Characterization and classification of different female hairline patterns in the Thai population

Abstract

Background: The hairline is an essential component of the human face. Disfigurement of the hairline may cause physical and psychological problems. Standard guidelines do not exist for female hairline designs, average values of infratemporal portion, hairline classifications, and preferences. Aims: We aimed to study hairline characteristics in Thai females and further compare the values with previous studies in different populations. Furthermore, we aimed to introduce a comprehensive hairline classification system that allowed an easy and detailed phenotypic characterization of female hairline. Patients/Methods: Healthy Thai females aged over 18 years were included in the study. Collection of demographic data, infratemporal measurements, and standard photography was performed. All collected data were analyzed to determine the standard values of each hairline dimension for comparison to previous studies. Results: Two hundred and twenty-nine females, with a mean age of 32.4 ± 8.6 years, participated in this study. The mean mid-frontal line was 6.45 ± 0.89 cm, which was not correlated with age. Lateral mounds, widow's peaks, and cowlicks were observed in 42.35%, 24.45%, and 1.74% participants, respectively. Our study revealed five patterns of the frontal hairline and four patterns of the temporal hairline. The mid-frontal line in Asian females trended longer than that in Caucasians, without statistical significance. Conclusions: Measurements of the infratemporal portions in Thai females revealed no change with age, and the mid-frontal line showed no statistically significant differences between Korean and Turkish participants. The hairline classification system introduced in our study was comprehensive and would be easily applicable in clinical practice. Female hairline dimensions and patterns reported in our study could provide reference values for hairline design in hairline restoration surgery as well as assist in accurate diagnosis of hair disorders.

Study of Frontal and Temporal Hairline Patterns in Japanese Subjects

“… 11 Natpracha et al reported: triangular, 44.97%; concave, 15.28%; linear, 34.39%; and convex, 5.24%. 9 In our study, inverted triangle (corresponding to concave triangle, triangular) accounted for 20.3%, inverted round (corresponding to concave oval, concave) accounted for 27.8%, straight accounted for 24.8%, and convex accounted for 27.2%, showing differences from the data reported by other researchers, but the appearance rates of the four types were roughly equal.…”

“… 8 , 9 , 19 In our study, when round and linear were combined, they accounted for 74.6%, which is consistent with previous studies. It has been reported that the mean length of the mid-frontal line measured in Caucasians was 5.54 cm (3.5–8.0 cm) 11 and 5.89 cm (4.5–9 cm), 19 and that measured in Asians was 6.45 ± 0.89 9 and 6.38 ± 0.89 cm. 8 Our measured value was 6.2 cm (range: 2–9.5 cm).…”

“… 8 Natpracha et al investigated the hairline in 229 Thai female volunteers and classified the female hairline into five types: triangular, linear, inverted triangle, concave, and convex. 9 Jung classified the normal forehead width with a vertical height of more than 2 cm higher than normal (6.38 cm) as bell shaped. 8 However, it was difficult to define and distinguish the differences between the round and bell shapes by observing figures and photographs; so they were combined as the round type in our questionnaire.…”

“…In the classification by Natpracha et al, M-shaped is classified as inverted triangle and convex based on the shape of both ends of the hairline, but these are also difficult to distinguish in a questionnaire, and so, were combined as M-shaped. 9 Koo et al classified Asian male hairlines into four types: linear, linear with a central protrusion, round, and round with a central protrusion. 10 Referring to the above four studies, we classified the frontal hairline into the following four types in preparation of the questionnaire: linear, triangular, round, and M-shaped (Fig.…”

“…In addition, a literature search was made to prepare a similar questionnaire concerning the temporal hairline types. Natpracha et al classified the temporal hairline shape into four types: triangular, linear, concave, and convex, 9 and Nusbaum et al classified it into concave triangle, straight, concave oval, and convex. 11 According to the photographs presented in these two references, triangular may correspond to concave triangular, linear may correspond to straight, and concave oval may correspond to concave.…”