Tag: statistics

J Clin Pediatr Dent. 2023 Sep;47(5):57-64. doi: 10.22514/jocpd.2023.053. Epub 2023 Sep 3.

ABSTRACT

In this in vitro study, fracture resistance was evaluated according to the post-diameter and -length in zirconia crown restorations on three-dimensional printed primary incisors undergone pulpectomy. One hundred-and-sixty primary incisor abutments were used which were artificially fabricated through 3D-printing. Each group was divided into two subgroups based on the zirconia post-diameter (1.5 mm and 2.0 mm) employed for post setting after pulpectomy. Furthermore, each group was divided into four subgroups based on the zirconia post-height (3.0, 4.0, 5.0 and 6.0 mm). Zirconia post setting was made by applying flowable resin after filling the pulp cavity with calcium hydroxide up to 3.0 mm below cemento-enamel junction (CEJ). Finally, a preformed zirconia crown of size #1 was cemented to the abutment through resin cement. A compressive load was applied to the middle palatal surface of incisors restored with zirconia crowns by using a universal testing machine at 145° angle which is the normal interincisal angle of children. The root fracture specimens were excluded and the samples fractured within crown and core parts were included in the final fracture resistance analysis. The group with 1.5-mm post-diameter and 5.0-mm post-height had the highest fracture resistance strength (130.63 ± 55.75 N) under masticatory pressure condition. Fracture resistance was statistically greater in 5.0-mm than in 4.0-mm and 3.0-mm post-height groups for 1.5-mm post-diameter subgroup. Moreover, 5.0-mm post-height subgroup had a statistically greater fracture resistance than that of 3.0-mm post-height subgroup for 2.0-mm post-diameter group. The 2.0-mm post-diameter subgroup had a statistically greater fracture resistance than that of 1.5-mm post-diameter subgroup for 3.0-mm and 4.0-mm post-heights. If zirconia post incorporation is required for deciduous incisor restoration, a post-length equal to facial CEJ level is recommended for gaining additional retention against masticatory pressure.

PMID:37732437 | DOI:10.22514/jocpd.2023.053

J Clin Pediatr Dent. 2023 Sep;47(5):51-56. doi: 10.22514/jocpd.2023.045. Epub 2023 Sep 3.

ABSTRACT

In this study, we investigated dental arch forms in a representative sample of children with mixed dentition. Twenty-four pairs of study models, belonging to twenty-four youngsters (twelve boys and twelve girls aged 8 to 9 years) with acceptable occlusion, were scanned and assessed by Ortho analyzer software. Three transversal and three vertical measurements were acquired to evaluate the lengths and widths of dental arches, and the ratios between these measurements were standardized. Next, the mean standardized parameters were used to define the dental arch form. Unpaired t-tests were used to analyze gender differences for all measures. Subsequently, frequencies and percentages were determined for each arch shape in both jaws and genders, and Pearson’s Chi-squared test was used to evaluate differences between genders. Males exhibited higher mean values for all measurements, but without statistical significance. The most prevalent dental arch was the mid form (83.3%) for both jaws and genders.

PMID:37732436 | DOI:10.22514/jocpd.2023.045

J Clin Pediatr Dent. 2023 Sep;47(5):37-42. doi: 10.22514/jocpd.2023.052. Epub 2023 Sep 3.

ABSTRACT

The term Molar-Incisor Hypomineralisation (MIH) is used to describe hypomineralised defects of systemic origin that affect at least one of the first permanent molars and often involves the permanent incisors. Antibiotic therapy during amelogenesis may be associated with enamel hypomineralisation. By examining children with Sickle Cell Disease (SCD), who take prophylactic antibiotics daily from birth until age five, it may be possible to determine if there is an increased prevalence of MIH in this population. The aim of this study was to determine the effect of long-term antibiotic use on the prevalence and severity of MIH in children with SCD. In a prospective cohort pilot study over a period of seven months, children aged 7-17 years, with SCD at Boston Children’s Hospital (n = 18) were examined for MIH. Information regarding peri-natal concerns, incidence of illness and antibiotic use were also collected. The results were compared to a group of control patients (n = 63) for prevalence and severity of MIH using Fisher’s exact test. The patients with SCD, 4/18 (22%) taking daily antibiotics did not show a statistically significant greater prevalence of MIH compared to the control group, 24/63 (38%). There was no correlation between MIH and pneumonia, asthma, fever, flu, otitis media, breastfeeding, gender and birth weight. However, an association was noted between premature birth and MIH (p ≤ 0.05). No correlation was found between long-term antibiotic use and higher prevalence of MIH in the SCD group compared to the control group. However, MIH may be more severe in those with a history of long-term antibiotics.

PMID:37732434 | DOI:10.22514/jocpd.2023.052

J Dev Orig Health Dis. 2023 Sep 21:1-11. doi: 10.1017/S2040174423000247. Online ahead of print.

