Comments on facial aging in law enforcement investigation.
Each year hundreds of thousands of individuals are reported missing in the United States, among them runaways, abducted children and young adults, senior citizens suffering from dementia, and fugitive criminals. Each year law enforcement agencies are charged with the task of locating these individuals, expending time and manpower in searches that may last years and may or may not be successful. Major difficulties in the location of missing persons and fugitives, especially in cases extending over long periods of time, are caused by changes in the facial appearance of these individuals, which result from the natural aging process, rough living, purposeful physical alterations, or a combination of these and still other factors. The following study describes age-related changes occurring naturally in the human face as well as characteristic changes in facial appearance caused by aspects of the environment; alcohol and other drug use; disease; and dental, medical, or cosmetic procedures. These changes, which can accentuate and hasten the normal aging process, are illustrated photographically and demonstrate the variation and complications involved in facial recognition and identification.
Aging: Biology and Chronology
Aging is a highly individual phenomenon. How this process manifests in a given individual is determined, in large part, by genetics and general human variation (Loth and Iscan 1994; Neave 1998; Novick 1988; Orentreich 1995). Like biological development, aging in different people does not take place at a uniform rate (Subtelny 1959), may occur in spurts, and is unpredictable with regard to the specific numerical age of an individual (Bulpitt 1995; Feik and Glover 1998; Loth and Iscan 1994; Neave 1998; White 1991). Differences in the rate of aging between men and women have been documented by many researchers, who attribute the seemingly faster onset of age in females to sex-specific characteristics such as skin thickness (which also varies racially and regionally) and hormonal activity--especially with relation to menopause (Callens et al. 1996; Dumont 1986; Feik and Glover 1998; Neave 1998). In both sexes, however, individual hormonal changes as well as diet, skin pigmentation, and level of physical activity play a significant role in the onset and visibility of physical aging (Kadunce et al. 1991; Landau 1989; Neave 1998; Novick 1988; Orentreich 1995).
The traditional concept of age and aging measures the number of years that have passed since a person's birth. When discussing cutaneous aging, however, it is important to differentiate between a number of different processes occurring on the molecular level, especially as these tend to overlap within the general category of biological aging. Chronologic aging, also called intrinsic or innate aging, refers to the gradual, progressive degeneration of tissues occurring throughout the body during a lifetime and is physically apparent in the skin, the organs, and all bodily systems. These physiological changes manifest within the body at fairly predictable stages in an average individual's life and represent inherited tendencies (Novick 1988; Uiotto 1997; Uiotto et al. 1989). Extrinsic aging or photoaging occurs as a product of exposure to sunlight and specifically involves the degenerative effects of actinic irradiation; only the sun-exposed portions of the body are subject to this type of damage (Kolb 1998b; Uiotto et al. 1989). Because these processes occur independently and simultaneously, the changes caused by extrinsic photoaging enhance and emphasize those produced by innate chronologic degeneration (Novick 1988; Uiotto 1997; Uiotto et al. 1989). It should be noted that depending on the genetics, health, and habits of a given individual, a person's biological age may differ--sometimes significantly--from his or her actual age in years (Feik and Glover 1998; Loth and Iscan 1994; Neave 1998).
