This is the final installment of the series on forensic Osteology. In the last two articles I discussed the first four of five questions a forensic osteologist may be asked to answer. These were: 1) Are the remains Human? 2) How long has this person been dead? 3) How many individuals are associated with the sit of the remains? 4) What was the age, sex, height and racial affiliation of the person in question?
The final question to be addressed by the forensic osteologist is 5) Are there pathological conditions in the form of evidence of disease that might aid the osteologist in identification of an individual. This can be done in several ways. There are some diseases that would cause profound disability and would be evident in the living individual. Other diseases that leave there mark on bone are more subtle but are specific to certain geographical regions. This in turn can indicate race.
Other diseases are age specific. Some diseases have been almost eradicated from the modern world and can indicate the antiquity of a burial or point to a geographic point of origin. Finally, some diseases such as cancer can cause bone injury which may be easily mistaken for trauma.
In this final article on Osteology I will briefly discuss some of these forms of disease which can affect the morphology of bones.
Treponemal Infections
This is a group of several diseases which can cause profound changes to bone. It is thought that they are caused by variations of the same pathogen. These infections are caused by bacteria and are spread through sexual activity and open wounds.
The diseases in these types of infections which cause damage or changes to bone are 1) Syphilis 2) Bejel and 3) Yaws. All three of these diseases cause similar destruction of bone and are difficult to distinguish from one and other(Ortner, 2003).
Syphilis is a disease which occurs worldwide. It is general transmitted sexually both orally and genitally. The disease occurs in three stages. Anywhere from two to ten days after infection a canker may appear in the area of initial infection. This may last for several weeks. This stage is followed by the appearance of a rash on the trunk, hands and feet. Flu like symptoms may also occur. The third stage is the tertiary stage in which the destruction of bone occurs (personal interview with Health Link Calgary, July 2006).
Syphilis is rare in Canada and the U.S. but does occur on occasion. The information I have does not say whether those infected in North America contracted it here or enter North America from travel abroad or immigration with the disease. It is easily treated with antibiotics. However, damage to bone which occurs in the tertiary stage is not reversible. It can take two to five years for the tertiary stage to occur (Ortner 2003)( Calgary Health link 2006).
I find it more likely that remains found in North America showing signs of Syphilis damage are one of several things. First the remains could be very old indicating a burial from a time when Syphilis was widespread. Second, the remains could be from an individual whose country of origin was one where Syphilis is still common and goes untreated for long periods of time.
Although the most common method of transmission is through sexual contact Syphilis can be transmitted from mother to fetus if the infection occurs late in the pregnancy (Ortner, 2003) (Calgary Health Link, 2006). Infection in the early stages of pregnancy almost always results in fetal death. Infections of Syphilis which are transmitted from mother to child are known as congenital rather than venereal infections. It is possible to find fairly young children in the tertiary stage although they would likely have come to North America from countries where the disease was left untreated for a long time. For forensic purposes the signs of a Syphilitic infection on either an adult or a child's remains could be use to indicate geographic region of origin in that is points to an infection likely contracted outside North America.
Syphilis in the tertiary stage causes destruction of the front of the upper and lower jaw, the nasal cavity and the skull. In very advanced cases the bone lesions and destruction will be evident on the entire skeleton (Ortner, 2003).
The two other diseases in this category are Bejel and Yaws. These are known as Endemic Syphilis which is contracted through open wounds or sores. Bejel occurs in the arid countries of the Mediterranean and West Africa. Yaws occurs in humid tropical countries (Calgary Health Link, 2006).
Both diseases cause similar damage to Syphilis. Yaws is however associated with a bowing of the tibia. Bejel is associated with destruction of the small bones in the hands. Both these disease are contracted in childhood as a rule (Ortner, 2003).
Although some of the symptoms of these three diseases are similar an investigator might be able make a guess at the race or approximate area of the world the person came from. If you are looking for a missing person who emigrated from West Africa as an adult this could help rule in or out any remains found.
Tuberculosis
TB was thought to be almost eradicated in Canada in the 1950's. It has however made a come back in recent years. On average there are 1500 to 2000 new cases reported each year (taken from www.phac-aspc.gov.ca/publicat/tbcan02 July 2006).
