- Email: [email protected]
Postmortem skeletal lesions
Forensic Science International
ELSEVIER
89 (1997)
155-165
hensic Science Interaatiml
Postmortem skeletal lesions Gerald Quatrehommea’b7*,
Mehmet Yagar igcan”
“Department of Anthropology, Florida Atlantic University, Boca Raton, FL 33431, USA bFaculte’ de M&deck de Nice, Laboratoire de Mkdecine tigale, 06107 Nice Cedex 5 France ‘Department of Anthropology, Florida Atluntic University, Boca Raton, FL 33431, USA
Received 26 March 1997; accepted 13 May I997
Abstract
Postmortem bone alterations are very frequent and can raise the issue of their nature (antemortem, perimortem or postmortem defects). The aim of this work is to study various aspects of defects which were not assessed as perimortem trauma, from a series of 50 defects examined, resulting from 24 forensic cases. This study emphasizes the variability of size, shape and number of postmortem defects. Usually the diagnosis of antemortem defects is helped by a careful examination of some characteristics as the edges of the defects, the areas of discoloration of the edges and of the whole bone. Elsewhere it appears very difficult to know the true nature (antemortem, postmortem, or perimortem alterations) of the bone. 0 1997 Elsevier Science Ireland Ltd. Keywords:
Skeletal lesions; Bone alterations; Bone defects
1. Introduction Postmortem skeletal lesions are usually studied in the field of archaeology [l-5]. An important issue is the differential diagnosis of perimortem trauma (for example, sharp force injuries, gunshot wounds) and postmortem lesions, usually due to animal activity [6-81, human activity [9] and environmental factors. Some forensic anthropological cases are published, demonstrating the difficulty to assess the different events, especially to assess if a bone trauma is of perimortem or *Corresponding author. Address for correspondence: Faculte de MBdecine de Nice, Laboratoire de MBdecine L&ale, 06107 Nice Cedex 2, France. Tel.: +33 4 92037763; fax: +33 4 92038148; e-mail: [email protected] 0379-0738/97/$17.00 Q 1997 Elsevier Science Ireland Ltd. All rights reserved. PII
SO379-0738(97)001
13-8
156
G. Quatrehomme, M.Y.
ipan
I Forensic Science International
89 (1997) 155-165
postmortem nature [lo-141. Postmortem alterations of the bones may be due to environmental factors (soil activity, weathering, mechanical erosion), and postmortem trauma (animal or human activity). In certain cases the diagnosis may be very difficult with an ante or perimortem trauma. The aim of this work is to study various aspects of defects which were not assessed as perimortem trauma, from a series of forensic cases, and to discuss the issue of the differential diagnosis between antemortem, perimortem, and postmortem trauma in bones.
2. Materials
and methods
Skeletal remains of victims of gunshot wounds were studied. In most cases the circumstances of injury, scene and investigation reports, autopsy reports, demographic data and photographs were available. Each defect was described (shape, location) and measured. Special attention was focused on the description of the area surrounding the defect, and the description of its edges, as well as associated features on the rest of the bone. Antemortem medical history was also noted. A total of 50 defects from 24 forensic cases were examined.
3. Results The location, shape, size, etiology of the lesions, as well as the total number of defects in each case are summarized in Table 1. Single defects were found in 15 cases, and multiple bone lesions in the others (two in six cases, three in one case, four in one case, and 15 in one case). Case Cl (Fig. 1A) and C2 (Fig. 1B and 1C) show thinning around the perimeter of the edge, with the most pronounced thinning on the margins of the hole. Edges are regular in both cases. There is a single defect in Cl (Fig. 1A) and multiple perforations (four) in C2 (Fig. 1B and 1C). Note that the shape of the defects is highly variable, even in the same case. In case C2, one is roughly oval or triangular, another semi-lunar (Fig. lB), and a third in the shape of a “club” (Fig. 1C). The skull in case Cl (Fig. 1A) was used for ceremonial activity. These two cases are thought to be the result of chemical and mechanical erosion from the soi1. Erosion due to chemical in the soil will hereafter be referred to as “soil chemical erosion.” Furthermore, in Cl, tooth marks support the hypothesis of animal activity (Fig. 1A). Case C3 (Fig. 1D) is an “anatomical specimen” or “trophy skeleton”. There are holes seen in the right humeral head, and right and left mandibular rami. The edges of the holes are very regular, the shape is perfectly round, and exactly match a drill. The same observations were made in case C14, with the hole drilled in the sagittal suture. In C4 there was a craniotomy two and a half years before death for a depressed fracture. The craniotomy is large, oval and slightly irregular (Table 1). Another large right paterial craniotomy with healing of the edges was observed in Cl 1. Cl2 (Fig. 1E) also featured a large defect with healing of the edges (in the left occipital bone impinging on the foramen magnum). Cl5 exhibits a roughly oval shaped defect with
G. Quatrehomme, M.Y.
ip,
1 Forensic Science International
89 (1997) 155-165
157
Table 1 Location, shape, size and possible etiology of bone lesions Case No.
Location
Shape
Size (cm)
Total N
Possible Etiology
Cl
L. temporo-parietal
Oval
2.5X1.5
1
c2
R. squamous temp.
“Clubs”
2.0X 1.6
5
Left frontal Left temporal
1 x0.5 1 X0.6
c4 c5
Left temporal R. humerus head R. mand. ramus L. mand. ramus Left parietal R. occ. fora. magn.
Oval, irreg. Triangle, irreg. Semi-lunar Round, reg. Round, reg. Round, reg. Oval Triangle
Animal, mechanical, and chemical Chemical, mechanical Idem Idem
0.7x0.3 0.2 0.2 0.2 5x3 4.5x4.5x3
C6
L. lambdoid suture
Oval
0.7x0.4
2
c7
L. occipital Occipital Right mastoid
Nearly round Very irreg. Round
0.1 5X2.5 1.5
2
Right frontal Right occiput Left occiput Left scapula R. parietal, vertex Right frontal Occ (near for. magn.) Frontal Sagittal suture Occ (near for. magn.) Occipital Left parietal Occ (near for. magn.) Right orbit Left orbit R. frontal fossa R. frontal fossa Right parietal Left maxilla Nose Two sides of skull Greater trochanter
Semi-lunar Round Round Oval Oval Oval, irreg. Triangle Oval Round Oval Oval Oval Round Round Oval Oval Oval Round Irregular Irregular Irregular Oval, irreg.