Stages of Aging
Although aging in general is unpredictable, the sequence of events involved in the process of aging represents a relatively predictable and progressively degenerative physical trend (Neave 1998). Evidence of biological aging usually appears between the ages of twenty and thirty (Kolb 1998b; Novick 1988), with physical changes first visible in the upper portion of the face. Horizontal creases develop in the forehead and the upper eyelids begin to droop, emphasizing the superior orbital groove and causing the eyes to appear smaller and more deeply set (Kolb 1998a; Neave 1988). Nasolabial grooves--laugh lines--and lateral orbital lines, commonly called crow's-feet, develop and deepen with increased age (Guy et al. 1977). Lines around the mouth, or circumoral striae, become apparent, and lines from the edge of the nose to the lateral part of the mouth will progressively deepen. With the onset of these changes there may also be a hollowing of the cheek area below the inferior border of the zygomatic arch, or cheekbone (Neave 1998). By age fifty, more fine lines develop in other areas of the face, the skin becomes thinner with a tendency to sag (Macho 1986; Novick 1988), and wrinkles start to appear on the neck (Neave 1988). Other changes in the skin include decreased tonicity and elasticity; increased dryness, roughness, and coarseness; and the appearance of age spots or other variations in skin color (Henry et al. 1997; Neave 1998; Novick 1988; Orentreich 1995; Uiotto et al. 1989). At the same time the skin is undergoing such physical alterations, an individual may show pattern balding and the depigmentation of scalp hair while experiencing increased hair growth or noticeable growth in areas of previously low growth (Neave 1998; Orentreich 1995; Thrasher and Lamberg 1995). Men and women of middle ages may display thicker, bushier eyebrows than in their younger years and may have hair growth in the nose and ears, or more noticeable growth in these areas (Novick 1988; Thrasher and Lamberg 1995). In women of advancing age, hair growth may also occur on the upper lip and chin (Novick 1988).
More general age-related trends affecting the appearance and profile of the face include the increasing prominence of the chin, the decreasing convexity of the skeletal nose, and the lengthening of the upper and lower lips (Subtelny 1959). These trends are particularly evident from birth until age eighteen, but their effects are seen, though less dramatically, into adulthood and beyond. With increasing age, the skeletal profile of the human face begins to lose its distinctive, protuberant appearance as changes in the shape and orientation of the nasal bones lead to a flattening of the facial features. At the same time, however, the soft tissue facial profile trends toward greater convexity with progressive age, demonstrating that the musculature and skin of the head and face do not always follow the development and shape of the underlying bony tissue (Subtelny 1959). This can pose difficulties in gauging the physical changes occurring in a missing or fugitive individual as well as in reconstructing the human face from skeletal remains.
The physical changes involved in the aging process are notable in that they are affected by and accentuate an individual's weight, an important factor in physical recognition and identification. In general, because facial aging is primarily due to a progressive loss of muscle tone and skin elasticity, with a corresponding deepening of creases in the face (Henry et al. 1997; Neave 1998; Orentreich 1995; Uiotto 1997; Uiotto et al. 1989), the combined effect of changes to the face is such that an aging individual may be described as tired. Changes in facial appearance can be especially pronounced in thin people (Neave 1998), who, with little excess body fat to minimize the visibility of age lines, may actually appear older than heavier individuals of the same age. While the age-related sagging and tightening of the skin can create a gaunt appearance in the thin, people with more body fat may not show age lines and wrinkles as obviously. The latter individuals, however, tend to develop double chins as supportive tissues are gradually lost (Kolb 1998a). Loss of even a few pounds of weight, especially as a product of poor nutrition, illness, and diseases such as cancer, can have a remarkable impact on an individual's appearance and do much in the way of aggravating the effects of the aging process.
Internal and External Factors Affecting Facial Aging
A number of factors contribute to and in many instances hasten the natural aging process. Prolonged or frequent exposure to environmental agents such as sunlight (ultraviolet radiation) and wind or arid climates can cause skin, particularly the more delicate skin of the face, to age prematurely (Kadunce et al. 1991; Landau 1989; Neave 1998; Novick 1988; Orentreich 1995; Uiotto 1997). In addition to the photodamage caused by sunlight, which dries and destroys the cells and underlying structure of the skin, exposure to the sun gives the skin a furrowed, thickened appearance and hastens the development of wrinkles (Kolb 1998a, 1988b; Neave 1998; Novick 1988; Uiotto 1997; Uiotto et al. 1989), especially around the eyes as a product of squinting. Aridity and wind likewise dehydrate the skin, contributing to the formation of wrinkles (Uiotto et al. 1989), but the effect of ultraviolet radiation from the sun on the facial tissues by far exceeds these agents in effect. With continued exposure to the sun and other elements, the color and texture of the face can change, becoming blotchy, yellowish, and leathery, with loose, inelastic, hyperpigmented skin (Uiotto 1997; Uiotto et al. 1989). Blood vessels lying close to the surface of the skin may become prominent as networks called spider veins, adding to the skin's overall mottled and blotched appearance (Novick 1988).
