Effect of placement angle, diameter, length and bone density on the pull-out strength of orthodontic mini-implants: An in vitro study.

OBJECTIVE: To evaluate the effect of the placement angle, diameter, length and bone density on the mechanical stability of orthodontic mini-implants by measuring their pull-out strengths. DESIGN: A total of 120 mini-implants of four different dimensions made from titanium were used. They measured 1.3 × 6.0mm, 1.3 × 8.0 mm, 1.5 × 6.0 mm and 1.5 × 8.0 mm. Synthetic polyurethane bone blocks (Saw Bones, USA) in two different densities were used. SETTING: Each size of mini-implant was inserted equidistantly into synthetic bone blocks of two different densities, in three different insertion angles of 30°, 60° and 90°. This resulted in 24 test groups with five mini-implants allocated to each group. METHODS: The pull-out strength was measured using an Instron Universal Testing Machine exerting a vertical force parallel to the long axis of the mini-implant until removal or failure occurred. Peak load at failure of the mini-implant was recorded in kN. RESULTS: Showed that mini-implants placed at an insertion angle of 30° offered least resistance to pull-out. Mini-implants 6.0 mm in length showed less pull-out strength compared to the longer 8.0-mm mini-implants. Mini-implants 1.3 mm in diameter provided similar pull-out values as 1.5-mm mini-implants. Bone densities of 0.20 g/cc and 0.32 g/cc did not affect the pull-out strength of mini-implants. CONCLUSION: From the study, it was concluded that a logical choice of mini-implant dimension and prudent use of placement technique can help achieve the treatment goals with a reduced hazard of mini-implant failure.

Association of DFNA5, SYK, and NELL1 variants along with HPV infection in oral cancer among the prolonged tobacco-chewers.

Southeast Asia, especially India, is well known for the highest use of smokeless tobacco. These products are known to induce oral squamous cell carcinoma. However, not all long-term tobacco-chewers develop oral squamous cell carcinoma. In addition, germline variants play a crucial role in susceptibility, prognosis, development, and progression of the disease. These prompted us to study the genetic susceptibility to oral squamous cell carcinoma among the long-term tobacco-chewers. Here, we presented a retrospective study on prolonged tobacco-chewers of Northeast India to identify the potential protective or risk-associated germline variants in tobacco-related oral squamous cell carcinoma along with HPV infection. Targeted re-sequencing (n = 60) of 170 genetic regions from 75 genes was carried out in Ion-PGM™ and validation (n = 116) of the observed variants was done using Sequenom iPLEX MassARRAY™ platform followed by polymerase chain reaction-based HPV genotyping and p16-immunohistochemistry study. Subsequently, estimation of population structure, different statistical and in silico approaches were undertaken. We identified one nonsense-mediated mRNA decay transcript variant in the DFNA5 region (rs2237306), associated with Benzo(a)pyrene, as a protective factor (odds ratio = 0.33; p = 0.009) and four harmful (odds ratio > 2.5; p < 0.05) intronic variants, rs182361, rs290974, and rs169724 in SYK and rs1670661 in NELL1 region, involved in genetic susceptibility to tobacco- and HPV-mediated oral oncogenesis. Among the oral squamous cell carcinoma patients, 12.6% (11/87) were HPV positive, out of which 45.5% (5/11) were HPV16-infected, 27.3% (3/11) were HPV18-infected, and 27.3% (3/11) had an infection of both subtypes. Multifactor dimensionality reduction analysis showed that the interactions among HPV and NELL1 variant rs1670661 with age and gender augmented the risk of both non-tobacco- and tobacco-related oral squamous cell carcinoma, respectively. These suggest that HPV infection may be one of the important risk factors for oral squamous cell carcinoma in this population. Finally, we newly report a DFNA5 variant probably conferring protection via nonsense-mediated mRNA decay pathway against tobacco-related oral squamous cell carcinoma. Thus, the analytical approach used here can be useful in predicting the population-specific significant variants associated with oral squamous cell carcinoma in any heterogeneous population.

Lifelong vegetarianism and breast cancer risk: a large multicentre case control study in India.

