Treatment of a transmigrated and an impacted mandibular canine along with missing maxillary central incisor: A case report

IntroductionTreatment of a case with impacted canines is complex and numerous options are available ranging from disimpaction to forced eruption.ObjectiveThe objective of this case report was to describe the treatment of a 19-year-old male, with a skeletal Class II, dental Class II Division 1 malocclusion, prognathic maxilla, proclined maxillary incisors, with missing left maxillary central incisor and bilateral mandibular canine impaction.MethodologyThe orthodontic treatment plan included forced eruption of the impacted canines and conversion of maxillary left lateral incisor to central incisor.ConclusionProper diagnosis and implementation of orthodontic biomechanics can minimize the amount of prosthetic and surgical intervention needed in the management of transmigrated canine and smile designing.     

居民健康调查资料中的缺失数据的多重估算

目的 解决居民健康调查数据中存在的数据缺失问题。充分利用所采集到的数据。得出更有效的统计推断，方法 运用建立在马尔科夫链蒙特卡罗方法基础上的多重估算技术，对缺失数据进行替换，产生多个完整的数据集，进行联合统计推断。结果 弥补了由于缺失数据所造成的信息损失，改善了统计推断的质量。结论 多重估算技术是解决社会调查资料中数据缺失问题的有效工具。     

Response and Non-response to a Quality-of-Life Question on Sexual Life: A Case Study of the Simple mean Imputation Method

We investigated the non-response rates to the question “I am satisfied with my sex life” in the Functional Assessment of Cancer Therapy – General questionnaire in Chinese (n = 769), Malay (n = 41) and Indian (n = 33) patients in Singapore, a multi-ethnic society whose residents are said to have a conservative sexual attitude. Non-response rates to the question were 44%, 22% and 24% in the three groups respectively. The rates were much higher than that reported previously in a US study (7%) and used in the associated simulation study of the simple mean imputation method. We further examined the Chinese respondents in detail. The odds of non-response and the scores among the responders were associated with several demographic and clinical characteristics. Using the checklist proposed by Fayers et al. [Stat Med 1998; 17: 679–696] to assess the data patterns, we found that the application of the simple mean imputation is questionable. We employed an alternative (multiple) imputation procedure that took into account covariates that predicted the odds of non-response and the observed response scores. We compared the analytic results based on different approaches to handling missing values, and found that analysis based on the simple mean imputation gave results similar to that based on multiply imputed data even in this quite extreme example.     

Methods for Missing Data Handling in Randomized Clinical Trials With Nonnormal Endpoints With Application to a Phase III Clinical Trial

In randomized clinical trials, when the endpoint is the change from baseline at the last scheduled visit, various parametric, semiparametric, and nonparametric methods have been developed to handle the possible missing data due to dropouts. Although the last observation carried forward (LOCF) and the mixed-effects model for repeated measures (MMRM) have been extensively compared and widely used, they may lead to biased results when the required distributional or missing mechanism assumptions are not satisfied. Nonparametric missing data handling methods including the last rank carried forward (LRCF) and mean rank imputation (MRI) relax the underlying distributional assumptions; however, conditions for them to be valid have been investigated to a very limited extent. This article rigorously derives asymptotic properties of the MRI method and proves its validity to test the primary endpoint under certain mild distributional and missing mechanism assumptions. The test-based estimator for the location difference between the treatment and the control groups is also derived when the randomized clinical trial has two arms under a location shift assumption. The investigated methods are applied to an illustrative phase III clinical trial. Simulation studies based on the empirical distributions from the illustrative clinical trial and additional intensive simulation studies, based on various prespecified distributions and missing mechanisms, were conducted to compare the MRI method with selected traditional methods including LOCF, MMRM, and LRCF and they confirmed the better performance of the MRI method in terms of the Type I error rate control and the power under certain mild conditions.     

联合支持早期种植修复前牙缺失临床观察

目的:观察应用非埋植型种植体与天然牙联合式支持早期修复前牙缺失的临床效果。方法:对73例前牙缺失患者植入95枚种植体并早期加载完成义齿修复,临床观察6～48个月。结果:成功率96.8%,修复体各项指标正常。结论:应用CDIC非埋植锥状种植体修复前牙缺失,采用种植牙——天然牙联合支持早期加载,可缩短修复周期,满足患者的美观要求。     

无锡市新区2007～2009年医疗机构法定传染病漏报调查

[目的]了解医疗机构法定传染病的报告情况,分析漏报原因。[方法]对医疗机构的不同部门开展传染病漏报调查。[结果]2007～2009年总漏报率为1.10%,社区卫生服务中心报告情况明显好于民营医疗机构,漏报较多的病种是细菌性痢疾、肺结核和风疹。[结论]医疗机构传染病报告工作仍存在薄弱环节,需要进一步加强内部管理,提高报告质量。     

