Assessment of dehydroepiandrosterone sulphate (DHEAS) and cortisol levels in saliva and their correlation to cervical vertebrae maturation method in males and females at different growth stages: a clinical study.

OBJECTIVE: The aim of this in-vivo study was to assess the salivary dehydroepiandrosterone sulphate (DHEAS) and cortisol levels, and their correlation to the Cervical Vertebrae Maturation method (CVM) in males and females at pre-pubertal, pubertal and post-pubertal growth stages. METHODS: 48 patients (24 males, 24 females) who were to undergo routine orthodontic treatment were screened according to the inclusion and exclusion criteria. Then subjects were grouped according to CVM stages, using lateral cephalogram, in pre-pubertal, pubertal and post-pubertal groups. Unstimulated saliva from the selected subjects was collected. DHEAS and cortisol levels in the salivary samples were estimated by Enzyme-Linked Immunosorbent assay (ELISA). Then they were compared to Cervical Vertebrae Maturation Method stages. One-way ANOVA test followed by Tukey's post-hoc test was used to compare the salivary DHEAS and cortisol levels between different CVM stages in males and females. Independent Student t-test was used to compare the mean salivary DHEAS and cortisol levels between different males and females in each CVM stage. RESULT: There was a progressive increase in salivary DHEAS and cortisol concentration as skeletal maturation progressed from CVM stages 1 and 2, CVM stages 3 and 4, reaching the highest value at CVM stages 5 and 6. Their levels were higher in males than females. CONCLUSION: The salivary DHEAS and cortisol levels can be useful as a potential indicator of skeletal maturation, to aid in the assessment of pubertal status.

Assessment of dehydroepiandrosterone sulphate (DHEAS) and cortisol levels in saliva and their correlation to cervical vertebrae maturation method in males and females at different growth stages: a clinical study

ABSTRACT Objective: The aim of this in-vivo study was to assess the salivary dehydroepiandrosterone sulphate (DHEAS) and cortisol levels, and their correlation to the Cervical Vertebrae Maturation method (CVM) in males and females at pre-pubertal, pubertal and post-pubertal growth stages. Methods: 48 patients (24 males, 24 females) who were to undergo routine orthodontic treatment were screened according to the inclusion and exclusion criteria. Then subjects were grouped according to CVM stages, using lateral cephalogram, in pre-pubertal, pubertal and post-pubertal groups. Unstimulated saliva from the selected subjects was collected. DHEAS and cortisol levels in the salivary samples were estimated by Enzyme-Linked Immunosorbent assay (ELISA). Then they were compared to Cervical Vertebrae Maturation Method stages. One-way ANOVA test followed by Tukey's post-hoc test was used to compare the salivary DHEAS and cortisol levels between different CVM stages in males and females. Independent Student t-test was used to compare the mean salivary DHEAS and cortisol levels between different males and females in each CVM stage. Result: There was a progressive increase in salivary DHEAS and cortisol concentration as skeletal maturation progressed from CVM stages 1 and 2, CVM stages 3 and 4, reaching the highest value at CVM stages 5 and 6. Their levels were higher in males than females. Conclusion: The salivary DHEAS and cortisol levels can be useful as a potential indicator of skeletal maturation, to aid in the assessment of pubertal status.

RESUMO Objetivo: O objetivo deste estudo in vivo foi avaliar os níveis salivares de sulfato de dehidroepiandrosterona (DHEAS) e de cortisol, e sua correlação com o método de maturação das vértebras cervicais (CVM) em homens e mulheres nas fases de crescimento pré-puberal, puberal e pós-puberal. Métodos: 48 pacientes (24 homens, 24 mulheres) que se submeteriam a tratamento ortodôntico de rotina foram selecionados de acordo com os critérios de inclusão e exclusão. Em seguida, usando telerradiografia lateral, os indivíduos foram agrupados de acordo com os estágios CVM, em grupos pré-puberal, puberal e pós-puberal. Foi feita coleta de saliva não estimulada nos indivíduos selecionados. Os níveis de DHEAS e cortisol nas amostras salivares foram avaliados pelo teste ELISA (Enzyme-Linked Immunosorbent assay). Em seguida, foram comparados aos estágios do método CVM. O teste ANOVA de uma via seguido pelo teste post-hoc de Tukey foi usado para comparar o DHEAS salivar e os níveis de cortisol entre os diferentes estágios de CVM em homens e mulheres. O teste t de Student independente foi usado para comparar a média de DHEAS salivar e os níveis de cortisol entre diferentes homens e mulheres em cada estágio de CVM. Resultados: Houve um aumento progressivo no DHEAS salivar e na concentração de cortisol à medida que a maturação esquelética progrediu dos estágios CVM 1 e 2, para os estágios CVM 3 e 4, atingindo o valor mais alto nos estágios CVM 5 e 6. Seus níveis foram maiores nos homens do que nas mulheres. Conclusões: Os níveis salivares de DHEAS e cortisol podem ser úteis como um potencial indicador de maturação esquelética, para auxiliar na avaliação do estado puberal.

