SEM of interproximal groove indicative of therapeutic practice at Pete Klunk Mounds, Illinois Savannah Leach Indiana University Bloomington, Department of Anthropology Acknowledgments Scanning Electron Microscopy 11-C40-38 Introduction References Results and Conclusion INTERPROXIMAL GROOVES Interproximal grooves are smooth and frequently polished indentations found between adjacent teeth. They are cylindrical in shape and are often characterized by their sharp margins and parallel striations along its interior running bucco- lingually. They are most commonly found near the cemento-enamel junction (CEJ). 1,2,3,4, Interproximal grooves have multiple etiologies 1,5 , which include: • Picking with a dental probe • Habitual • Therapeutic • Abrasive dietary components being consistently sucked through the teeth • Using teeth as tools • Antemortem chemical erosion Population based studies have found incidence rates as high as 8.9%. American Indian populations have recorded incidences as high as 1.6% 1 . Most of these grooves are found on the mesial or distal surfaces and are most frequently found in the maxillary posterior teeth. 1,3 Some evidence shows a male bias. 3 Turner and Cacciatore found that 9.8% of their samples had interproximal grooving associated with carious lesions. 1 Ubelaker and colleagues found that 92.31% of the 26 American Indian Individuals also display alveolar resorption near the location of the interproximal groove and 36.56% of the teeth with interproximal grooves are associate with interproximal caries, with the buccal edge being more definitively grooved. 2 The scanning electron micrographs (SEM) presented here will provide some insights into the etiology of the interproximal groove of a Middle Woodland individual from Pete Klunk Mounds in Calhoun County, Illinois. PETE KLUNK MOUND GROUP Gregory Perino began excavation on the Pete Klunk Mound Group in the field season of 1960 and it was completed the following year. Of the three mound groups in Kampsville, Illinois, Pete Klunk Mound Group is the largest and is located on the bluff north of town. The mounds, 14 in total, run north-south along the bluff overlooking the Illinois River. The site is primarily Middle and Late Woodland components, but there is also a minor Archaic portion, including an Archaic charnel pit and a small portion of Mound 7. 6 Scanning electron microscopy (SEM) works by using electrons, instead of light, to form an image. A beam of electrons is sent from the top of the microscope to the sample, located in a vacuum sealed chamber. The electrons hit the sample and are then ejected and collected by detectors, which change the x-rays and electrons into a signal that can be turned into a final image. All non-metal materials are covered in a conductive material to create a clearer image. 7 Scanning electron micrographs were obtained with the help of Barry Stein at the Electron Spectroscopy Center at Indiana University, Bloomington. The molar was sputter coated with approximately 45 nm of platinum using a Polaron SEM E5100 Coating Unit. Once sputter coated, the scanning electron micrographs were captured with a JEOL JSM-5800 LV, which has magnifications ranging from 18x to 300,000x and voltages from 0.3 to 30 kV . 1. Turner, CG and E Cacciatore. 1998. Interproximal Tooth Grooves in Pacific Basin, East Asian and New World Populations. Anthropological Science. 106: 85-94 2. Ubelaker, DH, RW Phenice, and WM Bass. 1969. Artificial Interproximal Grooving of the Teeth in American Indians. Am J Phys Anthropo 30:145-150 3. Luckacs, JR and RF Pastor. 1988. Activity-Induced Patterns of Dental Abrasion in Prehistoric Pakistan: Evidence from Mehrgarh and Harappa. Am J Phys Anthropo 76:377-398 4. Formicola, V. 1991. Interproximal Grooving: Different Appearances, Different Etiologies. Am J Phys Anthropo 86: 85-87 5. Berryman, HE, DW Owsley and AM Henderson. 1979. Non-carious Interproximal Grooves in Arikara Indian Dentitions. Am J Phys Anthropo. 50:209-212 6.. Perino, G. 1968. The Pete Klunk Mound Group, Calhoun County, Illinois: The Archaic and Hopewell Occupations. In: Hopewell and Woodland Site Archaeology in Illinois. Bulletin 6. Illinois Archaeological Survey, Urbana. pp. 9-124 7. Purdue University. 2014. Radiological and Environmental Management: Scanning Electron Microscope. Retrieved: 3/5/2015. http://www.purdue.edu/ehps/rem/rs/sem.htm 8. Stein, Barry. Personal Communication. IU Electron Microscopy Center I would like to thank Berry Stein and the Electron Microscopy Center at Indiana University Bloomington for assisting me with sputter coating and imaging. I would also like to thank Della Cook for advice and feedback. Thank you to Lita Sacks, Paige Wojcik and Olof Olafardottir for poster advice. Buccal Occlusal Lingual 11-C40-38 11-C40-38 is an older adult male (>50 years old) from Mound 11. Mound 11 is part of the Middle Woodland component of the site and is situated at the highest point of the crest. This individual was extended in a subfloor burial found on the outside of the mound. 6 The interproximal groove is located on the distal side of the 2 nd right maxillary molar along the CEJ. There is a caries located on the lingual edge of the groove in the cervical region. The groove is approximately 2.5 mm wide at the center and approximately 5 mm long. There is only a slight indentation on the third right maxillary molar, which could not be successfully photographed. The only dental pathology outside of this interproximal groove is the associated caries on the effected tooth and some minor bone resorption. No other individuals in the Middle Woodland component of the site have similar grooves. Future Research o The interproximal groove shows expected characteristics described in previous work o Macroscopic inspection shows the groove has a curvilinear outline, which suggests the insertion of a cylindrical object o Sharp edges can be seen in both the macroscopic examination and in the SEM. The SEM appears lighter around these sharp edges due to the Edge Effect (Micrograph B) o The Edge Effect is a result of many secondary electrons being emitted through the uneven surface 8 o The interproximal groove is located at the CEJ o The most frequently documented location of interproximal grooves is on maxillary posterior teeth, as seen here 1 o The SEM shows parallel striations along the interior of the groove (as indicated by the red arrows; Micrograph C and D) o Suggest abrasion and not chemical erosion as the causative process 5 o These striations run bucco-lingually o The non-perpendicular angle of insertion suggests the use of a non flexible tool during life o The best explanation for this groove is the dental probe hypothesis o No other members of this Middle Woodland population have interproximal grooves o Not likely the result of abrasive diet alone o Not likely from tool use (such as from processing sinew) o Habitual or Therapeutic? o The location of the interproximal caries at the lingual edge of the groove suggests therapeutic probing (Macroscopic Images and Micrograph A) o The caries would have likely caused regular pain o Massaging the area and surrounding gingiva with a tool may have helped to alleviate some of this discomfort The next steps in this project include: • Use experimental archaeology to determine material used as the dental probe • Investigate the individuals from other components of the Pete Klunk Mound group • Investigate other surrounding mound groups of Kampsville, Illinois A B C D