Hair Angle Research Articles

Invention of automated numerical algorithm adopting binarization for the evaluation of scalp hair coverage: An image analysis providing a substitute for phototrichogram and global photography assessment for hair diseases

BackgroundThe efficacy of therapeutic modalities for hair disease can be evaluated globally by photo assessment and more precisely by phototrichogram (PTG). However, the latter procedure is laborious, time consuming, subject to inter-observer variation, and requires hair clipping. ObjectiveTo establish an automated and patient/investigator friendly methodology enabling quantitative hair amount evaluation for daily clinical practice. MethodsA novel automated numerical algorithm (aNA) adopting digital image binarization (i.e., black and white color conversion) was invented to evaluate hair coverage and measure PTG parameters in scalp images. Step-by-step improvement of aNA was attempted through comparative analyses of the data obtained respectively by the novel approach and conventional PTG/global photography assessment (GPA). ResultsFor measuring scalp hair coverage, the initial version of aNA generally agreed with the cumulative hair diameter as assessed using PTG, showing a coefficient of 0.60. However, these outcomes were influenced by the angle of hair near the parting line. By integrating an angle compensation formula, the standard deviation of aNA data decreased from 5.7% to 1.2%. Consequently, the coefficient of determination for hair coverage calculated using the modified aNA and cumulative hair diameter assessed by PTG increased to 0.90. Furthermore, the change in hair coverage as determined by the modified aNA protocol correlated well with changes in the GPA score of images obtained using clinical trials. ConclusionThe novel aNA method provides a valuable tool for enabling simple and accurate evaluation of hair growth and volume for clinical trials and for treatment of hair disease.

The Training and Application of Silicone Products in Eyebrow Transplantation Simulation.

Because the structure of eyebrows is complicated, students need a lot of practice to become familiar with the distribution pattern of eyebrow hair. The current study was designed to investigate training methods for eyebrow design and planting practice before eyebrow hair transplantation to improve planting quality. Twelve surgical students were selected. The 6 students in the experimental group had never performed eyebrow transplantation surgery, whereas the 6 in the control group had experience of the procedure. Students in both groups received theoretical and simulated eyebrow hair transplantation instruction. Students were required to master standard eyebrow transplantation. The results of the experimental group and the control group were compared before and after training. The results revealed that the overall results of the experimental and control groups significantly improved compared with before training (P < .05). After theoretical training, 2-dimensional simulation training, and 3-dimensional simulation training, eyebrow shape, symmetry, hair angle, and density after the 3-dimensional simulation training were statistically significantly improved (P < .05). There was no statistically significant difference, and the students in the control group did not demonstrate any improvement in their capacity to arrange the eyebrows or shape them symmetrically. After training, however, the angle and density of the hair substantially improved. The experimental group's technical ability in simulated eyebrow planting significantly improved. The present study demonstrated that the students could develop their skills and get closer to the level of surgeons with experience in eyebrow transplant surgery by integrating theoretical lectures with practiced procedures.

Aesthetic Sideburn Reconstruction Using an Expanded Hair Bearing Skin Flap With Natural Hairline.

Hairline is the marginal line of hair growth on the scalp. Patients with sideburn defects, caused by tumor resection, severe infection, or burns, might have low self-esteem and mental stress. The purpose of this article was to explore a surgical method of applying the expanded scalp flap with natural hairline for cosmetic reconstruction of hairline, so as to provide reference for future clinical work. In this study, a retrospective analysis was conducted on 23 patients in the plastic surgery ward of the Plastic Surgery Hospital of the Chinese Academy of Medical Sciences from January 2015 to December 2018, who underwent expanded scalp flap cosmetic reconstruction of the sideburns with natural hairline (14 males and 9 females; average age, 18.7 ± 13.7 years). The follow-up time was 8 to 44 months. Patient satisfaction rate (scored 4 or more) was 95.7%, with an average score of 4.59. A total of 16 patients were very satisfied, and 6 were satisfied. There were 21 patients who had good flap survival, and 2 patients who had venous congestion at the distal end of the flap. One case relieved voluntarily 3 days postsurgery, and the other case had partial skin necrosis at the distal end, healing phase II. These 2 cases were classified as grade I according to the Clavien-Dindo classification. In 9 of the patients, the reconstructed sideburn presented a natural look with good hair angle and great size and shape, with average scores of 4.61, 4.52, and 4.48. The scars at the donor site were inconspicuous, and there were no complaints (average score, 4.61). The rest of the patients received satisfactory appearances after surgery. In conclusion, the technique described above presented a fine method for sideburn reconstruction. Based on the achieved aesthetic scores of our study, as well as the high patient satisfaction rate (95.7%), the aforementioned technique is acceptable for both surgeons and patients.

