Effects of Premature Delivery and Birth Weight on Eruption Pattern of Primary Dentition among Beijing Children.

OBJECTIVE: To evaluate the effect of premature delivery and birth weight (BW) on primary tooth eruption. METHODS: A total of 2,230 children aged 3 to 36 months from urban and rural areas in Beijing, China, were classified for analysis by gestational age at delivery (89 preterm and 2,141 full term) and BW (low, normal and high). The tooth eruption status of these children was examined and recorded every 3 months. RESULTS: The timing of first primary tooth eruption was significantly delayed in preterm infants (8.4 months versus 7.3 months for full term; P < 0.05). Furthermore, the number of teeth was significantly less for the preterm and low-BW groups at 12 to 18 and 24 to 30 months, but the number of teeth caught up with normal-BW children by 30 to 36 months. In contrast, the time of first tooth eruption of high-BW children was earlier, while the erupted teeth at each month range was more than the normal-BW group. This research also demonstrated a negative correlation (r = -0.202; P = 0.009) between the time of first primary tooth eruption and BW as well as a positive correlation between the number of erupted teeth and BW. CONCLUSION: Premature delivery and BW were the influencing factors for the timing of primary tooth eruption in children from Beijing, China. Recommendations for feeding habits and oral healthcare implementation may vary according to different primary tooth eruption status among individuals.

Report of the National Investigation of Resources for Oral Health in China.

OBJECTIVE: To investigate the current status and distribution of resources for oral health in China, by means of analysing national data from the National Investigation of Resources for Oral Health. METHODS: The National Investigation of Resources for Oral Health in China was performed in 2015, in parallel with the 4th National Oral Health Survey of China (2015 to 2016). A structured questionnaire on resources for oral health was used to collect the data of professional institutions and stomatological/dental workforce in each province. For each province, the local Investigation Group was responsible to summarise the status and distribution of institutions with stomatological/dental departments and stomatological/dental workforce. Descriptive analysis of resources for oral health was performed to learn about the number and percentage of each category both for each province and nationally. The ratio of number of stomatological/dental workforce to population was also calculated and compared with the criteria of the World Health Organisation (WHO). RESULTS: There were totally 75,399 stomatological/dental departments nationally in all professional institutions in the mainland of China, most of which were set in institutions of primary health care services. Institutions of private sectors accounted for a higher proportion (69.8%) which was over two-fold compared to that of public ones (30.2%). General hospitals were the major part of hospitals with stomatological/dental departments compared with stomatological/dental specialised hospitals. Stomatological/dental clinics were the majority of institutions of primary health care services, compared to community health care service centres/stations and township health care services. Amongst all professional institutions of public health with stomatological/dental departments, 35.0% were maternal and child health care services and 11.2% were institutions for prevention and control of oral diseases. The total number of stomatological/dental workforce in the country was 314,347, among whom 171,587 (54.6%) were stomatologists/dentists. The ratio of number of stomatologists/dentists to population was 1:7,768 nationally, which was lower than the WHO standard of 1:5,000. CONCLUSION: The National Investigation of Resources for Oral Health in China exhibited the current status and distribution of resources for oral health over the country, whereas insufficiencies of stomatological/dental workforce and institutions and inequalities of their distribution were found nationally. This could provide some policy suggestions for the health authorities in China to promote oral health in the Chinese population in the future.

Oral Health Status of 12-year-olds from Regions with and without Coverage of the National Oral Health Comprehensive Intervention Program for Children in China.

