Investigation of mechanical behavior of glass fiber reinforced extruded polystyrene core material composites

Layered composites are composite materials created by combining different layers of materials. Each layer can possess unique properties, often tailored to meet specific application or design requirements. These composites have found applications in various sectors due to their features, which include lightness, excellent impact properties, and customization according to specific application areas. In this study, glass fiber reinforced polymer foam core layered composite materials were produced. EPS polymer foam was used as the core material. During production, polymer foams and fibers were bonded to the upper and lower sides of the foams using resin. Samples were produced with 4 and 6 layers on both sides, totaling 8 and 12 layers, respectively. The vacuum bagging method was employed in production, utilizing the manual laying technique. Upon completion of production, the materials were cut into sizes conforming to standards and converted into samples. Subsequently, three-point bending and low-speed impact tests were conducted on the produced samples. As a result of the impact tests, perforation occurred in the 8-layer samples of 200 g m-2 glass fiber composites, while rebound was observed in the 12-layer samples. Although more deformation occurred in the 8-layer glass fiber composites of 300 g m-2 than in the 12-layer samples, both sets of experiments resulted in rebound. Similar results to the impact tests were obtained in three-point bending tests, with higher strengths observed in the 12-layer samples compared to the 8-layer samples. Composite samples with fiber layers of 300 g m-2 exhibited better performance than samples with 200 g m-2 fibers.

Three-dimensional changes in the location of soft tissue landmarks following bimaxillary orthognathic surgery

OBJECTIVES

We sought to determine the amount of three-dimensional (3D) movement of soft tissue landmarks in patients who underwent bimaxillary orthognathic surgery.

MATERIALS AND METHODS

We recruited 28 patients (11 women and 17 men), who had received one-piece Le Fort I osteotomy with maxillary advancement and impaction, and bilateral sagittal split ramus osteotomy for mandibular setback. The 3D images were acquired 1-7 days before surgery and at least 6 months after surgery using stereophotogrammetry. We recorded 50 coordinate measurements and correlated the movements between soft and hard tissues. Paired samples t‑test, independent samples t‑test, and Pearson's correlation analysis were used for statistical analysis.

RESULTS

Patients' ages ranged from 17-31 years (mean 20.4 ± 3.0 years). The mean advancement and impaction of the maxilla was 4.7 ± 1.2 and 2.2 ± 1.0 mm, respectively. The mean setback of the mandible was 4.2 ± 1.6 mm. Menton (Me) moved significantly closer to the midsagittal plane, and the bilateral alare (Al) and alar curvature (Ac) moved laterally. In addition, pronasale (Prn), bilateral Al, Ac, subnasale (Sn), subspinale (Ss), labiale superior (Ls), sublabiale (Sl), pogonion (Pog), and Me moved upwards. The bilateral cheek bone (Cbp), Al, Ac, Prn, Sn, Ss, Ls, and stomion (Sto) moved forward. Li, Sl, Pog, and Me moved backward. Interestingly, poor correlation was found between soft tissue landmarks and hard tissue movements.

CONCLUSION

We observed 3D coordinate changes in several soft tissue landmarks in the middle and lower thirds of the face. The results of this study may be useful for estimating postoperative changes in similar patients.

Wiskott-Aldrich syndrome: Two case reports with a novel mutation

BACKGROUND

The Wiskott-Aldrich syndrome (WAS) is X-linked recessive disorder associated with microplatelet thrombocytopenia, eczema, infections, and an increased risk of autoimmunity and lymphoid neoplasia. The originally described features of WAS include susceptibility to infections, microthrombocytopenia, and eczema.

AIM

In this case report, we present our experience about two cases diagnosed with a new mutation.

METHODS

We report phenotypical and laboratory description of two cases with WAS.

RESULTS

We, for the first time, detected a new hemizygote mutation of WAS gene (NM_000377.2 p.M393lfs^*102 (c.1178dupT)) in two patients. The first case was an 11-month-old boy presenting with complaints of recurrent soft tissue infection, ear infection, anemia, and thrombocytopenia with a low platelet volume. The second case was a 2-month-old boy presenting with thrombocytopenia and a low platelet volume. Both cases were the first-degree relatives: they were cousins and their mothers were sisters.

CONCLUSION

Herein, we report two cases of WAS and a new gene mutation which would disrupt the WAS protein function within the Polyproline (PPP) domain. This report adds to the growing number of mutations which cause complex clinical manifestations associated with WAS.

Clinical, radiographic, diagnostic and cephalometric features of pycnodysostosis in comparison with Turkish cephalometric norms: A case report

Pycnodysostosis is a rare genetic disorder and was first described in 1962 by Maroteaux and Lamy. The incidence of this anomaly is estimated to be 1.7 per 1 million births. The principal characteristics of this disorder are short stature, prominent eyes with blue sclera, beaked nose, cranial dysplasia, exposed fontanelles and cranial sutures, clavicular dysplasia, total/partial dysplasia of the terminal phalanges, obtused mandibular gonial angle, and generally increased bone density. Some features of pycnodysostosis are similar to osteopetrosis and cleidocranial dysostosis. Therefore, it must be distinguished from osteopetrosis and cleidocranial dysostosis in order to diagnose it in individuals of a younger age.The aims of this case report were to show the clinical, radiographic, and diagnostic features, as well as the cephalometric characteristics of pycnodysostosis in comparison with Turkish cephalometric norms.

Face Mask Therapy Effects in Two Skeletal Maturation Groups of Female Subjects with Skeletal Class III Malocclusions

Objective: To examine the effects of face mask therapy in adolescent and young adult female subjects with skeletal Class III malocclusion characterized by maxillary retrognathism.

Materials and Methods: The material consisted of pretreatment and posttreatment lateral cephalometric radiographs of 28 subjects with Class III malocclusions treated with a face mask. Twenty-eight patients age 10 to 16 years were divided into two groups: the adolescent group (15 female patients) and the young adult group (13 female patients). Within group and between group comparisons were made by paired t-test and Student's t-test, respectively.

Results: Forward displacement of the maxilla and clockwise rotation of the mandible occurred in both the adolescent and young adult groups. Maxillary-mandibular relationship exhibited an increase in the ANB angle and Wits appraisal, and the soft-tissue changes resulted in a more convex profile. The maxillary incisors moved forward while the mandibular incisors moved backward.

Conclusions: Face mask therapy improves skeletal Class III malocclusions by a combination of skeletal and dental changes. Although early treatment may be most effective, face mask treatment can provide a viable option for older children as well.