Muelas y molinossalud dentomaxilar en el norte de la península ibérica (siglos IX-XIX)

Resum

The morphological characteristics of the teeth and the tissues that form them make them extraordinarily resistant, and, therefore, one of the most valuable sources of information for the knowledge of past populations. The purpose of this study is to provide an alternative approach to the similarities and differences of urban and rural societies, through the analysis of dental and osteological indicators, as well as to improve the understanding of dentoalveolar and maxillofacial anatomy and pathology in human past populations. In this context, the social configuration of urban and rural areas was explored, emphasizing the understanding of the social construction of the city and highlighting the differences with the more distant rural world, the mountains. A historical framework of the environment of the analysed necropolises was created, aiming to contextualize, in a summarized image, the historical past of the north of the Iberian Peninsula corresponding to the extensive period between the 9th and early 19th centuries. In all, 532 adult individuals from six populations from the southern slopes of the Cantabrian Mountain range that cover three Northern provinces of the current Autonomous Community of Castilla y León were analysed. The individuals studied were exhumed from two cemeteries in the city of León (the church of San Salvador de Palat de Rey, n= 201, 13th-19th centuries; and Plaza del Grano, n= 31, 12th-18th centuries), and four rural nuclei in the mountain area (the Barrejo necropolis, n=24, 12th-13th century, Cordiñanes de Valdeón, León; the church of San Juan Bautista, n=237, 16th-19th centuries, Guardo, Palencia; the necropolis of San Roque, n= 19, 9th-12th centuries, Renedo de la Inera, Palencia; and the church of San Cosme and San Damián, n= 11, 12th-19th centuries, Encío, Burgos). The anthropological analysis consisted of estimating the biological profile of each individual and carrying out a paleopathological study of the dentoalveolar and maxillofacial area. The male individuals constituted 58.7% (312/532) of the total number of individuals whereas 41.3% (220/532) were females. The samples were divided according to their provenance (urban: 45.5%, 241/532; or rural mountain: 54.5%; 291/532), and to their chronology (medieval: 21.1%, 112/532; and post-medieval: 78.9%, 420/532). The dentoalveolar pathologies analysed were dental caries, periapical inflammation, periodontal disease, antemortem and perimortem tooth loss. Postmortem dental loss, dental anomalies and dental wear were also investigated. The dentitions were examined by visual inspection. Radiographs or topographies were performed in some relevant cases. In all, 17,024 dental alveoli were analysed, of which 9,547 (56.1%) could be evaluated. Of these, 2617 (27.4%) correspond to empty sockets due to postmortem tooth loss, and 3763 (39.4%) present bone remodelling due to antemortem tooth loss. In all, 3,167 (33.2% of all alveoli) in situ teeth were present, from which 282 (8.9%) had some type of dental anomaly or were not fully erupted, and 39 (1.2%) presented postmortem fractures preserving only root fragments. Several dental anomalies have been recorded, including those relative to tooth eruption patterns, dental morphology, number, size and colour of teeth. There were 20 (0.6%) teeth abnormally erupted, corresponding to 13 canines, six third molars and one lateral incisor. The third molars (46.2%) were the teeth presenting more eruption anomalies, namely the upper left one (27.1%). Dental agenesis was also predominantly recorded in third molars (41.5%). Regarding the canines, abnormal eruption was observed in 16 upper and one lower. A higher proportion of agenesis was found in the post-medieval era compared to the medieval one. In the medieval and urban samples, it was the male sex that presented the highest frequency of dental agenesis. The persistence of deciduous teeth was observed in nine individuals which also coincided with impactions of the upper and lower canines. A mesiodens was found in rural areas, and one paramolar and three peg-shaped maxillary lateral incisors were identified in the urban setting. In all, 2.3% of the teeth presented anomalies in the crown shape, all belonging to individuals from the populations of Cordiñanes, Guardo and both located in León. Regarding dental colouration, a pink tooth was registered in Palat de Rey. Four individuals belonging to the modern period showed black residue on the lingual face of the teeth [SJG-13(2), SJG-79, SJG-131(A), PRII-Ns -b-4N) possibly produced by consuming some type of chewing tobacco. In a modern individual (PR-5 Nn-a) the teeth presented a silver-grey colouration, whose concentration of mercury (20.66±0.21 μg/g) and arsenic (0.40±0.054 μg/g) turned out to be very high, indicating a possible combined and systematic medical treatment of syphilis. Dental wear was common in all samples. Some individuals showed specific and atypical patterns of wear were suggestive of using the mouth as a "third hand". Smith's (1984) grade 2 occlusal wear (moderate removal of cusps with slight dentin exposure) was recorded more frequently in Renedo and Guardo; grade 3 (complete removal of the cusps and small dentin exposure) was more common in the Cordiñanes necropolis and in Plaza del Grano. Finally, grade 4 (great dentin exposure in one or two cusps) was more commonly seen in Palat de Rey and in Encío. The individuals from the urban environment exhibited moderate degrees of occlusal wear, very similar to those presented by the rural individuals. The highest frequencies of intense occlusal wear were recorded in medieval times, being this the last historical period linked to notable dental wear in all the populations studied. Males presented greater occlusal wear rates in all populations. The male sex was also the one that presented the highest frequencies of