2.0 2.5 2.0 1.6x1.1 4.0x3.3 1.7X1.2 4.7x4.7x 1.7 0.9x0.7 0.8 5x4 8.2X6.3 0.5 X0.2 2.0 0.1 2.0X 1.o 0.7x0.5 0.6X0.4 0.8 5X2 4.0x3.0 0.2 to 3.0 2.0X0.7
c3
C8 c9 Cl0 Cl1 Cl2 Cl3 Cl4 Cl5 Cl6 Cl7 Cl8 Cl9 c20 c21 c22 C23 C24
3
1 1
1 2 1 1 2 1 1 1 I I 1 2 2 1 1 15 1
Idem Drill Idem Idem Craniotomy Chemical, ceremonial Chemical, ceremonial Idem Chemical Chemical, mechanical Chemical Chemical Idem Chemical Craniotomy Craniotomy Chemical Blunt Drill Chemical Chemical Postmortem manipulation Idem Water Idem Chemical Idem Chemical Unknown Idem Caustic Old gunshot wound with
158
G. Quatrehomme, M.Y. Ipan
I Forensic Science International
89 (1997) 155- 165
Fig. 1. (A) shows large oval defect at left temporo-parietal junction (Cl) with tooth marks around periphery (indicating animal activity). Effects of chemical and mechanical erosion are also involved. In Fig. C2 (B, C), chemical and mechanical factors created defects of varied shapes including oval, triangular, and semi-lunar, and “clubs” in the left frontal, the left temporal and the squamous region of right temporal. Perfectly round hole is the result of drilling in the sagittal suture in (D) (C14) of an anatomical specimen or “trophy skull”. (E) shows a large craniotomy with healing at the edge in right frontal bone (C12). Large, irregular occipital defects with thinning of the edges may have a chemical and mechanical origin (C7).
white discoloration of the edges in the same location. In Cl6 there is a large, irregular, roughly oval defect that encompasses the foramen magnum. A nearly round defect, 2 cm in diameter is seen in Cl8 (a child’s skull) caused by soil chemical erosion. This skull was used for ceremonial activity. A defect also encroaching on the foramen magnum was noted in C5. In this case the defect is roughly triangular, with thinning of the inner table, in a skull that had been buried for many years. The base of the skull (used for ceremonial activity) is missing and the edges are white, in contrast to the brown of the rest of the skull. In C6, the two defects are roughly oval. Soil is visible on inner and outer areas of the skull, along with embedded roots. Many parts of the skull are missing (e.g the base and part of the right vault). A slight defect is associated with the inner table of the left parietal. This skull too was used for ceremonial activity. In C7 (Fig. 1F) there is a large (5X2.5 cm) irregular occipital defect, an attenuated paper-thin internal table and an abnormal separation of sutures. The comers of the defect are rounded. There is white discoloration surrounding the lesion, along with erosion of the occipital condyles and right mastoid process. There was a postmortem fracture of the
G. Quatrehomme, M.Y.
i,wm I
Forensic Science International
89 (1997) 155-165
159
left styloid process (whose edges were white in colour), and numerous perforations on the skull. These lesions are considered postmortem defects formed by soil chemical and mechanical erosion. C8 has a semilunar defect, 2.0 cm in diameter, with no bevelling, attributed to postmortem erosion from the soil. In C9 (Fig. 2A), the right occiput and the left occiput display two roughly round defects with a white discoloration of the margins. Numerous white discolorations in various forms (e.g., spots and roughly parallel lines) appear on the cranial vault. The edges of the defect display thinning. Many parts of the bone are missing, including the right orbit, right maxillary sinus and right zygomatic process. This is a case of postmortem soil chemical and mechanical erosion. Cl0 (Fig. 2B) has slightly irregular, oval defect in the left scapula that is attributed to postmortem soil chemical erosion. Cl3 (Fig. 2C) features a regular oval, depressed fracture that looks like a tangential gunshot wound, but there is no bevelling. Cl7 (Fig.
Fig. 2. (A) shows quasi-symmetrical large defects near the foramen magnum (C9) which may exemplify chemical and mechanical erosion from the soil. In (B) there is a slight irregular, oval defect in the left scapula (ClO) resulting from postmortem chemical exposure. (C) has an oval depressed fracture in the frontal bone (C13) caused by blunt trauma. Regular oval defect (D) in left parietal of child skull used for ceremonial activity. Wormian bone displaced, perhaps through mishandling. In (E) (C21) postmortem alteration characterized by slightly irregular defect with thinning edges and coral-like appearance. Soil chemical erosion led to formation of two oval defects in right frontal fossa (F, C20).
160
G. Quatrehomme, M.Y.
igcan I Forensic Science International 89 (1997) 155-165
2D) is a child skull used for ceremonial activity. There is a regular oval defect in the left parietal that was created when a wormian bone was displaced, perhaps through careless handling. Cl9 shows a tiny (0.1 cm) round, and roughly oval (2X 1 cm) defect on the top, internal walls of the orbits. There is also widespread white discoloration often associated with soaking in water. Small irregular defects were found on top of the right orbit and the greater wing of the sphenoid, as well as small erosions of the palate, along with fractures of both internal walls of the orbits. In C21 (Fig. 2E), there is a round slightly irregular defect of 0.8 cm, with thinning of the edges. There are multiple perforations in the right frontal and parietal bones. This case likely results from submersion in water. C21 (Fig. 2E) exhibited multiple perforations on the right frontal and parietal bones. The coral-like appearance of the ectocranial surface may be confused with porotic hyperostosis, but it was not symmetrical nor bilateral and, in this case, was due to postmortem alteration. In C20 (Fig. 2F), there are two oval defects, without beleving or associated fractures, in the right frontal fossa. They were linked to soil chemical erosion. An unusual aspect of this case was that there were gunshot wounds in addition to postmortem erosions. In C8 overlapping defects are present in the left maxilla (5 X2 cm) and nose (4X3 cm). They resemble a perimortem gunshot exit wound or blunt trauma, but death was due to natural cause in this case. Case C23 is a rare instance of postmortem caustic alteration of the skull. Nine defects are visible on the right side of the skull and 6 on the left. All are concentrated on the anterior half of the skull (frontal, temporal, anterior half of the parietal) and range in size from 0.2 to 3 cm. The shapes are highly variable with sharp, irregular, paper-thin edges. There is a large white discoloration limited to the lateral portions of the skull. Previous photographs of the skull showed that it was badly deteriorated, but there was an increase in the number and size of defects a few years later.
4. Discussion Bone defects are frequently encountered in forensic anthropology. The first task is to assess if the defect is of antemortem, perimortem, or postmortem origin. In the present work, 24 forensic cases were discussed, and most display postmortem alterations. Postmortem processes can dramatically alter bones [5]. There were single defects in 15 cases, and many in others. With one exception, multiple cases usually had two defects. Antemortem wounds were rare in this series. In perimortem trauma, it is impossible to determine if the fracture or defect occurred just before, during, or after death. Atypical gunshot wounds must be systematically investigated when a perimortem wound is suspected. Nevertheless classical perimortem patterns, such as butterfly fractures [ 141, or even gunshot wounds [lo] may occasionally be inflicted postmortem. In these difficult cases precise examination of the bones can yield relevant clues. For example Mann and Owsley [lo] found in one case that pellets could only enter disarticulated bones, and that pellet holes interrupted weathering cracks, indicating their obvious postmortem nature.
