PATHOLOGICAL MANIFESTATIONS ON PALEOANTHROPOLOGICAL MATERIAL FROM RURAL bURIALS OF 14th—16th CENTURIES FROM THE TERRITORY OF POLOTSK LAND

The results of paleopathological study of osteological material obtained during archaeological excavations of rural burial grounds of the 14th—16th centuries, located on the territory of Polotsk land. In total, 72 individuals from three cemeteries were examined (Ives, Biruli and Dolgoe). The purpose of the work is to identify and analyze pathologies and nonspecific reactions of the body, determined on bone material. The study identified the most typical for the rural population of the studied burial grounds pathology and trauma — degenerative changes of the spine and joints, skull injuries, abscesses, caries, periodontitis, non-specific reactions of the body (porotic hyperostosis, cribra orbitalia, enamel hypoplasia, vascular reactions).

Introduction. Paleopathological studies of the rural population of the Belarusian Dvina region of the 14 th -16 th centuries significantly enrich the knowledge about the living conditions, providing material about the most characteristic diseases of the past centuries that existed in the studied region. The bioarchaeological direction is an ac tual vector of development of the anthropological science of Belarus. The research results supple ment the anthropological database with data on the lifestyle of ancient people, highlight regional features, and contain information about factors that had a direct impact on the occurrence and development of diseases among the rural popula tion.
For the first time in Belarus, the paleoanthro pological direction was developed by I. Salivon. In the 1960 s and 1970 s , under her leadership, excava tions of rural burial grounds of the 18 th -19 th cen turies were carried out in different regions of Be larus in order to collect and study the structural features of the bone remains of the population of this period. Based on the comparison of these materials with the data of previous researchers on the population of the 11 th -13 th centuries, the continuity of the main racial characteristics of the anthropological type in time is noted, the direc tion of epochal structural variability of the skel eton in general and the size of the head over the last millennium is traced (Цягака і інш. 2006, с. 37, 38).
An actively developing and promising area of modern paleoanthropology is the reconstruction of the type of physical activity and motor activ ity of ancient people associated with their oc cupation. O. Marfina's research of postcranial skeletons from burial mounds of the 12 th century in Drutsk, Vitebsk region revealed pathological structural changes in the bone system and traces of injuries (Марфина 2015, с. 71).
A significant contribution to the study of the dynamics of the anthropological composition of the Northern region of our country was made by the research of an anthropologist from Polotsk, O. Yemelyanchik. New arrivals of a large volume of paleoanthropological material from the Polotsk land of the 10 th -14 th centuries allowed it to prove the heterogeneity of the population during this period. Of particular interest are the paleoecologi cal works of O. Yemelyanchik, dedicated to deter mining the frequency of occurrence of the marker of anemic stress (cribra orbitalia; Марфина 2016, с. 71).
Materials and methods. The material for paleopathological research was the osteological collection of Polotsk State University (Belarus). Its formation was started in 2010, when the ar chaeologist V. Cherevko conducted archaeologi cal excavations of rural burial grounds in the vil lage of Ives and Dolgoe (Glubokoye district). In the following years, the burial ground near the village of Biruli (Dokshytsy district).
The sex and age composition of the studied se ries is shown in table.
Biruli (14 th -16 th ). The kurgan-zhalnik burial ground near the village of Biruli in the Dokshytsy district is located on the shore of lake Medzozol, and includes both burial mounds and ground burials with stone linings of later times. In 2011, the research of the Biruli burial ground was car ried out by archaeologists A. Voitekhovich and V. Cherevko. During the excavations, 5 burials were discovered, of which four were found with out inventory. Burial 5, which has an inventory (an earring), was dated to the 14 th -16 th centuries (чараўко 2012, с. 6-8).
Dolgoе (14 th -18 th ). The burial ground is located about 0.2 km northeast of the village of Dolgoе. During the excavations that were carried out in 2015, the archaeologist discovered 29 burials. There were no grave goods. The study revealed that part of the burial ground functioned in the 15 th -18 th centuries (чараўко 2016a, с. 177). At the same time, A. Voitekhovich conducted ex cavations of a mound with late medieval intake burials (8 burials). Analysis of burials in the com plex makes it possible to date them to the begin ning of the 16 th century. In general, 13 burials of good preservation were investigated on the site (вайцяховіч 2012, с. 33, 34).
Osteological material from the graves of Ives and Biruli was studied by the O. Yemelyanchik. The assessment of traumatic injuries and stress indicators, such as cribra orbitalia, caries, hypo plasia of tooth enamel was given. Based on the measurement of skulls, a characteristic of the an thropological features of the rural population was compiled (Емяльянчык, 2012). Also, O. Yemely anchik in his article presented the results of pale odemographic research of the Ives and Dolgoе burial grounds (Емельянчик 2017).
