Advances in Orthodontic Tooth Movement: Gene Therapy and Molecular Biology Aspect

Accelerated orthodontic tooth movement has been recently the topic of interest for orthodontic practitioners. Increased numbers of both clinical and research articles associated with the accelerated orthodontic treatment have been published in peer-reviewed journals in the last couple of years. Biochemical approaches such as administration of drugs, vitamins, and proteins and/or physical approaches such as surgery, vibration, and photobiomodulation have been widely reported and demonstrated the predicted outcome; however, the results are controversial. Very few reports addressed on genetic background of patients or utilization of molecular biological approach on the accelerated orthodontic treatment. In this chapter, we will discuss about biology of tooth movement and how the advances in gene therapy and molecular biology technology would shape the future of orthodontic treatment

Examination of Temperature Variability over Lahore (Pakistan) and Dhaka (Bangladesh): A Comparative Study

Lahore and Dhaka are rapid expanding and over populated cities of South Asia located in Pakistan andBangladesh respectively. The present study focuses on the evaluation of temperature variability in comparison of bothcities. This study primarily aims at the assessment and examination of temperature variations in both mega cities ofSouth Asia which are seasonal as well as the annual. The time series data were analysed by using statistical techniquesAutoregressive Moving Average Model (ARMA) and Autoregressive Integrated Average Model (ARIMA). The resultsreveal that the minimum temperature is increasing much faster than that of the maximum temperature of both cities.However, the temperature rise(in maximum and minimum) has been observed highest during the spring seasons in bothcities

Arch width changes in patients with Class II division 1 malocclusion treated with maxillary first premolar extraction and non-extraction method

Background: The aim of this study was to determine arch width changes during maxillary first premolars extraction and non-extraction treatment in patients with Class II division 1 malocclusion. Material and Methods: Dental casts of 91 Class II division 1 patients (36 males and 55 females) were evaluated. The minimum age of the subjects at the beginning of treatment was above 16 years. 48 patients were treated with extraction of the maxillary first premolars and 43 patients were treated without extraction. Pre- and post-treatment maxillary and mandibular inter-canine and inter-molar arch widths were measured. Results: At the end of treatment, maxillary and mandibular inter-canine widths of both groups increased significantly. The maxillary inter-molar width decreased in the extraction group and increased in the non-extraction group. The mandibular inter-molar width increased significantly in both groups. No significant differences were observed between males and females. Conclusions: The results of this study indicated that there was a tendency for an increase in arch width during both the extraction and non-extraction treatment except maxillary inter-molar width in the extraction cases

Shear bond strength and debonding characteristics of metal and ceramic brackets bonded with conventional acid-etch and self-etch primer systems: an in-vivo study

Background: Different in-vitro studies have reported various results regarding shear bond strength (SBS) of orthodontic brackets when SEP technique is compared to conventional system. This in-vivo study was designed to compare the effect of conventional acid-etching and self-etching primer adhesive (SEP) systems on SBS and debonding characteristics of metal and ceramic orthodontic brackets. Material and Methods: 120 intact first maxillary and mandibular premolars of 30 orthodontic patients were selected and bonded with metal and ceramic brackets using conventional acid-etch or self-etch primer system. The bonded brackets were incorporated into the wire during the study period to simulate the real orthodontic treatment condition. The teeth were extracted and debonded after 30 days. The SBS, debonding characteristics and adhesive remnant indices (ARI) were determined in all groups. Results: The mean SBS of metal brackets was 10.63±1.42 MPa in conventional and 9.38±1.53 MPa in SEP system, ( P =0.004). No statistically significant difference was noted between conventional and SEP systems in ceramic brackets. The frequency of 1, 2 and 3 ARI scores and debonding within the adhesive were the most common among all groups. No statistically significant difference was observed regarding ARI or failure mode of debonded speci mens in different brackets or bonding systems. Conclusions: The SBS of metal brackets bonded using conventional system was significantly higher than SEP system, although the SBS of SEP system was clinically acceptable. No significant difference was found between conventional and SEP systems used with ceramic brackets. Total SBS of metal brackets was significantly higher than ceramic brackets. Due to adequate SBS of SEP system in bonding the metal brackets, it can be used as an alternative for conventional system

Can galvanic skin conductance be used as an objective indicator of children?s anxiety in the dental setting?

Assessment of procedural distress is essential at assisting children during invasive dental treatments. This study aimed to determine the validity and reliability of galvanic skin response as a measure for assessment of dental anxiety in children. 151 children, aged 5-7 years, participated in this study. Similar dental treatments were rendered to all subjects. At the beginning and end of the session, modified child dental anxiety scale (MCDAS), clinical anxiety rating scale (CARS) and galvanic skin response (GSR) were used to determine children?s anxiety. GSR was significantly correlated with both MCDAS (rs=0.62, p=0.02) and CARS (rs=0.44, p=0.032). The correlation between MCDAS and CARS was also significant (rs = 0.9, P<0.001). Anxiety decreased during the session in both GSR (rs=0.52, p=0.001) and MCDAS scales (rs=0.77, p=0.001). CARS also showed a reduction between the initial and second assessment, but it was not statistically significant (rs=0.12, P=0.36). The findings suggest that GSR is a reliable and valid measure for assessment of children?s dental anxiety in the clinical context. GSR may help to identify clinically anxious children before dental treatment to provide appropriate interventions

The preliminary study of urbanization, fossil fuels consumptions and CO2 emission in Karachi

