Effect of Different Mini Implant Assisted Rapid Palatal Expansion (MARPE) Designs on Maxillary Protraction in Skeletal Class III malocclusion: An FEM Study.

Background: Four different designs of mini-implant-assisted rapid palatal expansion (MARPE) and protraction in nasomaxillary complex and mid-palatal sutures in late adolescent skeletal Class III malocclusion were compared using a three-dimensional finite element analysis. Methods: A finite element model of skull and related sutures was constructed using the computed tomography scan of a 16-year-old female patient with skeletal Class III and ANB of -2°. Four appliance designs: Type I: MARPE with palatal force, Type II: MARPE with buccal force, Type III: Hybrid hyrax with palatal force, and Type IV: Hybrid hyrax with buccal force. Protraction vectors were and analyzed using Ansys software (ANSYS 2021 R2). The displacement pattern of the nasomaxillary structures and the stress distribution in the sutures were examined in all four appliance designs. Results: All the appliance designs resulted in a forward movement of the maxilla, while Type I and III, which used palatal protraction force, caused the greatest forward displacement. In Type I, II, and III, along with forward movement, a clockwise rotation of maxilla was observed, while in Type IV, an anticlockwise rotation of maxilla was observed. Type I, II, and III resulted in higher stress distribution around the superior structures, while Type IV resulted in less stress distribution around the superior structures of maxilla. Conclusion: The forward displacement was enhanced when palatal plates were used to protract the maxilla. The effective appliance design for skeletal class III with open bite case was Type I, II, and III and Type IV for deep bite cases.

Excessive Daytime Sleepiness as a Risk Factor for Obstructive Sleep Apnoea among Public Transport Drivers: A Cross-Sectional Study.

Context: Excessive daytime sleepiness (EDS) due to obstructive sleep apnoea (OSA) is reported to be a major contributor to many road traffic accidents. Lack of awareness and diagnosis of OSA among public transport workers remains a threat to the society. Aims: The primary aim of this study was to assess the risk of OSA among transport drivers of south Kerala using modified Berlin questionnaire. The secondary objective included craniofacial assessment of the high-risk patients identified through the questionnaire using lateral cephalogram. Settings and Design: A cross-sectional study was conducted among 180 transport drivers of south Kerala. Methods and Material: Modified Berlin questionnaire and limited physical examination [body mass index (kg/m2), neck circumference (cm), waist circumference (cm), hip circumference and waist to hip ratio, blood pressure (mm Hg)] were recorded. The screened subjects were categorized as high-risk snorers and low-risk snorers based on modified Berlin questionnaire. Craniofacial morphological variations of high-risk group were assessed by lateral cephalograms. Statistical Analysis Used: The descriptive statistics were represented as mean and standard deviation and percentage. Inter-group comparison was performed with independent sample t test. Results: The study demonstrated 64.4% of subjects were non-snorers and 35.6% were snorers. Furthermore, among the snorers, 46.9% were identified as high-risk snorers, whereas the remaining 53.1% represented low-risk snorers. Conclusions: The study revealed the concealed risk of OSA among transport drivers could be screened through the questionnaires and demographics assessment. The application of the proposed screening protocol would triage and enhance safety of OSA affected transport drivers.

Evaluation of Strain and Insertion Torque of Mini-implants at 90° and 45° Angulations on a Bone Model using Three-Dimensional Finite Element Analysis.

Background: Temporary anchorage devices or mini-implants have gained great attraction due to its capability to provide absolute anchorage, low cost, versatility, and can be loaded immediately after placement. Aims and Objectives: The aim of this study is to use FEA analysis to assess the strain and insertion torque of mini-implants on a bone model at two distinct angulations of 45° and 90°. Materials and Methods: A computer-aided three-dimensional (3-D) model representing alveolar bone and mini-implants were developed using ANSYS software. Computed tomography scan images of the implant and the alveolar bone were taken and exported in DICOM format for 3-D image processing. The thickness of the bone model is 1 mm. Ti6Al4V orthodontic single and double threaded mini-implants (L = 7 mm, D = 1.5 mm) were inclined at 45° and 90° on to the bone surface to measure the insertion torque and strain produced. Results: Maximum insertion torque (MIT) for single-threaded mini implant at 45° and 90° angulations are 20.001 Nmm and 19.977 Nmm, respectively. MIT for double-threaded mini-implants obtained is 19.977 Nmm at 90° and 19.991 Nmm at 45° angulation. The strain of the bone at 90° angulation for single-threaded mini-implant is 0.00893 mm and for single-threaded mini implant at 45° angulation is 0.01257 mm. The strain in double-threaded mini-implant at 90° angulation is 0.0125 mm and that of 45° angulation is 0.01773 mm. Conclusion: For maximum stability single-threaded mini-implant with perpendicular insertion, angle is preferred.

