Influence of gender and bruxism on the masseter muscle: A population-based magnetic resonance imaging study.

INTRODUCTION: This study aimed to (1) examine the cross-sectional area (CSA) of the masseter muscle in relation to bruxism and (2) investigate if there are gender-related differences in the masseter muscle in a population-based magnetic resonance imaging (MRI) study. METHODS: The study included 720 subjects aged 30-89 years (391 women and 329 men) from the Study of Health in Pomerania, a cross-sectional population-based study assessing the prevalence and incidence of common population-relevant diseases and their risk factors in Northeastern Germany. The participants underwent both a whole-body MRI and a full oral examination. The CSAs of the masseter muscles on both sides were measured from MRI images. The presence or absence of awake and/or sleep grinding and clenching, unilateral chewing, and other parafunctional activities were obtained from the dental interview. Linear and ordinal logistic regression models were used to examine the associations between the CSAs of the masseter, bruxism, and gender. RESULTS: The frequency of bruxism and reports of muscle or joint pain were significantly higher in women. The analysis revealed that a larger masseter CSA was significantly associated with bruxism only in men. The larger CSA was manifested only in the higher frequency bruxers. CONCLUSIONS: Bruxism had heterogeneous effects on the masseter muscle between genders. Although a higher prevalence of bruxism was reported by women, the larger CSA of the masseter muscle was significantly higher in bruxing men but not in women. This study emphasizes the need for a gender-specific approach when evaluating the clinical implications of bruxism on the masseter muscle.

Proposing a communication module to enhance dental students' attitudes towards people with dementia: Phase 1 of a curriculum revision study.

INTRODUCTION: The number of mentally altered patients a dentist meets in practice is increasing and interaction with them can be very challenging. As a baseline for an interventional study, we want to assess the attitude of dental students and identify areas of improvement in patient communication. This work compares the attitude of dental students towards people suffering from dementia to the attitudes of trained medical caregivers and the general population. Our aim is to use the results to assess the need for training in communicating with mentally altered patients. MATERIALS AND METHODS: Fourth-year dental students attended two lectures on dementia given by a psychiatrist as part of the geriatric dentistry lecture and were questioned afterwards using the Dementia Attitude Scale. In 2016 and 2017, 73 students at the University of Greifswald were interviewed. The response rate was 84%. Using a factor analysis, the Dementia Attitude Scale's validated questions were interpreted and compared with data from nursing staff from Switzerland and the USA. RESULTS: The factor analysis of the data showed the same two-factor loadings as the comparative groups, and that dental students' attitude is more comparable to the general population than to medically trained nursing staff. CONCLUSION: Given the results, we conclude that the implementation of a communication module can serve in improving the attitude of dental students towards patients with dementia.

Na2C3O2: The First Crystalline Compound with the Elusive -C≡C-COO- Anion.

By reaction of sodium electride or NaC2H with the anhydrous sodium salt of propiolic acid, Na(OOC-C≡C-H), in liquid ammonia crystalline powders of Na2C3O2 were obtained. The structure analysis based on synchrotron powder diffraction data revealed that Na2C3O2 crystallizes in a monoclinic unit cell (I2/a, Z=4) exhibiting the elusive Y-shaped -C≡C-COO- anion, which is unprecedented in a crystalline compound up to now. IR/Raman and solid-state NMR spectroscopic investigations with assignments supported by DFT-based ab initio calculations confirm this finding. Reaction with sodium electride led to a higher crystallinity of the product, but additionally a by-product apparently due to decomposition and polymerization of Na2C3O2 was formed. No such by-product was observed in the reaction with NaC2H, which turned out to be a milder metalation route. However, the product of the latter reaction is less crystalline.

Quality of life in patients with obstructive sleep apnea: Results from the study of health in Pomerania.

Obstructive sleep apnea is known to be an overall public health problem that, among other things, increases morbidity and mortality. Risk factors as well as symptoms of this multidimensional sleep-related breathing disorder negatively affect quality of life. With our study we aimed to expose the association between obstructive sleep apnea and quality of life in the population of Pomerania, Germany. We utilized data from the population-based Study of Health in Pomerania (SHIP). Information on health status and risk factors about 4420 participants (2275 women) were gathered within the cohort SHIP-TREND, of which 1209 (559 women) underwent an overnight polysomnography and completed sleep questionnaires. The quality of life of the participants was measured using the Short-Form 12 questionnaire. For our study, an ordinal regression analysis with age, sex, body mass index and the Short-Form 12 health survey as predictors for apnea-hypopnea index was computed. The potential factors affecting quality of life are different between physical and mental dimensions of quality of life. Significant effects were found regarding age, sex, body mass index and the Short-Form 12 Mental Component Score, but not the Physical Component Score.

