Orofacial anatomical and occlusal changes in patients with sickle cell disease in Kuwait.

Objective: Sickle cell disease (SCD) is the most common hemoglobinopathy where morphologic changes to red blood cells affect the development of hard and soft tissues. The purpose of this study is to identify the craniofacial characteristics and maxillomandibular relationship in SCD patients and compare with unaffected subjects, through cephalometric radiographic assessment. Materials and Methods: The study included 44 Kuwaiti SCD patients (20 female, 24 male) as well as 44 age and gender matched controls. Digital lateral cephalometric, radiographs were recorded. SNA and ANB angles were measured and compared. Results: The mean SNA angle was found to be higher among the SCD cases (83.00 ± 3.22) than in controls (81.78 ± 4.58), but the difference was not statistically significant, (p = 0.146). The mean ANB angle in SCD cases (5.27 ± 2.36) was significantly higher, than that in controls (3.97 ± 2.23). The difference in means was statistically significant, (p = 0.01). Almost 50% of the SCD patients had class II malocclusion and 61.5% of the patients had prognathic maxilla. Conclusions: Patients with SCD in Kuwait exhibited characteristics of skeletal class II pattern malocclusion. They also showed evidence of compensatory maxillary expansion.

Three-dimensional characterization of naturally developed early caries lesions using high-resolution micro-computed tomography.

OBJECTIVES: The goal of this micro-Computed-Tomography (µCT) study was to characterize the structural parameters of natural, early proximal enamel caries lesions and correlate them with two-dimensional radiographic findings. METHODS: Extracted human premolar teeth with ICDAS score 2 proximal lesions were examined using visual-tactile, µCT and simulated bitewing radiographs (BTX). Sound enamel and caries-lesions' structural and mineral density (MD) parameters were analyzed which included surface layer (SL) status and thickness, depth of lesion, and MD. RESULTS: Thirty-six extracted premolars with 54 proximal early enamel caries lesions were analyzed. Lesions varied notably in lesion depth and MD. SL thickness ranged between 20 and 139µm. Three teeth (5.6%) had micro-cavitations upon the µCT examination despite being "clinically" non-cavitated. Cavitation status had no significant association with µCT nor BTX radiographic depth. Depth of lesions correlated weakly but statistically significantly with mineral loss (ML) at body of lesion (r=0.301, p=0.027). SL thickness also correlated negatively with ML at SL (r=-0.501, p<0.001). CONCLUSIONS: Early proximal enamel lesions with ICDAS 2 score as determined by visual-tactile examination exhibited a wide range of lesion parameters and cavitation status when examined by µCT. Visual-tactile examination may fail to detect micro-cavitations in enamel surface that are detectable by µCT. CLINICAL SIGNIFICANCE: Clinicians have direct access to early proximal enamel lesions during orthodontic separation, exfoliation, extraction or restoration of adjacent teeth. This study invites the clinician to consider more decisive management options in high risk individuals (e.g. micro-invasive techniques), given the finding of vast structural variability of such lesions.

Maternal, Decidual, and Neonatal Lymphocyte Composition Is Affected in Pregnant Kidney Transplant Recipients.

Pregnancy after renal transplantation is associated with an increased risk of complications. While a delicately balanced uterine immune system is essential for a successful pregnancy, little is known about the uterine immune environment of pregnant kidney transplant recipients. Moreover, children born to kidney transplant recipients are exposed in utero to immunosuppressive drugs, with possible consequences for neonatal outcomes. Here, we defined the effects of kidney transplantation on the immune cell composition during pregnancy with a cohort of kidney transplant recipients as well as healthy controls with uncomplicated pregnancies. Maternal immune cells from peripheral blood were collected during pregnancy as well as from decidua and cord blood obtained after delivery. Multiparameter flow cytometry was used to identify and characterize populations of cells. While systemic immune cell frequencies were altered in kidney transplant patients, immune cell dynamics over the course of pregnancy were largely similar to healthy women. In the decidua of women with a kidney transplant, we observed a decreased frequency of HLA-DR+ Treg, particularly in those treated with tacrolimus versus those that were treated with azathioprine next to tacrolimus, or with azathioprine alone. In addition, both the innate and adaptive neonatal immune system of children born to kidney transplant recipients was significantly altered compared to neonates born from uncomplicated pregnancies. Overall, our findings indicate a significant and distinct impact on the maternal systemic, uterine, and neonatal immune cell composition in pregnant kidney transplant recipients, which could have important consequences for the incidence of pregnancy complications, treatment decisions, and the offspring's health.

The suitability of panoramic radiographs for clinical decision making regarding root angulation compared to cone-beam computed tomography.