The racial distribution is interesting. In the north (Nunavut) all of the cases reported where in aboriginal populations. In Alberta and Ontario a large percentage of the cases reported where from people of foreign origin. In the east there is about a 50% split between foreign born and non aboriginal cases. The ages of the infected persons varies slightly with aboriginals at about 34 and all other Canadian born people infected at about 54. Non Canadian born victims were on average about 42 years of age (taken from www.phac-aspc.gov.ca/publicat/tbcan02 July 2006).
Therefore remains which show evidence of TB could be used help to estimate both race and age. For example a modern burial in the North showing signs of TB bone destruction and lesions might suggest that the remains were from someone of aboriginal descent.
Tuberculosis is a disease which is caused by the bacteria called Mycobacterium Bovis which is found in cattle products (Ortner, 2003). Once a human is infected Mycobacterium Tuberculosis can be passed from human to human. Once infected the disease causes a primary lung infection which is then spread through the blood if the immune response of the body is insufficient (Ortner, 2003).
T.B. can appear years after the original infection if illness, injury or malnutrition decreases the immune response of the body.
T.B. which has moved from the respiratory system to the rest of the body can affect both bones and joints. The more common sites of damage are the bones which contain red marrow (Ortner, 2003). In adults the ankles and knees are affected. In children the centers of ossification are commonly affected. In both groups the spine and ribs are involved.
Osteomyelitis
Osteomyelitis is a condition in which there is a build up of woven bone around a localized site usually in the legs or arms. There will also be holes in the bones where pus has drained (Ortner, 2003) (. This condition is caused by a Staphylococcus infection which enters the marrow cavity of a bone. Bacteria commonly enter through a wound but can be blood born. Blood born infections are more common in children (Ortner, 2003) (White & Folkens, 2003).
Periostitis
Periostis is not caused by a specific pathogen rather is a response by the body to injury. Woven bone forms over the site of injury. The literature on this particular condition disagrees. Ortner (2003) defines this as a disease which is found mainly in archeological sites and is not found in modern populations. White and Folkens (2003) disagree and say that it is not a disease but an immune response to injury. The injury may be chronic or sudden usually damaging but not breaking the bone. This condition usually occurs at site where the bone is close to the surface of the skin. Naturally les protection from muscle or fat would make a bone more susceptible to injury.
In modern forensic investigations it might be possible to use the presence of this condition to confirm identity by pointing to a particular occupation. For example in my youth I barrel raced at horse show and rodeos. As a result of this sport I have bumps of built up bone in the middle of my shins. This is a direct result of repeated collisions at high speed with an 80 gallon steel barrel full of sand. Now imagine I am murdered and my remains are found in skeletal form. The forensic osteologist might after estimating my age and height etc. question my family as to what activities I may have pursued in life to cause this condition. My family would say she rode dressage and barrel raced. The osteologist looks at the skeleton and notes fused vertebrae (Caused by repeated hip and back motion required to sit completely still on a horse in motion) in the lower back and bone damage to the mid shin. This she concludes is consistent with those activities. This evidence will not positively identify my remains but is will add to the evidence which says these are my bones.
Scurvy
Scurvy is a disease caused by a lack of vitamin C. Most people think of this disease as one which does not occur in the modern world. However it does occur in the modern world in very specific locations and may be an excellent indicator of race and age. Today the world Health Organization and other groups are reporting occurrences of Scurvy in the refugee camps of Somalia and the Sudan (taken from www.unsystem.org/scn/archives/scnnews02/ch4 July 2006). In rare cases this condition can occur in cases of abuse in which the child is severely malnourished.
Infantile Scurvy causes damage to the growth plates, thinning of the cortical bone and the skull becomes porous. In some cases lesion of the skull may occur (Ortner, 2003). The weakening of the bone leads to multiple and severe fractures.
Rickets
Rickets is caused by a lack of vitamin D. The absorption of vitamin D is directly related to exposure to sunlight. Rickets prevent bone from becoming calcified. As a result the bones become soft. Rickets is most commonly characterized by a bowing of the long bones. Over extended periods of time the ribs, spine and pelvis may also be affected.