Do brachycephaly and nose size predict the severity of obstructive sleep apnea (OSA)? A sample-based geometric morphometric analysis of craniofacial variation in relation to OSA syndrome and the role of confounding factors.

Obstructive sleep apnea is a common disorder that leads to sleep fragmentation and is potentially bidirectionally related to a variety of comorbidities, including an increased risk of heart failure and stroke. It is often considered a consequence of anatomical abnormalities, especially in the head and neck, but its pathophysiology is likely to be multifactorial in origin. With geometric morphometrics, and a large sample of adults from the Study for Health in Pomerania, we explore the association of craniofacial morphology to the apnea-hypopnea index used as an estimate of obstructive sleep apnea severity. We show that craniofacial size and asymmetry, an aspect of morphological variation seldom analysed in obstructive sleep apnea research, are both uncorrelated to apnea-hypopnea index. In contrast, as in previous analyses, we find evidence that brachycephaly and larger nasal proportions might be associated to obstructive sleep apnea severity. However, this correlational signal is weak and completely disappears when age-related shape variation is statistically controlled for. Our findings suggest that previous work might need to be re-evaluated, and urge researchers to take into account the role of confounders to avoid potentially spurious findings in association studies.

The Preventiometer - reliability of a cardiovascular multi-device measurement platform and its measurement agreement with a cohort study.

BACKGROUND: Multimedia multi-device measurement platforms may make the assessment of prevention-related medical variables with a focus on cardiovascular outcomes more attractive and time-efficient. The aim of the studies was to evaluate the reliability (Study 1) and the measurement agreement with a cohort study (Study 2) of selected measures of such a device, the Preventiometer. METHODS: In Study 1 (N = 75), we conducted repeated measurements in two Preventiometers for four examinations (blood pressure measurement, pulse oximetry, body fat measurement, and spirometry) to analyze their agreement and derive (retest-)reliability estimates. In Study 2 (N = 150), we compared somatometry, blood pressure, pulse oximetry, body fat, and spirometry measurements in the Preventiometer with corresponding measurements used in the population-based Study of Health in Pomerania (SHIP) to evaluate measurement agreement. RESULTS: Intraclass correlations coefficients (ICCs) ranged from .84 to .99 for all examinations in Study 1. Whereas bias was not an issue for most examinations in Study 2, limits of agreement for most examinations were very large compared to results of similar method comparison studies. CONCLUSION: We observed a high retest-reliability of the assessed clinical examinations in the Preventiometer. Some disagreements between Preventiometer and SHIP examinations can be attributed to procedural differences in the examinations. Methodological and technical improvements are recommended before using the Preventiometer in population-based research.

Polysomnographic characteristics of sleep in adults with and without physician-diagnosed atopic dermatitis: results from the Study of Health in Pomerania.

PURPOSE: To analyze sleep characteristics as measured with polysomnography (PSG) in adults from the general population with and without physician-diagnosed atopic dermatitis (AD). METHODS: We analyzed data from participants from the German population-based Study of Health in Pomerania (SHIP) TREND-0. AD was diagnosed in a standardized skin examination. The following polysomnographic parameters were measured: total sleep duration (min), sleep latency (min), wake after sleep onset (WASO; min), rapid eye movement (REM) latency (min), sleep efficiency (%), total number of wakefulness and movement episodes, stages of sleep (%), and apnea-hypopnea index (AHI). Additionally, the subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). We compared sleep characteristics of participants with and without AD. RESULTS: Among 1187 participants, 47 (4.0%) had AD. We found no differences between participants with and without AD in any of the analyzed PSG parameters except for the total number of wakefulness and movement episodes and the percentage of REM sleep. Participants with AD had a higher number of wakefulness and movement episodes, and a lower proportion of REM sleep compared to those without AD. Regarding subjective sleep parameters, no significant differences were found between participants with and without AD. CONCLUSION: Our data do not provide evidence for poor sleep quality in individuals with AD. Major limitations of the study include the unavailability of data on AD severity and the small number of participants with AD. Larger-scaled longitudinal studies considering disease severity and specific AD symptoms with an effect on sleep are required.

Socioeconomic factors do not predict sleep apnea in a population sample from Mecklenburg-Western Pomerania, Germany.