ABSTRACT

The deleterious effects of adversity are likely intergenerational, such that one generation’s adverse experiences can affect the next. Epidemiological studies link maternal adversity to offspring depression and anxiety, possibly via transmission mechanisms that influence offspring fronto-limbic connectivity. However, studies have not thoroughly disassociated postnatal exposure effects nor considered the role of offspring sex. We utilized infant neuroimaging to test the hypothesis that maternal childhood maltreatment (CM) would be associated with increased fronto-limbic connectivity in infancy and tested brain-behavior associations in childhood. Ninety-two dyads participated (32 mothers with CM, 60 without; 52 infant females, 40 infant males). Women reported on their experiences of CM and non-sedated sleeping infants underwent MRIs at 2.44 ± 2.74 weeks. Brain volumes were estimated via structural MRI and white matter structural connectivity (fiber counts) via diffusion MRI with probabilistic tractography. A subset of parents (n = 36) reported on children’s behaviors at age 5.17 ± 1.73 years. Males in the maltreatment group demonstrated greater intra-hemispheric fronto-limbic connectivity (b = 0.96, p= 0.008, [95%CI 0.25, 1.66]), no differences emerged for females. Fronto-limbic connectivity was related to somatic complaints in childhood only for males (r = 0.673, p = 0.006). Our findings suggest that CM could have intergenerational associations to offspring brain development, yet mechanistic studies are needed.

PMID:37732425 | DOI:10.1017/S2040174423000247

Stat Med. 2023 Sep 21. doi: 10.1002/sim.9900. Online ahead of print.

ABSTRACT

When multiple candidate subgroups are considered in clinical trials, we often need to make statistical inference on the subgroups simultaneously. Classical multiple testing procedures might not lead to an interpretable and efficient inference on the subgroups as they often fail to take subgroup size and subgroup effect relationship into account. In this paper, built on the selective traversed accumulation rules (STAR), we propose a data-adaptive and interactive multiple testing procedure for subgroups which can take subgroup size and subgroup effect relationship into account under prespecified tree structure. The proposed method is easy-to-implement and can lead to a more interpretable and efficient inference on prespecified tree-structured subgroups. Possible accommodations to post hoc identified tree-structure subgroups are also discussed in the paper. We demonstrate the merit of our proposed method by re-analyzing the panitumumab trial with the proposed method.

PMID:37732390 | DOI:10.1002/sim.9900

Sci Rep. 2023 Sep 20;13(1):15562. doi: 10.1038/s41598-023-42657-2.

ABSTRACT

Unsupervised clustering of intensive care unit (ICU) medications may identify unique medication clusters (i.e., pharmacophenotypes) in critically ill adults. We performed an unsupervised analysis with Restricted Boltzmann Machine of 991 medications profiles of patients managed in the ICU to explore pharmacophenotypes that correlated with ICU complications (e.g., mechanical ventilation) and patient-centered outcomes (e.g., length of stay, mortality). Six unique pharmacophenotypes were observed, with unique medication profiles and clinically relevant differences in ICU complications and patient-centered outcomes. While pharmacophenotypes 2 and 4 had no statistically significant difference in ICU length of stay, duration of mechanical ventilation, or duration of vasopressor use, their mortality differed significantly (9.0% vs. 21.9%, p < 0.0001). Pharmacophenotype 4 had a mortality rate of 21.9%, compared with the rest of the pharmacophenotypes ranging from 2.5 to 9%. Phenotyping approaches have shown promise in classifying the heterogenous syndromes of critical illness to predict treatment response and guide clinical decision support systems but have never included comprehensive medication information. This first-ever machine learning approach revealed differences among empirically-derived subgroups of ICU patients that are not typically revealed by traditional classifiers. Identification of pharmacophenotypes may enable enhanced decision making to optimize treatment decisions.

PMID:37730817 | DOI:10.1038/s41598-023-42657-2

Bull Math Biol. 2023 Sep 21;85(11):105. doi: 10.1007/s11538-023-01204-w.

ABSTRACT

Current research in Human Immunodeficiency Virus (HIV) focuses on eradicating virus reservoirs that prevent or dampen the effectiveness of antiretroviral treatment (ART). One such reservoir, the brain, reduces treatment efficacy via the blood-brain barrier (BBB), causing an obstacle to drug penetration into the brain. In this study, we develop a mathematical model to examine the impact of the BBB on ART effectiveness for mitigating brain HIV. A thorough analysis of the model allowed us to fully characterize the global threshold dynamics with the viral clearance and persistence in the brain for the basic reproduction number less than unity and greater than unity, respectively. Our model showed that the BBB has a significant role in inhibiting the effect of ART within the brain despite the effective viral load suppression in the plasma. The level of impact, however, depends on factors such as the CNS Penetration Effectiveness (CPE) score, the slope of the drug dose-response curves, the ART initiation timing, and the number of drugs in the ART protocol. These results suggest that reducing the plasma viral load to undetectable levels due to some drug regimen may not necessarily indicate undetectable levels of HIV in the brain. Thus, the effect of the BBB on viral suppression in the brain must be considered for developing proper treatment protocols against HIV infection.