Smoking and the use of drugs and alcohol are other well-known ways to speed the process of aging (Kadunce et al. 1991; Novick 1988; Uiotto 1997). Habitual smoking introduces toxic products into the body and exposes the skin to smoke both directly and indirectly. This combination can cause serious disruptions in the microvasculature of the skin, including changes in the amount and quality of elastin and collagen present in the skin as well as generalized dermal atrophy (Grady and Ernster 1992; Kadunce et al. 1991); the dehydration of the skin associated with frequent smoking may impart an unhealthy, pale, or grayish cast to the complexion. Circumoral striae and other facial lines that develop with time may become markedly more pronounced in smokers, and there is a direct positive association between smoking and the accelerated formation of wrinkles (Boyd et al. 1999; Novick 1988). Because smoking has significant multiplicative effects on the aging process and exposure to ultraviolet radiation, individuals who smoke with any regularity may appear old well beyond their actual chronological ages and older than their same-age, nonsmoking counterparts. It has been noted, however, that complexion wrinkles caused by prolonged exposure to the sun occur with greater prominence than those produced in conjunction with a smoking habit (Kadunce et al. 1991).
Alcoholism can lead to pronounced groupings of broken blood vessels--a condition called telangiectasis--similar to the spider veins caused by the natural weathering of the face. These networks are most often seen as red areas on the sides of the nose and in the cheek region (Novick 1988). On account of physiological variation in human blood vessels, however, some individuals are more prone to this reddening of the skin than others, and it cannot be assumed that the appearance of such blood vessels denotes alcoholism (Taskapan et al. 1997).
The abuse of stimulants, depressants, and other drugs can cause numerous skin irritations, including severe allergic reactions, dryness, chapping, and blistering, as well as changes in the color of the skin (Novick 1988). Combining drug use with alcohol may magnify the effects of each substance on the body, making an interpretation of the individual effects of these habits on the aging process difficult and unreliable.
Figures 1 and 2 are photographic series that illustrate the age-related changes occurring in two individuals over a period of forty years. Both series demonstrate the difficulties involved in determining age based on observation of an individual's facial structures, especially when complicated by the effects of smoking (Figure 1) and the use of alcohol
[FIGURES 1-2 OMITTED]
In both series of photographs, a change in the physical appearance of youth with the loss of buccal fat is evident: As deposits of fatty tissue along the sides of the jaw are lost or redistributed, the smooth, rounded lines associated with the young become the leaner, stronger edges of physical maturity and increased age (Neave 1998). Certain facial features in both individuals, such as the eyebrows, nose, lips, ears, and chin, are relatively stable in appearance throughout the aging process, though the nose and ears do change slightly in size and shape with age (Feik and Glover 1998; Macho 1986; Subtelny 1959).
This change is particularly visible in Figure 2, where a marked decrease in body fat between the ages of 50 and 60 lends a sharper, more prominent appearance to the ears and nose.
Aging in both individuals seems to progress at a fairly uniform pace through the fifth decade, with progressively degenerative changes occurring at a faster rate during the sixth and seventh decades. This hastened process is seen in the final photographs of both series, where changes in the naso-maxillary region present a foreshortened, more skeletally smooth, albeit wrinkled and sagging, facial aspect (Figure 1), and where changes in body weight and skin condition create a lined, stretched, and gaunt appearance (Figure 2). The degree to which smoking and alcohol contribute to or magnify the natural manifestation of age in these individuals is difficult to gauge.
Stress and Sleeping Patterns
Stress and its offshoot, sleep deprivation, can accelerate the aging process and are not unusual causes of premature age lines (Landfield 1995). Character lines and other distinctive wrinkles which occur as a product of gravity, smiling, frowning, and myriad other facial expressions are unavoidable, inevitable signs of the aging process that appear in everyone no matter the lifestyle of an individual (Landau 1989). Muscular tension caused by anxiety and stress, however, may produce and enhance distinct wrinkles in the forehead (transverse frontal lines), between the eyebrows (vertical grabellar lines), and around the mouth (circumoral striae; Loth and Iscan 1994). College students, new parents, individuals with increased workloads or long working hours, and others receiving too little sleep and stress relief may develop lines and wrinkles around the eyes sooner than individuals who enjoy more rest and relaxation. This has been observed by Kolb (1998a), whose analysis of facial features in Presidents of the United States describes the aggravation and accentuation of the aging process in these men following their terms of mandate.