The Battle begins: Is strip surgery really necessary?

To measure the effects of previous Follicular Unit Transplantation (FUT) procedure. The study was conducted in a private hair transplant clinic after obtaining informed consent. Only those patients were included who had a previous strip harvest surgery (FUT) and opted for Follicular Unit Excision/Extraction (FUE) procedure. In all the patients, the donor hairs were trimmed to about 1-2mm length. The width of the scar, the hair density above and below the scar, and hair angles above and below the scar were measured. All the patients underwent FUE procedure using 0.9mm serrated punch. Twenty attempts were made above and below the scar (about 0.5cm), and the total number of hair and transections was measured. All the data were analyzed statistically. Ten patients were included. The average width of the scar was 2.47 mm. The mean hair density was found to be 155.4 hairs per cm2 above the scar and 130.8 per cm2 below the scar. The mean hair angle was found to be 28.21 degrees above the scar and 39.19 degrees below the scar in midline occipital above the scar (P < .05). The average hair count was found to be 49.8 hairs above the scar and 47.2 hairs above the scar (P < .05). The transection of hair was doubled below the scar (P < .05) CONCLUSION: The Follicular Unit Transplantation (FUT) procedure does leave some impacts on the donor area other than the scar only. The change in angle results in higher transection of hair above the scar.

Surgical skills for female frontotemporal hairline reconstruction

Objective To explore the operative method and skill for female frontotemporal hairline reconstruction. Methods From October 2010 to October 2016, 120 female patients were performed with the hairline reconstruction. The follicular units were arranged irregularly, 40-55 FUs/cm2, with 30°-45° angle from the forehead skin and 15°-20° angle from the temporal skin. The finest hairs were selected and arranged in hairline margin. Results All the patients were followed up for 10-24 months. 95 patients were very satisfied, 25 patients were satisfied, and no patients were unsatisfied. 9 patients complained low density in the middle of the hairline and they had another surgery to improve the density. 3 patients＇s hairline was regular, and another graft was done to correct the unnatural appearance. 6 patients＇s hairs of the hairline margin were thick, but no further treatment was done. 1 patient underwent hair transplantation again, because of the still high hairline. 6 patients＇s transplanted hairs appeared curly, and the curly degree was decreased after 1-2 years. The density of the transplanted hair was (44.7±8.1) FU/cm2. The density of 9 cases who complained low density in the middle of the hairline, was (36.9±3.1) FU/cm2. The hair diameter of the hairline edge was (57.5±13.5) μm. The hair diameter of 6 cases who felt the hair thick was (70.2±5.1) μm. The angle of hair and the frontal skin was (40.2±8.5)°, The angle of hair and the temporal skin was (18.2±4.7)°. Conclusions In female frontotemporal hairline reconstruction, nature hairline is created by irregular arrangement of hairs, proper density and angle and exact arrangement of different diameter hairs. Key words: Hair; Transplantation, autologous; Forehead; Women; Hair line

Milk yield and hair coat characteristics of Holstein cows in a hot environment.

This study was conducted to evaluate the effects of hair coat characteristics on thermophysiological variables and body surface temperatures (BST), measured with infrared thermography, as well as milk yield of Holstein cows in a hot environment. Physiological and milk yield variables were assessed using 103 pluriparous Holstein cows. Also, hair angle (HA), density of hair coat (D), diameter of hair (HD), hair length (HL), weight of hair coat (Wt), and coat thickness (CT) were recorded. Biplot analysis (principal components analysis) revealed that HL was closely associated with Wt, CT, and HD and all these variables had a positive association with rectal temperature. Both CT and HL were found to be negatively associated with shoulder and neck temperature; tympanic temperature showed no association with BTS. Cows with short hair coat (length < 17mm) did not produce more milk in 305days than cows with longer hair coat (9673 ± 1604 vs. 9277 ± 817; P = 0.12). On the other hand, milk fat percentage at the middle of lactation was higher (P < 0.01) in cows with longer hair relative to cows with coat hair < 17mm (3.71 vs. 3.35%, respectively). In conclusion, physical characteristics of the coat of Holstein cows were not associated with the 305-day milk yield but cows with longer hair produced a greater milk fat percentage at the middle of lactation compared to cows with short hair.