PMID:37730794 | DOI:10.1007/s11538-023-01204-w

Sci Rep. 2023 Sep 20;13(1):15612. doi: 10.1038/s41598-023-42809-4.

ABSTRACT

Total hip arthroplasty (THA) is a successful orthopaedic surgical procedure, and its longevity depends on bearing components and implant fixation. Optimizing polyethylene and ceramics has led to improved wear parameters and contributed to improved long-term outcomes. The present systematic review investigated whether time span from implantation, patient characteristics and performance status exert an influence on liner wear and head migration in THA. This study was conducted in conformity to the 2020 PRISMA guidelines. All the clinical investigations which reported quantitative data on the amount of liner wear and head migration in THA were considered. Only studies which reported quantitative data at least on one of the following patient characteristics were suitable: mean age, mean BMI (kg/m²), sex, side, time span between the index THA and the last follow-up (months) were eligible. A multiple linear model regression analysis was employed to verify the association between patient characteristics and the amount of liner wear and/or head migration. The Pearson Product-Moment Correlation Coefficient was used to assess the association between variables. Data from 12,629 patients were considered. The mean length of the follow-up was 90.5 ± 50.9 months. The mean age of patients at surgery was 58.4 ± 9.4 years, and the mean BMI was 27.2 ± 2.5 kg/m². 57% (7199 of 12,629 patients) were women, and in 44% (5557 of 12,629 patients) THAs were performed on the left. The mean pre-operative Harris hip score was 46.5 ± 6.0 points. There was evidence of a moderate positive association between the amount of liner wear and the time elapsed between the index surgery to the follow-up (P = 0.02). There was evidence of a moderate positive association between the amount of head migration and the time elapsed between the index surgery to the follow-up (P = 0.01). No further statistically significant association was found. The time elapsed between the index surgery to the follow-up was the most important factor which influence the head migration and liner wear in THA. Patients’ characteristics and preoperative physical activity did not influence the amount of head migration and liner wear.

PMID:37730762 | DOI:10.1038/s41598-023-42809-4

Sci Rep. 2023 Sep 20;13(1):15590. doi: 10.1038/s41598-023-42433-2.

ABSTRACT

The spatial analysis of horizontal stress orientation is important to study stress sources and understand tectonics and the deformation of the lithosphere. Additional to the stress sources, the geometry of stress fields depends on the underlying coordinate reference system, which causes spatial distortions that bias the analysis and interpretation of stresses. The bias can be avoided when the stress field is decomposed and transformed into the reference frame of its first-order stress source. We present a modified and extended theory based on the empirical link between the orientation of first-order stresses and the trajectories of lateral plate boundary forces. This link is applied to analyze the orientation of horizontal stresses, their patterns, and tectonic structures from the perspective of their first-order source or cause. By using only parameters for the relative motion between two neighboring plates, we model the first-order orientation of the maximum horizontal stress that statistically fits the orientation of [Formula: see text]80% of the global stress data adjacent to plate boundaries. Considerable deviations of the observed stress from the predicted first-order stress direction can reveal the geometry of second-order stresses and confine areas where other stress sources dominate. The model’s simple assumptions, independence from the sample size, potential application to regional to global scale analysis, and compatibility with other spatial interpolation algorithms make it a powerful method for analyzing stress fields. For immediate use, the presented method is implemented in the free and open-source software package tectonicr, which is written in the computer language R.

PMID:37730752 | DOI:10.1038/s41598-023-42433-2

Sci Rep. 2023 Sep 20;13(1):15591. doi: 10.1038/s41598-023-42414-5.

ABSTRACT

Brain development is regularly studied using structural MRI. Recently, studies have used a combination of statistical learning and large-scale imaging databases of healthy children to predict an individual’s age from structural MRI. This data-driven, predicted ‘Brainage’ typically differs from the subjects chronological age, with this difference a potential measure of individual difference. Few studies have leveraged higher-order or connectomic representations of structural MRI data for this Brainage approach. We leveraged morphometric similarity as a network-level approach to structural MRI to generate predictive models of age. We benchmarked these novel Brainage approaches using morphometric similarity against more typical, single feature (i.e., cortical thickness) approaches. We showed that these novel methods did not outperform cortical thickness or cortical volume measures. All models were significantly biased by age, but robust to motion confounds. The main results show that, whilst morphometric similarity mapping may be a novel way to leverage additional information from a T1-weighted structural MRI beyond individual features, in the context of a Brainage framework, morphometric similarity does not provide more accurate predictions of age. Morphometric similarity as a network-level approach to structural MRI may be poorly positioned to study individual differences in brain development in healthy participants in this way.

PMID:37730747 | DOI:10.1038/s41598-023-42414-5