Habits such as smoking and the consumption of alcohol, which have their own effects on the physical aging process, may cause disruption in a person's sleeping habits and thus may aggravate the physical appearance of age in still other ways.
Age-Related Changes in the Facial Bones and Teeth
Remodeling and Resorption
Throughout life, bone tissue is continuously being formed, removed, and replaced (Briggs 1998; White 1991). During youth, particularly before the age of twenty and with peak velocity at puberty, the deposition, growth, and modeling of bony tissues predominates. This sequential, chronological process is physically evident in the changing shape, height, and facial structure of males and females with entry into early adulthood. By age 28 the formation and growth of the human skeletal system in most individuals is complete, and physical changes occurring after this developmental milestone primarily involve bone remodeling and resorption, and, eventually, tissue degeneration (Briggs 1998; Neave 1998; White 1991).
With increasing age the body resorbs much of the bone tissue composing the mandible (Neave 1998), causing the gums to recede and the roots of the teeth to become visible--hence the expression "long in the tooth," which can be used to describe an aged appearance. The wearing of the chewing surfaces (occlusal attrition) over time leads to the decreased vertical height of the face, an effect also caused by the flattening and remodeling of the temporomandibular joint as a product of arthritis (Neave 1998; Novick 1988).
Bone remodeling is linked to the functional need of an individual's body--where there is a need for bony tissue, it is deposited; where it is not needed, it is resorbed (White 1991). Depending on the loads and stresses placed on the skeletal system, nutrition, and other factors affecting the individual, the density and thickness of bone will vary (Briggs 1998). When a person loses teeth, for example, the demand for support in the bone surrounding the teeth will be decreased. This leads to a resorption of bone in those areas of disuse, a process which is more pronounced in the upper jaw than in the lower jaw. The presence of less bony tissue in the upper jaw decreases the height of the face and causes the lower jaw to appear more prominent. In addition, the loss of support tissues in the face leads to the formation of sags and wrinkles and affects the muscles of the lower face, which must compensate for the absence of teeth (Neave 1998). When teeth are lost from the lateral areas of the jaw, there can be a narrowing of the face as well as a hollowing of the cheeks; anterior tooth loss will produce a concave, witchlike profile (Neave 1998). Total loss of the teeth will severely affect the density and thickness of the jaw bones, resulting in the diminished size of the jaw area and a correspondingly foreshortened facial appearance. In this way tooth loss has a significant effect on both the underlying skeletal proportions of the face and the overlying soft tissues (Neave 1998), all of which play a role in the physical manifestation of age (Briggs 1998).
Replacement of the natural teeth with dentures may inhibit the continued resorption of bone in the upper and lower jaws to some extent (Fenton 1998), but a change in the density if not the physical thickness of the bone tissue in the jaws will usually be apparent.
Facial Changes Caused by Trauma and Surgery
Changes in the bony tissue of the face can also occur as a product of trauma (as during an accidental injury) or of therapeutic surgery to the facial area. These effects may be seen unilaterally, on one side of the face, or bilaterally, on both sides, depending on which structure or portion of the face is affected. Many boxers and other athletes have healed damage at the base of the nose that makes this area look broader and sometimes thicker. When the entire nose is involved in blunt-force trauma, it may acquire an irregular shape and there may be a divergence of the nose toward one side of the face. Such alterations in the shape or appearance of the face may hinder or even preclude recognition and identification.
