An overview of selected orthodontic treatment need indices

Orthodontics is a fast developing science as well as the field of medicine in general. The attempt of this book is to propose new possibilities and new ways of thinking about Orthodontics beside the ones presented in established and outstanding publications available elsewhere. Some of the presented chapters transmit basic information, other clinical experiences and further offer even a window to the future. In the hands of the reader this book could provide an useful tool for the exploration of the application of information, knowledge and belief to some orthodontic topics and questions

Treatment of labial soft tissue recession around dental implants in the esthetic zone using guided bone regeneration with mineralized allograft : a retrospective clinical case series

Objectives: Soft tissue augmentation procedures are often performed to correct gingival recesson on the facial aspects of implants in the esthetic zone. This retrospective clinical case series reports on the use of guided bone regeneration (GBR) and coronal advancement flap with resorbable membrane and allograft. Materials and methods: Records of 14 patients (7 male, 7 female) with a mean (SD) age of 36.78 (13.9) years who were treated for soft tissue recessions around implant-supported restorations in the maxillary central or lateral incisor location were analysed. Implant diameters ranged from 3.3-4.7 mm. All patients had bone loss confined to the labial surface of the implant. A solvent-dehydrated particulate mineralized allograft (Puros Cancellous Bone Allograft, Zimmer Biomet Dental, Palm Beach Gardens, FL) and a resorbable membrane (CopiOs Pericardium, Zimmer Biomet Dental) were used in a GBR surgical procedure in combination with a roughened titanium tenting screw placed 3-4 mm below the implant platform to restore unesthetic defects in the anterior maxilla. Results: All postoperative tissue changes from their preoperative states were statistically significant (p < 0.05, Wilcoxon Signed-Rank test). Mean [SD, 95% Confidence Interval (CI)] preoperative crestal bone thickness (measured 2 mm from crest and mid-implant buccal bone thickness) increased by 1.84 (0.89, 1.32-2.35) mm and 2.07 (0.81, 1.60-2.53) mm, respectively, approximately one year after treatment (p <0.001). Significant mean (SD, 95% CI) increases of 1.28 (0.53, 0.97-1.58) mm, 1.29 (0.81, 0.82-1.75) mm and 1.23 (0.53, 0.92-1.53) mm were also noted in soft tissue thickness, keratinized tissue width, and gingival height, respectively (p <0.001). Conclusion: Use of the allograft and xenogenic membrane effectively increased alveolar hard and soft tissue dimensions in the esthetic zone of the anterior maxilla. Future prospective clinical trials with a control group are needed to compare this technique with conventional methods such as connective tissue graft

Tooth size discrepancy in a Libyan population, a cross-sectional study in schoolchildren

Objetives: The aim of this cross-sectional study was to investigate the tooth size discrepancy (TSD) in a group of Libyan schoolchildren, and to compare TSD between sexes. Material and Methods: The sample comprised 333 Libyan schoolchildren (162 males with a mean (SD) age of 14.4 (1.1) years, and 171 females with a mean age of 14.1 (1.1) years). Anterior and overall TSD ratios were computed using descriptive statistics. Sex differences were statistically assessed using an independent t-test ( P <0.05). Results: Males showed significantly wider MD tooth width compared to females ( P <0.05), except for the maxillary first premolars and mandibular central incisors. There were significant differences ( P <0.05) between the paired (right and left sides) tooth measurements except for the maxillary and mandibular central and lateral incisors as well as mandibular canines. The mean (SD) for overall and anterior TSD ratios were 91.3% (2.1) and 78.2% (2.6), respectively, with no significant sex differences for both variables ( P > 0.05). The percentages of participants showing more than 2 SD variation for the anterior and overall ratios comprised 3% and 4.2% of the total sample, respectively. Conclusions: The anterior and overall TSD ratios for the examined subjects were established and showed no signi - ficant sexual dimorphi

Interplay of Fracture and Martensite Transformation in Microstructures:A Coupled Problem

We are witnessing a tremendous transition towards a society powered by net-zero carbon emission energy, with a corresponding escalating reliance on functional materials (FM). In recent years, the application of FM in multiphysics environments has brought new challenges to the mechanics and materials research communities. The underlying mechanism in FM, which governs several fundamental characteristics, is known as martensitic phase transformation (MPT). When it comes to the application of FM in the multiphysics context, a thorough understanding of the interplay between MPT and fracture plays a crucial role in FM design and application. In the present work, a coupled problem of crack nucleation and propagation and multivariant stress-induced MPT in elastic materials is presented using a finite element method based on Khachaturyan’s microelasticity theory. The problem is established based on a phase-field (PF) approach, which includes the Ginzburg–Landau equations with advanced thermodynamic potential and the variational formulation of Griffith’s theory. Therefore, the model consists of a coupled system of the Ginzburg–Landau equations and the static elasticity equation, and it characterizes evolution of distributions of austenite and two martensitic variants as well as crack growth in terms of corresponding order parameters. The numerical results show that crack growth does not begin until MPT has grown almost completely through the microstructure. Subsequent to the initial formation of the martensite variants, the initial crack propagates in such a way that its path mainly depends on the feature of martensite variant formations, the orientation and direction upon which the martensite plates are aligned, and the stress concentration between martensite plates. In addition, crack propagation behavior and martensite variant evaluations for different lattice orientation angles are presented and discussed in-detail

A framework to model thermomechanical coupled of fracture and martensite transformation in austenitic microstructures

