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 * __ Treponematosis __**

=__Definition__=

Treponematosis is a chronic, progressive, moderately acute bacterial infection (M.O. Smith) caused by a “cork-screw” shaped microorganism, [|Treponema], meaning twisted thread. Treponematosis also known as syphilis has been nicknamed the “great imitator” because its symptoms appear similar in skeletal remains to other diseases such as [|Leprosy], [|Tuberculosis], [|osteomyelitis], and [|neoplasm] making identifications difficult in the archaeological record.Treponemal infection leads to focal destruction and remodeling of the outer table of the bone and part of the diploe but does not affect the inner table (D.J Ortner). Syphilis can be divided into four different categories, Pinta, Yaws, Non-venereal syphilis (Endemic syphilis), and Venereal syphilis (Acquired and Congenital) (R.W. Mann, S.P. Murphy).

=__History and Hypotheses of Treponematosis__=

There are a few different hypotheses as to where and when Treponematosis started and the route it traveled to become worldwide. Archaeological evidence for each of these hypotheses further makes it difficult to determine where Treponematosis may have originated.
 * Treponematosis started in the Pre-Columbian New World (Americas) and traveled to the Pre-Columbian Old World (Europe) by means of [|Columbus] and his travels. The evidence for this theory is in the written record and specifically a syphilis epidemic in 1495 in Europe (D.L. Trembly).
 * Treponematosis traveled to the Americas by the use of Columbus and his travels from Europe. Other archaeological cases have found early skeletal material in Greece with signs of tertiary syphilis long before Columbus, indicating that this could have been where Treponematosis originated (D.L. Trembly).
 * Treponematosis started elsewhere other than Europe or the Americas. Some anthropologists suggest the origin may have been in certain parts of Southeast Asia, but became more evident in the written and archaeological record after Columbus’ travels in both the Americas and Europe (D.L. Trembly).

=__Different types of Treponematosis__=

1) [|Pinta], //Treponema carateum// is the least destructive type of syphilis and generally benign. Pinta means “spot”, “dot” or “mark” in Spanish and consequently is endemic to Mexico, Central and South America. It appears as a skin rash where the pigment changes and spreads all over the skin. Pinta is not spread through sexual contact and is the only variant of syphilis that never affects the skeleton (R.W. Mann, S.P. Murphy). Therefore it is not seen in the archaeological record.

2) __Yawtoc__ __ s ,__ //T////reponema pertenue// is a non-sexually transmitted type of syphilis that is endemic to juveniles. It is transmitted through close contact with a skin sore. This variation is found worldwide but more often found in areas of hot, humid and arid environments. It starts in childhood and becomes a localized, painful externally exposed lesion and if the sore is located near bone it can cause periostitis. In later stages of[| Yaws], gumma periostitis, osteomyelitis and anterior tibial distortion can develop (R.W. Mann, S.P. Murphy). These characteristics are similar to the tertiary stage of venereal syphilis generating difficulties in distinguishing between them.

3) __Endemic Syphilis__, //Treponarid [|bejel]// a non-sexually transmitted form of the treponemal infection found in warm, arid to semi-arid climates such as in Africa, the Middle East and Asia. This disease is spread through close human contact such as kissing as well as from inanimate objects such as utensils or drinking glasses. Some scientists advocate that this is an intermediate form of Treponematosis in between Yaws and Venereal syphilis due to bone lesions are uncommon in endemic syphilis and are difficult to distinguish from these two forms in the archaeological record (R.W. Mann, S.P. Murphy).

4) __Venereal syphilis__, //Treponema pallidum// “pale-twisted thread”, this is the only variant form of syphilis that is sexually transmitted (Acquired Syphilis). It is found worldwide and is the only type that can be transferred transplacentally (D.J Ortner), from mother to fetus [|(Congenital Syphilis]). This variant of treponemal infection shows up only 10-20% on the skeleton and only in the last stages of the disease (Tertiary stage). Evidence of infection can be displayed on the bone 2-10 years after the initial infection and most common bones affected are the tibia and craniofacial bones (R.W. Mann, S.P. Murphy).  Congenital syphilis infection during fetal development often kills the child before birth but milder versions ‘syphilis congentia tarda’ can remain dormant in a child for many years before exhibiting signs of treponemal infection (R.W. Mann, S.P. Murphy).