Single probe for real-time simultaneous monitoring of neurochemistry and direct-current electrocorticography.

We report a novel single neural probe for real-time simultaneous monitoring of multiple neurochemicals and direct-current electrocorticography (DC-ECoG). A major advance of this probe is the inclusion of two iridium oxide reference electrodes to improve sensor accuracy. The ECoG reference electrode is identical to the ECoG recording electrodes to significantly improve DC stability, while the reference for electrochemical sensors has 10-fold lower polarization rate to minimize the small current-induced drift in the reference electrode potential. In vitro, the single probe selectively measured oxygen (r(2)=0.985 ± 0.01, concentration range=0-60 mmHg, limit of detection=0.4 ± 0.07 mmHg) and glucose (r(2)=0.989 ± 0.009, concentration range=0-4mM, limit of detection=31 ± 8 µM) in a linear fashion. The performance of the single probe was assessed in an in vivo needle prick model to mimic sequelae of traumatic brain injury. It successfully monitored the theoretically expected transient brain oxygen, glucose, and DC potential changes during the passage of spreading depolarization (SD) waves. We envision that the developed probe can be used to decipher the cause-effect relationships between multiple variables of brain pathophysiology with the high temporal and spatial resolutions that it provides.

Comparison of Frictional Forces Generated by a New Ceramic Bracket with the Conventional Brackets using Unconventional and Conventional Ligation System and the Self-ligating Brackets: An In Vitro Study.

BACKGROUND: Fixed orthodontic mechanotherapy is associated with friction between the bracket - wire - ligature interfaces during the sliding mechanics. A sound knowledge of the various factors affecting the magnitude of friction is of paramount importance. The present study was done to analyze and compare the frictional forces generated by a new ceramic (Clarity Advanced) bracket with the conventional, (metal and ceramic) brackets using unconventional and conventional ligation system, and the self-ligating (metal and ceramic) brackets in the dry condition. MATERIALS AND METHODS: The various bracket wire ligation combinations were tested in dry condition. The brackets used were of 0.022″ × 0.028″ nominal slot dimension of MBT prescription: Stainless steel (SS) self-ligating bracket (SLB) of (SmartClip), SS Conventional bracket (CB) (Victory series), Ceramic SLB (Clarity SL), Conventional Ceramic bracket with metal slot (Clarity Bracket), Clarity Advanced Ceramic Brackets (Clarity(™) ADVANCED, 3M Unitek). These brackets were used with two types of elastomeric ligatures: Conventional Elastomeric Ligatures (CEL) (Clear medium mini modules) and Unconventional Elastomeric Ligatures (UEL) (Clear medium slide ligatures, Leone orthodontic products). The aligning and the retraction wires were used, i.e., 0.014″ nickel titanium (NiTi) wires and 0.019″ × 0.025″ SS wires, respectively. A universal strength testing machine was used to measure the friction produced between the different bracket, archwires, and ligation combination. This was done with the use of a custom-made jig being in position. RESULTS: Mean, standard deviation, and range were computed for the frictional values obtained. Results were subjected to statistical analysis through ANOVA. The frictional resistance observed in the new Clarity Advanced bracket with a conventional elastomeric ligature was almost similar with the Clarity metal slot bracket with a conventional elastomeric ligature. When using the UEL, the Clarity Advanced bracket produced lesser friction than the conventional metal bracket; but not less than the ceramic metal slot bracket. Ceramic SLB produced lesser friction when compared with the Clarity Advanced bracket with UEL, but the metal SLB produced the least friction among all the groups and subgroups. CONCLUSION: The present study concluded that the SS SLB produced least friction among all groups. Using the archwire and ligation method, frictional forces observed in the Clarity Advanced bracket and the conventional ceramic with metal slot bracket were almost similar; but the least resistance was determined in SS CB using both the ligation (CEL and UEL) system.

Evaluation of Nickel and Chromium Ion Release During Fixed Orthodontic Treatment Using Inductively Coupled Plasma-Mass Spectrometer: An In Vivo Study.