北京市不同来源居民死亡数据库的一致性与及时性分析

目的 通过对不同来源北京市死亡居民数据的描述和分析,了解不同来源数据的特点并探索进一步提高数据质量的方式。方法 收集、整理和对比公安、民政及卫生来源北京市户籍居民死亡数据,进行描述性分析,分析不同来源数据的特点及其一致性和及时性。结果 2013-2014年度公安、民政和卫生来源数据共387 003例,其中公安来源户籍居民数据95 318例,民政来源所有数据130 906例,卫生来源户籍居民数据160 779例。卫生和公安来源数据填报完整性及数据字段规范性较高。公安来源数据身份证号码填报率最高,民政来源数据报告及时性最高,卫生来源数据信息量最大。3种来源数据总体一致性及报告及时性较好,但死亡原因等字段一致性有待进一步提高。结论 北京市公安、民政及卫生来源交换数据总体质量较高,但是仍然存在问题需要进一步改进。     

Detection of virtual pitch up to 5kHz by mice

Natural sounds consist of a component at the fundamental frequency (f0) and its overtones. Pitch is perceived at f0, even when spectral energy at f0 is missing. This missing f0, or ‘virtual pitch’, is thought to be detected in the auditory cortex and related cortical areas, but the precise neural mechanisms are unknown. One possibility is that virtual pitch can be retrieved from the periodicity of sound waveforms. However, this mechanism requires the temporal accuracy in periodicity detection, and so far the detection of virtual pitch has only been demonstrated at frequencies lower than 1 kHz. We investigated the ability of mice to detect virtual pitch up to 5 kHz using a two-step sound discrimination test. In the first step of this test, mice were trained to discriminate between tone bursts at 2.5 and 5 kHz. In the second step, we tested the ability of mice to discriminate between virtual pitches at 2.5 kHz and at 5 kHz. It was demonstrated that the performance of mice to discriminate between virtual pitches at 2.5 and 5 kHz was significantly affected by previous discrimination learning between tone bursts, indicating that mice can detect virtual pitch up to 5 kHz.     

Periodontal status and whole salivary adipokines after scaling and root planing with and without adjunct antimicrobial photodynamic therapy in obese patients with periodontitis

ObjectiveWhole-salivary (WS) adiponectin and leptin levels after scaling and root planing (SRP) with and without antimicrobial-photodynamic-therapy (aPDT) in obese and normal-weight individuals with periodontitis remain uninvestigated. This study compared the effect of SRP without and with adjuvant aPDT on periodontal status and WS leptin and adiponectin levels (LAL) in obese patients with periodontitis.MethodsGroups 1 and 2 entailed obese patients without and with periodontitis. Groups 3 and 4 had normal weight individuals without and with periodontitis. Therapeutically, individuals with periodontitis were categorized into test- (SRP+aPDT) and control- (SRP alone) subgroups. All patients without periodontitis underwent routine dental prophylaxis. Clinical attachment loss (AL), gingival and plaque index (GI and PI), probing depth (PD), missing teeth (MT) and WS LAL were measured at baseline and at three months of follow-up. P<5% were graded statistically significant.ResultsAt baseline, clinicoradiographic variables were significantly higher among patients in test- and control-groups in groups 1 (P<0.01) and 3 (P<0.01) versus 2 and 4. In group 2 and 3, LL were significantly high at baseline compared with follow-up (P<0.01). There was no difference in periodontal parameters and WS adiponectin and LL in the test and control-groups at of follow-up. No correlation existed between salivary LAL and clinical periodontal parameters (PI, GI, PD and clinical AL). No correlation existed between age, gender and BMI and WS LAL.ConclusionIn the short-term, SRP with or without aPDT is ineffective in the treatment of periodontitis in obese patients with periodontitis.     

Simulation-Based Study Comparing Multiple Imputation Methods for Non-Monotone Missing Ordinal Data in Longitudinal Settings

The application of multiple imputation (MI) techniques as a preliminary step to handle missing values in data analysis is well established. The MI method can be classified into two broad classes, the joint modeling and the fully conditional specification approaches. Their relative performance for the longitudinal ordinal data setting under the missing at random (MAR) assumption is not well documented. This article intends to fill this gap by conducting a large simulation study on the estimation of the parameters of a longitudinal proportional odds model. The two MI methods are also illustrated in quality of life data from a cancer clinical trial.