the moist deciduous forest of Tirthamukh near Dumboor Lake, Tripura, India. It is similar to B. scintillans, B. chindwinensis and B. thomsonii but differs in plant size, hair characters, petiole length, flowers, stamens and fruits. A description with coloured photographs and information on the phenology and habitat are provided.

Quantitative measurement of hair diameter diversity as a diagnostic indicator of androgenetic alopecia in Korean males: A cross-sectional study

BackgroundThe conventional 20% threshold for hair diameter diversity (HDD), widely accepted for diagnosing androgenetic alopecia (AGA) in the vertex area, has not quantitatively analyzed. ObjectiveTo validate the HDD 20% threshold for AGA and develop a refined, Korean-specific criterion. MethodsThis study involved 240 male patients with AGA, categorized by the V stages of the basic and specific (BASP) classification. Phototrichogram images of the vertex region were analyzed using Image J software for hair thickness measurement. ResultsROC curve analysis determined the 45 μm hair diameter threshold as the most diagnostic for AGA, with an AUC value of 0.884 and a Youden index of 0.659. Optimal AGA diagnosis was achieved when over 21% of hair had a diameter of ≤ 45 μm. LimitationsRestriction to Korean male limits its applicability to a broader population, and using a specific hair diameter threshold does not account for individual variations in hair characteristics. ConclusionThe study validates the conventional HDD 20% threshold and proposes a more appropriate 45 μm threshold for Korean males, beyond the 40 μm. It concludes that while the HDD 20% remains a key method for early detection of vertex AGA, the definition of thin hair should be ethnicity-specific.

Potential Tick Defense Associated with Skin and Hair Characteristics in Korean Water Deer (Hydropotes inermis argyropus).

The Korean water deer (WD), a predominant wildlife species in South Korea, is listed as vulnerable by the IUCN Red List. Despite belonging to the same family, Cervidae, WD show significantly fewer adult ixodid tick infestations compared to roe deer (RD). Ticks, which cannot fly, engage in questing behavior in natural environments to latch onto hosts. They detect signals like body temperature and host skin chemicals to navigate through the hair coat to the preferred epidermis. In light of this, we performed an extensive comparative study of the skin tissue and hair characteristics of both deer species, focusing on elements contributing to the reduced tick bite incidence in WD. Remarkably, WD exhibited more prominent blood vessels, sebaceous glands, and sweat glands, which are crucial for skin barrier functions (p < 0.005). Moreover, WD had irregular scale patterns on their hair cuticles and possessed hair that was significantly stiffer and 2.83 times thicker than that of RD (p < 0.001). These characteristics potentially impede ticks from reaching the epidermis hair in WD and RD in the context of tick bite prevention. Further investigations in this area could enhance our understanding of tick-host dynamics and contribute to developing preventive measures against tick-borne diseases in other deer species.

Recent Progress in Hair Science and Trichology.

Hair is important to our appearance as well as to protect our heads. Human hair mainly consists of proteins (80-85%), melanin pigments (0-5%), water (10-13%), and lipids (1-6%). The physicochemical properties of hair have been studied for over 100 years. However, they are not yet thoroughly understood. In this review, recent progress and the latest findings are summarized from the following three perspectives: structural characteristics, delivery and distribution of active ingredients, and hair as a template. The structural characteristics of hair have been mainly investigated by microscopic and/or spectroscopic techniques such as atomic force microscopy integrated with infrared spectroscopy (AFM-IR) and rheological measurements. The distribution of active ingredients has been generally evaluated through techniques such as nanoscale secondary ion mass spectrometry (NanoSIMS). And finally, attempts to explore the potential of hair to be used as a substrate for flexible device fabrication will be introduced.

Physical, thermal and mechanical properties of horse tail and mane hairs

Purpose This study aims to comparatively reveal the physical, thermal and mechanical properties of horse tail and mane hairs, which have the potential to be used in many areas. Design/methodology/approach Physical properties of horsehairs such as diameter, density, moisture and water absorption were measured. Fourier transform infrared, field emission scanning electron microscopy and amino acid analyzes were applied to the hairs. Thermal stability of horsehair was investigated by thermogravimetric analysis and differential scanning calorimetry analysis. In addition, breaking strength and elongation values of mane and tail hairs were measured. Findings As a result of morphological analysis of horsehair, it was observed that there are usually gaps in the internal structure of horsehair, but the size and continuity of these gaps vary. It has been determined that there is a significant difference between the tenacity values of tail and mane hairs as well as geometric characteristics. In addition, amino acid analysis has shown that the amino acid contents of horse tail and mane hairs are similar and not much different from sheep’s wool. Originality/value Horsehair has been used for various purposes such as clothing, accessories, brushes, upholstery and reinforcement material. To use horsehair in accordance with its application area and performance characteristics, it is necessary to know its physical, thermal and mechanical properties. It is considerable to reveal the similar and different aspects of tail and mane hairs to determine whether they are alternatives to each other. Therefore, revealing the characteristics of tail and mane hairs comparatively constitutes the originality of this study.