BACKGROUND: The lower incidence of breast cancer in Asian populations where the intake of animal products is lower than that of Western populations has led some to suggest that a vegetarian diet might reduce breast cancer risk. METHODS: Between 2011 and 2014 we conducted a multicentre hospital based case-control study in eight cancer centres in India. Eligible cases were women aged 30-70 years, with newly diagnosed invasive breast cancer (ICD10 C50). Controls were frequency matched to the cases by age and region of residence and chosen from the accompanying attendants of the patients with cancer or those patients in the general hospital without cancer. Information about dietary, lifestyle, reproductive and socio-demographic factors were collected using an interviewer administered structured questionnaire. Multivariate logistic regression models were used to estimate the odds ratio (OR) and 95% confidence intervals for the risk of breast cancer in relation to lifelong vegetarianism, adjusting for known risk factors for the disease. RESULTS: The study included 2101 cases and 2255 controls. The mean age at recruitment was similar in cases (49.7 years (SE 9.7)) and controls (49.8 years (SE 9.1)). About a quarter of the population were lifelong vegetarians and the rates varied significantly by region. On multivariate analysis, with adjustment for known risk factors for the disease, the risk of breast cancer was not decreased in lifelong vegetarians (OR 1.09 (95% CI 0.93-1.29)). CONCLUSIONS: Lifelong exposure to a vegetarian diet appears to have little, if any effect on the risk of breast cancer.

'Plain lignocaine' vs 'Lignocaine with vasoconstrictor'-Comparative evaluation of pain during administration and post-extraction wound healing by a double blinded randomized controlled clinical trial.

OBJECTIVES: The aim of this double blinded randomized controlled clinical trial was to evaluate the efficacy of two local anaesthetic solutions, 'Plain lignocaine' and 'Lignocaine with vasoconstrictor', on pain during administration and post-extraction wound healing in patients undergoing therapeutic extractions. MATERIALS AND METHODS: Fifty patients indicated for therapeutic extraction of upper and lower premolars for orthodontic purpose were recruited for the study. Using a split-mouth study design, anaesthesia was achieved using lignocaine with adrenaline on the control side and plain lignocaine on the study side. Pain perception was measured by modified visual analogue scale and wound healing was assessed by Landry's Wound Healing Index. Sample allocation was done by simple randomization. The outcome parameters compared were (1) pain during administration of LA and (2) post-operative healing after extraction. Data analysis involved Chi-square test to compare proportions between treatment groups and independent sample t-test to compare mean values between treatment groups. SPSS version 22.0 was used to analyse the data. RESULTS: The study group demonstrated a statistically significant wound healing on day1 and day 3 between the study and control group with p < 0.001. In the control group 68% had severe pain, whereas only 2% had severe pain in the study group. The proportions between the two groups were statistically significant (p < 0.001). CONCLUSION: The patients who received Plain Lignocaine perceived less pain during injection of local anaesthetic solution when compared to patients who received lignocaine with vasoconstrictor. The early post-operative wound healing was better in patients anaesthetized by Plain Lignocaine.

Epigenetic pathogenesis of human papillomavirus in upper aerodigestive tract cancers.

Human papillomavirus (HPV) has been recently associated with squamous cell carcinoma of upper aerodigestive tract (SCC of UADT), but its possible role in promoting aberrant methylation in these tumors has largely remained unexplored. Herein, we investigated the association of HPV with aberrant methylation in tumor-related genes/loci consisting of the classical CpG Island Methylator Phenotype (CIMP) panel markers (p16, MLH1, MINT1, MINT2, and MINT31) and other frequently methylated cancer-related genes (DAPK1, GSTP1, BRCA1, ECAD, and RASSF1) and survival of UDAT cancers. The study includes 219 SCC of UADT patients from different hospitals of Northeast India. Detection of HPV and aberrant promoter methylation was performed by PCR and Methylation Specific PCR respectively. Association study was conducted by Logistic regression analysis and overall survival analysis was done by Kaplan-Meier plot. HPV was detected in 37% of cases, with HPV-18 as the major high-risk sub-type. Although HPV presence did not seem to affect survival in overall UADT cancers, but was associated with a favourable prognosis in head and neck squamous cell carcinoma. Hierarchical clustering revealed three distinct clusters with different methylation profile and HPV presence. Among these, the CIMP-high subgroup exhibited the highest HPV positive cases (66%). Furthermore, multivariate analysis revealed a strong synergistic association of HPV and tobacco towards modulating promoter hypermethylation in UADT cancer (OR = 27.50 [95% CI = 11.51-88.03] for CIMP-high vs. CIMP-low). The present study proposes a potential role of HPV in impelling aberrant methylation in specific tumor related loci, which might contribute in the initiation and progression of SCC of UADT.