A fully thermomechanical coupled phase-field (PF) model is presented to investigate the mechanism of austenite-to-martensite phase transformation (MPT) and crack initiation as well as its propagation in pure austenitic microstructures. The latent heat release and absorption involved in the MPT are explicitly taken into account by coupling the PF model with transient latent heat transfer. In order to consider temperature dependency in the PF model for MPT, a temperature-dependent Landau polynomial function, whose parameters are identified using molecular dynamics (MD) simulations, is proposed. Furthermore, the fracture surface energy is approximated based on the second-order PF model and then, the temporal evolution of the damage variable is given by the variational derivative of the total potential free energy of the system with respect to the damage variable. The achieved numerical results demonstrate that the model can be employed to predict the fracture mechanism of austenitic microstructures under a thermomechanical field in a multiphysics environment. The results reveal that the temperature has a tremendous impact on the growth rate of both martensitic variants and consequently on the crack growth path. The key contributions of this work are to shed light on the impact of thermal boundary conditions on the coupled process of MPT, crack initiation and growth

Clinical Reasoning in Nursing Students

Abstract Introduction: Diagnosis and understanding of patient conditions require nurses 'clinical reasoning skills, as in the absence of this skill; the nurses will not be able to diagnose the patients' condition and will impose harmful consequences on the patient. The purpose of this study is to evaluate and compare the clinical reasoning skills of the nursing students at Shahid Beheshti University of Medical Sciences at the end of theoretical courses in medical-surgical nursing in 2018. Methods: In this descriptive-comparative study, 150 nursing students from freshmen, sophomores, and juniors studying at the Faculty of Nursing and Midwifery of Shahid Beheshti University of Medical Sciences were selected by stratified sampling method. Students in each year comprised one category and the total number of was 3, also the number of students per category was 50, and the total number of categories will be equal to 9. Data were collected using a researcher-made questionnaire employing Key Feature Problem (KFP) method and analyzed using descriptive statistics by SPSS V.20 software. Results: The results showed that there is a significant difference between the grades of third-year students and those in their first and second years of study (P &lt;0.001). Based on the results, the clinical reasoning skill in the first year was poor (51.59 ± 0.06%), in the second year was very weak (48.41 ± 0.09%) and in third-year students was very weak (37.62 ± 0.88). Also, the average skill of clinical reasoning of all students was very weak with a mean percentage of 46.01%. Conclusions: The findings indicate that the level of students' clinical reasoning skills has been declined comparatively from freshmen to juniors. In general, the level of clinical skills in nursing students of Shahid Beheshti University of Medical Sciences is disappointingly low

Dental anomalies : prevalence and associations between them in a large sample of non-orthodontic subjects, a cross-sectional study

Background: To analyze the prevalence and associations between dental anomalies detectable on panoramic radiographs in a sample of non-orthodontic growing subjects. Methods: For this cross-sectional study, digital panoramic radiographs of 5005 subjects were initially screened from a single radiographic center in Rome. Inclusion criteria were: subjects who were aged 8–12 years, Caucasian, and had good diagnostic quality radiographs. Syndromic subjects, those with craniofacial malformation, or orthodontic patients were excluded and this led to a sample of 4706 subjects [mean (SD) age = 9.6 (1.2) years, 2366 males and 2340 females]. Sample was subsequently divided into four subgroups (8, 9, 10, and 11–12 year-old groups). Two operators examined panoramic radiographs to observe the presence of common dental anomalies. The prevalence and associations between dental anomalies were also investigated. Results: The overall prevalence of dental anomalies was 20.9%. Approximately, 17.9% showed only one anomaly, 2.7% two anomalies, while only 0.3% had more than two anomalies. The most frequent anomalies were the displacement of maxillary canine (7.5%), hypodontia (7.1%), impacted teeth (3.9%), tooth ankylosis (2.8%), and tooth transposition (1.4%). The lower right second premolar was the most frequent missing teeth; 3.7% had only one tooth agenesis, and 0.08% had six or more missing tooth (Oligodontia). Mesiodens was the most common type of supernumerary tooth (0.66%). Two subjects had taurodontic tooth (0.04%). Tooth transpositions and displacement of maxillary canine were seen in 1.4 and 7.5%, retrospectively (approximately 69 and 58% were in the 8 and 9 year-old groups, retrospectively). Significant associations were detected between the different dental anomalies (P < .05). Conclusions: The results of our study revealed significant associations among different dental anomalies and provide further evidences to support common etiological factors

A multidisciplinary treatment of congenitally missing maxillary lateral incisors: a 14-year follow-up case report

Absence of the maxillary lateral incisor creates an aesthetic problem which can be managed in various ways. The condition requires careful treatment planning and consideration of the options and outcomes following either space closure or prosthetic replacement. Recent developments in restorative dentistry have warranted a re-evaluation of the approach to this clinical situation. Factors relating both to the patient and the teeth, including the presentation of malocclusion and the effect on the occlusion must be considered. The objective of this study was to describe the etiology, prevalence and alternative treatment modalities for dental agenesis and to present a clinical case of agenesis of the maxillary lateral incisors treated by the closure of excessive spaces and canine re-anatomization. A clinical case is presented to illustrate the interdisciplinary approach between orthodontics and restorative dentistry for improved esthetic results. In this report, the treatment of a girl with a Class II malocclusion of molars and canines with missing maxillary lateral incisors and convex facial profile is shown. Treatment was successfully achieved and included the space closure of the areas corresponding to the missing upper lateral incisors, through movement of the canines and the posterior teeth to mesial by fixed appliances as well as the canines transformation in the maxillary lateral incisors. This is a 14-year follow-up case report involving orthodontics and restorative dentistry in which pretreatment, posttreatment, and long-term follow-up records for the patient are presented