This is also thought to be a disease of antiquity. However, the presence of this disease can indicate several things. The remains may be from an adult who is old enough to have suffered from this as a child. The remains may be from a person who has suffered from severe malnutrition or extended imprisonment. The remains may be from a person whose culture or religion requires certain members to remain indoors or completely covered by clothing (Ortner, 2003).
There is an adult form of rickets called Osteomalacia which can be a genetic or developed inability to process vitamin D. Kidney disease can also lead to rickets (Ortner, 2003).
Paget's Disease
This is an interesting disease in that is race specific. About 3% in every 4500 men over the age of forty show some signs of this disease. Thought to be viral in origin it cause extensive accumulation of woven bone and bone remodeling (Ortner, )2003. This disease occurs in Caucasian male. It never occurs in males of Asian descent and rarely in those of Negroid descent (Ortner, 2003). This condition could be very useful in determining race when the remains show signs of this disease.
Gout
Gout is a disease which can indicate the gender of the deceased. It typically occurs in males older than 40 years. It occurs in all populations. It is caused by a build up of sodium urale in the tissues. It causes an immune response by the body which in turn causes lesions and destruction of the bones of the lower extremities (Ortner, 2003).
Osteoporosis
Osteoporosis is the reduction of bone density cause by reduce estrogen levels. As a person ages the estrogen levels in the body drop causing the bones to become brittle. This typically occurs in women after menopause at about 50-60 years of age. It can occur in women who have had hysterectomies or the surgical removal of ovaries at an earlier age. In men osteoporosis occurs between the ages of 70-80(Ortner, 2003)(Calgary Health link, 2005).
Knowing the medical history of a possible missing person can help identify a person and determine approximate age.
Myeloma
Myeloma is a blood disorder which causes a specific pattern of bone lesions and skeletal damage. This disorder starts in the bones which contain marrow such as the long bones. Eventually it spreads by way of the blood to all areas of the skeleton concentrating in the trunk (Ortner, 2003) Myeloma causes destruction of the bone which appear as 5mm-2cm holes in the bone. These holes may have scalloped edges (Ortner, 2003) To the untrained eye these holes can appear to be bullet holes or sharp force trauma.
The presence of this disease is useful in two ways. First it occurs mostly in men. Second it usually occurs in men over 50 years of age. It is therefore useful in establishing age and gender.
Glanders
This disease is very common in Canada and the United States. Fortunately it is more common in horses and donkeys than in people. People can catch Glanders from a horse or donkey and then in turn infect another human but it is rare. It is highly contagious. As I have said before I worked with horses for many years I never caught Glanders although many of my horses did. I always wondered why the owners of race horses got so freaked out when their horses came down with Glanders. I know now that although rare Ganders can cause destruction of the nasal cavity and bone lesions and secondary involvement of the joints. Destruction of the nasal bones and damage to joints is bad if you are a race horse.
This disease is a sort of horse "mumps". The glands under the jaw swell and there is discharge from the nose. Eventually the swelling under the back of the jaw ruptures and drains.
I thought this disease was interesting in a forensic sense because in the rare case of a human infection some bone destruction and lesions can occur in the same patterns as occurs in horses. This could be useful to know if the remains you are examining might be those of a missing veterinarian or horse trainer.
Arthritis
Osteoarthritis is in general a disease of the elderly. Most people over the age of about 60 will show some extent of this disease (White & Folkens, 2005). It is cause by wear over many years. The presence and extent of osteoarthritis in human remains is a good indicator of the approximate age of the individual
Rheumatiod Arthritis
This type of arthritis is thought to be genetic or viral in origin. It can strike at any age but usually affects women over forty. Because of its prevalence in women over forty evidence of this disease could be used as an indicator of age and gender.
Tumors
There are more than 40 varieties of tumors which may cause damage to the skeleton (Ortner, 2003). Some of the damage particularly to the skull looks very similar to blunt force trauma to the skull. I thought that in a forensic investigation the presence of large holes in the skull might be assumed to indicate trauma. However, if one of the people on your missing persons list matches the height, age and gender of your remains but also had late stage cancer it could lead the investigation in another direct.
I have certainly only scratched the surface of the many diseases which can cause damage or changes to bone. However, I hope I have shown how some of the patterns of bone damage can help the forensic Osteologist answer questions such as the age, race, and gender of an individual based on the bones.
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