Comparative evaluation of displacement and stress distribution pattern during mandibular arch distalization with extra and inter-radicular mini-implants: a three-dimensional finite element study

ABSTRACT Objective: To compare the initial stress distribution and displacement on mandibular dentition using extra and inter-radicular mini-implants for arch distalization, by means of finite element analysis. Methods: For this study, two finite element models of the mandible were designed. The models consisted of periodontal ligament (PDL) and alveolar bone of all teeth until second molars. In the Case 1, bilateral extra-radicular buccal-shelf stainless steel mini-implants (10.0-mm length; 2.0-mm diameter) were placed between first and second permanent molars. In the Case 2, bilateral inter-radicular stainless steel mini-implants (10.0-mm length; 1.5-mm diameter) were placed between second premolar and first permanent molar. Power hook was attached between canine and first premolar at a fixed height of 8mm. In the two cases, 200g of distalization force was applied. ANSYS v. 12.1 software was used to analyze and compare von Mises stress and displacement in the mandibular dentition, PDL and bone. Results: Higher stresses were observed in mandibular dentition with the inter-radicular implant system. The amount of von Mises stress was higher for cortical bone (85.66MPa) and cancellous bone (3.64MPa) in Case 2, in comparison to cortical bone (41.93MPa) and cancellous bone (3.43MPa) in Case 1. The amount of arch distalization was higher for mandible in Case 1 (0.028mm), in comparison to Case 2 (0.026mm). Conclusion: Both systems were clinically safe, but extra-radicular implants showed more effective and controlled distalization pattern, in comparison to inter-radicular implants, in Class III malocclusion treatment.

RESUMO Objetivo: Comparar a distribuição da tensão inicial e o deslocamento na dentição inferior usando mini-implantes extra e inter-radiculares para distalização da arcada, por meio da análise de elementos finitos. Métodos: Dois modelos de elementos finitos da mandíbula foram criados, os quais consistiram de ligamento periodontal (PDL) e osso alveolar de todos os dentes até os segundos molares. No Caso 1, mini-implantes extra-radiculares de aço inoxidável (10,0 mm de comprimento; 2,0 mm de diâmetro) foram colocados bilateralmente na buccal-shelf entre o primeiro e o segundo molares permanentes. No Caso 2, mini-implantes de aço inoxidável inter-radiculares (comprimento de 10,0 mm; diâmetro de 1,5 mm) foram colocados bilateralmente entre o segundo pré-molar e o primeiro molar permanentes. Um Power hook foi preso entre o canino e o primeiro pré-molar a uma altura fixa de 8mm. Nos dois casos, foi aplicada força de distalização de 200g. O software ANSYS v. 12.1 foi usado para analisar e comparar a tensão de von Mises e o deslocamento na dentição inferior, ligamento periodontal e osso. Resultados: Maiores tensões foram observadas na dentição inferior com o sistema de implantes inter-radiculares. A quantidade de tensões de von Mises foi maior para osso cortical (85,66MPa) e osso esponjoso (3,64MPa) no Caso 2, em comparação com osso cortical (41,93MPa) e osso esponjoso (3,43MPa) no Caso 1. A quantidade de distalização da arcada inferior foi maior no Caso 1 (0,028 mm), em comparação com o Caso 2 (0,026 mm). Conclusão: Ambos os sistemas foram clinicamente seguros, mas os implantes extra-radiculares mostraram um padrão de distalização mais eficaz e controlado, em comparação com os implantes inter-radiculares, para tratamento da má oclusão de Classe III.

A Prospective Comparative Study: Stapler Hemorrhoidopexy vs Laser Hemorrhoidoplasty in the Treatment of Hemorrhoids

