OBJECTIVES: The aim of this study was to evaluate the disease burden of prostate cancer (PC) and assess key influencing factors associated with the disease expenditures of PC in the United States. METHODS: The total deaths, incidence, prevalence, and disability-adjusted life-years of PC were obtained from the Global Burden of Disease Study 2019. The Medical Expenditure Panel Survey was used to estimate healthcare expenditures and productivity loss and to investigate patterns of payment and use of healthcare resources in the United States. A multivariable logistic regression model was conducted to identify key factors influencing expenditures. RESULTS: For patients aged 50 and older, the burden for all age groups showed a modest increase over the 6-year period. Annual medical expenditures were estimated to range from US$24.8 billion to US$39.2 billion from 2014 to 2019. The annual loss in productivity for patients was approximately US$1,200. The top 3 major components of medical costs were hospital inpatient stays, prescription medicines, and office-based visits. Medicare was the largest source of payments for survivors. In terms of drug consumption, genitourinary tract agents (57.0%) and antineoplastics (18.6%) were the main therapeutic drugs. High medical expenditures were positively associated with age (p=0.005), having private health insurance (p=0.016), more comorbidities, not currently smoking (p=0.001), and patient self-perception of fair/poor health status (p<0.001). CONCLUSIONS From 2014 to 2019, the national real-world data of PC revealed that the disease burden in the United States continued to increase, which was partly related to patient characteristics.

Since an epidemic occur of Corona Virus Disease 2019(COVID-19) in December, 2019, all the dental healthcare service providers in our country have been greatly impacted. The strategy of managing the dental clinics is quite different from that of the medical healthcare clinics, and the key point of the administration of those dental healthcare providers is to focus on the management of outpatient care because they only supply just a little bit of inpatient care service but quite an large amount of outpatient care service. So we think the next step is to make plausible and effective scenarios to protect our dental healthcare staff and patients against corona virus infection during the treatments procedures after the reopening all of our dental clinics. To overcome this harsh condition, the infection prevention and control strategies adopted by the Stomatological Hospital, Southern Medical University were designed to be flexible and could be adjusted promptly according to the national and local governmental orders and latest guidelines released by the Centers for Disease Control and Prevention. All these prevention procedures and protocols were customized to fit our own situation and have been updated for several times based on the latest global pandemic reports. After going through the hardest time in the past four months, it’s considered that our COVID-19 prevention rules have been proved to be efficient and work well. Further more, it has made massive progress for the hospital in improving the capability of dealing with this state of emergency, especially by previewing and triaging patients strictly to cut off the possible coronavirus spreading from the original step, enhancing the standard precautions and those specific protocols made for minimizing the droplets, aerosol and contact transmission of COVID-19 indoors. Besides, a daily supervision system was set up as a routine job and a team of qualified infection prevention specialists were assigned to check and report every incorrect details during the whole procedure of dental practice. Meanwhile, the safety and well-being of the public and our medical workers could be also guaranteed through following those detailed prevention scenarios.

Objective : To investigate the oral health behavior of urban and rural students in the 12~15 year age group in Guangdong Province, aiming to provide informational support for adolescent oral health care. Methods : A multistage stratified sampling method with equal capacity and simple random sampling was applied to obtain representative samples. A total of 7 680 students aged 12 to 15 were selected from Guangdong Province, with 1 920 in each age group of 12, 13, 14 and 15 years; half were male and half were female, and half were from urban areas and half were from rural areas. According to the Fourth National Oral Health Epidemiology Questionnaire Survey Program, a standard questionnaire was designed to conduct on-the-spot investigations on sugar intake, brushing, dental floss usage, fluoride toothpaste usage. Results : ① Eating before a meal and before bed: the proportion of sweet snacks, sweet drinks and sugary drinks consumed ≥2 times/day was higher in the rural group than in the urban group (P < 0.001), with only sugary drinks consumed significantly differently by age (P < 0.001). ② The rural group had a significantly lower proportion of brushing ≥ 2 times/day, flossing habits and fluoride toothpaste habits than the urban Conclusions Among the students aged 12 to 15 in Guangdong Province, the rural group had a higher proportion of consuming desserts, sweet drinks and sweetened drinks. The proportion of brushing ≥ 2 times/day was lower, and the usage rate of floss and fluoride toothpaste was lower.