PURPOSE: Socioeconomic factors are known to modulate health. Concerning sleep apnea, influences of income, education, work, and living in a partnership are established. However, results differ between national and ethnic groups. Results also differ between various clinical studies and population-based approaches. The goal of our study was to determine if such factors can be verified in the population of Pomerania, Germany. METHODS: A subgroup from the participants of the population-based Study of Health in Pomerania volunteered for an overnight polysomnography. Their data were subjected to an ordinal regressions analysis with age, sex, body mass index (BMI), income, education, work, and life partner as predictors for the apnea-hypopnea index. RESULTS: Among the subgroup (N = 1209) from the population-based study (N = 4420), significant effects were found for age, sex, and BMI. There were no significant effects for any of the socioeconomic factors. CONCLUSION: Significant effects for well-established factors as age, sex, and BMI show that our study design has sufficient power to verify meaningful associations with sleep apnea. The lack of significant effects for the socioeconomic factors suggests their clinical irrelevance in the tested population.

Activation of MAPK overrides the termination of myelin growth and replaces Nrg1/ErbB3 signals during Schwann cell development and myelination.

Myelination depends on the synthesis of large amounts of myelin transcripts and proteins and is controlled by Nrg1/ErbB/Shp2 signaling. We developed a novel pulse labeling strategy based on stable isotope labeling with amino acids in cell culture (SILAC) to measure the dynamics of myelin protein production in mice. We found that protein synthesis is dampened in the maturing postnatal peripheral nervous system, and myelination then slows down. Remarkably, sustained activation of MAPK signaling by expression of the Mek1DD allele in mice overcomes the signals that end myelination, resulting in continuous myelin growth. MAPK activation leads to minor changes in transcript levels but massively up-regulates protein production. Pharmacological interference in vivo demonstrates that the effects of activated MAPK signaling on translation are mediated by mTOR-independent mechanisms but in part also by mTOR-dependent mechanisms. Previous work demonstrated that loss of ErbB3/Shp2 signaling impairs Schwann cell development and disrupts the myelination program. We found that activated MAPK signaling strikingly compensates for the absence of ErbB3 or Shp2 during Schwann cell development and myelination.

Illuminating the Dark Ages: Pupil Dilation as a Measure of Expectancy Violation Across the Life Span.

Mainly for methodological reasons, little is known about the course of development of early cognitive competencies diagnosed with the violation of expectation (VoE) method in infants. The goal of this research was to evaluate the use of pupillometry as a unified approach to assess expectancy violations during and beyond the "dark ages" between 1 and 3 years. We tested children aged 1-6 years and adults (N = 279) with pictures of animals combined with matching or mismatching animal sounds. All age groups exhibited significantly greater pupil dilation in mismatched than matched trials. We conclude that pupillometry is a viable alternative to the VoE method that, by contrast to the latter, can be used throughout the life span.

Adrenergic Repression of the Epigenetic Reader MeCP2 Facilitates Cardiac Adaptation in Chronic Heart Failure.

RATIONALE: In chronic heart failure, increased adrenergic activation contributes to structural remodeling and altered gene expression. Although adrenergic signaling alters histone modifications, it is unknown, whether it also affects other epigenetic processes, including DNA methylation and its recognition. OBJECTIVE: The aim of this study was to identify the mechanism of regulation of the methyl-CpG-binding protein 2 (MeCP2) and its functional significance during cardiac pressure overload and unloading. METHODS AND RESULTS: MeCP2 was identified as a reversibly repressed gene in mouse hearts after transverse aortic constriction and was normalized after removal of the constriction. Similarly, MeCP2 repression in human failing hearts resolved after unloading by a left ventricular assist device. The cluster miR-212/132 was upregulated after transverse aortic constriction or on activation of α1- and ß1-adrenoceptors and miR-212/132 led to repression of MeCP2. Prevention of MeCP2 repression by a cardiomyocyte-specific, doxycycline-regulatable transgenic mouse model aggravated cardiac hypertrophy, fibrosis, and contractile dysfunction after transverse aortic constriction. Ablation of MeCP2 in cardiomyocytes facilitated recovery of failing hearts after reversible transverse aortic constriction. Genome-wide expression analysis, chromatin immunoprecipitation experiments, and DNA methylation analysis identified mitochondrial genes and their transcriptional regulators as MeCP2 target genes. Coincident with its repression, MeCP2 was removed from its target genes, whereas DNA methylation of MeCP2 target genes remained stable during pressure overload. CONCLUSIONS: These data connect adrenergic activation with a microRNA-MeCP2 epigenetic pathway that is important for cardiac adaptation during the development and recovery from heart failure.

