The Establishment Of The Database For3Dimensional (3D) Of Teeth And Epidemiological Research Of The Pulp Stone About Ancient Human In Lintong Region, Xi’an City

Very often, the specimens of the ancients teeth are more likely to be damaged and lossduring lab process. In this study, in order to tackle with the problem, modernimageological technique was explored to be used to save the digital data of the teeth.Firstly,517teeth unearthed in Shanren kiln site of Lintong region were scanned byMicro-CT. After the data processed by6steps of Mimics software including imageimporting, crop project, thresholding,3D calculation from mask and simulation,3D modelwas reconstructed for every tooth. The reconstructed3D models had high similarity to theteeth. By the software, every part of the tooth could be separated and measured accurately.It was demonstrated that the3D model had super precision and the error rate was onlybetween0.21%to4.99%. The results suggested that the technique of scanning and3Dreconstruction may be a suitable approach for saving digital data of the ancients teeth. Itcan not only preserve the integration of teeth specimens, but also get their accurate3D data.Secondly, the database of all teeth3D models reconstructed was established withAccess2007software. The database was very convenient, and its framework was concise.It possesed all information, such as serial number, gender, age of teeths host, and sum ofthe teeth. The database ran stably, and data input and retrieval system was simple andconvenient. With the Mimics10.013D reconstruction software, every3D model of teethwas exactly represented, which it contributes to the query of the data and the sharing ofresources, and facilitates anatomic morphology study of teeth.Lastly, the pulp stones of all teeth specimens were detected. Among the517teethspecimens,30teeth were found to have pulp stones. The general incidence rate was5.80%.The incidence rate was0.64%(1/157) in the anterior teeth group,2.99%(2/67) in thecanine group,2.22%(4/180) in the premolar group, and20.35%(23/113) in the molargroup. The incidence rate of pulp stones in the molar group was statistically higher thanthat in the other groups (p<0.05). There was no significant deviation among the incidencerates in different age stages (p>0.05). To compare different wear degree among the teeth,the incidence rate of the teeth with3degree wear was much than that of the teeth with1or2degree wear (p<0.01or0.05). In summary, the incidence rate of pulp stones exhibitedclose correlation with the location and wear degree of tooth. The mola rs were moreinclined to have pulp stones than incisors, canines and premolars. The more seriouslytooth wear, the higher the incidence rate of pulp stones it had. There was no significantrelationship between incidence rate of pulp stones and host s age.