Analysis of the changes in scalp hair angles: In vivo and in vitro comparison before and after tumescence.

To estimate the hair shaft exit angles and also to check the effect of tumescence on the hair angles. Ten patients undergoing first session of strip hair restoration were included. The strip was marked at the level of external occipital protuberance and superior nuchal line. Three hairs were marked, one near upper end, one near lower end, and one in the middle. About 10 mL of 0.5% xylocaine with adrenaline was used with the needle in the subdermal level. The hair angles were measured. After the strip harvest, small slivers were prepared and photographed. The hair shaft exit angles of the three hairs were calculated using the computer software. The Kruskal-Wallis test and multiple comparisons (Bonferroni's correction) were used to analyze the data statistically. The mean age of the patients was 23.4 years. The average preinjection (in vivo) hair angle was 52.82° with 52.96° in upper hairs (43.2° -61.2° ), 51.77° in middle hairs (43.4° -61.3° ), and 53.72° in lower hairs (38.4° -61.3° ). The average postinjection (in vivo) hair angle was 65.34° with 65.05° in upper hairs (55.1° -86.4° ), 65.63° in the middle hairs (56.4° -71.2° ), and 65.35° in the lower hairs (51.3° -75.2° ). Similarly, the postexcision (in vitro) hair angles was 71.91° with 70.83° in upper hairs (range, 56.8° -95.7° ), 72.19o in middle hairs (64.3° -78.5° ), and 72.71° in the lower hairs (63.9° -81.4° ). The proper assessment of hair angles is very important and can be altered by the injection technique.

Comparison of Hair Shafts Angles Using a Curved Blade: An Innovation.

Background:The study was conducted to compare the angles of the hair shafts created by straight/flat blade and curved blade.Materials and Methods:The study was conducted in a private hair transplant surgery center. Five patients undergoing thefirst session of hair transplant were included. In each patient, 1 cm2 area was selected in the anterior hairline in midline. Five slits were created with 1.0 mm straight/flat blade and five slits were created with 1.0 mm curved blade in each patient. After the slits creation, the grafts were inserted into the slits. The custom-made macrophotography technique was used to take high-magnification photographs of the grafts. The software was used to measure the angle of the hair at the level of the skin. The angles of all the hair shafts were measured in both the groups. The data were then analyzed statistically using paired t-test.Results:A total of five patients were included in the study. The mean age of the patients was 35.0 years. The mean hair angle of the hair shafts created with straight/flat blade was 17.42°, whereas the average hair shaft angle created with curved blade was 9.56°. The hair shafts angles varied from 14.3° to 23.1° while using straight blade. The hair shafts angle resulting due to curved blade ranged from 8.6° to 11.3°.Conclusion:The curved blade created the slits which were more acute than the slits created by the straight/flat blade.

Effect of season on haircoat characteristics and physiological parameters of Holstein-Gyr x Guzerá crossed heifers

This study aimed to investigate haircoat characteristics and physiological parameters in summer and winter, morning and afternoon periods, of Holstein-Gyr x Guzerá crossed heifers in tropical environment. For this, twenty crossbred dairy heifers (Holstein-Gyr x Guzerá), reared in the city of Ibiá, Minas Gerais state, Brazil. Haircoat thickness, i.e. distance from skin surface until hairend, average hair length, number of hairs per unit area, hair angle to the skin surface, cardiac and respiratory rates, rectal and body surface temperatures were measured. Data underwent analysis of variance and the means were compared by F test at 5% significance, except heart and respiratory rates and skin temperature within the season, which were compared by Mann Whitney test at 5%. For rectal temperature, the maximum value found was 39.53 °C in the summer afternoon. In the afternoon, rectal temperature was higher in summer compared to winter. Respiratory and heart rates and coat surface temperature were higher in the summer (34.00 movements min-1; 78.60 beats min-1; 37.97 °C respectively) compared to the winter (27.47 movements minutes -1; 58.72 beats min-1; 34,94ºC, respectively). Haircoat thickness and hair length were larger in winter (0.73; 1.82 cm, respectively) compared to summer (0.49; 1.11 cm, respectively). We concluded that the season of the year and day period interfere with most of the physiological parameters for thermoregulation and haircoat characteristics of crossbred heifers (Holstein-Gyr x Guzerá); however, they keep homeothermy, therefore are adapted to the region, and may be an alternative to be used by farmers of this region.