Intentional Modification of Facial Appearance
In some cases, changes in the appearance of the facial region can be explained by alterations in the position of the teeth or in the number of teeth due to orthodontic treatment. Though such treatment is mainly performed on children and adolescents, it is not uncommon in adults and is likely to impart a greater change in appearance in these older individuals, especially as it may be used more to achieve aesthetic goals rather than in response to functional imperfections (Landau 1989).
Most aesthetic dental work involves the extraction of premolars and molars in the upper or lower jaws. Removal of the wisdom teeth in the maxilla will cause the face to appear narrower, a characteristic thought to enhance beauty. Removing premolars from the mandible and pulling the remaining lower teeth together by means of orthodontics can markedly alter the profile of the face and lessen the effect of an inherited dominant chin. Where the extraction of teeth would not adequately improve the appearance of a too-prominent chin, surgical corrections may be used to produce dramatic changes. Some aesthetic treatments of this nature, especially those involving surgery and an associated restructuring of the face, may alter an individual's facial appearance to the extent that identification is extremely difficult.
Untreated dental or surgical problems may also result in distinctively altered facial characteristics. An individual with an open bite, for instance, may compensate for the situation with muscular action in the chin area; over time this condition will create grooves and wrinkles in that region (Landau 1989). When combined with facial changes produced by age, changes of this type may impair recognition of an individual.
Cosmetic plastic surgery is usually performed in individuals older than 40 years of age (Kolb 1998a). The most common surgical procedure is the lifting of the eyebrows and forehead, which produces small scars at the hairline and in the cartilage of the ear. Other common surgical procedures involve collagen implants and the correction of facial features with undesired shapes and sizes, such as the nose (Landau 1989). Aesthetic lip reductions and lip enhancements, the latter procedure achieving popularity in the fashion world in recent years, may also impart a markedly different appearance to the face. Because the attributes of facial features can be so modified, size and shape with regard to physiognomy may not always assist in identification.
Physical changes caused by the aging process may be offset or hidden in a variety of ways, many of which introduce additional changes to individual appearance. Cosmetics may be used to subtract a quantity of years from the face--though they may be employed equally well to add a semblance of age and maturity (Feik and Glover 1998). Corrective lenses may be worn to compensate for deteriorating eyesight. Gray hair may be dyed; thinning hair and baldness may be covered with wigs and toupees or combatted with hair transplants. Though not physically modifying the facial features, these external additions to an individual's appearance may make identification more difficult.
When used irrespectively of age or perceived necessity, external artifacts pose a particular problem in the recognition and identification of individuals. Fugitives seeking to conceal their identities may exchange glasses for contact lenses (or vice versa), alter hairstyles or colors, and add or eliminate mustaches and beards. In combination with the loss or addition of weight and plastic surgery, these measures--which individually may not seem overly drastic--can significantly increase or decrease a person's apparent age (Heafner 1996).
Many factors, alone or in varying combinations, will aggravate or enhance facial aging and thus alter the appearance of an individual. For this reason, attempting to age a photograph--an often outdated or poor-quality photograph--of a missing or fugitive person for law enforcement purposes cannot be accomplished in a simple, straightforward manner. Even with knowledge of the biological changes expected to occur at different stages in the aging cycle, depicting an individual portrayed in a photograph as he or she would appear any number of years later is subject to many considerations. Because lifestyle, individual genetic disposition and variation, gender, ethnicity, environmental exposure, personal habits, and medical history all have an impact on the appearance and extent of the aging process in a given person, all must be factored into an artist's rendering of age as applied to that individual. Given also that a criminal on the lam has every reason to alter or disguise his or her features, the potential use of external artifacts--which likely do not correspond to age--must be added to the mix. The possibilities and variations involved with the aging process, natural or hastened, are such that facial recognition, identification, and reconstruction are best classed together as an art rather than a science.
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Michael A. Taister
Sandra D. Holliday
Visual Information Specialists
Investigative and Prosecutive Graphic Unit
Federal Bureau of Investigation
H. I. M. Borrman
Department of Forensic Medicine
University of Goteborg
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|Author:||Taister, Michael A.; Holliday, Sandra D.; Borrmman, H.I.M.|
|Publication:||Forensic Science Communications|
|Date:||Apr 1, 2000|
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