Evaluation of Antibacterial Effect of Hybrid Nano-coating of Stainless Steel Orthodontic Brackets on Streptococcus Mutans - An In vitro Study.

Nano-coating of orthodontic brackets with a combination or hybrid of metals and metal oxides may reduce the streptococcus mutans count and incidence of enamel decalcification seen around brackets in patients undergoing fixed orthodontic treatment. In total, 255 orthodontic brackets (3M Unitek, Monrovia, California, USA) were divided into one control group (group I) of 60 and three experimental groups of 65 each (groups II, III, and IV). The experimental group brackets were coated with a combination of silver-zinc oxide, copper oxide -zinc oxide, and silver-copper oxide nanoparticles using physical vapour deposition method. The two nanoparticles used for each group were mixed in the ratio of 1:1 by weight for providing a uniform hybrid coating. Sixty brackets from each group were used for microbiological evaluation of antibacterial activity against Streptococcus mutans in blood agar medium, and the remaining five brackets from each experimental group were used for SEM analysis to check the uniformity of the coating. Nano-coated brackets demonstrated better antibacterial properties than uncoated brackets. Copper oxide-zinc oxide nanoparticles coated brackets demonstrated better antibacterial properties than the silver-zinc oxide and silver- copper oxide coated brackets.

Two by Two Factorial Design using Metformin and Curcumin for Second Primary Head and Neck Cancer Prevention Trial.

OBJECTIVE: The 2x2 factorial design is an effective method that allows for multiple comparisons, especially in the context of interactions between different interventions, without substantially increasing the required sample size. In view of the considerable preclinical evidence for Curcumin and Metformin in preventing the development and progression of head and neck squamous cell carcinoma (HNSCC), this study describes the protocol of the clinical trial towards applying the drug combination in prevention of second primary tumors. METHODS: We have applied the trial design to a large phase IIB/III double-blind, multi-centric, placebo-controlled, randomized clinical trial to determine the safety and efficacy of Metformin and Curcumin in the prevention of second primary tumours (SPT) of the aerodigestive tract following treatment of HNSCC (n=1,500) [Clinical Registry of India, CTRI/2018/03/012274]. Patients recruited in this trial will receive Metformin (with placebo), Curcumin (with placebo), Metformin, and Curcumin or placebo alone for a period of 36 months. The primary endpoint of this trial is the development of SPT, while the secondary endpoints are toxicities associated with the agents, incidence of recurrence, and identifying potential biomarkers. In this article, we discuss the 2x2 factorial design and how it applies to the head and neck cancer chemoprevention trial. CONCLUSION: 2x2 factorial design is an effective trial design for chemoprevention clinical trials where the effectiveness of multiple interventions needs to be tested parallelly.

Evaluation and comparison of planum clival angle in three malocclusion groups : A CBCT study.