Advancements in Graft Placement Techniques.

For decades, the placement of follicular units (FUs) into incisions in the recipient area was exclusively carried out using forceps. In 1992, Dr. Choi introduced an instrument known as the "implanter," which had the advantage of simultaneously creating incisions and placing FUs without damaging sensitive parts. Its initial popularity was greater in the East, primarily due to the characteristics of Asian hair. Asian hair is typically straight and thick, with FUs mostly consisting of just one or two hair.With the description of the follicular unit excision (FUE) technique in 2002 and its widespread adoption nearly a decade later, the advantages of using the implanter also gained popularity in the West. The uniformity in the size of FUs provided by the FUE technique and the possibility of delegating the placement were key attractions in the use of this placement tool. In addition to the traditional Korean implanter with a sharp needle, other implanters and inserters have been described.The choice of implantation technique depends on individual adaptation and the advantages and disadvantages offered by each instrument. Although forceps allow for safe placement in the hands of well-trained teams, the increased fragility of FUs obtained with the FUE technique has led to the growing acceptance of techniques that employ implanters and inserters.

Preliminary study on variations in local varieties of bornean ironwood (Eusideroxylon zwageri Teijsm. & Binn.) based on vegetative characters

Bornean Ironwood (Eusideroxylon zwageri), a monotypic species of Eusideroxylon, is threatened due to its rarity in its natural habitat. It is a Class I timber commodity in Indonesia and known with several local varieties determined by local people. This study aimed to described the local varieties of ironwood from Kalimantan by taxonomic study. Field exploration had been carried out during 2022 to 2023 in North Kalimantan, East Kalimantan, and West Kalimantan provinces to collect herbarium specimens of ironwood local varieties. The specimens were then observed and characterized in Laboratory of Plant Biosystematics-BRIN. Observation was also done for ironwood collection available at Herbarium Bogoriense. Fourty one characters extracted from vegetative parts, such as stems, twigs and leaves were used to find clades within ironwood species. Phenetic analysis generated six clades in which hair characters on twigs and leaves and color variations of twigs and petiole were the main informative characters that differentiate between clades at an infraspecific level. Anatomical characters cannot be used as supporting characters in this study. Support from deeper morphological analysis involving more specimens and species groups affiliated with the genus Eusideroxylon, as well as molecular analysis is needed to strengthen the grouping at an infra-specific level.

Pediculosis capitis risk factors in schoolchildren: hair thickness and hair length

The human head lice is a cosmopolitan ectoparasite that causes pediculosis. The main way of spreading lice is through direct head-to-head contact. It is popular knowledge that some individuals are more susceptible to contracting head lice than others. Reports of individuals who have never been affected by the disease are common, even living in the same environment and under the same conditions as people who regularly have lice infestations. Previous research has been carried out on the risk of this infection associated with different human factors like gender or age. However, studies on the influence of the individual hair characteristics are scarce. The objective of the study was to analyze the pediculosis risk using geographical location, gender, age and individual hair characteristics as variables. Pediculosis was diagnosed through the detection of living lice in the hair. This cross-sectional school-based epidemiological study was conducted in 310 schoolchildren aged 1 to 13 years of schools in 4 municipalities situated in the State of Paraná, Brazil. The prevalence of head louse infection in primary school students was 49.35 %. The Odds Ratio of presence of pediculosis (OR) was estimated using multivariate logistic regression analysis. The results obtained indicate that hair length and thickness increase the risk of infection. Furthermore, the inclusion of hair color, hair shape, kind of hair-scale as covariates increases the risk of pediculosis, indicating that these variables partly explain this susceptibility and that pediculosis is independent of gender. A smaller hair diameter may favor insect fixation to the hair in the nymphal phases. These results may explain why girls are a greater risk as they let their hair grow for cultural reasons, i.e., being of female gender is an agglutinating variable. The conclusions drawn may explain the discrepancies obtained in previous analyses.

Advancements in Graft Placement Techniques.

For decades, the placement of follicular units (FUs) into incisions in the recipient area was exclusively carried out using forceps. In 1992, Dr. Choi introduced an instrument known as the "implanter," which had the advantage of simultaneously creating incisions and placing FUs without damaging sensitive parts. Its initial popularity was greater in the East, primarily due to the characteristics of Asian hair. Asian hair typically has straight and thick hair, with FUs mostly consisting of just one or two hairs. With the description of the FUE technique in 2002 and its widespread adoption nearly a decade later, the advantages of using the implanter also gained popularity in the West. The uniformity in the size of FUs provided by the FUE technique and the possibility of delegating the placement were key attractions in the use of this placement tool. In addition to the traditional Korean implanter with a sharp needle, other implanters and inserters have been described. The choice of implantation technique depends on individual adaptation and the advantages and disadvantages offered by each instrument. Although forceps allow for safe placement in the hands of well-trained teams, the increased fragility of FUs obtained with the FUE technique has.