Evidence-based medicine (EBM) has rapidly developed in recent years and is currently a hotspot in international medicine. The guiding principle behind EBM is that any medical decision should be determined based on objective clinical and scientific evidence, doctor's professional skills and experience, and patient's needs and desires. This paper introduces the concept and practice of EBM and explains how it can be used to solve the issues in stomatology.
Evidence-Based Medicine ; Humans ; Oral Medicine

Objective:To evaluate the effectiveness and treatment feature of maxillary incisor extraction in orthodontics.Methods:9 patients underwent orthodontic treatment with maxillary incisor extraction,5 female and 4 male,with an average age of 1 7.2 years at the start,were included.5 patients were treated by extraction of both upper incisors and lower first premolars,4 by extraction of the abnor-mal incisor and the first premolars in the other three quadrants.Cephalometric and Bolton index analysis were carried out.Results:Sat-isfactory treatment results were observed in all patients.Before treatment the predicted Bolton index of the patients of the anterior ratio and the overall ratio were 80.1 4% and 91 .3%,after orthodontic treatment 78.68% and 90.28%,respectively.Cephalometric analysis showed that U1 -NA(mm),U1 -NA,L1 -NB(mm),L1 -NB,U1 -SN,L1 -MP,UL-E and LL-E were decreased(P <0.05).Conclu-sion:Individual treatment plan based on Bolton index analysis and the corresponding techniques and methods,the patients with abnor-mal upper incisors can be effectively treated with the extraction of maxillary incisors.

Objective To explore the characters of cognitive dysfunction for first-ever lacunar infarction (LI). Methods 136 first-ever diagnosed LI patients were evaluated with Alzheimer's disease assessment scale (ADAS) 72 h, 2 weeks, 1 month, 3 months and 6 months after attack. The scores were compared with the baseline and those of 76 normal control. Results Memory: during the first 72 h, significant difference was shown between the every location of LI (including the basal ganglia, corona radiate,frontal lobe, temporal lobe,parietal lobe, periventricular location, centrum semiovale, thalamus) and normal control (P<0.05); but between the certain location of LI and that of normal control 2 weeks, 1, 3 and 6 months after attack (P<0.05). Language: there was significant difference between every location of LI and normal control 72 h, 2 weeks and 1 month after attack (P<0.05), but between the certain location of LI and that of normal control 3 and 6 months after attack (P<0.05). Practice: there was significant difference through every visit time point of all the LI patients compared with normal control (P<0.05). Attention: Significant difference (P<0.05) was found between every location LI patients and normal control 72 h after attack, but between certain location LI patients and normal control 2 weeks, 1, 3 and 6 months after attack (P<0.05). Orientation:LI was insufficient to cause to decline in orientation. Conclusion There are mild to severe cognitive dysfunctions in the first-ever diagnosed LI patients, which need pay attention to and intervene in time.

Objective To study the effect of lovastatin on the expression and activity of β-site APP cleaving enzyme (BACE1). Methods The SH-SY5Y cells were treated by lovastatin. Cell viability was assessed by MTT assay, and the levels of cholesterol were assayed spectrophotometrically, and the activity of BACE1 was detected by fluorometric assay, and the expression level of BACE1 was detected by Western Blot. Results Compared with the control group, the cholesterol levels were decreased by 33.0% (3.33 vs. 4.97; F=5.13, P =0.020) and the activity of BACE1 was reduced by 13.8% (343.14 vs. 398.22; F=3.773, P =0.035) after 24h treatment of 5μmol/L lovastatin; the cholesterol levels were decreased by 49.2% (2.65 vs. 5.22; F=12.239, P =0.001) and the activity of BACE1 was reduced by 38.0% (274.75 vs. 443.14; F=13.610, P <0.01). Treatment with 5μmol/L lovastatin,for 48 h did affect the expression level of BACE1. Conclusions Lovastatin do not affect the expression level of BACE1, but may inhibit its activity and decrease the cholesterol level, thus providing a new approach to prevent or treat Alzheimer's disease (AD).

It is a trend that clinical researchers overemphasize on hypothesis testing and the P value. However, P value has some limitations in the presentation of study results. Power is a tool for study design and results explanation, especially for negative results. Confidence interval contains more information for clinical results than P value. P value, power, and 95% confidence interval should be provided in the clinical reports to facilitate the interpretation of the results.

