Dermatoglyphics in Health and Oral Diseases-A Review

Dermatoglyphics refers to study of the intricate dermal ridge configurations on the skin covering the palmar and plantar surfaces of hand and feet. It is a branch of physical anthropology, medicine and genetics. Dermatoglyphic patterns are assumed to be genetically controlled although the exact mechanism of inheritance in still unknown. After their complete formation, they are unaffected by the environment, and this explains their unique role, as an ideal marker for individual identification and the study of populations, as well as detection of defects due to intra-uterine irregularities in the early weeks of pregnancy. However it is still at infancy in the world of dentistry where the co-relation of dental conditions with that of dermatoglyphic patterns is done. Hence the present paper reviews the work conducted by various authors on application of dermatoglyphics in dentistry along with the advantages and patterns of dermatoglyphics. INTRODUCTION The modern study of the hand is thus far removed from the popular image of the soothsaying hand reader uttering mysterious incantations in an arcane language. Rather, through decades of scientific research, the hand has come to be recognised as a powerful tool in the diagnosis of psychological, medical and genetic conditions. For dermatoglyphic research and the discoveries of medical science have corroborated many of the traditional claims of hand analysts and has provided a firm empirical basis for the modern study of chirology. The word ‘dermatoglyphics’ comes from two Greek words (derma, skin and glyphe, carve) and refers to the epidermal skin ridge formations which appear on the fingers, palms of the hands and soles of the feet [1]. This term was coined by Harold Cummins in 1926 [2]. It is known that finger and palm prints are formed during the 6-7th week of the embryonic period and are completed after 10-20 weeks of gestation [2]. Genetic process of dermatoglyphic traits is complex and is not perfectly known [3]. Their variable characteristics are not duplicated in other people, even in monozygotic twins or even in the same person, from location to location [4]. Abnormalities in these areas are influenced by a combination of hereditary and environmental factors, but only when the combined factors exceed a certain level, can these abnormalities be expected to appear [5]. Widespread interest in epidermal ridges developed only in the last several decades when it became apparent that many patients with chromosomal aberrations had unusual ridge formations [6]. Thus the study of dermatoglyphics is considered as a window of congenital abnormalities and is a sensitive indicator of intrauterine anomalies as abnormal dermatoglyphic patterns have been observed in several non–chromosomal genetic disorders and other diseases whose aetiology may be influenced directly or indirectly by genetic inheritance [7]. Early detection can aid the clinician to anticipate health problems in children and initiate preventive and protective health measures at a very young age. Over the past 150 years, dermatoglyphics has been a useful tool in understanding basic questions in biology, medicine, genetics and evolution, in addition to being the best and most widely used method for personal identification [8]. However it is still at infancy in the world of dentistry where the co-relation of dental conditions with that of dermatoglyphic patterns is done. Hence the present paper reviews the work conducted by various authors on application of dermatoglyphics in dentistry along with the advantages and patterns of dermatoglyphics [7]. ADVANTAGES The major advantages of the dermatoglyphics are: i) They are fully developed at birth and thereafter remain unchanged for life. ii) Scanning or recording of their permanent impressions can be accomplished rapidly, inexpensively, conveniently and without causing any trauma to the patient or hospitalization. Issrani et al. (2013) Email: JSM Dent 2(4): 1044 (2014) 2/5 Central METHODS OF RECORDING DERMATOGLYPHICS Reviewing the literature one can find number of methods for recording dermatoglyphics. Variability lies in their requirements for equipment, time and experience, and in the quality of the prints produced. The various methods that can be employed are: [9] i) Ink method, ii) Inkless method, iii) Transparent adhesive tape method, and iv) Photographic method. DERMATOGLYPHIC PATTERN CONFIGURATION Dermatoglyphic landmarks The three basic dermatoglyphic landmarks found on the fingertip patterns are tri-radii, cores and radiants [8]. i) Tri-radius: It is formed by the confluence of three ridge systems that form angles of approximately 120o with one another. ii) Core: It is in the approximate centre of the pattern. iii) Radiant: They emanate from the tri-radius and enclose the pattern area. Fingertip patterns The ridge patterns on the distal phalanges of the fingertips are divided into the three groups: arches, loops, and whorls. i) Arches: It is the simplest pattern found on fingertips. It is formed by succession of more or less parallel ridges, which traverse the pattern area and form a curve that is concave proximally (Figure 1). Sometimes, the curve is gentle; at other times it swings more sharply so that it may also be designated as a low or high arch respectively. The arch pattern is subdivided into two types: a) Simple or plain arch composed of ridges that cross the fingertip from one side to the other without recurving. b) Tented arch composed of ridges that meet at a point so that their smooth sweep is interrupted. ii) Loops: It is the most common pattern on the fingertip. A series of ridges enter the pattern area on one side of the digit, recurve abruptly, and leave the pattern area on the same side (Figure 2). The loop pattern is subdivided into two types: a) Ulnar loop composed of ridges that open on the ulnar side. b) Radial loop composed of ridges that open on the radial side. Loops may vary considerably in shape and size. They may be large or small, tailor short, vertically or horizontally oriented, plain loop or double loop. Occasionally, transitional loops can be found which resemble whorls or complex patterns. iii) Whorls: It is any ridge configuration with two or more tri-radii. One tri-radius is on radial and the other on the ulnar side of the pattern (Figure 3). Subtypes of whorl patterns include: a) Plain/simple/concentric whorl composed of ridges that are commonly arranged as a succession of concentric rings or ellipses. b) Spiral whorl is a configuration in which ridges spiral around the core in either a clockwise or a counter clockwise direction. c) Central pocket whorl is a pattern containing a loop within which a smaller whorl is located. Central pockets are classified as ulnar or radial according to the side on which the outer loop opens. d) Lateral pocket/twinned loop pattern is composed of interlocking loops. e) Accidentals/complex patterns are one in which patterns cannot be classified as one of the above patterns. Some represent a combination of two or more configurations such as a loop and a whorl, triple loops and other unusual formations. Figure 1 Arches.