The degree of preservation of osteological ma terial was determined according to the method of N. Mamonova (Мамонова и др. 1989, с. 51-53). The gender and age of adult individuals were de fined using a comprehensive method to identify structural features of the skull and pelvic bones (Buikstra, Ubelaker 1994, p. 18, 20).
When determining the biological age of adult individuals, the degree of obliteration of the cra nial sutures, as well as the degree of the teeth abrasion, was taken into account. However, using that feature may be erroneous, since the odonto logical material is not well preserved in the col lection (Piontek 1996, s. 151). The age of children was determined by the degree of development of the dental system using the scheme of D. Ulebak er (Buikstra, Ubelaker 1994, p. 51). If the post cranial skeleton was preserved, the degree of os sification of the skeleton was taken into account (Piontek 1996, s. 148).
To obtain reliable frequency numbers, the preservation of the skeleton for each group of pathological conditions was taken into account. For diseases of the spine, the safety of vertebral bodies and articular processes was at least 50 %. For traumatic skull injuries, individuals with a preserved skull without a lower jaw were allowed. For caries, the safety of molars in at least one of the jaws was taken into account. When calculat ing cases of inflammatory diseases of the dental system (abscesses and paradontopathies), indi viduals who had at least one of the jaws preserved were taken into account. For porotic hyperostosis, the preservation of the cranial vault was impor tant. At the same time, an osteological material with preserved orbital parts of the frontal bone was used for cribra orbitalia. Enamel hypoplasia was accounted for among individuals with the majority of teeth in one of the jaws. Skeletons with preserved brow arches were used to assess the prevalence of vascular reaction.
Results and discussion. Among the an cient rural population represented by the burial grounds of Ives, Biruli and Dolgoe, the follow ing pathological changes of the spine and joints were registered: degenerative changes of the ver tebral bodies, Schmorl nodes, spondyloarthrosis and spondylosis of the vertebrae, systemic joint lesions and osteoarthrosis of the hip joint. Their appearance can be associated with both the natu ral process of wear and tear of the body and with intense physical activity that affects the skeletal system of a person throughout his life. Degenerative lesions of the spine can manifest as dystrophic change in the intervertebral disc and adjacent vertebral bodies (жарков 1994, с. 16). Traces of degeneration of vertebral bodies were found in the rural population from the bur ial ground of Ives and Biruli ( fig. 1). There were 11 cases (11/20) of mostly mild to moderate de velopment. Traces of the disease were detected in the buried at the age of 30-50 years, pathologi cal changes were more often registered in men.
The study also recorded herniation of the ver tebral bodies (Schmorl's nodes). Schmorl nodes are formed when the vertebral plate is damaged, and the compressed cartilage penetrates the body of the neighboring vertebrae and forms a hernia. Schmorl nodes are extremely common, especially in the lower thoracic and lumbar regions, and are easily recognized in the skeleton as depressions on the vertebral surfaces (Waldron 2008, p. 45). In addition to serious physical exertion and in juries, the occurrence that pathological changes may be associated with the loss and weight of the human body (Trzciński 2017, p. 308). The pres ence of traces of hernias of vertebral bodies were detected in 7 individuals (7/20) from the Ives and Biruli burial grounds, in men of 30-50 years old.
The study of the ancient population also re vealed traces of spondyloarthrosis. Spondyloar throsis is a dystrophic lesion of the arch-proc ess joints that develops in the same sequence of morphological changes as in osteoarthrosis of the peripheral joints (Крутько и др. 2013, с. 7). On osteological material, spondyloarthrosis lesions represent porosity, bone deformation, erosion and development of osteophytes in the area of archprocess joints. Degeneration of the facet joints of the vertebrae can lead to a hernia of the vertebral bodies that are under pressure from the altered bone articular surface (Ortner, Putschar 1981, p. 555). Degenerative-dystrophic changes in the joints of the facet vertebrae were registered in the rural population of the Ives and Biruli burial grounds. A total of 8 cases (8/20) of spondyloar throsis were recorded ( fig. 2), the majority of cas es -in the male, aged 30-50 years.
The study showed the presence of a specific spine disease -deforming spondylosis. In case of disease, the vertebral bodies are soldered by narrow arched brackets, sometimes only partly ossified (Рейнберг 1963, с. 348). The disease most often is a result of chronic overload of the spine, causing tears in the peripheral parts of the fibrous ring of intervertebral discs in the area of their attachment to the edge of the vertebral body (Рохлин 1965, с. 55). In the Ives and Biruli burial grounds, pathological changes were detect ed in 8 individuals (8/20; fig. 3). Among them, 6 men, one woman and one individual whose gen der could not be determined. At the time of death, all were over 30 years old. The presence of such changes indicates serious disorders in the spine, which in turn could lead to the functioning prob lems of the musculoskeletal system.