buccal/labial chipping in the overall sample, which can be related to the use of teeth for non-chewing activities or to the persistent ingestion of hard foods (hazelnuts, walnuts, hard vegetables, dried meat, etc.). Individuals from Plaza del Grano revealed a high frequency of atypical dental wear in males. The triple pattern (chipping-LSAMAT-TGMOS) was recorded in 24 teeth, of which 20 belonged to males and four to females, with no differences relative to the provenance or chronology. In the rural environment, both sexes would carry out a multitude of activities for the manufacture of agricultural and livestock tools, for both daily and family use. On the other hand, in the urban environment, men had more tasks related to trade, whereas women would continue with the daily activities within home. In both environments, the work would entail the use of teeth as a "third hand" in different activities (fabric manufacturing, sewing, shoemaking, carpentry, etc.). The anthropological variables, tooth type and location, sex and age group influenced all dentoalveolar pathologies studied. The greatest number of caries was found at the occlusal surfaces, followed by the root surfaces, the interproximal contact areas, being the smooth surfaces the least affected by cariogenic activity. The females had the highest caries frequencies in all locations with the exception of interproximal caries, for which there were no differences between the sexes. Occlusal caries occurred more frequently in urban areas, whereas interproximal caries and root surface caries were more affected in rural areas. Smooth surface caries only showed differences between environments, presenting high frequencies exclusively in females from rural areas. Occlusal caries, smooth surface caries and root surface caries presented higher frequencies in post-medieval times and interproximal caries in medieval times. On the contrary, females from medieval times had the highest prevalence of root surface caries The frequency of periodontitis in septal areas was always greater than 50%, being higher in urban environments and medieval times. Gingivitis and moderate periodontitis were very common, although compatible with good dental function until relatively old ages. In all populations, the inter-molar and inter-premolar septal areas were the most susceptible to periodontal rupture, with male septa being the most affected. The least prone was the inter-incisal area. Gingivitis was more frequently observed in the younger age groups. No individual had a completely healthy periodontium. Only a small proportion of the population experienced severe periodontitis that compromised the survival of the teeth. The most destructive periodontitis occurred relatively early and increased considerably with age. Even so, periodontitis is not believed to have been the main cause of early tooth loss. Regarding periapical inflammation, most of the individuals with periapical inflammation registered only cysts (or granulomata), which correspond to relatively benign and asymptomatic lesions. Only 3.2% of the individuals presented abscesses. No cases of osteomyelitis were detected. Antemortem tooth loss was higher in rural areas and in post-medieval times, with females losing teeth more frequently. These results could reflect the arrival of new foods from the 16th century onwards, as well as the shift from the preparation of highly fibrous and abrasive foods to more processed foods with a softer and stickier consistency. These foods, such as potatoes and corn, are more prone to adhere both to the occlusal surface and to the smooth surface of the teeth, especially the posterior ones. In general, the high rates of dental caries observed in mountain population samples during the Middle Ages suggest that these populations would consume carbohydrates such as cereals and, later, potatoes, corn and the new sugars. In the Modern Age, the rural population of the church of San Juan Bautista de Guardo had the highest caries frequencies over urban populations. However, the Barrejo necropolis showed the greatest periodontitis in both sexes. The high prevalence of periodontal disease in the medieval rural populations of Barrejo in Cordiñanes and San Cosme and San Damián in Encío could be related to an abrasive diet, poor in vitamins, and rich in protein and lipids of animal origin. A final factor that may have influenced differences in dental disease between study samples is oral hygiene.Given the results obtained in this work, the potential of Dental Anthropology in the research of the lives of past populations was reinforced. This study shows that dentoalveolar pathologies were very common, and probably had a significant effect on the lives of people living in the north of the Iberian Peninsula until the advent of new models of hygiene and dental care in the late 19th century. The presence of perimortem dental loss and violent injuries in two skulls recovered from the church of San Salvador de Palat de Rey, with the probable use of swords, points to violent confrontations with weapons in the city of Leon, in the 16th-18th centuries. Finally, new cases compatible with benign fibro-osseous lesions, Stafne´s bone defects and the consequences of indirect trauma to the mandibles were presented and discussed. The first known evidence of possible medication with mercury and arsenic in the treatment of syphilis in the city of León was also described. Case reports of new and uncommon pathologies have the potential of adding information regarding geographic distribution, differential diagnosis, biological profile, as well as establishing new prevalence points for diseases that were previously unknown in the osteoarchaelogical record of specific geographic regions. The cases here described contribute to a better knowledge of orthodontic anomalies and patterns of dentoalveolar and maxillofacial pathologies in the 9th-19th centuries populations from the north of the Iberian Peninsula.