Objective:To validate the accuracy of three-dimensional anatomical models reconstructed from cone beam CT (CBCT) using micro-CT as the gold standard, and to evaluate the feasibility of performing anatomical analyses on such models.Methods:A total of 13 isolated deciduous teeth with intact roots were collected, including 5 anterior teeth and 8 molars, with a total of 34 root canals. The teeth were extracted from children aged 3-9 years who visited Peking University Hospital of Stomatology from January 2019 to April 2022 due to trauma or periapical disease, and were then scanned by micro-CT (with a voxel size of 0.018 mm) and CBCT (with a voxel size of 0.125 mm), respectively. Using a threshold-based semi-automated region segmentation method, anatomical models of these isolated teeth were reconstructed from the two CTs. Subsequently, the two CT reconstructed models were registered based on the iterative closest point algorithm, followed by deviation analysis. The key anatomical parameters were measured on the micro-CT and CBCT models, respectively, and the differences were calculated.Results:The CBCT reconstruction models were relatively accurate in the hard tissue morphology, and 97.1% (33/34) of the root canals were identified accurately. When it comes to the deviation analysis, the average distance between the matched points on the CBCT reconstruction models and the micro-CT models was (0.01±0.03) mm for the hard tissue, and (0.00±0.03) mm for the pulp chambers and canals, which did not affect clinical observation. The hard tissue and root canal length of CBCT models were both smaller than those of micro-CT models ( P<0.05), with a 95% limits of agreement of (-0.70, 0.14) mm for the hard tissue, and a 95% limits of agreement of (-1.93, 1.00) mm for the pulp chambers and canals. The impact of these differences on clinical operations was all within the acceptable range. Conclusions:Using micro-CT as a validate standard, CBCT with a voxel size of 0.125 mm was proved to be an effective tool for the reconstruction of deciduous teeth. Therefore, the reconstructed models were appropriate for studying deciduous teeth anatomy.

Objective:To validate the accuracy of three-dimensional anatomical models reconstructed from cone beam CT (CBCT) using micro-CT as the gold standard, and to evaluate the feasibility of performing anatomical analyses on such models.Methods:A total of 13 isolated deciduous teeth with intact roots were collected, including 5 anterior teeth and 8 molars, with a total of 34 root canals. The teeth were extracted from children aged 3-9 years who visited Peking University Hospital of Stomatology from January 2019 to April 2022 due to trauma or periapical disease, and were then scanned by micro-CT (with a voxel size of 0.018 mm) and CBCT (with a voxel size of 0.125 mm), respectively. Using a threshold-based semi-automated region segmentation method, anatomical models of these isolated teeth were reconstructed from the two CTs. Subsequently, the two CT reconstructed models were registered based on the iterative closest point algorithm, followed by deviation analysis. The key anatomical parameters were measured on the micro-CT and CBCT models, respectively, and the differences were calculated.Results:The CBCT reconstruction models were relatively accurate in the hard tissue morphology, and 97.1% (33/34) of the root canals were identified accurately. When it comes to the deviation analysis, the average distance between the matched points on the CBCT reconstruction models and the micro-CT models was (0.01±0.03) mm for the hard tissue, and (0.00±0.03) mm for the pulp chambers and canals, which did not affect clinical observation. The hard tissue and root canal length of CBCT models were both smaller than those of micro-CT models ( P<0.05), with a 95% limits of agreement of (-0.70, 0.14) mm for the hard tissue, and a 95% limits of agreement of (-1.93, 1.00) mm for the pulp chambers and canals. The impact of these differences on clinical operations was all within the acceptable range. Conclusions:Using micro-CT as a validate standard, CBCT with a voxel size of 0.125 mm was proved to be an effective tool for the reconstruction of deciduous teeth. Therefore, the reconstructed models were appropriate for studying deciduous teeth anatomy.

ObjectiveTo explore the etiology and biochemical markers of acute liver failure (ALF) in children.Methods The cause and the biochemical markers of ALF in children who were treated in December 2014 to January 2011 were ana-lyzed retrospectively.ResultsA total of 67 children were enrolled, including 31 females and 36 males. According to the cause of the disease, the children were divided into non-genetic metabolic group, genetic metabolic group, and cryptogenic group. In the non-genetic metabolic group (29 cases, 43.28%) there were 12 cases of drug-induced ALF, 5 cases of Reye syndrome, 3 cases of hemophagocytic syndrome, 3 cases of herpes simplex virus infection, 2 cases of autoimmune hepatitis, one of case mushroom poisoning one case of hepatitis A virus infection, one case of cytomegalovirus infection and one case of sepsis respectively. In the genetic metabolic group (14 cases, 20.90%) there were 6 cases of Wilson’s disease, 2 case of glycogen storage disease, 2 of cas-es progressive familial intrahepatic cholestasis, 2 cases of neonatal intrahepatic cholestasis caused by citrin deifciency, one case of very long-chain acyl coenzyme A dehydrogenase deifciency and one case of primary carnitine deifciency. In the cryptogenic group there were 24 cases (35.82%). The serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin, blood glucose level and AST/ALT were statistically signiifcantly different in genetic metabolic group from in non-genetic me-tabolism disease group and cryptogenic group, (P<0.05). The genetic metabolic group had the lowest levels of serum ALT, AST, albumin and glucose while the genetic metabolic group had the highest ratio of AST/ALT.ConclusionsThe etiology of ALF in children are complex. Genetic metabolic disease should be considered when the child with ALF has no signiifcantly elevated ALT, extremely high ratio of AST/ALT, combined with hypoproteinemia and hypoglycemia.