Clinical and laboratory features of COVID-19 patients infected with SARS-CoV-2 variant B.1.1.7 versus those infected with other SARS-CoV-2 strains:A retrospective observational study

Objective:To investigate the clinical symptoms of coronavirus disease 2019(COVID-19)patients with and without B.1.1.7 mutation.Methods:This retrospective observational study included COVID-19 patients who were divided into two groups,the mutation and the non-mutation group.Demographics characteristics,clinical characteristics,laboratory parameters,and mortality rates were recorded and compared between the two groups.Results:A total of 196 patients were included in the study.The relationship between the mutant virus status and sex,age,comorbidity,survival status,and disease severity was not significant(P>0.05).No significant differences were found in duration of hospitalization between the mutation and the non-mutation group(P>0.05).However,there was a statistically significant difference between patients with and without mutant viruses in hemoglobin,mean platelet volume,procalcitonin,low density lipoprotein,iron-binding capacity,potassium,calcium,C-reactive protein,folate,creatine kinase myocardial band,D-dimer,and international normalized ratio(P<0.05).Conclusions:No significant difference is found in mortality rate,disease severity or duration of hospitalization between the patients with and without variant B.1.1.7.Careful monitoring of COVID-19 patients is required for all variants.

Clinical relevance of distolingual roots and periodontal status in mandibular first molars: a cross-sectional study employing CBCT analysis

Objectives:Distolingual root of the permanent mandibular first molar(PMFM-DLR)has been frequently reported,which may complicate the treatment of periodontitis.This study aimed to assess the morphological features of PMFM-DLR and investigate the correlation between the morphological features of PMFM-DLR and periodontal status in patients with Eastern Chinese ethnic background.Materials and methods:A total of 836 cone beam computed tomography(CBCT)images with 1497 mandibular first molars were analyzed to observe the prevalence of PMFM-DLR at the patients and tooth levels in Eastern China.Among them,complete periodontal charts were available for 69 Chinese patients with 103 teeth.Correlation and regression analyses were used to evaluate the correlation between the morphological features of DLR,bone loss,and periodontal clinical parameters,including clinical attachment loss(CAL),probing pocket depth(PPD),gingival recession(GR),and furcation involvement(FI).Results:The patient-level prevalence and tooth-level prevalence of DLR in mandibular first molars were 29.4%and 26.3%,respectively.Multiple linear regression analysis suggested that bone loss at the lingual site and CAL were negatively affected by the angle of separation between distolingual and mesial roots in the transverse section,while they were significantly influenced by age and the angle of separation between distobuccal and mesial roots in the coronal section.Conclusions:The prevalence of PMFM-DLR in Eastern China was relatively high in our cohort.The morphological features of DLR were correlated with the periodontal status of mandibular first molars.This study provides critical information on the morphological features of DLR for improved diagnosis and treatment options of mandibular molars with DLR.