Crucial role for Ca2(+)/calmodulin-dependent protein kinase-II in regulating diastolic stress of normal and failing hearts via titin phosphorylation.

RATIONALE: Myocardial diastolic stiffness and cardiomyocyte passive force (F(passive)) depend in part on titin isoform composition and phosphorylation. Ca(2+)/calmodulin-dependent protein kinase-II (CaMKII) phosphorylates ion channels, Ca(2+)-handling proteins, and chromatin-modifying enzymes in the heart, but has not been known to target titin. OBJECTIVE: To elucidate whether CaMKII phosphorylates titin and modulates F(passive) in normal and failing myocardium. METHODS AND RESULTS: Titin phosphorylation was assessed in CaMKIIδ/γ double-knockout (DKO) mouse, transgenic CaMKIIδC-overexpressing mouse, and human hearts, by Pro-Q-Diamond/Sypro-Ruby staining, autoradiography, and immunoblotting using phosphoserine-specific titin-antibodies. CaMKII-dependent site-specific titin phosphorylation was quantified in vivo by mass spectrometry using stable isotope labeling by amino acids in cell culture mouse heart mixed with wild-type (WT) or DKO heart. F(passive) of single permeabilized cardiomyocytes was recorded before and after CaMKII-administration. All-titin phosphorylation was reduced by >50% in DKO but increased by up to ≈100% in transgenic versus WT hearts. Conserved CaMKII-dependent phosphosites were identified within the PEVK-domain of titin by quantitative mass spectrometry and confirmed in recombinant human PEVK-fragments. CaMKII also phosphorylated the cardiac titin N2B-unique sequence. Phosphorylation at specific PEVK/titin N2B-unique sequence sites was decreased in DKO and amplified in transgenic versus WT hearts. F(passive) was elevated in DKO and reduced in transgenic compared with WT cardiomyocytes. CaMKII-administration lowered F(passive) of WT and DKO cardiomyocytes, an effect blunted by titin antibody pretreatment. Human end-stage failing hearts revealed higher CaMKII expression/activity and phosphorylation at PEVK/titin N2B-unique sequence sites than nonfailing donor hearts. CONCLUSIONS: CaMKII phosphorylates the titin springs at conserved serines/threonines, thereby lowering F(passive). Deranged CaMKII-dependent titin phosphorylation occurs in heart failure and contributes to altered diastolic stress.

Morphology and anatomical variability of the external auditory canal: A population-based MRI study.

BACKGROUND: The external auditory canal (EAC) exhibits a complex morphology and strong inter-individual variations. However, these have not yet been comprehensively described in the literature. PURPOSE: This study aims to determine the width, height and cross-sectional area of the cartilaginous portion of the EAC and to describe the three-dimensional morphology and variability of different EACs. METHODS: Magnetic resonance imaging was performed on 870 subjects (401 male, 469 female, resulting in 1740 EACs) who participated in the longitudinal, population-based cohort study 'Study of Health in Pomerania-START-3'. The height and width were measured in the cartilaginous part of the EAC, between the first and second bend. The variability of the EAC morphology was visualized in three-dimensional models. RESULTS: The mean height (vertical length) of the EAC was 8.62 mm (SD = 2.42) on the right, 8.47 mm (SD = 2.36) on the left. The width (horizontal length) was 4.08 mm (SD = 1.6) on the right, 3.93 mm (SD = 1.64) on the left. The EAC cross-section was 28.6 mm2 (SD = 15.19) on the right, 27.15 mm2 (SD = 14.33) on the left. The average cross-sectional area of the EAC in men was higher than in women. Subjects with larger body size had larger cross-sectional areas. Subjects with higher body mass index tended to have smaller cross-sections. Although the average EAC had an oval shape, a three-dimensional comparison of different EACs revealed strong individual variation in morphology. CONCLUSION: This study enhances the understanding of otolaryngologists and anatomists regarding the complex morphology and variability of the cartilaginous portion of the EAC.

Differential contribution of nitrifying prokaryotes to groundwater nitrification.

