Objective: To explore the trajectory of the development of permanent caries in 12- to 16-year-old students in Liuyang and to provide a reference for the prevention and management of caries. Methods: Primary and secondary school students who were registered within the Liuyang jurisdiction were screened for caries from September to November by the Liuyang Center for Disease Control and Prevention. A total of 7 297 students between the ages of 12 and 16 years with complete permanent dentition caries monitoring records and traceable deciduous dentition caries monitoring records were selected from 2013 to 2019, and a zero-inflated negative binomial-latent class growth model (ZINB-LCGM) was established to describe the trajectory of the development of individual caries using the decayed missing filled teeth (DMFT) indicators. Results: DMFT of 12- to 16-year-old students in Liuyang were mainly decayed teeth (DT), with the majority occurring in the first permanent molar. According to the ZINB-LCGM model, the students were classified into three latent categories, "slow growth pattern" (28.55%), "rapid growth pattern" (6.59%), and "stable pattern" (64.86%), which followed different nonlinear caries growth trajectories. Females with deciduous teeth caries were more likely to have trajectories showing a “rapid growth pattern” and a “slow growth pattern”. There were significant differences in the trajectories between men and women, as well as between those with and without primary dentition caries. Conclusion The trajectory of the development of caries in 12-16-year-old students shows heterogeneity in terms of different developmental patterns of latent categories, suggesting that females with deciduous dental caries should receive more attention.

Objective To compare the dosimetric differences in volumetric modulated arc therapy (VMAT) of Monaco planning system for nasopharyngeal carcinoma between Pareto and Constrained optimization in order to provide a reference for future mode selection. Methods Select 20 patients with nasopharyngeal carcinoma whom were calculated by Pareto and Constrained modes in the same CT image. Prescription dose of target PGTV, PTV1 and PTV2 was 70.29、60.39 and 54.45 Gy with 33 fractions, 5 times a week. The differences in target dose, organs at-risk dose, monitor units and segments were compared in the condition of 95% of the target volume reached the prescribed dose. Results Compared with Pareto group, Constrained group achieved a better HI and CI. CI of PGTV and PTV1 signed statistical differences (P < 0.05). Dose of OARs in Constrained group were all lower than those in Pareto group except Optical-l and lens-l. The differences of spinal cord prv dose and V₃₀ of Parotid-r between two groups was significant (P < 0.05) while the differences of monitor units and segments between two groups was not significant (P > 0.05). Conclusion The length of middle turbinate is negatively correlated with the occurrence and severity of CMS. There is no significant correlation between the degree of curling and the occurrence of CMS, but patients with lower degree of curling of middle turbinate may have more serious CMS.