PURPOSE: Cranial base flexure is an overlooked topic in craniofacial research. The aim of this retrospective observational study was to compare a new parameter, the planum clival angle (PCA), which represents cranial base flexure, in skeletal class I, II, and III malocclusions using cone beam computed tomographic images (CBCT) and correlate PCA with the stages of the fusion of the spheno-occipital synchondrosis (SOS). MATERIALS AND METHODS: A total of 125 CBCTs were divided into two groups based on chronological age (19-25 years and 12-18 years). The CBCT images from 57 subjects (19-25 years old) were categorized into three groups based on their skeletal malocclusion for measuring PCA and cranial base angles (CBA). In the second group, comprising 68 CBCT data sets of individuals in the age group of 12-18 years, the PCA angle was correlated with stages of fusion of the SOS. Data were statistically analyzed using independent samples t test, one-way analysis of variance (ANOVA, intergroup), Pearson correlation, and χ2 test. RESULTS: There was a statistically significant linear correlation (P < 0.001) between the two parameters PCA and CBA but no significant difference was found in PCAs between the three groups. One-way ANOVA to compare the PCA values in the three stages of fusion of the SOS revealed a highly significant relationship in male subjects (p < 0.001), thereby, suggesting that as fusion progresses, the planum clival angle increases. The χ2 test to compare the planum clival angle in males and females revealed that SOS fusion occurred earlier in females. CONCLUSION: There is a constant dynamic change in the value of the parameter PCA that progresses until completion of SOS fusion. The SOS fuses earlier in females. Assessment of the stage of fusion of the SOS can be used in deciding whether growth modification of the craniofacial complex is still possible during orthodontic therapy.

The Effects of Eucalyptus Oil, Glutathione, and Lemon Essential Oil on the Debonding Force, Adhesive Remnant Index, and Enamel Surface During Debonding of Ceramic Brackets.

Objective: The present study aimed to find a chemical reagent that would reduce the debonding force to enable easier debonding of the ceramic brackets, thus reducing enamel damage as well as chair side time. Methods: The study included 4 groups -control (distilled water), eucalyptus oil, glutathione and lemon essential oil for immersing teeth bonded with ceramic brackets. Samples (25 in each group), extracted first premolars, were mounted and immersed in their respective solution for a duration of 10 minutes following which they were tested to evaluate the debonding force using the INSTRON universal testing machine. The amount of adhesive left behind on the enamel surface was evaluated using adhesive remnant index (ARI) score and surface changes were checked using a scanning electron microscope. Results: Teeth immersed in glutathione showed the greatest amount of reduction in debonding force (p=0.001) compared with other groups. ARI scores were low for specimens immersed in glutathione. SEM images showed that teeth in the glutathione group had a cleaner enamel surface, suggesting less or no adhesive was left behind and no sign of enamel damage after debonding ceramic brackets. Conclusion: Specimens that were immersed in glutathione for a duration of 10 minutes before debonding of ceramic brackets showed the greatest reduction in debonding force compared with control and demonstrated peel off effect with no enamel damage. Glutathione can be used as an effective reagent during the clinical debonding of ceramic brackets.

Effect of Ethyl Alcohol Wet Bonding on Shear Bond Strength in Orthodontic Brackets - An In vitro Study.

Aim: To evaluate the effect of ethyl alcohol wet bonding on the shear bond strength of orthodontic brackets. Materials and Methods: 90 premolar teeth were collected and divided into 6 groups - conventional dry, conventional wet, MIP dry, MIP wet, ethanol dry, and ethanol wet. The teeth were bonded as per the requirements for each group. The teeth were then immersed in water to ensure complete polymerization. Shear bond strength was evaluated using a UTM machine and the ARI scores were also noted. Statistical analysis was done for the SBS and ARI scores obtained. Results: The highest SBS was obtained with conventional dry and the least SBS was obtained with conventional wet groups. The SBS of ethanol wet bonding was significantly less than that of the MIP wet group but was significantly more than the conventional wet group. ARI scores also suggested that there is more cohesive failure than adhesive failure in the wet MIP and ethanol groups. Conclusion: The mean SBS (6.5 MPa) was within the optimal bond strength as per the study by Reynolds et al. (1976). Ethanol can be used as a cheaper alternative to MIP.

Streptococcus mutans levels in patients who received orthodontic brackets bonded using probiotic impregnated resin composite - a randomized clinical trial.