The ecophysiology of complete ammonia-oxidizing bacteria (CMX) of the genus Nitrospira and their widespread occurrence in groundwater suggests that CMX bacteria have a competitive advantage over ammonia-oxidizing bacteria (AOB) and archaea (AOA) in these environments. However, the specific contribution of their activity to nitrification processes has remained unclear. We aimed to disentangle the contribution of CMX, AOA and AOB to nitrification and to identify the environmental drivers of their niche differentiation at different levels of ammonium and oxygen in oligotrophic carbonate rock aquifers. CMX ammonia monooxygenase sub-unit A (amoA) genes accounted on average for 16 to 75% of the total groundwater amoA genes detected. Nitrification rates were positively correlated to CMX clade A associated phylotypes and AOB affiliated with Nitrosomonas ureae. Short-term incubations amended with the nitrification inhibitors allylthiourea and chlorate suggested that AOB contributed a large fraction to overall ammonia oxidation, while metaproteomics analysis confirmed an active role of CMX in both ammonia and nitrite oxidation. Ecophysiological niche differentiation of CMX clades A and B, AOB and AOA was linked to their requirements for ammonium, oxygen tolerance, and metabolic versatility. Our results demonstrate that despite numerical predominance of CMX, the first step of nitrification in oligotrophic groundwater appears to be primarily governed by AOB. Higher growth yields at lower ammonia turnover rates and energy derived from nitrite oxidation most likely enable CMX to maintain consistently high populations.

Menopause Is Associated with Obstructive Sleep Apnea in a Population-Based Sample from Mecklenburg-Western Pomerania, Germany.

Objective: Menopause is associated with multiple health risks. In several studies, a higher incidence or a higher risk for obstructive sleep apnea (OSA) in post-menopausal than pre-menopausal women is reported. This study was designed to verify such a connection between menopause and OSA in a population-based sample. Methods: For a subsample (N = 1209) of the Study of Health in Pomerania (N = 4420), complete polysomnography data was available. Of these, 559 females completed a structured interview about their menstrual cycle. Splines and ordinal regression analysis were used to analyze the resulting data. Results: In the ordinal regression analysis, a significant association between the apnea-hypopnea index (AHI) and menopause indicated that post-menopausal women had a substantially higher risk of OSA. In accordance with previous studies, risk indicators such as body mass index (BMI), age, and the influence of hysterectomies or total oophorectomies were included in the model. Conclusions: Our results clearly confirmed the assumed connection between menopause and OSA. This is important because OSA is most often associated with male patients, and it warrants further research into the underlying mechanisms.

Cellular stress affects the fate of microbial resistance to folate inhibitors in treatment wetlands.

The environmental prevalence of antimicrobial resistance (AMR) has come into focus under the One Health concept. Wastewater treatment systems are among the significant sources of AMR in the environment. In such systems, it is uncertain to which extent antimicrobials present at sub-inhibitory concentrations constitute a selective pressure for bacterial maintenance and acquisition of antibiotic resistance (AR) genes. Here, we mapped AMR to inhibitors of folate biosynthesis in an aerated and a non-aerated horizontal subsurface flow treatment wetland receiving the same pre-treated municipal wastewater. General water characteristics and the concentrations of folate inhibitors were determined to define the ambient conditions over the longitudinal axis of the two treatment wetlands. Profiling of AMR as well as class 1 integrons, a carrier of AR genes against folate inhibitors and other antimicrobials, was conducted by cultivation-dependent and -independent methods. The wetlands achieved mean reductions of AR gene copy numbers in the effluents of at least 2 log, with the aerated system performing better. The folate inhibitors had no noticeable effect on the prevalence of respective AR genes. However, there was a transient increase of AR gene copy numbers and AR gene cassette composition in class 1 integrons in the aerated wetland. The comparison of all data from both wetlands suggests that higher levels of cellular stress in the aerated system promoted the mobility of AR genes via enhancing the activity of the DNA recombinase of the class 1 integron. The findings highlight that environmental conditions that modulate the activity of this genetic element can be more important for the fate of associated AR genes in treatment wetlands than the ambient concentration of the respective antimicrobial agents. By extrapolation, the results suggest that cellular stress also contributes to the mobility of AR gene in other wastewater treatment systems.

The Realization of Clinker-Reduced, Performance-Based Sustainable Concrete by the Micro-Filler, Eco-Filler Concept.