G. Quatrehomme, M.Y. ipn
I Forensic Science International
89 (1997) 155-165
161
4.1. Antemortem defects Antemortem trauma can be assumed when there is healing of the edges of a fracture or defect. There were three cases of surgical trephinations (C4, Cl 1, C12, Fig. 1E). The large size of the defect with healing of the edges made the diagnosis obvious. Pathological conditions can also be manifest in bone. Primary or secondary cancers are rarely encountered in forensic anthropological practice. In myeloma the bone usually displays multiple small, well defined, lytic lesions, with no sclerosis of adjacent bone. In this disease, isolated lesions are rare [15]. A similar pattern is also seen in rare diseases like histiocytosis-X [ 161. Infectious diseases can cause defects in the bone, these include syphilis, tuberculosis, fungal infections (as blastomycosis), or more commonly chronic pyogenic osteomyelitis. But these manifestations are obviously from an antemortem, not perimortem process. Nevertheless, in the presence of a defect within an area of osteomyelitis, one must rule out a gunshot wound with secondary osteomyelitis, as in case C23. Congenital enlargement of the parietal foramina must not be confused with gunshot wounds, trephinations, or injuries. In the absence of bone destruction the smoothness of new bone surfaces can indicate the degree of healing. Additional evidence of new bone regeneration may be manifest by an increase in both size (bulging), and density [ll]. Postmortem erosion leads to a thinning of the bone that produces a beveled appearance. However, this is a very gradual bevelling that should not be confused with that produced by the entry or exit of a projectile. Longitudinal or spiral fractures of the shaft which have sharp, regular edges, of the same colour as the rest of the surface, indicate a perimortem fracture. In contrast, recently broken dry bones usually show rougher, more jagged fractures [17], and the surface of the fracture is usually lighter in colour than the adjacent areas. 4.2. Postmortem defects Postmortem defects can be caused by trauma or environmental factors. The latter include soil chemical erosion, exposure to the elements (sun, water), and mechanical erosion. Soil activity is the primary cause of bone changes through soil chemical erosion. This process involves demineralization by an acid environment and decomposition of bone proteins by bacteria. The bones become lighter, and some parts disappear. The remaining fragments have rounded borders, and can be found anywhere in the skeleton [ 111. Many factors can alter the rate of this process, including soil acidity (pH) and permeability, moisture, temperature, microorganisms, soil type, method of burial, and even the antemortem condition of the bone at the time of death [ 131. Some depositional conditions can even destroy teeth [17]. There is better bone preservation in well drained, temperate zones with low water tables, and neutral or slightly alkaline soil pH. Furthermore, dark stained surfaces suggest that these parts of the bone may have been at least partially covered with organic debris. Dark staining of the exposed surfaces of fragmented and eroded bone sites indicate that the damage is not recent [lo]. Broken surfaces are usually lighter than the stained outer areas, because the latter have been exposed all or most of the postmortem interval [lo]. Soil based lesions were diagnosed in 14 cases in this series. These defects displayed
162
G. Quatrehomme, M.Y. Iycan I Forensic Science International
89 (1997) 155-165
various shapes: roughly oval (in 11 cases), roughly triangular (in three cases), semi-lunar (in two cases), and “club-shaped” (one case). All cases were irregular and difficult to describe as a known geometric shape (C7, Fig. lF), and the location of the defects varied (Table 1). Associated features were important to consider: these include thin attenuated edges, often accompanied by white discoloration. The absence of bevelling, and associated radiating or concentric fractures (common in intermediate or high velocity projectile strikes) is also highly suggestive of postmortem trauma. Weathering changes occur when a bone is exposed to rain or sun. Its surface deteriorates concurrently with the loss of organic content. Water exposure was found in two cases (C21, Fig. 2E, and C19). In these cases, the skulls were very clean, white, and well preserved. Associated features included small irregular defects at the top of the right orbit and right greater wing of the sphenoid, as well as small erosions of the palate, and fractures of the internal walls of both orbits. Marine exposure usually involves bleaching of the bones, and association with algae and barnacles if the skeleton is submerged long enough. Most cases of environmental modifications also involve mechanical erosion. This produces lesions with regular, attenuated, paper-thin edges (case C2, Fig. 1B and lC, case C7, Fig. 1F and cases C6 and C21, Fig. 2E). Mechanical erosion develops over long periods of time from small movements of the bone against a hard surface. Sandblasting involves abrasion of the bone by grit, and is observed when bone is lying on the surface of the land, or transported in a river. Sun exposure (case C9, Fig. 2A and case C15), resulted in bleaching. Involved areas range from small spots or lines to large whitened areas without well defined borders. The result of sun exposure is diffuse if most of the bone is exposed. However, small areas of distinct discolorations may occur if these are selectively targeted by partial covering over a long period [ 121. The pattern may allow reconstruction of the position of the bone during the period of exposure [ 131. Different discolorations on a given skeleton can also reveal position. Areas exposed to the sun are bleached white, while those on the ground will be darkly stained [18]. Bleaching usually indicates sun exposure for at least a few months [lo]. In general, weathered bones display a network of fine, roughly parallel or spiderweb surface cracks, that becomes progressively deeper and wider [19]. Cracking usually points to a period of 2 years or more [lo]. Blue-green algae can colonize on a substrate such a bone and become visible to the naked eye in 2-3 weeks, under favourable environmental conditions [6]. A combination of high temperature and humidity progressively deteriorates the surface of the bone (especially when there are fluctuations in both of these conditions), as does the freeze-thaw cycle in cold climates. Hard elements like falling rocks may break bones, as well as normal earth movements around a burial. Postmortem alteration was also encountered in this series. Caustic alteration of bones is rarely mentioned in the literature. One case in this series had several defects, with porosity and thin edges around the opening. In a murder case [12], a caustic substance was used to prevent recognition of the individual. It caused a perforation through the frontal sinus with irregular eroded margins, surrounded by a large white eroded area confined to the outer table. There was a sharp contrast between the affected and unaffected areas.