=__Skeletal Evidence of Treponematosis__=

__Cranium__
The most common areas of the cranium that exhibits treponemal infection are on the frontal bone. Osteoperiostitic lesions of the cranial vault seem to start and are mostly confined but not limited to the frontal bone, a common type is tertiary [|gummatous]. The base of the skull is not often affected by treponemal infection; generally Treponematosis affects areas of bone that are near the skin surface (R.W. Mann, S.P. Murphy). Treponematosis affects the outer layer of the skull ([|periosteum]), which leaves clear and distinguishable marks on the ectocranial surface. These specific markings on the skull are thickened areas of the vault called ‘caries sicca lesions’ and there are three different types. 1) __Stellate scarring__: star-like scars that appear as smooth-rimmed furrows and radiate from a central point, also called radial scars. 2) __Cavitations__: areas of depressed bone that does not affect the inner layer of the cranial vault (endosteum). 3) __Nodes__: smooth sclerotic bone that creates the composition of the walls and rims of cavitations. In untreated cases of Treponematosis on the cranium old focal areas of the infection will heal and new ones will form near the old areas. The healed foci will leave a depressed (cavitations), smooth, sclerotic surface (nodes), surrounded by a radial grooved scar (stellate scar) (R.W. Mann, S.P. Murphy).

__Craniofacial__
Remodeling of the nasal aperture is common with most variants of syphilis and generally affects the soft tissue of the nose and surrounding area. It is not seen in the archaeological record until later stages when bone resorption can be observed. This creates a broad, rounded nasal cavity that appears much larger and almost empty in the craniofacial region (D.J Ortner). The edges of destruction are smooth, sclerosis bone. The section of craniofacial region affected by Treponematosis is the bony septum, hard palate turbinates and the lateral walls of the maxillary sinuses (D.L. Hutchinson, D.S. Weaver). The thin nasal bones are destroyed by infection and remodeling occurs adjacent to the nasal aperture, [|periostitis] occurs at the nasal aperture and deterioration of the nasal spine and the nasal floor take place. These characteristics are indicative of treponemal infection and a specific condition called “gangosa” which is used to describe the same craniofacial characteristics for the Yaws variant of syphilis (D.L. Hutchinson, D.S. Weaver).

__Post-Cranial__
The most common area for treponemal infection of the post-cranial skeleton is the tibia. It is ten times more affected than any other bone of the post-cranial skeleton. Lesions of the tibia can be separated into gummatous and non-gummatous osteoperiostitis lesions (D.J Ortner). The most distinguishing characteristic of treponemal infection on the post-cranial skeleton is the “bowing” of the tibia. It occurs on the anterior plane, where the bone is closest to the skin surface. It is a distortion of the anterior long axis of the tibia, this feature is called “sabre tibia” as well it is also referred to as “sabre shins” and “boomerang leg” (M.O. Smith). Other post-cranial bones that usually display evidence of treponemal infection is the other distal lower limb bone (fibula), proximal lower limb bone (femur), upper limb bones (humerus, radius and ulna), clavicle and hand and foot bones (M.O. Smith). Treponematosis may also affect the spinal vertebrae, although rare and generally mistaken for Tuberculosis, except treponemal infection affects the cervical vertebrae (D.L. Hutchinson, D.S. Weaver) and Tuberculosis commonly affects the lower vertebrae.
 * Gummatous lesions are more characteristic of Treponematosis and will create a localized tumor-like enlargement of the affected bone area.
 * Non-gummatous is not diagnostic of Treponematosis. Its a localized form which leaves bone thick and heavy by creating a plaque-like layer on the bone specifically in areas of increased overlying muscle tissue (femur) or bones near the skin surface (clavicle) (D.J Ortner).[[image:Picture_2.png width="168" height="178" align="right" caption="Tibial Bowing, Sabre Tibia. Image courtesy of K.C. Nystrom" link="http://onlinelibrary.wiley.com.login.ezproxy.library.ualberta.ca/doi/10.1002/oa.1142/pdf"]]