During osteological examination, traces of de generative pathology of the hip joint, coxarthrosis, were also recorded. Gradually, as the arthrosis progresses, pain and limited mobility in the joint increase, and lameness appears (Герасименко 2007, с. 28). It is known that various conditions predispose to the development of hip arthrosis, including congenital hip dislocation, displace ment of the femoral epiphysis, and Legg-Kalve-Pertes disease (Waldron 2008, p. 38).
Traces of osteoarthrosis of the hip joint were recorded in a 30-40-year-old man from Biruli.
A special case of degenerative-dystrophic changes in the joints was identified during the study of osteological material from the graves of Ives and Biruli. In 3 individuals, namely men of 30-50 years old, traces of the costal-transverse joints osteoarthrosis were found. The deform ing arthrosis of these joints, which in some cas es causes the back pain, is particularly often in adulthood and in the elderly age. By this disease, the marginal bone growth can reach significant sizes on the head of the rib and on the transverse process of the vertebra (Рохлин 1965, с. 50).
In the course of the study, the analysis of in juries to the skull and postcranial skeleton was carried out. D. Ortner suggested that the cause of injuries in ancient populations may be the fol lowing factors: war, violence within the family, human activity during harvest or hunting, in tentional and unintentional injury in the course of ritual actions, as well as physiological factors that could lead to bone fractures, such as senile osteoporosis (Ortner 2003, p. 119).
The study of the osteological collection revealed the presence of antemortal injuries and post-trau matic changes in all three burial grounds. A total of 3 cases (3/32) of skull injuries were identified. Injuries were localized on the frontal, parietal and occipital bones. In one case, the zygomatic bone was damaged. According to the nature of the damage, there are two groups. The first is chopping or cutting damage -1 case (Biruli). The second one is depressed fractures -2 cases (Ives -1, Dolgoе -1; fig. 4). The study revealed postcranial skeletal injuries with signs of heal ing. They are fractures with displacement of the radius (Ives) and fibula (Biruli). Injuries were re corded in two men over 40 years of age.
An indicative aspect of the health status and morbidity of the ancient population is the pres ence of diseases of the dental system.
One of the important indicators of the popula tion's health is the presence of caries -a local pathological process that manifests itself after teeth eruption, with demineralization and soften ing of the hard tissues of the tooth, followed by the formation of a defect in the form of a cavity. The cause of its occurrence is a cariogenic situ ation on the surface of a sensitive tooth during prolonged fermentation of sugars food by enzyme forming microorganisms of dental plaque (Леус, Горегляд, чудакова 2002, с. 67, 68).
Dental surfaces that are susceptible to poten tial caries include occlusal surfaces; smooth crown surfaces, including mesiodistal (interproximal) surfaces that come into contact with other teeth and buccal-lingual surfaces; and the root, which may be directly affected by caries after a gum and supporting bone recession. Each of these surfaces has a different cariogenic potential, so when com bined with oral bacteria and diet, they cause dif ferent patterns of caries (Ortner 2003, p. 590).
Caries was registered in 14 people (14 cases out of 35 individuals; fig. 5) and was mainly local ized on the molars of the upper and lower jaws, affecting various tooth surfaces. Traces of the dis ease were present on the teeth of both men and women aged 9 to 50+ years.
The subsequent development of caries can lead to the defeat of the pulp and the spread of inflam mation inside the dental canal. In this case, bacte rial invasion causes rapid necrosis of the vascular network of the canal and soft tissues, spreading the necrosis process to the top of the root and surrounding spongy bone, causing a periapical abscess (Aufderheide, Rodriguez- Martin 1998, p. 403). On the craniological material, the conse quences of an abscess are recorded in the form of caverns (cavities) located in the area of the roots of one or more adjacent teeth. An acute abscess, acting on the soft tissues surrounding the tooth, penetrates through the bone to the soft tissues, thus forming an opening. In some cases, there are serious consequences and the disease becomes po tentially life-threatening (Waldron 2008, p. 242). Acute inflammatory processes were registered among individuals of all burial grounds. Pale opathological examination of jaws revealed the presence of 9 cases (9/43) of periapical abscesses in individuals aged 30-50 years.