To evaluate the effect of impregnating an orthodontic resin composite with probiotic bacteria (Lactobacillus rhamnosus GG) on the levels of Streptococcus mutans (S. mutans) in patients undergoing orthodontic treatment. Thirty patients were randomly selected and allotted by block randomization to two groups: an experimental group, who received brackets bonded with probiotic impregnated resin composite and a control group, who received brackets bonded with conventional light cure resin composite. Plaque samples were collected before (ET0 and CT0) and two months (ET1 and CT1) after bonding. Levels of S. mutans were assessed using the colony count method. Two months after bonding of the brackets, the S. mutans levels had decreased with statistical significance in the experimental group (p = 0.001), but not in the control group (p = 0.137). Impregnation of resin composite with probiotic bacteria for the purpose of preventing formation of white spot lesions on enamel holds promise. Long-term evaluation would be necessary to provide confirmatory results.

Survival rate and stability of surface-treated and non-surface-treated orthodontic mini-implants: a randomized clinical trial.

OBJECTIVES: This clinical trial was conducted to evaluate the stability and failure rate of surface-treated orthodontic mini-implants and determine whether they differ from those of non-surface-treated orthodontic mini-implants. TRIAL DESIGN: Randomized clinical trial with a split-mouth study design. SETTING: Department of Orthodontics, SRM Dental College, Chennai. PARTICIPANTS: Patients who required orthodontic mini-implants for anterior retraction in both arches. METHODS: Self-drilling, tapered, titanium orthodontic mini-implants with and without surface treatment were placed in each patient following a split-mouth design. The maximum insertion and removal torques were measured for each implant using a digital torque driver. The failure rates were calculated for each type of mini-implant. RESULTS: The mean maximum insertion torque was 17.9 ± 5.6 Ncm for surface-treated mini-implants and 16.4 ± 9.0 Ncm for non-surface-treated mini-implants. The mean maximum removal torque was 8.1 ± 2.9 Ncm for surface-treated mini-implants and 3.3 ± 1.9 Ncm for non-surface-treated mini-implants. Among the failed implants, 71.4% were non-surface-treated mini-implants and 28.6% were surface-treated mini-implants. CONCLUSION: The insertion torque and failure rate did not differ significantly between the groups, whereas the removal torque was significantly higher in the surface-treated group. Thus, surface treatment using sandblasting and acid etching may improve the secondary stability of self-drilling orthodontic mini-implants. TRIAL REGISTRATION: The trial was registered in the Clinical Trials Registry, India (ICMR NIMS). Registration number: CTRI/2019/10/021718.

Evaluation of the Difference in the Rate of Canine Retraction Assisted by Piezocision and Discission in Human Subjects: A Preliminary Parallel-Arm Prospective Clinical Study.

Objective: The objective of the study was to evaluate the rate of orthodontic tooth movement assisted by piezocision and discission in extraction cases. Methods: Twelve adults (20-35 years) requiring upper premolar extraction for orthodontic treatment were included in this preliminary parallel-arm clinical study. Participants (randomly allocated) in Groups A and B received piezocision and discision-assisted corticotomy cuts at the premolar extraction site, respectively, contralateral side served as the control. Canine retraction was started bilaterally using closed coil NiTi (Nickel titanium) springs. A schedule of fortnightly activation was followed for 3 months. Stage models were made monthly (M0, M1, M2, M3). Models were scanned using a 3-shape intraoral scanner, and the displacement of the canine was measured bilaterally in the stage models. A self-designed questionnaire was used to assess patients pain and satisfaction levels on a visual analogue scale. Results: The rate of canine retraction at the piezocision site was twice that at the control site in group A (p=0.007). The rate of canine retraction at the dissection site was twice that at the control site in group B (p=0.012). However, there was no significant difference in the rate of retraction between the two surgical techniques. Pain and disturbance were noticed in the discission group at 50 and 67% respectively. Conclusion: Discision is comparable to piezocision for accelerating orthodontic tooth movement. Although dissection can speed orthodontic treatment, it should be used with caution as it could pose technical and clinical difficulties, particularly in the posterior buccal region of the oral cavity.

Reproducibility of linear and angular cephalometric measurements obtained by an artificial-intelligence assisted software (WebCeph) in comparison with digital software (AutoCEPH) and manual tracing method.