In times of climate change, the reduction in embodied greenhouse gas emissions is a premise for sustainable concrete infrastructure. As Portland cement clinker is mainly responsible for the high CO2 emissions of concrete, its reduction is necessary. In order to be sustainable, the concrete must meet processing, mechanical and durability properties while taking cost aspects into account. The paper presents (i) the "micro-filler/eco-filler concept" for achieving a clinker reduced, optimised binder and (ii) a performance-based approach to put sustainable "Eco-concrete" into practice. Clinker is substituted by locally available inert fillers by at least two different particle size fractions and supplementary cementitious materials. The method is based on particle packing optimisation, reduction in water demand and optimisation of the mix ratio of the binder blend, which allows the performance requirements to be met. The new Eco-concretes deliver the desired performance in terms of processability, strength and durability (water penetration, frost, carbonation and chloride resistance) while lowering the environmental impact in comparison to standard concrete. One of the new mixes was used for a small animal passage tunnel. The direct comparison of the developed Eco-concrete and standard concrete showed a 24% reduction in CO2, while achieving satisfactory workability, stripping strength and durability performance.

Preventiometer, a Novel Wellness Assessment Device, Used With Healthy Volunteers: A Phase 2 Study.

BACKGROUND: We previously reported on a pilot study to assess the incorporation of a novel wellness assessment device, the Preventiometer (iPEx5 GmbH, Greifswald, Germany), into an academic medical practice. The present follow-up study expands on those data and evaluates the acceptability of the assessment process in a larger sample population. OBJECTIVE: The aim of this study was to evaluate participant satisfaction with the Preventiometer wellness assessment. METHODS: A total of 60 healthy volunteers participated. Each participant underwent a comprehensive wellness assessment with the Preventiometer and received data from more than 30 diagnostic tests. A 32-question survey (with a numeric rating scale from 0 to 10) was used to rate the wellness assessment tests and participants' impressions of the wellness assessment. RESULTS: Each assessment had a significantly higher rating than 7 (P < .001), and the majority of participants agreed or strongly agreed that they were satisfied (98.3%), and they strongly agreed that they were engaged the entire time (93.2%), and liked the instant test results feature of the Preventiometer device (93.2%). CONCLUSION: This study confirms findings from our previous pilot study regarding the feasibility of the Preventiometer as a wellness assessment tool. The study further demonstrated that 98% of participants were satisfied with the assessment and that all of them would recommend it to others.

Three-Year-Olds Solved a Mental Rotation Task Above Chance Level, but No Linear Relation Concerning Reaction Time and Angular Disparity Presented Itself.

Three-year-olds and 4-year-olds have severe difficulties solving standard mental rotation tasks. Only 5-year-olds solve such tasks above chance reliably. In contrast studies relying on simplified mental rotation tasks indicate that infants discriminate between an object and its mirror image. Furthermore in another simplified mental rotation task with 3-year-olds, a linear relation between angular disparity and reaction time typical for mental rotation was revealed. Therefore it was assumed that 3-year-olds' capabilities are underestimated. In the current study, 3-year-olds were trained in two isolated sessions to solve standard mental rotation tasks and were tested in a third session. Three-year-olds solved this test above chance as a group - a substantial number of them doing so on an individual level. However, a linear relation between angular disparity and reaction time, that would indicate an analog mental transformation, was not discernable. Nevertheless, these findings are in accordance with a continuous line describing mental rotation in infants and older children. And, these also indicate that children's mental rotation capabilities might be underestimated.

Mental rotation and the human body: Children's inflexible use of embodiment mirrors that of adults.

Adults' mental rotation performance with body-like stimuli is enhanced if these stimuli are anatomically compatible with a human body, but decreased by anatomically incompatible stimuli. In this study, we investigated these effects for kindergartners and first-graders: When asked to mentally rotate cube configurations attached with human body parts in an anatomically compatible way, allowing for the projection of a human body, children performed better than with pure cube combinations. By contrast, when body parts were attached in an anatomically incompatible way, disallowing the projection of a human body, children performed worse than with pure combinations. This experiment is of specific interest against the background of two different theoretical approaches concerning imagery and the motor system in development: One approach assumes an increasing integration of motor processes and imagery over time that enables older children and adults to requisition motor resources for imagery processes, while the other postulates that imagery stems from early sensorimotor processes in the first place, and is disentangled from it over time. The finding that children of the two age groups tested show exactly the same effects as adults when mentally rotating anatomically compatible and incompatible stimuli is interpreted in favour of the latter approach. Statement of contribution What is already known on this subject? In mental rotation, adults perform better when rotating anatomically possible stimuli as compared to rotating standard cube combinations. Performance is worse when rotating anatomically impossible stimuli. What does this study add? The present study shows that children's mental transformations mirror those of adults in these respects. In case of the anatomically impossible stimuli, this highlights an inflexible use of embodiment in both age groups. This is in line with the Piagetian assumption of imagery being based on sensorimotor processes.