G. Quatrehomme, M.Y.
ipn
I Forensic Science International
89 (1997) 155-16.5
163
Murderers often try to cover up their crime by incinerating the body. However, burning may also be accidental, sometimes occurring several years after death. Yet the effects of natural fires are usually not as severe as in intentional cremation where the objective is to destroy the body. Defects in burned bones may be confused with gunshot wounds, especially when the skull is shattered by increasing pressure and heat, but the combination of a gunshot wound in a burned body cannot be ruled out without careful examination. Heat can also cause postmortem amputations in long bones. Burning dry bones causes cracking of the surface, and longitudinal splitting, but no warping or twisting [1,20]. Burning of green or fleshed covered bone creates curved transverse fracture lines, irregular longitudinal splitting, and marked warping [13] often due to muscle contractions. Animal activity can be diagnosed with certainty when tooth marks are found on the bone as in Cl (Fig. 1A). In addition, the thinness of the surfaces surrounding the defect, and presence of regular, thinned edges also show that soil activity and mechanical erosion also occurred in this case. Other animal activity, such as scattering, is expected when remains are found on the surface. Different animals can inflict distinctive damage (e.g., chewing, gnawing, crushing) depending on their size, strength, and tooth structure [ 171. They sometimes can be confused with blunt/sharp trauma or gunshot wounds, but postmortem activity usually does not result in bevelling, or radiating or concentric fractures. Plant activity can cause etching through the interaction between plants roots and soil bacteria which secrete enzymes. Insoluble bone mineral is changed to water soluble compounds usable for plants [ 111. Usually reticulate and white in colour, a network of shallow grooves is observed. They are usually more intricate and multidirectional than scoring marks [6]. Separation of skull sutures leading to bone dislocation can result from pressure caused by the plant grow. Postmortem manipulation of bones can lead to severe damage, especially in delicate areas like the internal walls of the orbits, or foramen magnum. This was observed in case C19, and probably in case Cl7 (Fig. 2D), where the bones were mishandled during modern ceremonial activity. This can lead to serious diagnostic problems, because, for example, gunshot wounds in these areas may not show bevelling. Other sources of potentially confusing damage include excavation, transport, cleaning, metal tool use, and autopsy protocols. Perforations of the skull or long bones for hanging is associated with ceremonial activity. Similar deformations can be seen when bones are kept as trophies. In C3 (Fig. lD), the holes were very regular and round. The absence of bevelling and radiating or concentric fractures easily confirmed the diagnosis. Ceremonial activity can also feature feathers glued on skulls, associated small animal skeletons, and wax tracks on skull from candles. Trophy bones are often painted or glazed and attempts are sometimes made to place them in pseudo-anatomical articulation. 4.3. Perimortem
trauma
Perimortem trauma must be ruled out and differentiated whenever bone abnormalities are observed. Fig. 2C (C13) is a typical example of blunt trauma-this rarely occurs
164
G. Quatrehomme, M.Y. igcan I Forensic Science International
89 (1997) 155-165
postmortem. In C8, fractures and defects were seen in the left maxilla and nose, but it was impossible to determine if the defects were created just before death (in a fall by a chronic alcoholic), in the postmortem period, or both. In conclusion, there are many problems associated with the diagnosis of postmortem defects. Thus particular care must be exercised when skeletal remains are examined in forensic cases because the diagnosis can carry grave legal consequences.
Acknowledgements The authors thank Dr. Joseph Davis for his kindness. We are grateful to Dr. Susan R. Loth for her critical editing of the manuscript, and thank the FAU Photography Department staff for their assistance and appreciate Joyce Baker’s help. The senior author is very grateful to Professor A. Ollier for granting him sabbatical leave and Dean P. Rampal for encouraging him to conduct research at Florida Atlantic University.
References [l] R.S. Baby, Hopewell cremation practices. The Ohio Historical Society. Papers in Archaeology, Number 1, 1954. [2] A.K. Behrensmeyer, Taphonomic and ecologic information from bone weathering, Paleobiology 4 (1978) 150-162. [3] D.R. Brothwell, Digging up Bones, Cornell University Press, Ithaca, New York, 1981. [4] D.P. Gifford, Taphonomy and paleoecology: a critical review of archaeology’s sister disciplines, Adv. Archaeol. Method Theory 4 (1981) 365-438. [5] R. Bonnichsen, M.H. Sorg (Eds.), Bone Modification, Centre for the Study of the First Americans, Orono, Maine, 1989. [6] W.D. Haghmd, D.T. Reay, D.R. Swindler, Tooth mark artifacts and survival of bones in animal scavenged human skeletons, J. Forensic Sci. 33 (1988) 985-997. [7] C.G. Turner, Taphonomic reconstructions of human violence and cannibalism based on mass burials in the American Southwest, in: G.M. LeMoine, A.S. MacEachem (Eds.), A Question of Bone Technology, University of Calgary Archeological Association, Calgary, 1983, pp. 219-240. [8] T.D. White, N.E. Toth, Engis: preparation damage, not ancient cutmarks, Am. J. Phys. Anthropol. 78 (1989) 361-367. [9] P. Villa, C. Bouville, J. Courtin, D. Helmer, E. Mathieu, P. Shipman, G. Belluomini, M. Branca, Cannibalism in the Neolithic, Science 233 (1986) 431-436. [lo] R.W. Mann, D.W. Owsley, Human osteology: key to the sequence of events in a postmortem shooting, J. Forensic Sci. 37 (1992) 1386-1392. [l l] D. Morse, The skeletal pathology of trauma, in: D. Morse, J. Duncan, J. Stoutamire (Eds.), Handbook of Forensic Archaeology and Anthropology, Rose Printing Company, Tallahassee, FL, 1983, pp. 145- 186. [ 121 D.H. Ubelaker, Alterations in human bones and teeth as a result of restricted sun exposure and contact with corrosive agents, J. Forensic Sci. 33 (1988) 540-546. [ 131 D.H. Ubelaker, Human Skeletal Remains, Taraxacum, Washington, 1989. [14] D.H. Ubelaker, Differentiation of perimortem and postmortem trauma using taphonomic indicators, J. Forensic Sci. 40 (1995) 509-512. [ 151 D.J. Ortner, W.G. Putschar, Identification of Pathological Conditions in Human Skeletal Remains, Smithsonian Institution Press, Washington, D.C., 1981. [16] M.R. Zimmerman, M.A. Kelley, Atlas of Human Paleopathology, Praeger Publishers, New York, 1982. [17] T.D. White, P.A. Folkens, Human Osteology, Academic Press, San Diego, 1991.
G. Quatrehomme, M.Y. ipan
I Forensic Science International
89 (1997) 155-165
165
[IS] R.W. Mann, W.M. Bass, L. Meadows, Time since death and decomposition of the human body: variables and observations in case of experimental field studies, J. Forensic Sci. 35 (1991) 103-I 11. [19] N.C. Tappen, The relationship of weathering cracks to split-line orientation in bone, Am. J. Phys. Anthropol. 31 (1969) 191-198. [20] L.R. Binford, Bones: Ancient Men and Modem Myths, Academic Press, New York, 1981.