The general state of health, peculiarities of hy giene habits, and dental pathology determine the condition of the periodontal tissue that surrounds the teeth. These diseases have a common nameperiodontopathies. The origin and causes of these diseases in the anthropological literature are pri marily considered as general markers of adverse environmental conditions (Козак 2010, с. 115, 116). In the process of identifying pathologies of the dental system, 19 cases (19/35) of periodontal disease were recorded. Pathological periodontal changes were equally present among both men and women aged 18 years and older.
The development of teeth is controlled by a ge netic factor and environmental conditions that are relatively independent of those factors that affect the development of the jaws. Because of this inde pendence, the sizes of the two types of structures may not match. Insufficient space for teeth leads to crowding of teeth (Ortner 2003, p. 598).
Some diseases can leave unspecific signs of stress on the bones and teeth. This is typical for individuals with injuries and degenerative pathologies, as well as for certain infectious dis eases and nutritional deficiencies (Cohen, Armel agos 1984, p. 15, 16).
The emergence of difficulties in diagnosing the manifestations of physiological stress, represented by porotic hyperostosis (cribra orbitalia), and the multifactorial development of signs of enamel hy poplasia and vascular reaction causes a number of difficulties in the process of studying them. These changes can be attributed to non-specific reactions of the body that indicate unfavorable living condi tions (бужилова и др. 1998, с. 16).
Among the rural population of the Belarusian Dvina region of the 14 th -16 th centuries, the fol lowing manifestations of stress conditions were recorded: porotic hyperostosis, cribra orbitalia, enamel hypoplasia, vascular reaction on the su perciliary arch. Porotic hyperostosis is character ized by symmetrically located lesions of the cra nial vault, which can be fixed on the frontal and parietal bones, less often occipital. In the process of changes, areas of the skull thicken due to the compaction of the diploid layer, and the surface plate on the contrary is thinned, which leads to the appearance of porosis (Aufderheide, Rodrigu ez- Martin 1998, p. 348). In childhood, diploe con tains red bone marrow, so it is believed that the expansion of this space is a result of the body's need to produce and store more red blood cells in the event of anemia (Lewis 2007, p. 111, 112). During the study, traces of porotic hyperostosis were recorded in 10 individuals (10/49) from the graves of Ives, Biruli and Dolgoe. Mostly lesions were localized on the parietal bones of the skull. In most cases, stress markers were recorded in the male aged 18 to 50 years.
A specific manifestation of porotic hyperostosis is cribra orbitalia. Currently, there are a number of hypotheses among paleopathologists about the factors contributing to the formation of this stress indicator in the form of porosity in the upper in ner region of the orbits. Walker and colleagues suggest that cribra orbitalia is the result of mega loblastic anemia acquired by infants as a result of the synergistic effect of depleted maternal vitamin B12 stores and unsanitary living condi tions that contribute to additional nutrient losses from gastrointestinal infections during weaning (Walker et al 2009, p. 119).
At the same time, paleopathological studies have shown that such morphological changes could be caused by other diseases: inflammation of the skull bones (periostitis, osteitis and osteo myelitis), inflammatory processes of the scalp or Сribra orbitalia as nonspecific stress marker was found in 21 individuals from the graves of Ives, Biruli, and Dolgoe ( fig. 6). In most cases this stress marker affected either both or only the left eye socket. When assessing the intensity of these lesions were assigned to the porotic and cribrotic type. In 7 cases (7/10), lesions were detected in children 3-15 years old, as well as in 6 cases in women aged 18-50 years, 4 cases among men 20-40 years old, and 4 cases in individu als of indeterminate gender older than 50 years (adults -14/43).
The manifestations of enamel hypoplasia in the population provides valuable information about the general state of health of the popula tion and the stress that it experienced at an early age. Enamel hypoplasia -uneven development of the thickness of the enamel cover, which occurs due to insufficient calcification during the forma tion of the tooth (бужилова 1998, с. 102). The feature has the form of transverse lines-furrows of various depths that encircle the tooth along the perimeter (transverse hypoplasia) or pits located on the surface of the tooth enamel (point hypopla sia; Козак 2010, с. 133).
The appearance of enamel hypoplasia has several reasons associated with negative envi ronmental factors. First, there is the likelihood of prolonged breastfeeding, which is common in low-social groups. With this type of nutrition, children have hypovitaminosis (lack of vitamins and trace elements), which leads to the formation of enamel hypoplasia. Second, hypovitaminosis, characterized by generally poor and irregular nu trition of the population. Also, another possible cause is seen in the consequences of rickets. This disease is caused by a lack of vitamin D, which is produced by the body under the influence of ul traviolet light, and also comes with products rich in this vitamin (бужилова 2005, с. 51).