As one of the most common chronic diseases of the oral cavity, caries gradually accumulate over the lifetime and affect approximately 80% of the world population. The epidemiological characteristics of the disease are specific in terms of regional distribution, temporal distribution and population distribution. Caries prevalence and mean decayed, missing and filled permanent teeth (mean DMFT) scores are the most commonly used indexes in oral epidemiology. Caries prevalence is used to describe the frequency of caries over a certain period of time. In addition, DMFT scores reflect the severity of caries in the population. The caries prevalence and the severity of caries are assessed as part of a dynamic process. In developing countries, caries prevalence is higher among urban populations than among rural populations. Currently, the epidemic characteristics of caries in urban and rural areas are changing, and the caries prevalence of urban residents is lower than that of rural residents. This article is a chronological review of the Oral Health Epidemiological Surveys of China from 1983 to 2015, the Preventive Dentistry study and other related studies. It is concluded that the epidemic characteristics of caries in urban and rural areas in China have changed from a higher caries prevalence in urban areas compared to that in rural areas to a lower caries prevalence in urban areas compared to that in rural areas. Several factors, such as the dynamic development of differences in dietary habits, economic levels and access to oral medical resources of urban and rural residents might have led to changes in caries prevalence in urban and rural areas. The caries prevalence of rural residents has increased greatly, which indicates that the caries prevention efforts of the relevant departments should be focused more on rural areas in the future.

Objective : To research the root and root canal morphology of maxillary second permanent molars in the Guangfu population of the Lingnan area. Methods: A total of 1220 maxillary second permanent molars were collected from the 723 CBCT images of the Guangfu population. The root and root canal configurations were observed and counted, and the morphological characteristics and changes were compared and analyzed. Results: The maxillary second permanent molars included 709 three-root molars, 417 double root molars, 68 single root molars and 26 four-root molars. The difference in the detection rate of each root type in different sex and age groups was not statistically significant (P > 0.05). Root canal morphdogy of maxillary second permanent molars: type Ⅷ (3-3) was the most common type of root canals in single root molars, accounting for 63.25%. Significant differences in the detection rates of canal configurations were noted among the three subtypes of fused root canals in double root molars (P < 0.01). Root canal morphology of the mesiobuccal root of the three-root molars was mainly typeⅠ (1-1), significantly accounting for 78.84%. Significant sex and age differences were noted in the detection rate of type Ⅰ and Ⅳ root canals (P < 0.01). In addition, 75.86% of maxillary second permanent molars had symmetrical roots, and 73.64% of the bilateral teeth had symmetrical roots and canals. Conclusion The root and root canal morphology of maxillary second permanent molars in the Guangfu population in the Lingnan area are different compared with other areas at home and abroad.

As a professional method to prevent decayed teeth and an oral public health project, pit and fissure sealant is widely used domestically. How to evaluate the effect and benefit of the community pit and fissure closure project, especially the community full coverage pit and fissure closure project, requires investigation. The Guangzhou Children′s Pit and Fissure Sealing Project was carried out in an orderly manner and was administered normatively. A retrospective cohort study with use of a sample survey was used in this program. According to cavity occurrence and reservations of sealant in the first permanent molar, the samples were divided into the following two groups: the sealing group with indication and the sealing group without indication. Reservations of sealant, cavity incidence, reduced incidence, net profit, cost-effectiveness and cost-benefits of the program were evaluated. Some promotable experiences were summarized during this project. Various relevant theories and reports of the pit and fissure sealant project evaluation were reviewed and previous studies were discussed in this article. By analyzing the methods and results of the pit and fissure sealant project in Guangzhou, suggestions are made for project evaluation, especially sample grouping and evaluation indicators, which was refer to a further study for the pit and fissure sealing project.

Objective : To investigate the current status of gingival bleeding and dental calculus in the 12- to 74-year old population in Guangdong Province with the aim of providing information to support oral health care. Methods : A stratified, multistage, random sampling design was used to obtain 7 provincially representative sample groups consisting of 8, 544 Guangdong residents aged 12, 13, 14, 15, 35-44, 55-64 and 65-74 years old with a 50/50 gender ratio. The status of gingival bleeding and dental calculus in the whole mouth was assessed according to the Guidelines of the Fourth National Oral Health Survey using a CPI probe. The resulting data were analyzed using the SAS9.2 package. Results : The prevalence of gingival bleeding in residents aged 12, 13, 14, 15, 35-44, 55-64 and 65-74 years old was 43.75%, 42.76%, 49.06%, 39.38%, 81.94%, 90.97%, and 84.03%, respectively, while the average number of teeth with gingival bleeding per person was 1.95, 2.07, 2.59, 2.39, 9.62, 10.36, and 9.98, respectively. In the 12-, 13-, 14-, and 15-year-old groups, peak prevalence was observed at age 14 (P < 0.05). In the 35-74-year-old group, the prevalence and mean number of teeth with gingival bleeding per person increased with age, and both parameters reached a peak in the 55-64-year-old group. The prevalence of dental calculus in the 12-, 13-, 14-, 15-, 35-44-, 55-64- and 65-74-year-old group was 40.57%, 41.09%, 45.05%, 54.84%, 98.96%, 97.22%, and 92.01%, respectively, and on average, each person had 1.61, 1.71, 2.14, 3.52, 20.30, 20.55, and 17.26 teeth, respectively, with dental calculus. The prevalence and mean number of teeth with dental calculus increased with age. In the 35- to 74- year-old group, the prevalence of dental calculus was higher in urban areas than in rural areas and the mean number of teeth with dental calculus was higher in males than in females. Otherwise, there were no significant differences in the prevalence or the mean number of teeth with dental calculus or gingival bleeding between urban and rural areas or between males and females. Conclusion There is a high prevalence of both gingival bleeding and dental calculus in all 7 age groups in Guangdong, indicating that poor oral hygiene and gingival inflammation are common in Guangdong Province.