ELSEVIER
89 (1997)
155-165
hensic Science Interaatiml
Postmortem skeletal lesions Gerald Quatrehommea’b7*,
Mehmet Yagar igcan”
“Department of Anthropology, Florida Atlantic University, Boca Raton, FL 33431, USA bFaculte’ de M&deck de Nice, Laboratoire de Mkdecine tigale, 06107 Nice Cedex 5 France ‘Department of Anthropology, Florida Atluntic University, Boca Raton, FL 33431, USA
Received 26 March 1997; accepted 13 May I997
Abstract
Postmortem bone alterations are very frequent and can raise the issue of their nature (antemortem, perimortem or postmortem defects). The aim of this work is to study various aspects of defects which were not assessed as perimortem trauma, from a series of 50 defects examined, resulting from 24 forensic cases. This study emphasizes the variability of size, shape and number of postmortem defects. Usually the diagnosis of antemortem defects is helped by a careful examination of some characteristics as the edges of the defects, the areas of discoloration of the edges and of the whole bone. Elsewhere it appears very difficult to know the true nature (antemortem, postmortem, or perimortem alterations) of the bone. 0 1997 Elsevier Science Ireland Ltd. Keywords:
Skeletal lesions; Bone alterations; Bone defects
1. Introduction Postmortem skeletal lesions are usually studied in the field of archaeology [l-5]. An important issue is the differential diagnosis of perimortem trauma (for example, sharp force injuries, gunshot wounds) and postmortem lesions, usually due to animal activity [6-81, human activity [9] and environmental factors. Some forensic anthropological cases are published, demonstrating the difficulty to assess the different events, especially to assess if a bone trauma is of perimortem or *Corresponding author. Address for correspondence: Faculte de MBdecine de Nice, Laboratoire de MBdecine L&ale, 06107 Nice Cedex 2, France. Tel.: +33 4 92037763; fax: +33 4 92038148; e-mail: [email protected] 0379-0738/97/$17.00 Q 1997 Elsevier Science Ireland Ltd. All rights reserved. PII
SO379-0738(97)001
13-8
156
G. Quatrehomme, M.Y.
ipan
I Forensic Science International
89 (1997) 155-165
postmortem nature [lo-141. Postmortem alterations of the bones may be due to environmental factors (soil activity, weathering, mechanical erosion), and postmortem trauma (animal or human activity). In certain cases the diagnosis may be very difficult with an ante or perimortem trauma. The aim of this work is to study various aspects of defects which were not assessed as perimortem trauma, from a series of forensic cases, and to discuss the issue of the differential diagnosis between antemortem, perimortem, and postmortem trauma in bones.
2. Materials
and methods
Skeletal remains of victims of gunshot wounds were studied. In most cases the circumstances of injury, scene and investigation reports, autopsy reports, demographic data and photographs were available. Each defect was described (shape, location) and measured. Special attention was focused on the description of the area surrounding the defect, and the description of its edges, as well as associated features on the rest of the bone. Antemortem medical history was also noted. A total of 50 defects from 24 forensic cases were examined.
3. Results The location, shape, size, etiology of the lesions, as well as the total number of defects in each case are summarized in Table 1. Single defects were found in 15 cases, and multiple bone lesions in the others (two in six cases, three in one case, four in one case, and 15 in one case). Case Cl (Fig. 1A) and C2 (Fig. 1B and 1C) show thinning around the perimeter of the edge, with the most pronounced thinning on the margins of the hole. Edges are regular in both cases. There is a single defect in Cl (Fig. 1A) and multiple perforations (four) in C2 (Fig. 1B and 1C). Note that the shape of the defects is highly variable, even in the same case. In case C2, one is roughly oval or triangular, another semi-lunar (Fig. lB), and a third in the shape of a “club” (Fig. 1C). The skull in case Cl (Fig. 1A) was used for ceremonial activity. These two cases are thought to be the result of chemical and mechanical erosion from the soi1. Erosion due to chemical in the soil will hereafter be referred to as “soil chemical erosion.” Furthermore, in Cl, tooth marks support the hypothesis of animal activity (Fig. 1A). Case C3 (Fig. 1D) is an “anatomical specimen” or “trophy skeleton”. There are holes seen in the right humeral head, and right and left mandibular rami. The edges of the holes are very regular, the shape is perfectly round, and exactly match a drill. The same observations were made in case C14, with the hole drilled in the sagittal suture. In C4 there was a craniotomy two and a half years before death for a depressed fracture. The craniotomy is large, oval and slightly irregular (Table 1). Another large right paterial craniotomy with healing of the edges was observed in Cl 1. Cl2 (Fig. 1E) also featured a large defect with healing of the edges (in the left occipital bone impinging on the foramen magnum). Cl5 exhibits a roughly oval shaped defect with
G. Quatrehomme, M.Y.
ip,
1 Forensic Science International
89 (1997) 155-165
157
Table 1 Location, shape, size and possible etiology of bone lesions Case No.
Location
Shape
Size (cm)
Total N
Possible Etiology
Cl
L. temporo-parietal
Oval
2.5X1.5
1
c2
R. squamous temp.
“Clubs”
2.0X 1.6
5
Left frontal Left temporal
1 x0.5 1 X0.6
c4 c5
Left temporal R. humerus head R. mand. ramus L. mand. ramus Left parietal R. occ. fora. magn.
Oval, irreg. Triangle, irreg. Semi-lunar Round, reg. Round, reg. Round, reg. Oval Triangle
Animal, mechanical, and chemical Chemical, mechanical Idem Idem
0.7x0.3 0.2 0.2 0.2 5x3 4.5x4.5x3
C6
L. lambdoid suture
Oval
0.7x0.4
2
c7
L. occipital Occipital Right mastoid
Nearly round Very irreg. Round
0.1 5X2.5 1.5
2
Right frontal Right occiput Left occiput Left scapula R. parietal, vertex Right frontal Occ (near for. magn.) Frontal Sagittal suture Occ (near for. magn.) Occipital Left parietal Occ (near for. magn.) Right orbit Left orbit R. frontal fossa R. frontal fossa Right parietal Left maxilla Nose Two sides of skull Greater trochanter
Semi-lunar Round Round Oval Oval Oval, irreg. Triangle Oval Round Oval Oval Oval Round Round Oval Oval Oval Round Irregular Irregular Irregular Oval, irreg.