Aims:Stapler hemorrhoidopexy (SH) has evolved over time as a procedure of choice over conventional surgery due to less postoperative pain. Laser hemorrhoidoplasty (LH) is a novel procedure aimed at shrinking the terminal branches of hemorrhoidal arteries with fewer complications. The present study is aimed to compare these procedures (SH and LH).Study Design:Prospective comparative study.Place and Duration of Study:Patients operated for hemorrhoids at the Department of General, MI & Bariatric Surgery, Artemis Hospitals, Gurgaon from April 2018 to March 2019. Methodology:50 patients with grade II-III hemorrhoids were allocated to two groups: Stapler hemorrhoidopexy(SH) and Laser hemorrhoidoplasty (LH) with 25 patients in each group. Results were compared and patients were followed up for minimum period of 3months Results:The mean operative time was 24.6 min (LH) and 28.6 min (SH) (P=.122). The average blood loss was 8.32 ml (LH) and 11.64 ml (SH) (P <.05). The mean hospital stay 21.44 hours (LH) and 32.64 hours (SH) (P <.05). Mean postoperative pain score (VAS) at 12 hours was 2.64 (LH) and 4.76 (SH) (P <.05), at 24 hours was 1.88 (LH) and 3.6 (SH) (P <.05), at 1 week was 0.36 (LH) and 0.88 (SH) (P =.054) and at 3 months 0.04 (LH) and 0.12 (SH) (P =.53). One patient in LH (4%) had postoperative bleeding on 4th postoperative day. In SH group, 2 (8%) had severe postoperative pain with VAS > 8, requiring longer hospital stay, 2 (8%) had bleeding on the same day, 1(4%) had bleeding on follow up and 1 (4%) had recurrence. Conclusion:In terms of early postoperative pain and complications, LH offers better results as compared to SH. It was associated with a shorter hospital stay and earlyreturn to work. No significant complications were noted in LH compared to SH. LH is an extremely viable alternative to the popular SH for grade II-III hemorrhoids.

Perception of smoking habits and related diseases among society

Background: Smoking is practiced by a third of world’s population. Tobacco is leading cause of deaths world over. Six million people (1/8 second) die from tobacco each year. Objective of this study was to study demographic profile and awareness regarding tobacco smoking among people of Rohilkhand, Bareilly.Methods: Randomly selected individuals of Rohilkhand region. Questionnaire method involved.Results: Among 1040 sample size, 70% were males with mean age of 37.68 years. 73.94% population belonged to upper lower socio-economic class. 52% (62.9% male and 26.6% females) were current smokers of which 60.6% were exclusive beedi smokers. 50% were unaware of oral and lung cancer due to smoking. 34% were unaware about effects of passive smoking. 48.48% smokers report cough with expectoration as commonest symptom. 60% finds peer group influential for the behavior. 76.9% smokers are willing to quit smoking. 63.4% are open for counseling. 26% were unaware of ban/law related to smoking in public places. 68% believe there is increasing trend in prevalence of its use, among minors, educational institutes and hospitals.Conclusions: Despite high awareness of ill effects of smoking, there is an increasing trend in prevalence of smoking with an increased involvement of minors attributed to peer pressure. People are unaware of passive smoking and its harmful effect on body. Moreover, advertisements, visuals and captions have failed in making an impact. There occurs a need of awareness programmes, intervention sessions, medical therapy and strict anti-smoking laws by the government, social welfare and healthcare volunteers to help people quit and control the menace in society.

Interleukin-1-induced iNOS expression in human lung carcinoma A549 cells: Involvement of STAT and MAPK pathways.

For understanding of signaling molecules important in lung cancer growth and progression, IL-1 effect was analyzed on iNOS expression and key signaling molecules in human lung carcinoma A549 cells and established the role of specific signaling molecules by using specific chemical inhibitors. IL-1 exposure (10 ng/ml) induced strong iNOS expression in serum starved A549 cells. Detailed molecular analyses showed that IL-1 increased expression of phosphorylated STAT1 (Tyr701 and Ser727) and STAT3 (Tyr705 and Ser727) both in total cell lysates and nuclear lysates. Further, IL-1b exposure strongly activated MAPKs (ERK1/2, JNK1/2 and p38) and Akt as well as increased nuclear levels of NF-κB and HIF-1 in A549 cells. Use of specific chemical inhibitors for JAK1 kinase (piceatannol), JAK2 kinase (AG-490), MEK1/2 (PD98059) and JNK1/2 (SP600125) revealed that IL-1-induced iNOS expression involved signaling pathways in addition to JAK-STAT and ERK1/2-JNK1/2 activation. Overall, these results suggested that instead of specific pharmacological inhibitors, use of chemopreventive agents with broad spectrum efficacy to inhibit IL-1-induced signaling cascades and iNOS expression would be a better strategy towards lung cancer prevention and/or treatment.