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Digit Abnormalities (The following article is reprinted from the Oct.--Dec. 1994 issue of the Texas Div.-- I.A.I. newsletter)
by CHARLES PARKER
Abstract: A listing of the common abnormalities that affect digits and
epidermal ridges of the hands and feet. Medical technology in this day and time has decreased the occurrence of digit abnormalities that a fingerprint technician might encounter as opposed to the earliest part of this century because of reconstructive surgery. However there may come a time in a technicians career where they might encounter one or more different types of abnormalities. The following description of these digit conditions are the most common of the digit abnormalities and not every condition or the cause of the conditions are covered in this paper. For the purpose of this paper I have broken digit abnormalities into different groups: Digit Malformations and Friction Ridge Malformations.
DIGIT MALFORMATIONS Brachydactyly: Having abnormal short digits. This condition is described as a shortness of the fingers which is distinguished by one or both phalanges missing. It appears that pattern types can still be observed and classification is possible if the digit can be recorded. Ectrodactyly: Complete or partial absence of digits. Also referred to as Oligodactyly. This condition is described as the absence of one or more digits. In one reported case in Mexico, a male's right hand had only one digit and the friction ridge surface wholly covered the single digit. When friction ridges are present patterns can usually be observed; however the problem is to determine which fingers are missing so the remaining digits can be properly recorded in the correct finger blocks. Macrodactyly: This condition is described as a abnormal largeness of a digit or digits, which can be almost twice the length and diameter of a regular digit. The pattern type is still observable and classification is possible. Orthodactyly: With this condition the digits cannot be flexed and is usually associated with Symphalangism. A high degree of difficulty in obtaining rolled prints of a quality for classification purposes. Polydactyly: Also referred to as Hyperdactyly. This condition is probably the most common of digit malformations, and is described as one or more extra digits. This can be either the thumb or little finger. In some reported cases the extra digit is perfectly formed and in other cases it can be very small as to appear like a small appendage. A split thumb would fall into this category. In most cases the extra appendage appears to have a complete pattern and is classifiable. Symphalangism: A fusion or stiffening of the joints. This condition is described as the end to end fusion of the phalanges of the fingers or toes. As in Orthodactyly the problem is recording the ridge detail that is present.
Syndactyly: This malformation is commonly referred to as webbed fingers
and is described as the side to side fusion of the digits. This fusion
can be just two digits or all digits joined together. Mostly two separate
patterns exist but problems occur because the lack of a well defined delta
or deltas. This condition is probably the second most occurring malformation.
FRICTION RIDGE MALFORMATIONS Aplasia: Also referred to as Dysplasia in some sources. This condition exhibits the lack of epidermal ridges with all the flexion creases remaining normal. Some research shows that the palmar and plantar surfaces do not exude perspiration. Cuspal: In this condition the ridges flow from the base of the finger in an upward direction to the tip of the finger. There is not defined formation of patterns although the ridges themselves appear normal. When observed this condition is given the same classification as a tented arch. Dissociation: This condition is described as the formation of individual pore elements that fail to merge into continuous ridges. Dissociation can cover the whole fingerprint or can occur only in a small part of the pattern. One source has stated that medical studies have revealed that a marked tendency for dissociated ridges can be found in the fingerprints of schizophrenics, epileptics, albinism, and mongolism. However dissociation can also occur in people not suffering from such afflictions. Dysplasia: Also referred to as Aplasia in some sources. This condition can be described as the incomplete development of friction ridges, resulting in a patternless surface. As one can see it is described very much like Dissociation, the difference is that in Dysplasia even the pore elements are not well defined. Hypoplasia: The arrested, incomplete, or underdevelopment of friction ridge size. In this condition the ridge patterns are normal but the height of the ridges are reduced which causes problems in the proper recording of the ridge detail because the ink covers the furrows as well as the ridges. This condition can be inherited, or acquired, and is sometimes associated with abnormalities in the genetic chromosomes. Twin Ridges: Also called split or paired ridges. It can be described as a ridge split down the middle by a small furrow causing two ridges with the same flow and characteristics.
This listing is not complete and although I have examples of most of the conditions, I am always looking for more. If you have examples of Digit Abnormalities on file with your agency, I would appreciate a copy or photograph.
This article was reprinted in “THE PRINT” |