Examination of the Exit Angle of Hair at the Skin Surface versus the Internal Angle of Hair as It Relates to the FUE/FIT Harvesting Method

The FUE/FIT (follicular unit extraction/follicular isolation technique) procedure continues to gain acceptance as a method for harvesting donor grafts. The procedure is based on removing follicular units (FUs) or portions of FUs to use as grafts. A manual punch, mechanized punch, or robotic device is used to remove the FUs. No matter which method of harvesting is selected, there is concern regarding recovering intact FUs and avoiding transection of hair follicles. A common approach is to align the opening of the punch used with the path of the trimmed hair follicles of an FU and dissect along this path. While some hair follicles under the skin may follow the angle above the skin, others may not, which can lead to greater transection rates. Hair follicles within dissected slivers were examined from 13 patients. The internal and external hair growth angles of over 300 follicles were examined. Below, we examine the approach to harvesting and the means to decrease transection rates by understanding the path of hair follicles within the skin and as they emerge from the skin.

Innovative modified hair follicle harvesting technique with reverse rake scalp elevator for lower occipital donor area in follicular unit extraction hair transplantation.

Follicular unit extraction (FUE) is one of the widely practiced minimally invasive follicular harvesting techniques employed during hair transplantation. FUE technique has an advantage of utilising lower occipital area and supra-auricular region as a safe donor area described by Unger, in addition to the standard occipital donor area used in strip method (follicular unit transplant). Despite its potential advantages such as rapid recovery, minimal scarring and reduced post-operative pain; its widespread acceptance is limited due to various factors in variable contribution like steeper learning curve and potentially higher follicular transection rates (FTRs). The main practical drawbacks in harvesting FUE from lower occipital donor region that lie inferior to the standard donor area, is its acute angle (10°–15°) of emergent hair from scalp skin, higher variance angle (15°–35°) between hairs below the skin and hair exit angle above the skin and comparatively loose scalp, preventing to provide stable platform for punching. Hair transplant surgeon faces difficulty in aligning and engaging the FUE punch leading to very high hair follicle transection rate, and therefore, it is not a preferred site for harvesting follicles in FUE. Authors description of modified technique using reverse rake scalp elevator helps in negating the acute angle of the hair follicles exit from scalp skin and reducing the variance angle between emergent hair and hair below the skin in lower occipital region thereby reducing FTR. Furthermore, an added advantage of reducing the overall operative time and surgeon fatigue, improve donor area healing, availability of a comparatively larger donor area which increases the confidence of the beginners. This method will be of help as it is easy to duplicate and follow by novice hair transplant surgeons and also for those who are routinely doing mega hair transplants sessions.

Physiological parameters, hair coat morphological characteristics and temperature gradients in holstein-gyr crossbred cows

The aim of this study was to assess physiological parameters, hair coat morphological characteristics and temperature gradients in crossbred Holstein-Gyr cows in the municipality of Tapira, Minas Gerais (MG), Brazil. Forty-nine lactating cows from six Holstein (H) and Gyr (G) genetic groups (1/4H 3/4G, 3/8H 5/8G, 1/2H 1/2G, 5/8H 3/8G, 3/4H 1/4G and 7/8H 1/8G) were distributed in a completely randomized design. The dry-bulb temperature and relative humidity were recorded, and the temperature and humidity index (THI) was calculated. The rectal temperature, respiratory rate and body surface temperature were measured, as were hair thickness, numbers, length and angle. Cows with a greater than 50% Holstein breed ratio (5/8H 3/8G, 3/4H 1/4G and 7/8H 1/8G) showed a higher respiratory rate and greater hair length than animals with genetic composition equal to or greater than 50% Zebu (1/2H 1/2G, 3/8H 5/8G and 1/4H 3/4G). Animals from the 1/2 and 1/4 HG genetic groups showed the greatest hair angle (P<0.05). With respect to climatic characteristics, the examined locality was within the thermoneutral zone and therefore did not impose conditions of thermal stress. The animals exhibited thermoregulation and hair coat characteristics that were within physiological parameters.