Objective: To investigate the dental fluorosis status of permanent teeth of a 12-year-old population of Guangdong Province to provide informational support for oral health care in Guangdong. Methods : An equal-sized cross-sectional random-sample assessment was carried out among 1 920 urban and rural residents of Guangdong Province, half male and half female, aged 12 years. We examined the dental fluorosis status of complete permanent teeth crown based on a health survey and the criteria of clinical dental fluorosis from the fourth national oral health survey. The data were analyzed by SAS9.2 to investigate the prevalence and community fluorosis index as well as gender and urban and rural differences, and compared with the prevalence of fluorosis in Guangdong Province in 2005 and 1995. Results : In the 12-year-old population, the prevalence of dental fluorosis was 5.05%, and the community fluorosis index was 0.108. There was no significant difference between genders（P > 0.05）, but there was a significant difference between subjects from urban and rural areas（P < 0.05）. There were significant differences among prevalence of dental fluorosis and community fluorosis index in 1995, 2005 and 2015—2016（P < 0.05）. Conclusion The prevalence of dental fluorosis and the community fluorosis index of 12-year-old people of Guangdong Province are relatively low, but there is an upward trend.

Objective: To understand the level and current status of oral health knowledge among people aged 35-44 years in Guangdong Province and to provide a reference for oral health education in Guangdong Province. Methods: An equal-sized, stratified, multistage, random sampling design was applied to obtain representative sample groups consisting of 288 Guangdong residents aged 35-44 years in four urban areas and four rural areas with a gender ratio of one to one. According to the Guideline of the 4th National Oral Health Survey, a questionnaire survey was conducted, and a statistical analysis of the questionnaire responses related to oral health knowledge was performed. Results: In total, 288 people participated in the survey, of which 95.8 percent were aware that “Oral health is very important to their own lives, and the prevention of oral diseases depends on themselves first”, 76.0% recognized that “Regular oral examination is very necessary”, and 66.7% disagreed that “Teeth were innate and had little to do with their own protection”. The percentages of participants that agreed with the statements “Eating sugar can cause dental caries”, “Oral disease may affect general health”, “Bacteria may cause dental caries” and “Bacteria may cause gum inflammation” were 87.2%, 84.7%, 80.9%, and 80.2%, respectively. However, the rates of awareness that teeth could be protected by fluoride and by pit and fissure sealant were only 36.8% and 18.8%, respectively. Conclusion General knowledge of oral health care was relatively high among adults aged 35-44 years in Guangdong Province, but knowledge of fluoride, pit and fissure sealing and caries prevention was relatively low. Oral health education should be continuously improved, especially regarding the popularization of oral health knowledge.

Obiective To investigate the current status of remaining teeth and edentulous jaw arch of people aged 35-44, 55-64 and 65- 74 in Guangdong province. Methods An equal- sized stratified multi-stage randomly sampling design was applied to select a total of 288 Guangdong residents in urban and rural areas, and the subjects were between the age of 35-44, 55-64 and 65-74, with a gender ratio of half to half. The status of remaining teeth and edentulous jaw arch were assessed according to the Guideline for the 4th National Oral Health Survey. Results 88.89% subjects in the 35-44 year group had more than 28 teeth and 100% subjects had more than 20 teeth, with an average of 29.88 teeth remaining and no edentulous jaw. The average remaining teeth was 26.06 in the group of 55-64 year, with 87.50% subjects having more than 20 teeth, 59.03% subjects having 28 or more teeth, 4.16% subjects having single edentulous jaw arch, and 1.04% subjects having both edentulous jaw arch. 73.96% and 35.07% subjects in the group of 65-74 year had 20 above or 28 above remaining teeth, respectively, and the average teeth was 22.94. There were 8.34% subjects having single edentulous jaw arch and 1.39% subjects having both edentulous jaws. In the 35-44 and 65-74 year group, the prevalence of missing teeth in the female was significantly higher than the male (P < 0.05), while no significant difference was found between urban and rural areas (P > 0.05). More remaining teeth were noticed in current survey (2015) when compared to the data in 2005 (P < 0.05). Conclusion The 35-44 year people have few lost teeth, and over half of the elderly people have several lost teeth. Elderly people with edentulous arch are very few.