The dynamic rotation of Langer's lines on facial expression.
ABSTRACT Karl Langer investigated directional variations in the mechanical and physical properties of skin [Gibson T. Editorial. Karl Langer (1819-1887) and his lines. Br J Plast Surg 1978;31:1-2]. He produced a series of diagrams depicting lines of cleavage in the skin [Langer K. On the anatomy and physiology of the skin I. The cleavability of the cutis. Br J Plast Surg 1978;31:3-8] and showed that the orientation of these lines coincided with the dominant axis of mechanical tension in the skin [Langer K. On the anatomy and physiology of the skin II. Skin tension. Br J Plast Surg 1978;31:93-106]. Previously these lines have been considered as a static feature. We set out to determine whether Langer's lines have a dynamic element and to define any rotation of the orientation of Langer's lines on the face with facial movement. One hundred and seventy-five naevi were excised from the face and neck of 72 volunteers using circular dermal punch biopsies. Prior to surgery a vertical line was marked on the skin through the centre of each naevus. After excision distortions of the resulting wounds were observed. The orientation of the long axis of each wound, in relation to the previously marked vertical line, was measured with a goniometer with the volunteer at rest and holding their face in five standardised facial expressions: mouth open, smiling, eyes tightly shut, frowning and eyebrows raised. The aim was to measure the orientation of the long axis of the wound with the face at rest and subsequent rotation of the wound with facial movement. After excision elliptical distortion was seen in 171 of the 175 wounds at rest. Twenty-nine wounds maintained the same orientation of distortion in all of the facial expressions. In the remaining wounds the long axis of the wound rotated by up to 90 degrees . The amount of rotation varied between sites (p>0.0001). We conclude that Langer's lines are not a static feature but are dynamic with rotation of up to 90 degrees . It is possible that this rotation in the axis of mechanical tension will affect the appearance of the resulting scar.
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ABSTRACT: We performed an in vivo three-dimensional analysis of anisotropic changes in the dermal birefringence of mechanically deformed human skin using polarization-sensitive optical coherence tomography (PS-OCT). The papillary-dermal birefringence of the forehead increased significantly when the skin was shrunk parallel to the body axis, and decreased significantly when the skin was shrunk perpendicular to the body axis. En-face images of the papillary-dermal birefringence revealed variations among individual subjects, and that both shrinking parallel to and stretching in perpendicular to the body axis promoted the formation of macro rope-like birefringent domains. We found that PS-OCT is useful for understanding anisotropic properties of collagen structure in the skin.Biomedical Optics Express 09/2011; 2(9):2623-31. · 3.18 Impact Factor
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ABSTRACT: Forces acting in facial skin have been suggested to show directionality. Non-invasive methods of measuring this directionality may thus provide information related to aging processes. The Reviscometer(®) RVM600 device is capable of measuring directionality of forces on the skin. This device has not been used previously in a published study to evaluate changes in directionality of forces on facial skin with aging. The first objective of this pilot study was to investigate relationships between mechanical directionality using the Reviscometer(®) RVM600, the Cutometer(®) MPA580, and aging of the facial skin in a supine position. In addition, the study investigated relationships between mechanical directionality and 'skin sagging,' which may be caused by gravity. To validate this as a new measurement of mechanical directionality, we also performed double-blinded trials on two groups of subjects, with one group using a product containing an anti-aging substance and the other group using a placebo product without an anti-aging substance. We examined 91 healthy Japanese women with a mean age of 48.5 years (range, 20-79 years) at the three sites on the face using the Reviscometer(®) RVM600 and the Cutometer(®) MPA580, and evaluation was performed for skin sagging in September and November 2008, and January 2009. The Reviscometer(®) RVM600 was used to measure resonance-running time (RRT) every 10° from 0° to 350°. Evaluation of skin sagging was undertaken by making marks on the face and using face photographs taken in both sitting and supine positions to calculate the sagging index. Usage testing was conducted on 38 healthy Japanese women in a double-blinded study with one group, using a preparation containing Yomogi AGEs Clearing (YAC) extract and another group using the same preparation without the YAC extract from October 2008 to April 2009. Mean age of these subjects was 44.0 years (range, 30-60 years). Measurements were taken at the three sites on the face using the Reviscometer(®) RVM600 and the Cutometer(®) MPA580 and sagging index. A significant correlation was identified between RRT parameters and subject age at all three measurement sites. Significant correlations between sagging index and RRT values were found for 110-170° and 290-350° only at the center of the cheek. Significant differences in RRT values were noted for 110-150° and 300-350° at this site between subjects with and without the use of YAC extract. A similar trend was found in sagging index for this site alone between subjects with and without YAC extract. The use of non-invasive procedures to measure skin mechanical parameters on the face in all directions may evaluate aging and effective preventive and restorative support.Skin Research and Technology 02/2011; 17(1):101-7. · 1.41 Impact Factor
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ABSTRACT: The skin fulfills one of its most important functions, that is protection from mechanical injuries, due to the mechanism of reversible deformation of the structure. Human skin is a complex living material but in biomechanical tests it reveals its homogeneous nature. Biomechanical skin parameters change with time. Results of thickness measurements, where the skin was subjected to pressure, revealed that the Young's modulus increased linearly with age. The process of ageing is the reason why the skin becomes thinner, stiffer, less tense and less flexible. Skin tension measured during in vivo uniaxial load and the elasticity modulus are higher in children than in elderly adults. Furthermore, mean ultimate skin deformation before bursting is 75% for newborns and 60% for the elderly. Several types of the main lines were distinguished on the skin. The static lines, described by Langer, correspond to the lines of maximum tension, the Kraissl's lines correspond to the movements of the skin during muscle work, whereas the Borges lines are the relaxed skin tension lines. Biomechanical tests of the human skin help to quantify the effectiveness of dermatological products, detect skin diseases, schedule and plan surgical and dermatological interventions and treatments.Postepy Dermatologii I Alergologii 10/2013; 30(5):302-306. · 0.66 Impact Factor