Besides it, enamel hypoplasia can be formed due to fever, birth trauma, congenital syphilis, low birth weight, severe malnutrition in child hood, rickets and hypocalcemia, tuberculosis, zinc deficiency and intrauterine malnutrition due to insufficient nutrition of the mother (Lewis 2007, p. 105).
Enamel hypoplasia was recorded in 4 individu als (4/37) from all three burial grounds ( fig. 7). In two men 30-50 years old, one child 10-11 years old, and one individual of unknown gender 20-30 years old.
Pathological changes in the brow ridge («orange pill») registered in the ancient rural population have several causes. According to M. Schultz's vascular reaction is a consequence of infection of the bone (ostitis) in purulent frontitis and eth moiditis (inflammation in the frontal sinus and ethmoid cells). Another reason for these changes, not only on the brow arches, but also on the zy gomatic, temporal and other bones of the skull, may be chronic skin irritation from parasite bites and, as a result, inflammation of the periosteum (Козак 2010, с. 173).
Along with this, according to A. Buzhilova, spe cific changes in the brow are associated with the impact of low temperatures on the human body (бужилова 1998, с. 104, 105).
During the study of the ancient population, 9 cases (9/40) of the «orange pill» appearance were registered in individuals from the graves of Ives, Biruli and Dolgoe. Traces of the reaction were re corded in the area of the brow ridges and along the edge of the zygomatic bone. Stress occurred mainly in men aged 30-50 years. This indicates an active daily activity of the male population. Women, most likely, were in more comfortable conditions, or wore hats that reduced the possible impact of cold on the body.
Conclusions. Analysis of the bones of the postcranial skeleton of the ancient rural popula tion of the Belarusian Dvina region showed that the nature of the spread of diseases of the spine and the degree of joint wear is associated with the impact of physical exertion on the body. The type and location of injuries on skeletons in the study populations indicate that some men were involved in armed or domestic conflicts, while the possibil ity of domestic injuries and accidents is not ex cluded. Traces of pathological changes in the den tal system of individuals of all the studied burial grounds indicate the prevalence of this group of diseases among the ancient rural population. Car ies, abscesses of the jaw and traces of periodontal disease are the result of an unbalanced diet and a lack of vitamins. During the study of the rural population of the 14 th and 16 th centuries, specific signs were discovered that indicate the exist ence of physiological stresses due to a number of factors. The causes or factors of stress the most important were: lack of vitamins and minerals, which is most keenly felt at an early age, various inflammatory and infectious diseases that weak en the immune system, as well as the social and climatic conditions, of the population life.

PATHOLOGICAL MANIFESTATIONS ON PALEOANTHROPOLOGICAL MATERIAL FROM RURAL bURIALS OF 14 th -16 th CENTURIES FROM THE TERRITORY OF POLOTSK LAND
Paleopathology deals with the identification and research of diseases that are fixed on the osteological material of ancient people. This anthropological direc tion, using a variety of methods, answers the questions of the origin and spread of diseases in ancient popula tions. The results of such studies help to reveal the fol lowing aspects: the influence of the environment, and consequently the adaptation of a person to its changes, Hrytskevich, D. S. Pathological Manifestations on Paleoanthropological Material from Rural Burials... professional occupations of the population, and related types of physical activity, diet, causes of physiological stress and the level of development of medicine.
The aim of the study is to assess the incidence of the rural population of the Belarusian Dvina region of the 14 th -16 th centuries by conducting a paleopathological study of bone material.
During the study, an anthropological examination of the remains of 72 people belonging to the rural popu lation of the 14 th -16 th centuries was carried out. The osteological material was obtained during the archaeo logical excavations of three rural burial grounds in the Belarusian Dvina region-Ives, Biruli, and Dolgoe. Dur ing the research, special attention was paid to the iden tification and registration of paleopathological changes in bone material.
As a result, signs of the following groups of patholo gies were identified: degenerative-dystrophic changes in the spine and joints, skull injuries, dental system pathologies (caries, abscesses, paradontopathies), non specific reactions of the body (porotic hyperostosis, cri bra orbitalia, enamel hypoplasia, vascular reaction).
As a result of the work performed to identify and interpret pathological changes, the main aspects re flecting changes in the health status of the ancient population due to a number of factors were identified: the manifestation of an active lifestyle of individuals, the influence of sanitary and hygienic conditions that existed in rural settlements of the studied period, and the supposed stressful situations to which the popula tion was more or less exposed.
Keywords: rural population of the Belarusian Dvina region of 14 th -16 th centuries, osteology, pale opathology, degenerative-dystrophic changes, injuries, dental pathologies, non-specific reactions of the body.