2.0 2.5 2.0 1.6x1.1 4.0x3.3 1.7X1.2 4.7x4.7x 1.7 0.9x0.7 0.8 5x4 8.2X6.3 0.5 X0.2 2.0 0.1 2.0X 1.o 0.7x0.5 0.6X0.4 0.8 5X2 4.0x3.0 0.2 to 3.0 2.0X0.7
c3
C8 c9 Cl0 Cl1 Cl2 Cl3 Cl4 Cl5 Cl6 Cl7 Cl8 Cl9 c20 c21 c22 C23 C24
3
1 1
1 2 1 1 2 1 1 1 I I 1 2 2 1 1 15 1
Idem Drill Idem Idem Craniotomy Chemical, ceremonial Chemical, ceremonial Idem Chemical Chemical, mechanical Chemical Chemical Idem Chemical Craniotomy Craniotomy Chemical Blunt Drill Chemical Chemical Postmortem manipulation Idem Water Idem Chemical Idem Chemical Unknown Idem Caustic Old gunshot wound with
158
G. Quatrehomme, M.Y. Ipan
I Forensic Science International
89 (1997) 155- 165
Fig. 1. (A) shows large oval defect at left temporo-parietal junction (Cl) with tooth marks around periphery (indicating animal activity). Effects of chemical and mechanical erosion are also involved. In Fig. C2 (B, C), chemical and mechanical factors created defects of varied shapes including oval, triangular, and semi-lunar, and “clubs” in the left frontal, the left temporal and the squamous region of right temporal. Perfectly round hole is the result of drilling in the sagittal suture in (D) (C14) of an anatomical specimen or “trophy skull”. (E) shows a large craniotomy with healing at the edge in right frontal bone (C12). Large, irregular occipital defects with thinning of the edges may have a chemical and mechanical origin (C7).
white discoloration of the edges in the same location. In Cl6 there is a large, irregular, roughly oval defect that encompasses the foramen magnum. A nearly round defect, 2 cm in diameter is seen in Cl8 (a child’s skull) caused by soil chemical erosion. This skull was used for ceremonial activity. A defect also encroaching on the foramen magnum was noted in C5. In this case the defect is roughly triangular, with thinning of the inner table, in a skull that had been buried for many years. The base of the skull (used for ceremonial activity) is missing and the edges are white, in contrast to the brown of the rest of the skull. In C6, the two defects are roughly oval. Soil is visible on inner and outer areas of the skull, along with embedded roots. Many parts of the skull are missing (e.g the base and part of the right vault). A slight defect is associated with the inner table of the left parietal. This skull too was used for ceremonial activity. In C7 (Fig. 1F) there is a large (5X2.5 cm) irregular occipital defect, an attenuated paper-thin internal table and an abnormal separation of sutures. The comers of the defect are rounded. There is white discoloration surrounding the lesion, along with erosion of the occipital condyles and right mastoid process. There was a postmortem fracture of the
G. Quatrehomme, M.Y.
i,wm I
Forensic Science International
89 (1997) 155-165
159
left styloid process (whose edges were white in colour), and numerous perforations on the skull. These lesions are considered postmortem defects formed by soil chemical and mechanical erosion. C8 has a semilunar defect, 2.0 cm in diameter, with no bevelling, attributed to postmortem erosion from the soil. In C9 (Fig. 2A), the right occiput and the left occiput display two roughly round defects with a white discoloration of the margins. Numerous white discolorations in various forms (e.g., spots and roughly parallel lines) appear on the cranial vault. The edges of the defect display thinning. Many parts of the bone are missing, including the right orbit, right maxillary sinus and right zygomatic process. This is a case of postmortem soil chemical and mechanical erosion. Cl0 (Fig. 2B) has slightly irregular, oval defect in the left scapula that is attributed to postmortem soil chemical erosion. Cl3 (Fig. 2C) features a regular oval, depressed fracture that looks like a tangential gunshot wound, but there is no bevelling. Cl7 (Fig.
Fig. 2. (A) shows quasi-symmetrical large defects near the foramen magnum (C9) which may exemplify chemical and mechanical erosion from the soil. In (B) there is a slight irregular, oval defect in the left scapula (ClO) resulting from postmortem chemical exposure. (C) has an oval depressed fracture in the frontal bone (C13) caused by blunt trauma. Regular oval defect (D) in left parietal of child skull used for ceremonial activity. Wormian bone displaced, perhaps through mishandling. In (E) (C21) postmortem alteration characterized by slightly irregular defect with thinning edges and coral-like appearance. Soil chemical erosion led to formation of two oval defects in right frontal fossa (F, C20).
160
G. Quatrehomme, M.Y.
igcan I Forensic Science International 89 (1997) 155-165
2D) is a child skull used for ceremonial activity. There is a regular oval defect in the left parietal that was created when a wormian bone was displaced, perhaps through careless handling. Cl9 shows a tiny (0.1 cm) round, and roughly oval (2X 1 cm) defect on the top, internal walls of the orbits. There is also widespread white discoloration often associated with soaking in water. Small irregular defects were found on top of the right orbit and the greater wing of the sphenoid, as well as small erosions of the palate, along with fractures of both internal walls of the orbits. In C21 (Fig. 2E), there is a round slightly irregular defect of 0.8 cm, with thinning of the edges. There are multiple perforations in the right frontal and parietal bones. This case likely results from submersion in water. C21 (Fig. 2E) exhibited multiple perforations on the right frontal and parietal bones. The coral-like appearance of the ectocranial surface may be confused with porotic hyperostosis, but it was not symmetrical nor bilateral and, in this case, was due to postmortem alteration. In C20 (Fig. 2F), there are two oval defects, without beleving or associated fractures, in the right frontal fossa. They were linked to soil chemical erosion. An unusual aspect of this case was that there were gunshot wounds in addition to postmortem erosions. In C8 overlapping defects are present in the left maxilla (5 X2 cm) and nose (4X3 cm). They resemble a perimortem gunshot exit wound or blunt trauma, but death was due to natural cause in this case. Case C23 is a rare instance of postmortem caustic alteration of the skull. Nine defects are visible on the right side of the skull and 6 on the left. All are concentrated on the anterior half of the skull (frontal, temporal, anterior half of the parietal) and range in size from 0.2 to 3 cm. The shapes are highly variable with sharp, irregular, paper-thin edges. There is a large white discoloration limited to the lateral portions of the skull. Previous photographs of the skull showed that it was badly deteriorated, but there was an increase in the number and size of defects a few years later.
4. Discussion Bone defects are frequently encountered in forensic anthropology. The first task is to assess if the defect is of antemortem, perimortem, or postmortem origin. In the present work, 24 forensic cases were discussed, and most display postmortem alterations. Postmortem processes can dramatically alter bones [5]. There were single defects in 15 cases, and many in others. With one exception, multiple cases usually had two defects. Antemortem wounds were rare in this series. In perimortem trauma, it is impossible to determine if the fracture or defect occurred just before, during, or after death. Atypical gunshot wounds must be systematically investigated when a perimortem wound is suspected. Nevertheless classical perimortem patterns, such as butterfly fractures [ 141, or even gunshot wounds [lo] may occasionally be inflicted postmortem. In these difficult cases precise examination of the bones can yield relevant clues. For example Mann and Owsley [lo] found in one case that pellets could only enter disarticulated bones, and that pellet holes interrupted weathering cracks, indicating their obvious postmortem nature.