INTRODUCTION: It has been suggested that human errors during manual tracing of linear/angular cephalometric parameters can be eliminated by using computer-aided analysis. The landmarks, however, are located manually and the computer system completes the analysis. With the advent of Artificial Intelligence in the field of Dentistry, automatic location of the landmarks has become a promising tool in digital Orthodontics. METHODS: Fifty pretreatment lateral cephalograms obtained from the Orthodontic department of SRM dental college (India) were used. Analysis were done by the same investigator using the following methods: WebCeph™, AutoCEPH© for Windows or manual tracing. Landmark identification was carried out automatically by Artificial Intelligence in WebCeph™ and with a mouse driven cursor in AutoCEPH©, and manually using acetate sheet and 0.3-mm pencil, ruler and a protractor. The mean differences of the cephalometric parameters obtained between the three methods were calculated using ANOVA with statistical significance set at p<0.05. Intraclass correlation coefficient (ICC) was used to determine both reproducibility and agreement between linear and angular measurements obtained from the three methods and intrarater reliability of repeated measurements. ICC value of >0.75 indicated good agreement. RESULTS: Intraclass correlation coefficient between the three groups was >0.830, showing good level of agreement, and the value within each group was >0.950, indicating high intrarater reliability. CONCLUSION: Artificial Intelligence assisted software showed good agreement with AutoCEPH© and manual tracing for all the cephalometric measurements.

Co-Creation of Breast Cancer Risk Communication Tools and an Assessment of Risk Factor Awareness: A Qualitative Study of Patients and the Public in India.

BACKGROUND: Low awareness of BC and its associated risk factors causes delays in diagnosis and impacts survival. It is critical to communicate BC risk to patients in a format that they are easily able to understand. Our study aim was to develop easy-to-follow transmedia prototypes to communicate BC risk and evaluate user preferences, alongside exploring awareness of BC and its risk factors. METHODS: Prototypes of transmedia tools for risk communication were developed with multidisciplinary input. A qualitative in-depth online interview study was undertaken using a pre-defined topic guide of BC patients (7), their relatives (6), the general public (6), and health professionals (6). Interviews were analyzed using a thematic approach. FINDINGS: Most participants preferred pictographic representations (frequency format) of lifetime risk and risk factors and storytelling using short animations and comic strips (infographics) for communicating genetic risk and testing: "In a short time, they explained it very well, and I liked it". Suggestions included minimizing technical terminology, decreasing the delivery speed, "two-way dialogue", and using local "language for different locations". There was low awareness of BC, with some understanding of age and hereditary risk factors but limited knowledge of reproductive factors. INTERPRETATION: Our findings support use of multiple context-specific multimedia tools in communicating cancer risk in an easy-to-understand way. The preference for storytelling using animations and infographics is a novel finding and should be more widely explored.

National Cancer Grid Virtual Tumor Boards of Head and Neck Cancers: An Innovative Approach to Multidisciplinary Care.

PURPOSE: Virtual tumor board (VTB) via videoconference facility involving multiple specialists in the decision making for various tumors is well accepted, especially in high-income countries. Information on virtual tumor boards for head and neck cancers especially from low- and middle-income countries is sparse. In this study, we have audited the findings of the National Cancer Grid VTBs performed for head and neck cancers. METHODS: All patients discussed in the head and neck VTBs at our center between December 2016 and February 2022 were included in the study. Details such as the type of institute sending patients for discussion, its location, subsites within the head and neck region, histopathology, treatment setting or question for the VTB, and availability of guidelines for such patient scenarios were assessed. Also, a survey was sent to assess the usefulness of the VTBs. RESULTS: A total of 208 patients were discussed in 54 VTB sessions. The most common head and neck sites discussed in the VTBs were the oral cavity (n = 64, 30.7%) followed by skull base/nose and paranasal sinuses/eyelid-orbit tumors (n = 49, 23.5%). Nonsquamous cell carcinoma was the most common histopathology discussed; recurrent cancers/residual diseases were the most common treatment settings (n = 134, 64.4%) for which there were no existing guidelines. Survey results showed that most VTB decisions were implementable, and respondents felt that VTBs were a useful educational tool as well. CONCLUSION: Our study affirms the feasibility of VTBs in low- and middle-income countries' health care systems for managing uncommon malignancies and clinical situations, which act as an important educational platform.

