Objective:To compare the performance of 4 mainstream convolutional neural network models in one-step automatic di-agnosis of cervical vertebra maturation(CVM)and sagittal skeletal type on lateral cephalogram.Methods:600 lateral cephalograms were collected.2 orthodontists were included to determine the stage of CVM and semi-automatic measurement of sagittal skeletal type.After the data set was enhanced,80％was used as the training set and 20％as the test set.The same training method was used to compare the performance of convolutional neural network models of InceptionV3,ResNet50,ShuffleNetV2 and VGG16).Results:The accuracy of InceptionV3,ResNet50,ShuffleNetV2 and VGG16 in distinguishing CVM stage was 98.44％,89.85％,60.55％and 67.97％,and the accuracy of sagittal bone surface classification 96.56％,92.19％,80.00％and 88.13％,respec-tively.Conclusion:Among the 4 convolutional neural network models,InceptionV3 has the best overall learning performance for CVM stage and sagittal skeletal type classification.

Objective:To compare the performance of 4 mainstream convolutional neural network models in one-step automatic di-agnosis of cervical vertebra maturation(CVM)and sagittal skeletal type on lateral cephalogram.Methods:600 lateral cephalograms were collected.2 orthodontists were included to determine the stage of CVM and semi-automatic measurement of sagittal skeletal type.After the data set was enhanced,80％was used as the training set and 20％as the test set.The same training method was used to compare the performance of convolutional neural network models of InceptionV3,ResNet50,ShuffleNetV2 and VGG16).Results:The accuracy of InceptionV3,ResNet50,ShuffleNetV2 and VGG16 in distinguishing CVM stage was 98.44％,89.85％,60.55％and 67.97％,and the accuracy of sagittal bone surface classification 96.56％,92.19％,80.00％and 88.13％,respec-tively.Conclusion:Among the 4 convolutional neural network models,InceptionV3 has the best overall learning performance for CVM stage and sagittal skeletal type classification.

The main mineral component of natural tooth was determined as calcium apatite many years ago; most of them exist in the form of hydroxyapatite with different crystallites. If a tooth decayed, the crystalline of hydroxyapatite would be changed and decomposed. In our experiment, a natural tooth with caries was measured by high resolution XRD equipment: X'pert Pro. Three spots which included normal enamel, normal dentin and caries tissue were analyzed. The results showed that tooth was a kind of biological mixed crystal composed of many crystal phases, the main crystal phase was hydroxyapatite. From normal enamel to normal dentin and to caries tissue, the length of the a-axis of hydroxyapatite crystallite increased, the length of the c-axis of hydroxyapatite crystallite remained unchanged. The crystal sizes were: normal enamel D002 = 27.600 nm; normal dentin D002 = 16.561 nm; caries tissue D002 = 13.163 nm. Crystallinity: normal enamel>normal dentin>caries tissue. According to our experiment, tooth could be conveniently studied by high resolution microdiffracion XRD equipment.
Dental Caries ; metabolism ; Dental Enamel ; chemistry ; Dentin ; chemistry ; Humans ; Tooth ; chemistry ; X-Ray Diffraction ; methods

Objective To analyse the CT features of solitary bronchioalveolar carcinoma(SBAC) so that to improve the CT diagnostic accuracy.Methods CT findings of 39 cases with SBAC proved by operation and pathology were studied,and an analysis as compared with 48 cases other type of peripheral pulmonary carcinoma.Results CT findings included lobulations in 32,spiculation in 33,pleural tags in 25,bronchovascular bundles in 14,vacuole or/and bronchiologram in 18 and ground glass changs in 8 cases.Conclusion The characteristic CT manifestations of SBAC are:(1)Vacuole or/and bronchiologram;(2)Long spiculation;(3)Ground-glass.It is important to recognize the CT appearances of SBAC in order to improve diagnostic ability.

To explore the relationship of the expression of CD44v6 with tumor recurrence in parotid pleomorphic adenoma and its clinical significances,SP immunohistochemical staining was employed in the 10 cases of CPA and 10 cases of PA,10 cases of normal parotids.The relationship of the expression of CD44v6 with tumor recurrence in parotid pleomorphic adenoma was studied.The positive rate of expression of CD44v6 in CPA was much lower than that in PA tissues,the positive rate of expression of CD44v6 in CPA and PA was significantly higher than that in normal parotid tissues.The expression of CD44v6 in CPA tissues was lower than that in PA tissues and may be correlated with tumor recurrence.