Características do pelame de vacas Holandesas em ambiente tropical: um estudo genético e adaptativo

As características do pelame (espessura da capa, comprimento médio dos pêlos, número de pêlos por unidade de área, densidade de massa dos pêlos, ângulo de inclinação dos pêlos com respeito a superfície da epiderme e diâmetro médio do pêlos) foram avaliadas em 973 vacas da raça Holandesa, entre novembro de 2000 e abril de 2001, numa área localizada 20cm abaixo da coluna vertebral, no centro do tronco, tanto nas malhas brancas como nas negras. As amostras de pêlos foram obtidas com um alicate comum adaptado. O método da Máxima Verossimilhança Restrita (REML) foi usado para estimar os componentes de variância e covariância sob modelo animal, sendo empregado o sistema MTDFREML. Os resultados mostraram que as características do pelame preto são diferentes das do branco, quando os animais são criados em ambiente tropical. O pelame preto apresentou-se menos denso, com pêlos mais curtos e grossos devido à maior necessidade de perder calor, enquanto que, o pelame branco é mais denso e com pêlos mais compridos, oferecendo uma melhor proteção contra à radiação solar direta. A seleção de vacas predominantemente negras pode ser uma boa escolha para aumentar a resistência do gado Holandês às condições do ambiente tropical, principalmente à radiação solar, quando esses animais são criados a campo, devido a que a epiderme sob esse tipo de malhas é altamente pigmentada. Tal seleção pode ser facilmente realizada, considerando a alta herdabilidade (h²=0,75) para a proporção de malhas negras. Esta seleção deve ser realizada no sentido de um pelame menos denso, com pêlos curtos e grossos favorecendo as perdas de calor sensível e calor latente.

AN ANALYSIS OF CALIFORNIA SEA OTTER (ENHYDRA LUTRIS) PELAGE AND INTEGUMENT

AbstractThe sea otter is associated with a cold, marine habitat, has no insulating fat layer, and relies on its fur layer for insulation. Soiled pelage provides inadequate insulation and can lead to hypothermia and death. Information on sea otter pelage, the surface and bound lipids found in the pelage, and histology of the integument is thus relevant to the development of rehabilitation and management techniques for sea otters soiled with oil. We present detailed data on the sea otter pelage and integument, including hair bundle density (737–2,465 bundles per cm2), hair density per bundle (19–91.1), total hair density (26,413–164,662 hairs per cm2), guardhair length (8.2–26.9 mm), underfur length (4.6–15.8 mm), guardhair diameter (44.0–106.0 μ), underfur diameter (7.6–11.9 μ), angle of hair with respect to the skin (61.9°‐ 84.3°) and structure of individual hairs as seen with a scanning electron microscope. The hydrocarbon squalene was found to be the major component of the lipids associated with the pelage. Various layers of skin from eight sites on a single animal are described histologically. With the exception of density of the hair coat, sea otter integument is similar to that of domestic carnivores.

Origin of summating potential.

The relationship between sound and cochlear potentials is considered in the light of von Békésy's observations of movement of the cochlear partition and Davis' variable-resistance theory of hair-cell function. An equation is derived relating hair angle to basilar-membrane movement. The equation is φ = arcot (Yα+cotφ0) where φ is the hair angle and α is proportional to basilar-membrane movement. φ0 is the resting hair angle. Y is the ratio of the distance between basilar membrane and hair cell apex to the distance between tectorial membrane and hair-cell apex. It is shown that the sigmoidal shape of this function leads to a linear dependence of microphonics on sound intensity, generation of harmonics, and production of positive and negative summating potentials by inner and outer hair cells, respectively. The behavior of the cochlear potentials, including the effect of sound pressure in reversing summating potential polarity, effect of cochlear pressure changes, and reversal of summating potential polarity with anoxia, is also accounted for. A mechanical model of the organ of Corti, used to illustrate our theory, is described, together with results obtained from the model.