BACKGROUND: The study compared clinical decisions regarding root angulation correction and root proximity based on the interpretation of Panoramic (PAN) versus Cone-Beam Computed Tomography (CBCT) images. METHODS: A total of 864 teeth from 36 existing, radiographic patient records at a university dental clinic with concurrent PAN and CBCT images were assessed using PANs, then using CBCTs in a blinded manner by two orthodontists. Teeth were rated regarding the need for root repositioning, the direction of repositioning and existence of root proximity. Frequencies, rating time and intra- and inter-examiner Cohen's Kappa were calculated. RESULTS: There was 73.7-84.5% agreement between PAN-based and CBCT-based orthodontists' decisions regarding the need to reposition roots. Root proximity was more frequently reported on PANs than CBCTs by one examiner (p = 0.001 and p = 0.168). Both PANs and CBCTs had moderate to substantial intra-examiner, within-radiograph-type reliability with Kappa values of 0.686-0.79 for PANs, and 0.661 for CBCTs (p < 0.001). Inter-examiner and inter-radiograph-type Kappa values ranged from 0.414 to 0.51 (p < 0.001). Using CBCT decisions as a reference, 78.9% of PAN decisions were coincident, 9.3% would have been repositioned on CBCT but not on PAN, 11.3% would not have been repositioned on CBCT but were on PAN, and 0.3% would have been repositioned in the opposite direction on CBCT versus PAN. Additionally, CBCT images required more time per tooth to assess than PANs (p < 0.001). CONCLUSIONS: PAN-based clinical decisions regarding root angulation had comparable statistical reliability and substantial agreement with CBCT-based clinical decisions.

A Comparative Study of the Examination Pattern of Panoramic Radiographs Using Eye-tracking Software.

AIM: To analyze the differences between novice and expert orthodontists examining panoramic radiographs with incidental findings of varying difficulty. The null hypothesis states no difference in the examination pattern of panoramic radiographs between novice and expert orthodontists. MATERIALS AND METHODS: Expert and novice orthodontic observers were asked to examine six panoramic radiographs with incidental findings of varying difficulty. The eye-tracking software recorded and analyzed their eye movements during the examination. After examining each radiograph, the observers were asked questions about the radiograph. All these collected data were analyzed to compare the performance of the two sets of observers. RESULTS: The total number of observers was 72 in the novice group and 64 in the expert group. There was only one statistically significant finding between the two groups of observers, which was the end time. Expert orthodontists recorded longer panoramic radiograph examination times. CONCLUSION: There is no significant difference in the abilities of expert and novice orthodontists to examine panoramic radiographs and identify incidental findings. CLINICAL SIGNIFICANCE: Orthodontists might benefit from additional education and continued training in examining and reporting radiographs commonly utilized by this specific group of dental specialists, such as panoramic and cephalometric radiographs.

Are three-dimensional airway evaluations obtained through computed and cone-beam computed tomography scans predictable from lateral cephalograms? A systematic review of evidence.

OBJECTIVE: To systematically review the literature correlating upper airway parameters between lateral cephalograms (LC) and cone-beam computed tomography (CBCT) or computed tomography (CT) scans to determine the utility of using LC to predict three-dimensional airway parameters. MATERIALS AND METHODS: Both electronic and manual searches of the included studies were performed by two reviewers, and the quality of the studies that met selection criteria were assessed. RESULTS: A total of 11 studies from the literature met the selection criteria. Assessed outcome variables showed correlation r < .7 between the LC and CT scans. The correlation between the LC and CBCT ranged from weak to strong with -.78 ≤ r and r ≤ .93 reported in the nasopharyngeal segment. In the oropharyngeal segment, a weak to strong correlation was reported with a range of -37 ≤ r and r ≤ .83 between the CBCT and LC. All associations in the hypopharyngeal segment showed a weak correlation. Four of studies were of weak quality, five were of moderate quality, and two were rated to be of strong quality. CONCLUSION: No strong correlations were reported between the LC and CT scans. However, the LC-derived adenoid-nasopharyngeal ratio and the linear measurement (posterior nasal spine, PNS, to posterior pharyngeal wall) had a strong correlation with upright nasopharyngeal area and volume in the CBCTs. The area measurement in conventional LC can be also used as an initial screening tool to predict the upright three-dimensional oropharyngeal volumetric data. The variability of the hypopharyngeal segment cannot be predicted by LCs. However, more well-designed studies are needed to determine the clinical utility of using LC to predict airway size.

Dental and dental hygiene students' diagnostic accuracy in oral radiology: effect of diagnostic strategy and instructional method.