Objective To study the mechanisms of increasing amyloid [β1-42 (Aβ42) level by presenilin-1 (PS-1) mutation of V97L.Methods Expression level of neprilysin (NEP) in nontransfected, or mock vector, wild type (wt) PS-1 and V97L-PS-1-transfected SH-SY5Y cells were assessed by reverse transcriptional-polymerase chain reaction (RT-PCR) and Western blot.The level of Aβ42 was also assessed by enzyme linked immunosorbent assay (ELISA).Results The mRNA level of NEP was decreased significantly in PS-1 V97L transfected cells (0.650 ± 0.010) compared to that in normal cells (1.090 ± 0.015), wt PS-1 gene (1.040 ± 0.021) and mock (1.080 ± 0.020) stably transfected cell lines (t = 9.236, 10.452, 5.678; all P < 0.01).Although there was a decreased tendency in the protein expression of NEP in PS-Ⅰ V97L transfected cells (1.000 ± 0.126)compared to that in normal cells (1.020 ± 0.110), wt PS-1 gene (1.040 ±0.110), mock (2.130 ±0.130) stably transfected cell lines, nosignificant differences were found.The expression of Aβ42 was increased significantly in PS-1 V97L transfected cells compared to other cell lines (t = 2.109, 3.355, 3.976; all P < 0.01).Conclusions PS-1 V97L mutation can decrease the transcription of NEP, however, in contrast, this mutation also resulted in increased Aβ42.The mechanism needs further analysis.

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Objective To study the time of monoclonal immunoglobulinemia of undetermined significance (MIUS) transforming into multiple myeloma (MM),and the changes of immunoglobulin level and the clinical features.Methods A retrospective analysis was conducted in 22 patients with MM.According to the follow-up of immunoglobulin levels,patients were divided into formal and informal groups.The changes in immunoglobulin,serum calcium,hemoglobin and creatinine concentrations,and the time of MIUS transforming into MM were detected,and the impact of treatment on the prognosis was analyzed.Results The median age at diagnosis as MIUS was 69 years in formal group and 79 years in informal group.The median time for MIUS transforming into MM was 9.8 years in formal group and 1.3 years in informal group (P 0.006).The initial average concentration of immunoglobulin in patients with MIUS was 12.5 g/L (2.0-31.6 g/L) in informal group and 11.5 g/L (2.8-29.0 g/ L) in formal group (P＞0.05).There were no significant differences in levels changes of immunoglobulin,serum calcium,hemoglobin,creatinine index before and after the outcome.The transfer time for MIUS transforming into multiple myeloma was 9.8 years and 9.7 years,and the survival time was 13.6 years and 13.5 years in patients with versus without treatment (P＞ 0.05).Conclusions Regular formal follow up can accurately assess the transfer time for MIUS to MM,and the transfer time is longer in formal groups than in informal group.The changes in concentrations of immune globulin,serum calcium,hemoglobin,and creatinine cannot serve as indicators for outcome evaluation.Drug treatment neither delays the progress time of MIUS to MM nor reduces the complications of MM and nor prolongs the survival time.

A molecularly imprinted electrochemiluminescence sensor for detection of cinchonine based on surface self-assembly of molecularly imprinted membrane on magnetic nanoparticles was developed. Cinchonine was used as template and lauryl mercaptan was used as assembling monomer. The morphology and particle size distribution of the magnetic nanoparticles were characterized by TEM, and the infrared spectroscopy was used to study the structure and composition of cinchonine, molecularly imprinted membrane before and after elution. The results showed that, cinchonine could be specifically assayed with a linear relationship between the signal intensity and the logarithm of concentrations of cinchonine in the range of 1×10-10 mol/L to 9×10-8 mol/L. The detection limit for cinchonine was 3. 5×10-11mol/L. The sensor was used for the determination of cinchonine in serum samples, with the recoveries of 98. 8% to 104. 7%.

Objective To evaluate the indications and effectiveness of lower incisor extraction in orthodontics.Methods Twenty-three adult patients with lower incisor extraction were included in the study.The cases consisted of 14 female and 9 male patients with an average age of 23.2 years at the start.One single lower incisor was extracted in 17 patients and the other tow upper premolars were extracted in 6 patients.Cephalometric and casts analyses were carried out.Results Total treatment time was 13-23 months.All extraction space was closed after the treatment.All patients achieved satisfactory treatment results,with normal overbite and overjet and stable occlusal relationship.There were no significant changes before and after treatment on cephalometric analysis.The intercanine width was reduced by from pretreatment to posttreatment [(26.89--2.89) mm vs (23.92-t-1.54) mm (P＜0.05)].Conclusions The intercanine width is reduced after lower incisor extraction.In order to achieve satisfactory clinical effect,we should carefully select cases and pay attention to the corresponding techniques and methods.