BACKGROUND: Fixed orthodontic appliances with the use of stainless steel brackets and archwires made of nitinol have a corrosive potential in the oral environment. Nickel and chromium ions released from these appliances act as allergens apart from being cytotoxic, mutagenic and carcinogenic in smaller quantities in the range of nanograms. This study was done to evaluate the release of nickel and chromium ions from orthodontic appliances in the oral cavity using Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). MATERIALS AND METHODS: Saliva samples from 30 orthodontic patients undergoing treatment with 0.022″ MBT mechanotherapy were collected prior to commencement of treatment, after initial aligning wires and after 10-12 months of treatment. Salivary nickel and chromium ion concentration was measured in parts per billion (ppb) using ICP-MS. RESULTS: Mean, standard deviation and range were computed for the concentrations of ions obtained. Results analyzed using ANOVA indicated a statistically significant increase of 10.35 ppb in nickel ion concentration and 33.53 ppb in chromium ion concentration after initial alignment. The ionic concentration at the end of 10-12 months of treatment showed a statistically significant increase in of 17.92 ppb for chromium and a statistically insignificant decrease in nickel ion concentration by 1.58 ppb. Pearson's correlation coefficient showed a positive correlation for an increase in nickel concentration after aligning, but not at the end of 10-12 months. A positive correlation was seen for an increase in chromium ion concentration at both time intervals. CONCLUSION: Nickel and chromium ion concentration in saliva even though below the recommended daily allowance should not be ignored in light of the new knowledge regarding effects of these ions at the molecular level and the allergic potential. Careful and detailed medical history of allergy is essential. Nickel free alternatives should form an essential part of an orthodontist's inventory.

Comparison of Galvanic Currents Generated Between Different Combinations of Orthodontic Brackets and Archwires Using Potentiostat: An In Vitro Study.

BACKGROUND: Technological advances in wire selection and bracket design have led to improved treatment efficiency and allowed longer time intervals between appliance adjustments. The wires remain in the mouth for a longer duration and are subjected to electrochemical reactions, mechanical forces of mastication and generalized wear. These cause different types of corrosion. This study was done to compare the galvanic currents generated between different combinations of brackets and archwires commonly used in orthodontic practices. MATERIALS AND METHODS: The materials used for the study included different commercially available orthodontic archwires and brackets. The galvanic current generated by individual materials and different combinations of these materials was tested and compared. The orthodontic archwires used were 0.019″ × 0.025″ heat-activated nickel-titanium (3M Unitek), 0.019″ × 0.025″ beta-titanium (3M Unitek) and 0.019″ × 0.025″ stainless steel (3M Unitek). The orthodontic brackets used were 0.022″ MBT laser-cut (Victory Series, 3M Unitek) and metal-injection molded (Leone Company) maxillary central incisor brackets respectively. The ligature wire used for ligation was 0.009″ stainless steel ligature (HP Company). The galvanic current for individual archwires, brackets, and the different bracket-archwire-ligature combinations was measured by using a Potentiostat machine. The data were generated using the Linear Sweep Voltammetry and OriginPro 8.5 Graphing and Data Analysis Softwares. The study was conducted in two phases. Phase I comprised of five groups for open circuit potential (OCP) and galvanic current (I), whereas Phase II comprised of six groups for galvanic current alone. RESULTS: Mean, standard deviation and range were computed for the OCP and galvanic current (I) values obtained. Results were subjected to statistical analysis through ANOVA. In Phase I, higher mean OCP was recorded in stainless steel archwire, followed by beta-titanium archwire, heat-activated nickel titanium archwire, laser-cut bracket and metal-injection molded bracket, respectively. The difference in mean OCP recorded among the groups was found to be statistically significant in aerated phosphate buffered saline solution. The galvanic current (I) for metal-injection molded stainless steel brackets showed significantly higher values than all the other materials. Phase II results suggested that, in the couples formed by the archwire-bracket-ligature combinations, the bracket had more important contribution to the total galvanic current generated, since there were significant differences between galvanic current among the 2 brackets tested but not among the 3 wires. The galvanic current of the metal-injection molded bracket was significantly higher than that of laser-cut bracket. Highest mean current (I) was recorded in metal-injection molded bracket when used with heat-activated nickel titanium archwire while lowest mean current (I) was recorded in laser-cut bracket when used with beta-titanium archwire. CONCLUSION: The present study concluded that the bracket emerged to be the most important factor in determining the galvanic current (I). Higher mean current (I) was recorded in metal-injection molded bracket compared to laser-cut bracket. Among the three archwires, higher mean current (I) was recorded in heat-activated nickel-titanium, followed by stainless-steel and beta-titanium respectively. When coupled together; highest mean current (I) was recorded in metal-injection molded bracket when used with heat-activated nickel titanium archwire while lowest mean current (I) was recorded in laser-cut bracket when used with beta-titanium archwire.