__Dentition__
Dental evidence in the archaeological record is seen in congenital syphilis. Treponemal infection affects the permanent teeth and it is rarely seen to affect deciduous teeth (K.C. Nystrom). These types of irregular characteristics are not due to other common dental diseases such as [|abscesses], [|caries] or [|periodontal disease] (D. L. Hutchinson, D.S. Weaver). There are four different types of dental abnormalities associated with congenital syphilis. 1) Shortened edges in upper central incisors, the teeth are short and narrow and the angles created appear as if the incisors were rounded off (K.C. Nystrom). There is a deep vertical notch made by breaking away or non-development of the middle lobe on the tooth crown. This dental characteristic is a reliable indicator of congenital syphilis and is called [|Hutchinson’s incisors] after [|Sir Jonathon Hutchinson] (K.C. Nystrom). 2) A groove-like hypoplastic defect on upper and lower canines, a groove near the point of the crown, which is often misdiagnosed as attrition (K.C. Nystrom). 3) Abnormal close positioning of the cusps of the upper and lower first molars, called “bud molars” or Moon’s molars. This is another key characteristic for congenital syphilis (K.C. Nystrom). 4) Defect on the upper and lower first premolars, most of the body of the tooth appears normal but the last part or the very tip of the root is missing. It has an “eaten away” appearance (K.C. Nystrom).

=__Key Diagnostic Characteristics__=

The tertiary stages of Treponematosis can affect any part of the skeleton although there are specific areas it affects first and are the most distinctive to Treponematosis.
 * Anterior distortion of the tibia (sabre tibia, ‘boomerang leg’).[[image:Picture_8.png align="right" caption="Treponematosis affecting the entire skeleton. Image courtesy of D.J. Ortner"]]
 * Periostisis of the cranium (specifically stellate lesions).
 * Hutchinson’s incisors and Moon’s molars.

=__Archaeological Difficulties__=

With these specific characteristics it is much easier to determine the type of pathology in skeletal remains. Although there are other cases in which it is difficult to distinguish between syphilis and other pathologies. Many pathological processes cause bone deformation, resorption, and remodeling in a similar fashion to the forms of syphilis such as trauma, osteomyelitis, mycotic infections, Tuberculosis, Leprosy, myeloma, carcinoma and osteosarcomas (D.L. Hutchinson, D.S. Weaver). In determining the pathology in archaeological remains it is often simpler to conclude with more skeletal material from the same individual, which is not often the ideal case.

=__References__=
 * H.R. Buckley., N. Tayles. 2003. Skeletal Pathology in a Prehistoric Pacific Island Sample: Issues in Lesion Recording, Quantification and Interpretation. //American Journal of Physical Anthropology.// **122** :303-324.
 * Y.S. Erdal. 2006. A Pre-Columbian Case of Congenital Syphilis from Anatolia (Nicaea, 13th Century AD) //International Journal of Osteoarchaeology.// **16**:16-33
 * D.L. Hutchinson., D.S. Weaver. 1998. Two Cases of Facial Involvement in Probable Trenoemal Infection from Late Prehistoric Coastal North Carolina. //International Journal of Osteoarchaeology.// **8** :444-453.
 * R.W. Mann., S.P. Murphy. 1990. Regional Atlas of Bone Disease: A Guide to Pathologic and Normal Variation in Human Skeleton. 143-146.
 * K.C. Nystrom. 2010. Dental Evidence of Congenital Syphilis in 19th Century Cemetery from Mid-Hudson Valley. //International Journal of Osteoarchaeology.// []
 * D.J. Ortner. 2003. Identification of Pathological Conditions in Human Skeletal Remains. (Second Edition). 273-319.
 * M.O. Smith. 2008. Adding Insult to Injury: Opportunistic Treponemal Disease in a Scalping Survivor. //International Journal of Osteoarchaeology.// **18** :589-599.
 * D.L. Trembly. 1996. Treponematosis in Pre-Spanish Western Micronesia. //International Journal of Osteoarchaeology.// **6** :397-402
 * J.L. Turk. 1995. Syphilitic caries of the skull- the changing face of medicine. //Journal of the Royal Society of Medicine// . **88** :146-149.