Pattern Of Allergic Contact Dermatitis In School Children In Selayang Hospital, Malaysia

Background: Allergic contact dermatitis (ACD) was thought to be infrequent in children. However, there was an increasing number of case reports and cross-sectional studies in the past three decades indicating that ACD is not as rare as previously thought. Understanding the pattern of allergic contact dermatitis in children would help with the diagnosis and prevention of this disease. Aim: This study explored the spectrum of contact allergens in schoolchildren. Methodology: This is a retrospective analysis of all primary and secondary schoolchildren who underwent patch test at the Department of Dermatology, Hospital Selayang, Malaysia between January 2012 and March 2013. Patch tests were performed with European Baseline Series and other additional commercial series from Chemotechnique Diagnostics in IQ chambers. The parameters studied included sites of dermatitis, positive patch test reactions and sources of the allergens. Readings were recorded according to the International Contact Dermatitis Research Group recommendation. Results were analyzed using the SPSS Version 12.0. Results: 84 out of 327 (25.7%) patients who underwent patch tests were primary and secondary schoolchildren. Of the 84 schoolchildren, 60.7% had at least one positive patch test reaction. The most common allergens were preservatives found in cosmetic series (51%), rubber chemicals (47.1%), nickel sulfate (31.3%), fragrances (19.6%) and topical medicaments (19.6%). The majority (86%) of patients with facial dermatitis were positive to allergens in dental series, whereas 41.9% of patients with dermatitis involving the upper limbs and 50% of patients with dermatitis involving the lower limbs had positive patch test to rubber chemicals. Patients with dermatitis involving the trunk mostly had positive patch test to fragrances (50%). Sources of fragrances were mainly found in toiletries, topical medicaments and cosmetics. Discussion: This results of this study were interesting because of the high rate of sensitization to preservatives, mainly paraben mix. There were also high sensitization rates to rubber chemicals, which could be due to contact with rubberized shoes, sports equipment and stationery. Conclusions: Schoolchildren with face, limbs or trunk dermatitis should be patch tested with additional dental, rubber and fragrance series respectively.

Evaluation of the effect of bracket and archwire composition on frictional forces in the buccal segments.

Aim of the study: The aim of this study was to consider friction in buccal segment attachments during overjet reduction by means of sliding mechanics. Friction was compared in Stainless Steel, Titanium and Cobalt Chromium brackets, using Stainless Steel and Beta Titanium wires. Materials and Methods: This in-vitro study comprised 18 samples (6 x 3 brackets of different materials-stainless steel, titanium and cobalt chromium). Each jig comprised of a buccal segment model of two premolar brackets and a molar tube simulating the upper posterior buccal segment. Each jig was coupled with the wire of 0.019 x 0.025 inch dimension and was tested with a Universal Testing Machine. Ligation was achieved using low friction elastomeric modules (Slide TM , Leone, Italy), a non-conventional elastomeric module. Results: All three bracket systems showed significantly higher frictional forces for the beta titanium wire than for the stainless steel wire. When coupled with the stainless steel wire, the titanium bracket showed the least friction, followed by stainless steel and cobalt chromium brackets. When coupled with the beta titanium wire, the titanium brackets again showed the least friction; while the difference in frictional levels between the stainless steel and cobalt chromium brackets was not statistically significant. The titanium brackets showed the least friction among all the groups tested for both wires. Conclusion: Titanium bracket with Beta Titanium wires could and probably should be the alternative metal bracket used in the nickel sensitive patient.

Resorte de Coffin: estudio de 2 diferentes tipos de ligas metálicas / Coffin appliance: study of 2 different types of metal alloys

La aparición de los alambres con una baja cantidad de níquel son un gran avance en ortodoncia, supliendo la necesidad de ortodoncia para pacientes que pueden tener hipersensibilidad de este ión, pero no se conoce mucho acerca de las propiedades mecánicas de estos alambres. El objetivo de este estudio fue probar la hipótesis de que no hay diferencia en el desempeño mecánico de los alambres de acero inoxidable y alambres de acero inoxidable con bajo contenido de níquel, evaluando la fuerza, resistencia y módulo de elasticidad producida por el resorte de Coffin hecho con alambre de 0,032 y 0,036 pulgadas. Se construyeron 60 unidades de Coffin, 30 para cada tipo de aleación, siendo 15confeccionadas con alambre de 0,032 pulgadas y 15 con alambre de 0,036 pulgadas. Todos los arcos fueron sometidos a la prueba mecánica de compresión en la máquina EMIC DL-10000, simulando 4, 6, 9 y 12 mm de activación. El análisis de varianza y comparación múltiple (ANOVA) y la prueba de Tukey (p <0,05) fueron utilizados para evaluar la fuerza, resistencia y módulo de elasticidad. Los grupos que utilizaron alambre de 0,036 pulgadas presentaron estadísticamente (p <0,05) mayores niveles de fuerza, resistencia y módulo de elasticidad en comparación con dispositivos con 0,032 pulgadas de alambre para ambas aleaciones. Para el mismo espesor, no hubieron diferencias estadísticamente significativas entre los 2 tipos de aleaciones, con excepción de los dispositivos con activación de 9 mm y espesor de 0,036 pulgadas que mostraron una diferencia estadística (p <0,05). Los resortes de Coffin evaluados para ambas aleaciones metálicas produjeron fuerzas adecuadas para el tratamiento ortodontico, por lo que debe ser correctamente planificada su aplicación clínica.

The emergence of stainless steel wire made of low-nickel content was a major breakthrough in the orthodontic, supplying the need for orthodontics patients who may have hypersensitivity by this ion, but do not know much about the mechanical properties of these wires. The objective of this study is to test the hypothesis that there is no difference between stainless steel wires and low-nickel stainless steel ones regarding their mechanical behaviour. Force, resilience, and elasticity modulus produced by Coffin appliances made of 0.032-inch and 0.036-inch wires were evaluated. Sixty appliances Coffin were made, thirty for each type of alloy being fifteen for each wire thickness. All the arches were submitted to mechanical compression test by using an EMIC DL-10000 machine simulating activations of 4, 6, 9, and 12 mm. Analysis of variance (ANOVA) with multiple comparisons and Tukey’s test were employed (p< 0.05) for assessing force, resilience, and elasticity modulus. The groups using the 0.036 inch presented statistically (p<0.05) higher levels of force, resiliency and elasticity modulus when compared to the arches using the 0.032 inch wire for both alloys. The Coffin appliances for both alloys evaluated can produce adequate forces for orthodontic treatment as long as their clinical application is correctly planned.

An overview of orthodontic material degradation in oral cavity.

Various types of metallic orthodontic appliances are used in the management of malocclusion. These appliances are placed in oral environnent under many stresses and variations such as masticatory forces, appliance loading, temperature fluctuations, varieties of ingested food and saliva. These metals undergo electrochemical reactions with the oral environment resulting in dissolution or formation of chemical compounds. Various microorganisms and many aggressive ions containing oral environment can cause material degradation (corrosion) and its associated problems during long time exposure. Orthodontic alloys must have excellent corrosion resistance to the oral environment, which is highly important for biocompatibility as well as for orthodontic appliance durability. This article reviews various aspects of corrosion (surface degradation) of orthodontic alloys. It explores the emerging research strategies for probing the biocompatibility of materials. During orthodontic treatment, use of nickel free, better corrosion resistance alloys and less use of fluoride containing toothpaste or gel is expected.