Morphological Study Of The Dens Invaginatus And Craniofacial Bones Of Chinese About2200Years Ago In Xi’an Region

Objective: To observe the characteristics of dens invaginatus in permanent teethfrom ancient Chinese people using micro-CT scanning technique. The prevalence, affectedteeth and common types of dens invaginatus were reported, and the root canal morphologyof abnormal tooth were measured. To investigate the morphology features of thecraniofacial bones from ancient Chinese individuals that lived2,200years ago using spiralCT scanning technique. Then we can accumulate the relevant information of Chineseabnormal tooth and craniofacial bone physical anthropology.Methods: A total of517permanent teeth (224anterior teeth and293posterior teeth)from67ancient Chinese people were scanned and reconstructed by micro-CT and Mimics software. Based on the method of endodontics, the teeth from2,200years ago which wereexcavated from the terra-cotta site of the Qin dynasty in xi’an region were observed. Theprevalence of DI was recorded.According to the research methods of root canal morphology, the root canal anatomyof12normal and21abnormal maxillary lateral incisors of ancient individuals that lived2,200years ago were investigated. For each teeth, the length, bucco-lingual and mesio-distaldiameters were measured at cervical, middle and apical third of the root canals.Craniofacial bones from9ancient Chinese people were scanned and reconstructed byspiral CT and Mimics software. Based on the method of anthropometry, physicalanthropology, and the orthodontics, the data of ancient craniofacial bone from2,200yearsago which were excavated from the Wanli contry in xi’an region and saved in the schoolof cultural heritage of Northwest University was measured. The sample consisted of9complete skulls, including5males and4females.4orbital measurements,12facialmeasurements,8mandibular measurements, and9angular measurements were reported.The results were analyzed by SPSS18.0software.Result:①The overall prevalence of DI in67individuals was31.34%. DI wasfound in25teeth out of517teeth (4.83%). All of the25affected teeth were maxillarylateral incisors. The invaginated lingual fossa occurred most frequently, followed by theradicular grooves, while lingual cusp deformity and dens in dente were not found in thepresent study. The fossae sometimes correspond with radicular grooves. The bilateralincidence was19.05%.②The difference was not found between the length of root canal between abnormaland normal maxillary lateral incisors. There were discrepancies on diameters between themiddles bucco-lingually, apical foramens at each cross section of the two groups. Nodifference was found between the two groups about the canal tapers.③Reported the orbital measurements. There were no differences in measured valuesbetween genders. The facial length, width and height data were reported fromthree-dimensional, and showing that there are differences in projects. The mandibularmeasurements and angular measurements were reported in detail. Conclusion: The data may provide information for teeth and craniofacialmorphology, and provide initial data for post-series studies. We created3D model of theancient teeth and craniofacial bones by using CT and reconstruction software. It will beconvenient for sharing and reusing the digital resources.