There has been much debate surrounding diagnostic strategies and the most appropriate training models for novices in oral radiology. It has been argued that an analytic approach, using a step-by-step analysis of the radiographic features of an abnormality, is ideal. Alternative research suggests that novices can successfully employ non-analytic reasoning. Many of these studies do not take instructional methodology into account. This study evaluated the effectiveness of non-analytic and analytic strategies in radiographic interpretation and explored the relationship between instructional methodology and diagnostic strategy. Second-year dental and dental hygiene students were taught four radiographic abnormalities using basic science instructions or a step-by-step algorithm. The students were tested on diagnostic accuracy and memory immediately after learning and one week later. A total of seventy-three students completed both immediate and delayed sessions and were included in the analysis. Students were randomly divided into two instructional conditions: one group provided a diagnostic hypothesis for the image and then identified specific features to support it, while the other group first identified features and then provided a diagnosis. Participants in the diagnosis-first condition (non-analytic reasoning) had higher diagnostic accuracy then those in the features-first condition (analytic reasoning), regardless of their learning condition. No main effect of learning condition or interaction with diagnostic strategy was observed. Educators should be mindful of the potential influence of analytic and non-analytic approaches on the effectiveness of the instructional method.

Test-enhanced learning and its effect on comprehension and diagnostic accuracy.

CONTEXT: In health professions education, tests have traditionally been used to assess the skills and knowledge of learners. More recently, research in psychology and education has shown that tests can also be used to enhance student memory; a phenomenon called the 'testing effect'. Much of the research in this domain has focused on enhancing rote memory of simple facts, and not on the deeper comprehension and application of complex theoretical knowledge necessary to diagnose and manage patients. The purpose of this study was to examine the effects of testing on students' comprehension of the basic science mechanisms and diagnostic accuracy. METHODS: Undergraduate dental and dental hygiene students (n = 112) were taught the radiographic features and pathophysiology underlying four intrabony abnormalities. Participants were divided into two groups: the test-enhanced (TE) condition and the study (ST) condition. Following the learning phase, the TE condition group completed an interventional test that tested the basic science mechanisms and the ST condition group was given additional study passages without being tested. Participants in both groups then completed a diagnostic test and a memory test immediately after the learning phase and 1 week later. RESULTS: A main effect of testing condition was found. The participants in the TE condition group outperformed those in the ST condition group on immediate and delayed testing. Unlike the diagnostic test, the memory test showed no difference between the groups. CONCLUSION: The inclusion of the basic science test appears to have improved the students' understanding of the underlying disease mechanisms learned and also improved their performance on a test of diagnostic accuracy.

Integration of basic sciences and clinical sciences in oral radiology education for dental students.

Educational research suggests that cognitive processing in diagnostic radiology requires a solid foundation in the basic sciences and knowledge of the radiological changes associated with disease. Although it is generally assumed that dental students must acquire both sets of knowledge, little is known about the most effective way to teach them. Currently, the basic and clinical sciences are taught separately. This study was conducted to compare the diagnostic accuracy of students when taught basic sciences segregated or integrated with clinical features. Predoctoral dental students (n=51) were taught four confusable intrabony abnormalities using basic science descriptions integrated with the radiographic features or taught segregated from the radiographic features. The students were tested with diagnostic images, and memory tests were performed immediately after learning and one week later. On immediate and delayed testing, participants in the integrated basic science group outperformed those from the segregated group. A main effect of learning condition was found to be significant (p<0.05). The results of this study support the critical role of integrating biomedical knowledge in diagnostic radiology and shows that teaching basic sciences integrated with clinical features produces higher diagnostic accuracy in novices than teaching basic sciences segregated from clinical features.

The role of basic sciences in diagnostic oral radiology.

Although it is generally taken for granted that dental education must include both basic science and feature-based knowledge components, little is known about their relative roles in visual interpretation of radiographs. The objectives of this study were twofold. First, we sought to compare the educational efficacy of three learning strategies in diagnostic radiology: one that used basic scientific (pathophysiologic) information, one that used feature lists structured with an organizational tool, and one that used unstructured feature lists. Our second objective was to determine whether basic scientific information provides conceptual coherence or is merely a simple means for organizing feature-based knowledge. Predoctoral dental and undergraduate dental hygiene students (n=96) were randomly assigned into three groups (basic science, structured algorithm, and feature list) and were taught four confusable intrabony entities. The students completed diagnostic and memory tests immediately after learning and one week later, and these data were subjected to a 3x2 repeated measures ANOVA. For the diagnostic test, students in the basic science group outperformed those assigned to the feature list and structured algorithm groups on immediate and delayed testing (p<0.05). A main effect of learning condition was found to be significant. On the memory test, performance was similar across all three groups, and no significant effects were found. The results of this study support the critical role of basic scientific knowledge in diagnostic radiology. This study also refutes the organized learning theory and provides support for the conceptual coherence theory as a possible explanation for the process by which basic science aids in diagnosis.