According to population, Karachi is the first largest city of Pakistan and 9th largest in the world. During last three decades, it has faced mass urbanization, huge population growth, many fold increase in vehicles and industrial development. As a result the demand of more energy in form of fossil fuels increased for domestic, industrial and transportation purpose. In this research the maximum available data of Karachi about urbanization, population and vehicles growth, industrialization, energy consumption and CO2 emissions are analyzed. Time periods considered for this work are according to the availability of the data. The results show that during 1947 to 2008, both urban population and urban area increased to 1500%. During 1990 to 2008, the percentage growth in vehicles is double than that of population growth during this time period. During 1980 to 2007 the consumption of oil and petrol, natural gas and coal increased to 219%, 365% and 287%, respectively. The emission of CO2 jumped from 39 million metric tons in 1980 to 151 million metric tons in 2007

Comparison of the effect of pharmacotherapy and neuro-feedback therapy on oral health of children with attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is a chronic and progressive mental disorder related to the childhood period. This study aims to compare the oral health of two groups of ADHD children: those under pharmacotherapy and those under neuro-feedback therapy. 72 ADHD children (aged 6?12) were divided into two 36 member groups: The pharmacotherapy group and the neuro-feedback therapy group. Unstimulated salivary flow (USF), DMFT, and plaque index were assessed in these children. Statistical analysis was carried out on the data with the independent t-test, which was performed using SPSS 16. The significance level of the study was p<0.05. In this study, the USF of ADHD children who used Ritalin was found to be significantly less than that of the neuro-feedback group (1.25 ± 1.21 vs. 1.91 ± 1.16 ml/min; p=0.002). Also, the plaque index (5.9 ± 3.1 vs. 3.94 ± 1.9; p=0.018) and DMFT scores (39% ± 9% vs. 31% ± 9%; p=0.018) were significantly higher for the pharmacotherapy group. Neuro-feedback therapy is preferable to Ritalin treatment for ADHD children in terms of their oral health status

The Effect of Different Mixing Methods on the Properties of Calcium-enriched Mixture Cement: A Systematic Review of in Vitro Studies

Introduction: It has been shown that the mechanical and physical properties of Calcium Enriched Mixture (CEM) cement are influenced by the mixing methods. Despite several studies conducted on different mixing methods of CEM cement, there is no systematic review to summarize the results. This systematic review was conducted to investigate the effect of different mixing techniques on mechanical and physical characteristics of CEM cement. Methods and Materials: A professional librarian with skills in informatics conducted a systematic search by searching electronic databases PubMed/MEDLINE and Scopus and Ovid for English language peer-reviewed articles published between 1992 and April 2019. Results: Initial searches from all sources identified 1175 references. Two of the authors examined the titles, abstracts of these articles and the full reports of 20 studies were obtained, and data extraction was performed. Seven studies satisfied the eligibility criteria for the review. The effect of different mixing methods was investigated on bacterial microleakage, push-out bond strength, flow rate, compressive strength, solubility, pH, film thickness, dimensional changes, working time, setting time and quality of the apical plug. Conclusion: Based on the results of this systematic review, some of the important properties of CEM cement were affected by different mixing methods. Although none of these mixing methods could improve all the properties, mechanical and manual methods were more effective compared to ultrasonic method.  Keywords: Calcium-enriched Mixture Cement; Systematic Review; Ultrasoni

Zeolite-silver-zinc nanoparticles : biocompatibility and their effect on the compressive strength of mineral trioxide aggregate

This study was carried out to evaluate the biocompatibility of zeolite-silver-zinc (Ze-Ag-Zn) nanoparticles and their effect on the compressive strength of Mineral Trioxide Aggregate (MTA). Biocompatibility was evaluated by an MTT assay on the pulmonary adenocarcinoma cells with 0.05, 0.1, 0.25, 0.5, 1 and 5 mg/mL concentrations of Ze-Ag-Zn. For compressive strength test, four groups containing 15 stainless-steel cylinders with an internal diameter of 4 and a height of 6 mm were prepared and MTA (groups 1 and 2) or MTA + 2% Ze-Ag-Zn (groups 3 and 4) were placed in the cylinders. The compressive strength was evaluated using a universal testing machine 4 days after mixing in groups 1 and 3, and 21 days after mixing in groups 2 and 4. There was no significant difference between cytotoxicity of different concentrations. The highest (52.22±18.92 MPa) and lowest (19.57±5.76 MPa) compressive strength were observed in MTA group after 21 days and in MTA + 2% Ze-Ag-Zn group after four days, respectively. The effect of time and 2% Ze-Ag-Zn on the compressive strength were significant (P<0.05). Mixing MTA with Ze-Ag-Zn significantly reduced and passage of time from day four to 21 significantly increased the compressive strength. Mixing MTA with 2% Ze-Ag-Zn had an adverse effect on the compressive strength of MTA, but this combination had no cytotoxic effects

Effect of the TiO2 nanoparticles on the selected physical properties of mineral trioxide aggregate

Some of the efforts to improve the properties of Mineral Trioxide Aggregate (MTA) include incorporation of some nanoparticles such as Titanium dioxide (TiO2). The aim of this study was to evaluate the effect of TiO2 nanoparticles on the setting time, working time, push-out bond strength and compressive strength of MTA. The physical properties to be evaluated were determined using the ISO 6786:2001 and 9917 specifications. Fifteen samples of each material (MTA or MTA with 1% weight ratio of TiO2 Nanoparticles) were prepared for any evaluated physical property. Data were analyzed using descriptive statistics and T-test. Statistical significance was set at P<0.05. There was the significant effect of the material type (presence and absence of TiO2 nanoparticles) on the push-out bond strength, compressive strength, working time and setting time, with significantly higher values achieved in the group with TiO2 nanoparticles than the group without these particles (P=0.01 for the setting time and compressive strength, P=0.03 for the working time and P=0.001 for the bond strength). Based on the findings of this in vitro study, incorporation of the TiO2 nanoparticles with weight ratio of 1% increased the setting time, working time, compressive strength and push out bond strength of MTA