G. Quatrehomme, M.Y. ipn
I Forensic Science International
89 (1997) 155-165
161
4.1. Antemortem defects Antemortem trauma can be assumed when there is healing of the edges of a fracture or defect. There were three cases of surgical trephinations (C4, Cl 1, C12, Fig. 1E). The large size of the defect with healing of the edges made the diagnosis obvious. Pathological conditions can also be manifest in bone. Primary or secondary cancers are rarely encountered in forensic anthropological practice. In myeloma the bone usually displays multiple small, well defined, lytic lesions, with no sclerosis of adjacent bone. In this disease, isolated lesions are rare [15]. A similar pattern is also seen in rare diseases like histiocytosis-X [ 161. Infectious diseases can cause defects in the bone, these include syphilis, tuberculosis, fungal infections (as blastomycosis), or more commonly chronic pyogenic osteomyelitis. But these manifestations are obviously from an antemortem, not perimortem process. Nevertheless, in the presence of a defect within an area of osteomyelitis, one must rule out a gunshot wound with secondary osteomyelitis, as in case C23. Congenital enlargement of the parietal foramina must not be confused with gunshot wounds, trephinations, or injuries. In the absence of bone destruction the smoothness of new bone surfaces can indicate the degree of healing. Additional evidence of new bone regeneration may be manifest by an increase in both size (bulging), and density [ll]. Postmortem erosion leads to a thinning of the bone that produces a beveled appearance. However, this is a very gradual bevelling that should not be confused with that produced by the entry or exit of a projectile. Longitudinal or spiral fractures of the shaft which have sharp, regular edges, of the same colour as the rest of the surface, indicate a perimortem fracture. In contrast, recently broken dry bones usually show rougher, more jagged fractures [17], and the surface of the fracture is usually lighter in colour than the adjacent areas. 4.2. Postmortem defects Postmortem defects can be caused by trauma or environmental factors. The latter include soil chemical erosion, exposure to the elements (sun, water), and mechanical erosion. Soil activity is the primary cause of bone changes through soil chemical erosion. This process involves demineralization by an acid environment and decomposition of bone proteins by bacteria. The bones become lighter, and some parts disappear. The remaining fragments have rounded borders, and can be found anywhere in the skeleton [ 111. Many factors can alter the rate of this process, including soil acidity (pH) and permeability, moisture, temperature, microorganisms, soil type, method of burial, and even the antemortem condition of the bone at the time of death [ 131. Some depositional conditions can even destroy teeth [17]. There is better bone preservation in well drained, temperate zones with low water tables, and neutral or slightly alkaline soil pH. Furthermore, dark stained surfaces suggest that these parts of the bone may have been at least partially covered with organic debris. Dark staining of the exposed surfaces of fragmented and eroded bone sites indicate that the damage is not recent [lo]. Broken surfaces are usually lighter than the stained outer areas, because the latter have been exposed all or most of the postmortem interval [lo]. Soil based lesions were diagnosed in 14 cases in this series. These defects displayed
162
G. Quatrehomme, M.Y. Iycan I Forensic Science International
89 (1997) 155-165
various shapes: roughly oval (in 11 cases), roughly triangular (in three cases), semi-lunar (in two cases), and “club-shaped” (one case). All cases were irregular and difficult to describe as a known geometric shape (C7, Fig. lF), and the location of the defects varied (Table 1). Associated features were important to consider: these include thin attenuated edges, often accompanied by white discoloration. The absence of bevelling, and associated radiating or concentric fractures (common in intermediate or high velocity projectile strikes) is also highly suggestive of postmortem trauma. Weathering changes occur when a bone is exposed to rain or sun. Its surface deteriorates concurrently with the loss of organic content. Water exposure was found in two cases (C21, Fig. 2E, and C19). In these cases, the skulls were very clean, white, and well preserved. Associated features included small irregular defects at the top of the right orbit and right greater wing of the sphenoid, as well as small erosions of the palate, and fractures of the internal walls of both orbits. Marine exposure usually involves bleaching of the bones, and association with algae and barnacles if the skeleton is submerged long enough. Most cases of environmental modifications also involve mechanical erosion. This produces lesions with regular, attenuated, paper-thin edges (case C2, Fig. 1B and lC, case C7, Fig. 1F and cases C6 and C21, Fig. 2E). Mechanical erosion develops over long periods of time from small movements of the bone against a hard surface. Sandblasting involves abrasion of the bone by grit, and is observed when bone is lying on the surface of the land, or transported in a river. Sun exposure (case C9, Fig. 2A and case C15), resulted in bleaching. Involved areas range from small spots or lines to large whitened areas without well defined borders. The result of sun exposure is diffuse if most of the bone is exposed. However, small areas of distinct discolorations may occur if these are selectively targeted by partial covering over a long period [ 121. The pattern may allow reconstruction of the position of the bone during the period of exposure [ 131. Different discolorations on a given skeleton can also reveal position. Areas exposed to the sun are bleached white, while those on the ground will be darkly stained [18]. Bleaching usually indicates sun exposure for at least a few months [lo]. In general, weathered bones display a network of fine, roughly parallel or spiderweb surface cracks, that becomes progressively deeper and wider [19]. Cracking usually points to a period of 2 years or more [lo]. Blue-green algae can colonize on a substrate such a bone and become visible to the naked eye in 2-3 weeks, under favourable environmental conditions [6]. A combination of high temperature and humidity progressively deteriorates the surface of the bone (especially when there are fluctuations in both of these conditions), as does the freeze-thaw cycle in cold climates. Hard elements like falling rocks may break bones, as well as normal earth movements around a burial. Postmortem alteration was also encountered in this series. Caustic alteration of bones is rarely mentioned in the literature. One case in this series had several defects, with porosity and thin edges around the opening. In a murder case [12], a caustic substance was used to prevent recognition of the individual. It caused a perforation through the frontal sinus with irregular eroded margins, surrounded by a large white eroded area confined to the outer table. There was a sharp contrast between the affected and unaffected areas.