OBJECTIVE: To investigate the oral health status and related factors of 12-year-olds from regions with and without coverage of the National Oral Health Comprehensive Intervention Program in China by means of analysing national data from the 4th National Oral Health Survey. METHODS: Data of 12-year-olds participating in the 4th National Oral Health Survey of China were used for statistical analysis. Children who were recruited in the survey completed a dental examination and filled in a questionnaire. Oral health status, pit-and-fissure sealant history, oral hygiene behaviours, sugar consumption habits, status of dental service utilisation, and oral health knowledge were compared between children from regions with and without coverage of the national programme. For the number of decayed, missing and filled permanent teeth (DMFT) and its components, as well as the number of teeth with pit-and-fissure sealants, mean values were statistically tested to see if significance existed between regions covered by the national programme and uncovered regions, whereas caries prevalence and percentage of pit-and-fissure sealants presented were also compared. RESULTS: Data from 27,821 12-year-old children were analysed, among whom 7,726 were from regions covered by the national programme and 20,095 were from uncovered regions. Statistical significance was found in caries experience and activity, pit-and-fissure sealant history, sugar consumption habits, utilisation of dental services and oral health knowledge when compared between the covered and uncovered regions. Prevalence of dental caries and indices for caries experience and activity was lower in regions covered by the national programme than those not covered, while the percentage of pit-and-fissure sealants presented and the number of teeth with pit-and-fissure sealants exhibited higher in the covered regions. This remained the same even if we focused only on the first molars instead of the full dentition. CONCLUSION: The National Oral Health Comprehensive Intervention Program for Children in China potentially contributed to better oral health status, behaviour and knowledge in 12-year-old children. The expansion and extension of coverage of the national programme was expected to be beneficial for improving oral health status in children, as well as constructing teams of oral and dental workforce and working mechanisms in some underdeveloped regions.

Permanent Teeth Caries Status of 12- to 15-year-olds in China: Findings from the 4th National Oral Health Survey.

OBJECTIVE: To investigate the dental caries status of teenagers in China by means of analysing national data from the 4th National Oral Health Survey of China. METHODS: Data for 12- to 15-year-olds participated in the 4th National Oral Health Survey of China were used for statistical analysis. Children who were recruited in the survey completed a dental examination and filled in a questionnaire. Social demographic factors, oral hygiene behaviours, sugar consumption habits, status of dental service utilisation, and pit-and-fissure sealant history were compared between adolescents with caries experiences and those without. For decayed, missing and filled permanent teeth (DMFT) and each of its components, mean values were statistically tested to see if significance existed between or among different categories of all involved variables. RESULTS: In total, data from 27,821, 30,961, 30,691 and 29,128 Chinese 12-, 13-, 14-, and 15-year-olds respectively, were analysed. Social demographic factors, sugar consumption and dental service utilisation showed statistical significance when compared between those with and without dental caries experience in the 12- and 15-year-old groups. Certain categories of these factors above also had important influence on the mean value of the number of decayed teeth (DT), filled teeth (FT) and DMFT, and they might be potential determinants of dental caries experience of permanent teeth for teenagers. CONCLUSION: Dental caries in 12- and 15-year-old Chinese adolescents was impacted by certain social demographic and dental behavioural factors, which could provide some implications for policy makers and dental public health professionals when attempting to enhance oral health status for those teenagers in the early stages of permanent dentition.

Evaluation of the Effect of the Closed-eruption Technique on Impacted Immature Maxillary Incisors.

OBJECTIVE: To investigate the effects of the closed-eruption technique on impacted immature maxillary incisors. METHODS: The contour and position of the gingival margin, root development, and pulp status were evaluated in 50 impacted immature maxillary incisors immediately after treatment and 2 years later. RESULTS: Chronic periapical periodontitis and trauma of the primary teeth were the main causes of impacted immature maxillary incisors. The average treatment time was 11 months. After treatment, the contour of the impacted incisor gingival margin, which had already erupted, conformed with the contralateral incisors; the gingival margin positions of 34 (68%) impacted incisors were the same as those of the contralateral incisors but the other 16 (32%) were more apical. All roots developed normally; pulp vitality was normal and conformed with the contralateral incisor change into a period. Three (6%) impacted incisors were slightly labially inclined because the dilacerated part of their roots was too long. CONCLUSION: The closed-eruption technique is an effective method of treating impacted immature maxillary incisors.

Early dental treatments for patients with cleidocranial dysplasia.

