Understanding the sources, function, and irreplaceable role of cobamides in organohalide-respiring bacteria.

Halogenated organic compounds are persistent pollutants that pose a serious threat to human health and the safety of ecosystems. Cobamides are essential cofactors for reductive dehalogenases (RDase) in organohalide-respiring bacteria (OHRB), which catalyze the dehalogenation process. This review systematically summarizes the impact of cobamides on organohalide respiration. The catalytic processes of cobamide in dehalogenation processes are also discussed. Additionally, we examine OHRB, which cannot synthesize cobamide and must obtain it from the environment through a salvage pathway; the co-culture with cobamide producer is more beneficial and possible. This review aims to help readers better understand the importance and function of cobamides in reductive dehalogenation. The presented information can aid in the development of bioremediation strategies.

Are platelet concentrate scaffolds superior to traditional blood clot scaffolds in regeneration therapy of necrotic immature permanent teeth? A systematic review and meta-analysis.

BACKGROUND: The effectiveness of platelet concentrates in promoting root development of necrotic immature permanent teeth is unclear. The present study evaluated whether the platelet concentrate protocol was superior to the traditional blood clot protocol in regeneration therapy. METHODS: We searched Electronic databases, such as PubMed, Cochrane Library, ClinicalTrials and EMBASE. Randomized controlled trial studies, cohort studies, case-control studies and cross-sectional studies were included, in which platelet-rich concentrates were tested for periapical healing and root development, with the blood clot treatment protocol as the control group. Clinical and radiographic outcomes were considered. Selected articles were assessed for risk of bias. Pooled risk ratios (risk ratio, RR) were calculated for clinical success, responses to cold and electric pulp tests, periapical lesions, apex closure, root lengthening, and thickening of the dentin walls. Subgroup meta-analysis were conducted according to the type of platelet concentrate used. RESULTS: Of the 1272 screened studies, 13 randomized controlled studies, 2 case-control studies and 1 cohort study were selected, in which 465 immature necrotic permanent teeth, particularly incisors and premolars, were treated. Of these 465 teeth, 457 (98.2%) in both the control and experimental groups remained clinically asymptomatic for the entire study duration, whereas eight (1.8%) showed signs and symptoms of failure, including spontaneous pain, sensitivity to percussion or reinfection. Compared with control teeth, teeth treated with PRP achieved better apical healing than BC group (RR 1.13, 95% CI 1.01-1.26, P = 0.03), and teeth treated with platelet concentrates showed improved apical closure (RR 1.04, 95% CI 0.86-1.25, P = 0.69), root lengthening (RR 1.01, 95% CI 0.74-1.39, P = 0.93), and thickening of the dentin walls (RR 1.35, 95% CI 0.95-1.93, P = 0.09), although these differences were not statistically significant. CONCLUSIONS: Platelet concentrates can be used as successful scaffolds for regenerative endodontic treatment of necrotic immature permanent teeth, and PRP as a scaffold may achieve better periapical healing of teeth with periapical inflammation, although they did not differ significantly from conventional blood clot scaffolds in development of the root.

Skeletal class II malocclusion caused by mouth breathing in a pediatric patient undergoing treatment by interceptive guidance of occlusion.

A 7-year 10-month-old boy was evaluated for mouth breathing and snoring habits. Examination revealed soft convex tissues, maxillary protrusion, mandibular retrusion, and a class II sagittal osteofascial pattern. The patient failed a water holding test. He was clinically diagnosed with skeletal class II malocclusion caused by mouth breathing. Under interceptive guidance of occlusion (iGo), the malocclusion improved with fixed maxillary expansion using functional appliances and interventional treatment of mouth breathing by lip closure exercises. These treatments enabled the patient to gradually return to nasal breathing and guided him to develop physiological occlusion for a coordinated jaw-to-jaw relation. At the 5-year 2-month post-correction follow-up visit (at the age of 13 years), the patient had stable occlusion, a coordinated osteofascial pattern, and normal dentition, periodontium, and temporomandibular joints.

[A study of dental caries and risk factors in children of Guangxi area].

PURPOSE: To observe the trends of dental caries and identify risk factors which may be associated with caries among children in Guangxi province between 2011 and 2013. METHODS: Three age groups of children (3-year-old, 6-year-old, 12-year-old) were selected from 3 urban and rural areas in Guilin, Baise and Beihai of Guangxi province and examined annually from 2011 to 2013.The caries prevalence, mean DMFT/dmft, caries incidence rate and filling rate were recorded. The data was analyzed with SPSS19.0 software package. RESULTS: The caries prevalence, mean DMFT/dmft and caries incidence rate in the 3 groups were increased year by year. The caries prevalence of deciduous teeth in 3-year-old group was 53.2%, 68.7% and 79.1% respectively, and the growth rate was 48.6%; The mean dmft was 2.34, 4.06 and 5.68, and the caries incidence rate increased from 55.9% to 61.2%. In the 6-year-old group, the caries prevalence of permanent teeth was 8.6%, 21.6% and 48.0% respectively, and the growth rate was 458.1%; The mean DMFT was 0.13, 0.34 and 0.99, and the caries incidence rate increased from 15.6% to 36.6%. The caries prevalence of permanent teeth in 12-year-old group was 52.8%, 60.2% and 71.3%, and the growth rate was 35.0%; The mean DMFT was 1.49, 1.92 and 2.96, and the caries incidence rate increased from 26.1% to 46.9%. The frequency of drinking soft drink or sweet, taking sweets at bedtime or after brushing teeth, brushing teeth with help, frequency of brushing, fluoride toothpaste may be the risk factors related to dental caries among children in this study. CONCLUSIONS: Dental caries increase fast among children in Guangxi area. It is necessary to take appropriate measures to improve children's oral health.