Evaluation and comparison of stresses and displacements generated by four different types of asymmetric maxillary expansion appliances in true unilateral crossbite using finite element method.

INTRODUCTION: True unilateral posterior crossbite can be efficiently treated by using asymmetric expansion appliances that essentially exert unilateral expansion forces thereby minimizing iatrogenic overexpansion of the normal pretreatment side. AIM: To evaluate and compare the stresses and displacements generated by four different types of asymmetric maxillary expansion appliances in true unilateral crossbite using the finite element method. MATERIALS AND METHODS: A CBCT image of the skull was obtained from a 12-year-old female patient with a true unilateral posterior crossbite on the right side, for the FEM study. Asymmetrically split acrylic plate with jackscrew (ASAPJ), NORD crossbite expander, Asymmetric Maxillary Expansion appliance (AMEX), Asymmetrical Rapid Maxillary Expansion (ARME) appliances were simulated with a given force specific to the appliance. Von Mises stresses, displacements in the x, y, z-axis, and changes in the axial inclination were evaluated and compared on the selected skeletal and dental landmarks. RESULTS: Overall ARME seemed to generate the highest asymmetric von Misses stress on skeletal landmarks followed by NORD; ASAPJ and lowest by the AMEX. ARME also produced the highest asymmetric expansion followed by AMEX; NORD and lowest with the ASAPJ. NORD produced the minimum extrusion and buccal tipping of the canine and 1st molar followed by ASAPJ; AMEX and maximum by the ARME. CONCLUSION: Each of the four appliances expanded the maxillary arch more on the crossbite side as compared to the non-crossbite side, but the pattern of stress distribution, displacement and change in the axial inclination were unique for each appliance.

Barriers and facilitators in implementing population based common cancer screening through community health workers.

Population based cancer screening was initiated in India in 2016 owing to an increased burden of cancers. A feasibility health system study was done by utilising community health workers (CHWs) to conduct the cancer screening. The current study is a qualitative study to elicit the barriers and facilitators in implementing population based cancer screening through CHWs. The study was conducted at three subcentres of Dholai block of Cachar district, Assam, India and Cachar Cancer Hospital and Research Center, Silchar. The participants of the study were CHWs, master trainer nurses and women from community. Three focus group discussions (FGDs) and one in-depth interview (IDI) were conducted at the provider level and seven IDIs of women from the community. The FGDs and IDIs were audio recorded after taking verbal consent from the participants. The verbatims were prepared following translation and transcription and data analysis using ATLAS ti ver 8. The major barrier faced by the community was a lack of motivation to get screened which stemmed from various factors such as personal beliefs, attitudes and fear. The major facilitators were accessibility of tests, family support and CHWs as screening service providers. The major barriers for CHWs were difficulty in motivating the community, lack of support from supervisors and lack of motivation to work. The major facilitators were convenience of screening during home visits, empowerment, skill enhancement and teamwork. Population based cancer screening was a new concept for the community under study. Cancer screening by CHWs was well accepted by the community. Awareness generation among the community was a major factor in improving screening coverage. The study highlights that training and motivation of CHWs can improve the uptake of cancer screening services. CHWs felt empowered with the new skills imparted and were able to carry out screening.

Brachytherapy Localization Radiographs with Conventional Diagnostic X-Ray Machine.

With conventional diagnostic X-ray machines with over couch X-ray tubes, it is not possible to obtain anteroposterior (AP) and lateral (Lat) radiographs without changing the posture of the patients. In an old 300 mA X-ray machine with a fluoroscopy screen (12.4 kg) (1995 model), by substituting the screen with suitable counterweight and making provision to take the hoist pillar up to the edge of the wall, we could get isocentric setup for a hospital stretcher kept near the chest stand. This setup provided acceptable AP-Lat radiographs for brachytherapy localization using "Perspex jig" (Nucletron, Netherlands) and field check radiographs in head and neck, esophagus patients for treatment planning.