OBJECTIVE: To explore the early dental interventional strategies for adolescent patients and a child patient with cleidocranial dysplasia (CCD). METHODS: Surgical exposure using the apically repositioned flap technique combined with orthodontic traction was used in the adolescent patients whose ideal treatment time for initiating treatment was missed. For the child patient whose ideal treatment time for initiating treatment was not missed, the simple surgical exposure method was carried out in order to promote the eruption of the impacted incisors. RESULTS: All the impacted maxillary incisors of the three CCD patients were successfully positioned into a proper alignment either through the two stages of crown exposure and the elastic traction or simple surgical exposure. CONCLUSION: Crown exposure surgery combined with light force orthodontic traction provides an effective approach to treat the typical dental abnormalities of adolescent CCD patients. Simple surgical exposure was also an effective way for a child CCD patient for whom the most ideal time for initiation of treatment was not missed.

DNA repair biomarkers predict response to neoadjuvant chemoradiotherapy in esophageal cancer.

PURPOSE: The addition of neoadjuvant chemoradiotherapy prior to surgical resection for esophageal cancer has improved clinical outcomes in some trials. Pathologic complete response (pCR) following neoadjuvant therapy is associated with better clinical outcome in these patients, but only 22% to 40% of patients achieve pCR. Because both chemotherapy and radiotherapy act by inducing DNA damage, we analyzed proteins selected from multiple DNA repair pathways, using quantitative immunohistochemistry coupled with a digital pathology platform, as possible biomarkers of treatment response and clinical outcome. METHODS AND MATERIALS: We identified 79 patients diagnosed with esophageal cancer between October 1994 and September 2002, with biopsy tissue available, who underwent neoadjuvant chemoradiotherapy prior to surgery at the Massachusetts General Hospital and used their archived, formalin-fixed, paraffin-embedded biopsy samples to create tissue microarrays (TMA). TMA sections were stained using antibodies against proteins in various DNA repair pathways including XPF, FANCD2, PAR, MLH1, PARP1, and phosphorylated MAPKAP kinase 2 (pMK2). Stained TMA slides were evaluated using machine-based image analysis, and scoring incorporated both the intensity and the quantity of positive tumor nuclei. Biomarker scores and clinical data were assessed for correlations with clinical outcome. RESULTS: Higher scores for MLH1 (p = 0.018) and lower scores for FANCD2 (p = 0.037) were associated with pathologic response to neoadjuvant chemoradiation on multivariable analysis. Staining of MLH1, PARP1, XPF, and PAR was associated with recurrence-free survival, and staining of PARP1 and FANCD2 was associated with overall survival on multivariable analysis. CONCLUSIONS: DNA repair proteins analyzed by immunohistochemistry may be useful as predictive markers for response to neoadjuvant chemoradiotherapy in patients with esophageal cancer. These results are hypothesis generating and need confirmation in an independent data set.

[Experimental study on the characteristics polycyclic aromatic hydrocarbon emissions of diesel engine burnt by different fuels].

The polycyclic aromatic hydrocarbons (PAHs) were measured by glass fiber filter and XAD-2 collector, ultrasonic extraction, soxhlet extraction and GC-MS analysis equipment. The exhaust emission of the DI single cylinder diesel engine fueled with pure diesel, biodiesel and biodiesel blends of 50% (B50) were measured. The results indicate that the particle-phase PAHs emissions of diesel engine decrease with the increasing of load. The gas-phase PAHs emissions of diesel engine decrease with the increasing of load in the beginning and it turns to going up with further increasing of load. The particle-phase and gas-phase PAHs emissions of biodiesel decrease and mean concentration are lower than that of diesel. The total PAHs emission concentration of biodisesl is 41.1-70.1 microg/m3. Total PAHs mean concentration emissions of biodiesel is decreased 33.3% than that of diesel. The mass proportion of three-ring PAHs emissions of those 3 kinds tested fuels is about 44% in the total PAHs. Biodiesel can increase the proportion of three-ring PAHs. Toxic equivalence of PAHs emissions of biodiesel are greatly lower than that of diesel. It is less harmful to human than diesel fuel.