Introduction Few original studies have described prevalence and severity of clinical symptoms of primary ciliary dyskinesia (PCD). This systematic review and meta-analysis aimed to identify all published studies on clinical manifestations of PCD patients, and to describe their prevalence and severity stratified by age and sex.

BackgroundMycoplasma genitalium is a common cause of non-gonococcal non-chlamydial urethritis and cervicitis. Testing of asymptomatic populations has been proposed, but prevalence in asymptomatic populations is not well established. We aimed to estimate the prevalence of M. genitalium in the general population, pregnant women, men who have sex with men (MSM), commercial sex workers (CSWs) and clinic-based samples.MethodsWe searched Embase, Medline, IndMED, African Index Medicus and LILACS from 1 January 1991 to 12 July 2016 without language restrictions. We included studies with 500 participants or more. Two reviewers independently screened and selected studies and extracted data. We examined forest plots and conducted random-effects meta-analysis to estimate prevalence, if appropriate. Between-study heterogeneity was examined using the I2 statistic and meta-regression.ResultsOf 3316 screened records, 63 were included. In randomly selected samples from the general population, the summary prevalence was 1.3% (95% CI 1.0% to 1.8%, I2 41.5%, three studies, 9091 people) in countries with higher levels of development and 3.9% (95% CI 2.2 to 6.7, I2 89.2%, three studies, 3809 people) in countries with lower levels. Prevalence was similar in women and men (P=0.47). In clinic based samples, prevalence estimates were higher, except in asymptomatic patients (0.8%, 95% CI 0.4 to 1.4, I2 0.0%, three studies, 2889 people). Summary prevalence estimates were, in the following groups: pregnant women 0.9% (95% CI 0.6% to 1.4%, I2 0%, four studies, 3472 people), MSM in the community 3.2% (95% CI 2.1 to 5.1, I2 78.3%, five studies, 3012 people) and female CSWs in the community 15.9% (95% CI 13.5 to 18.9, I2 79.9%, four studies, 4006 people).DiscussionThis systematic review can inform testing guidelines for M. genitalium. The low estimated prevalence of M. genitalium in the general population, pregnant women and asymptomatic attenders at clinics does not support expansion of testing to these groups.Registration numbersPROSPERO: CRD42015020420

With the rapid progression of additive manufacturing and the emergence of new 3D printing technologies, accuracy assessment is mostly being performed on isosymmetric-shaped test bodies. However, the accuracy of anatomic models can vary. The dimensional accuracy of root mean square values in terms of trueness and precision of 50 mandibular replicas, printed with five common printing technologies, were evaluated. The highest trueness was found for the selective laser sintering printer (0.11 ± 0.016 mm), followed by a binder jetting printer (0.14 ± 0.02 mm), and a fused filament fabrication printer (0.16 ± 0.009 mm). However, highest precision was identified for the fused filament fabrication printer (0.05 ± 0.005 mm) whereas other printers had marginally lower values. Despite the statistically significance (p < 0.001), these differences can be considered clinically insignificant. These findings demonstrate that all 3D printing technologies create models with satisfactory dimensional accuracy for surgical use. Since satisfactory results in terms of accuracy can be reached with most technologies, the choice should be more strongly based on the printing materials, the intended use, and the overall budget. The simplest printing technology (fused filament fabrication) always scored high and thus is a reliable choice for most purposes. therefore apply to different fields of medicine and dentistry. With the continuous development of each individual technology, none stand out significantly from the others and so all are represented in the daily medical routine.Even though AM was introduced into medicine many years ago, the production of anatomical models often is still one of the main areas of application [3][4][5][6]. In opinion polls, surgeons still tend to regard anatomical models as advantageous for daily work [7]. For instance, anatomical models offer numerous advantages over other learning resources in understanding complex anatomical correlations [8]. The combination of optical and tactile sensitivity leads to a superior understanding and has defined the concept "touch to comprehend" [9]. A meta-analysis of 158 studies from 2005 to 2015 described further advantages such as possibilities for preoperative planning and time savings in the operating room, but emphasized that accuracy was not satisfactory in 34 studies [10]. Although most manufacturers provide the specifications in terms of accuracy, these are mostly uncertain in the final clinical application. In addition, most tests are performed on isosymmetric-shaped bodies [11], but the use of anatomical models may reveal larger dimensional errors. Measurements with skull and mandibular models revealed incorrect or completely missing anatomy [12]. Even deformations of 3D printed dental surgical guides were reported [13]. Inaccuracies in 3D printing applications can lead to inappropriate treatment that could harm the patient.Identical procedures with the same material under the same circumstances do not necessary lead to identical results. Statistical standards descr...