G. Quatrehomme, M.Y.
ipn
I Forensic Science International
89 (1997) 155-16.5
163
Murderers often try to cover up their crime by incinerating the body. However, burning may also be accidental, sometimes occurring several years after death. Yet the effects of natural fires are usually not as severe as in intentional cremation where the objective is to destroy the body. Defects in burned bones may be confused with gunshot wounds, especially when the skull is shattered by increasing pressure and heat, but the combination of a gunshot wound in a burned body cannot be ruled out without careful examination. Heat can also cause postmortem amputations in long bones. Burning dry bones causes cracking of the surface, and longitudinal splitting, but no warping or twisting [1,20]. Burning of green or fleshed covered bone creates curved transverse fracture lines, irregular longitudinal splitting, and marked warping [13] often due to muscle contractions. Animal activity can be diagnosed with certainty when tooth marks are found on the bone as in Cl (Fig. 1A). In addition, the thinness of the surfaces surrounding the defect, and presence of regular, thinned edges also show that soil activity and mechanical erosion also occurred in this case. Other animal activity, such as scattering, is expected when remains are found on the surface. Different animals can inflict distinctive damage (e.g., chewing, gnawing, crushing) depending on their size, strength, and tooth structure [ 171. They sometimes can be confused with blunt/sharp trauma or gunshot wounds, but postmortem activity usually does not result in bevelling, or radiating or concentric fractures. Plant activity can cause etching through the interaction between plants roots and soil bacteria which secrete enzymes. Insoluble bone mineral is changed to water soluble compounds usable for plants [ 111. Usually reticulate and white in colour, a network of shallow grooves is observed. They are usually more intricate and multidirectional than scoring marks [6]. Separation of skull sutures leading to bone dislocation can result from pressure caused by the plant grow. Postmortem manipulation of bones can lead to severe damage, especially in delicate areas like the internal walls of the orbits, or foramen magnum. This was observed in case C19, and probably in case Cl7 (Fig. 2D), where the bones were mishandled during modern ceremonial activity. This can lead to serious diagnostic problems, because, for example, gunshot wounds in these areas may not show bevelling. Other sources of potentially confusing damage include excavation, transport, cleaning, metal tool use, and autopsy protocols. Perforations of the skull or long bones for hanging is associated with ceremonial activity. Similar deformations can be seen when bones are kept as trophies. In C3 (Fig. lD), the holes were very regular and round. The absence of bevelling and radiating or concentric fractures easily confirmed the diagnosis. Ceremonial activity can also feature feathers glued on skulls, associated small animal skeletons, and wax tracks on skull from candles. Trophy bones are often painted or glazed and attempts are sometimes made to place them in pseudo-anatomical articulation. 4.3. Perimortem
trauma
Perimortem trauma must be ruled out and differentiated whenever bone abnormalities are observed. Fig. 2C (C13) is a typical example of blunt trauma-this rarely occurs
164
G. Quatrehomme, M.Y. igcan I Forensic Science International
89 (1997) 155-165
postmortem. In C8, fractures and defects were seen in the left maxilla and nose, but it was impossible to determine if the defects were created just before death (in a fall by a chronic alcoholic), in the postmortem period, or both. In conclusion, there are many problems associated with the diagnosis of postmortem defects. Thus particular care must be exercised when skeletal remains are examined in forensic cases because the diagnosis can carry grave legal consequences.
Acknowledgements The authors thank Dr. Joseph Davis for his kindness. We are grateful to Dr. Susan R. Loth for her critical editing of the manuscript, and thank the FAU Photography Department staff for their assistance and appreciate Joyce Baker’s help. The senior author is very grateful to Professor A. Ollier for granting him sabbatical leave and Dean P. Rampal for encouraging him to conduct research at Florida Atlantic University.
References [l] R.S. Baby, Hopewell cremation practices. The Ohio Historical Society. Papers in Archaeology, Number 1, 1954. [2] A.K. Behrensmeyer, Taphonomic and ecologic information from bone weathering, Paleobiology 4 (1978) 150-162. [3] D.R. Brothwell, Digging up Bones, Cornell University Press, Ithaca, New York, 1981. [4] D.P. Gifford, Taphonomy and paleoecology: a critical review of archaeology’s sister disciplines, Adv. Archaeol. Method Theory 4 (1981) 365-438. [5] R. Bonnichsen, M.H. Sorg (Eds.), Bone Modification, Centre for the Study of the First Americans, Orono, Maine, 1989. [6] W.D. Haghmd, D.T. Reay, D.R. Swindler, Tooth mark artifacts and survival of bones in animal scavenged human skeletons, J. Forensic Sci. 33 (1988) 985-997. [7] C.G. Turner, Taphonomic reconstructions of human violence and cannibalism based on mass burials in the American Southwest, in: G.M. LeMoine, A.S. MacEachem (Eds.), A Question of Bone Technology, University of Calgary Archeological Association, Calgary, 1983, pp. 219-240. [8] T.D. White, N.E. Toth, Engis: preparation damage, not ancient cutmarks, Am. J. Phys. Anthropol. 78 (1989) 361-367. [9] P. Villa, C. Bouville, J. Courtin, D. Helmer, E. Mathieu, P. Shipman, G. Belluomini, M. Branca, Cannibalism in the Neolithic, Science 233 (1986) 431-436. [lo] R.W. Mann, D.W. Owsley, Human osteology: key to the sequence of events in a postmortem shooting, J. Forensic Sci. 37 (1992) 1386-1392. [l l] D. Morse, The skeletal pathology of trauma, in: D. Morse, J. Duncan, J. Stoutamire (Eds.), Handbook of Forensic Archaeology and Anthropology, Rose Printing Company, Tallahassee, FL, 1983, pp. 145- 186. [ 121 D.H. Ubelaker, Alterations in human bones and teeth as a result of restricted sun exposure and contact with corrosive agents, J. Forensic Sci. 33 (1988) 540-546. [ 131 D.H. Ubelaker, Human Skeletal Remains, Taraxacum, Washington, 1989. [14] D.H. Ubelaker, Differentiation of perimortem and postmortem trauma using taphonomic indicators, J. Forensic Sci. 40 (1995) 509-512. [ 151 D.J. Ortner, W.G. Putschar, Identification of Pathological Conditions in Human Skeletal Remains, Smithsonian Institution Press, Washington, D.C., 1981. [16] M.R. Zimmerman, M.A. Kelley, Atlas of Human Paleopathology, Praeger Publishers, New York, 1982. [17] T.D. White, P.A. Folkens, Human Osteology, Academic Press, San Diego, 1991.
G. Quatrehomme, M.Y. ipan
I Forensic Science International
89 (1997) 155-165
165
[IS] R.W. Mann, W.M. Bass, L. Meadows, Time since death and decomposition of the human body: variables and observations in case of experimental field studies, J. Forensic Sci. 35 (1991) 103-I 11. [19] N.C. Tappen, The relationship of weathering cracks to split-line orientation in bone, Am. J. Phys. Anthropol. 31 (1969) 191-198. [20] L.R. Binford, Bones: Ancient Men and Modem Myths, Academic Press, New York, 1981.