Comparative evaluation of apically extruded debris using three different thermomechanically heat treated file systems with two different motions: An in vitro study.

Introduction and Aim: Postoperative inflammation and endodontic failure occur due to apical extrusion of debris. The purpose of this in vitro study was to assess the amount of apically extruded debris during the root canal preparation using rotary and reciprocating nickel-titanium instrumentation systems. Materials and Methods: The mesiobuccal canals of seventy five mature, human mandibular molars were randomly divided into three groups (n = 25 teeth/group). Each group was instrumented using one of the three different instrumentation systems: Hyflex EDM (HEDM) rotary file, Flexicon X7 rotary, and Flexicon X1 reciprocating files. The canals were irrigated using distilled water. The debris extruded apically was collected in preweighed Eppendorf tubes and assessed with an electronic balance and compared. Statistical Analysis: Data were statistically analyzed by one-way analysis of variance and the intergroup comparison with single factor ANOVA. Results: The Flexicon X1 reciprocating system showed the maximum amount of apical extrusion of debris among all the groups. The least amount of debris was observed in Flexicon X7 rotary instrument (P > 0.05). Conclusion: Flexicon X7 rotary extruded significantly lesser amount of debris than Flexicon X1 reciprocating and HEDM rotary file systems.

Tyrosine kinase domain mutations in chronic myelogenous leukemia patients: A single center experience.

INTRODUCTION: Despite the impressive responses achieved with tyrosine kinase inhibitor (TKI) therapy, treatment resistance develops in 16-33% of patients of chronic myelogenous leukemia (CML). Of the BCR-ABL1 dependent mechanisms, mutations in the tyrosine kinase domain (TKD) are the commonest cause of resistance. MATERIAL AND METHODS: Allele specific oligonucleotide - polymerase chain reaction (ASO-PCR) was done for testing the six common TKD mutations, T315I, G250E, E255K, M244V, M351T, and Y253F. RESULTS AND CONCLUSION: TKD mutation study was done on 83 patients. Of these 44 (53%) were positive for one or more mutations. On analyzing specific mutations, E255K was the commonest mutation seen in 24 (29%) cases, followed by T315I in 23(28%) cases. Y253F mutation was not seen in the present study sample. In the present cohort of 83 patients, 29 (35%) cases were positive for single mutation, 12 (14%) had two mutations and 3 (4%) had three mutations.

Epidemiological study on prevalent risk factors and craniofacial skeletal patterns in obstructive sleep apnea among South Indian population.

CONTEXT: Obstructive sleep apnea (OSA) is a condition affecting the upper airway among a vast number of people around the world. AIMS: To determine the prevalent risk factors of OSA and its association with craniofacial skeletal pattern. SETTINGS AND DESIGN: Cross-sectional, community-based study. MATERIALS AND METHODS: In the first stage, questionnaire and physical examination were done for 1000 subjects between 20 and 70 years of age. Subjects were categorized as snorers and non-snorers. Snorers were further grouped as high-risk and low-risk snorers. In the second stage, polysomnography (PSG) was done for randomly selected high-risk subjects. Craniofacial skeletal pattern of OSA-diagnosed subjects were compared with non-OSA subjects using lateral cephalograms. STATISTICAL ANALYSIS: Analysis was performed using IBM SPSS 20. Independent sample t-test was used. A P value < 0.05 was considered as statistically significant. RESULTS: The study population represented the following: high-risk snorers: 22.4%, low-risk snorers: 13.9%, and non-snorers: 63.7%. Excessive daytime sleepiness was present in 7.7%. Among high-risk, 80 underwent PSG, and 75 were diagnosed as OSA (94%) and 5 non-OSA subjects. Increased body mass index and neck circumference were statistically significant. Cephalometric evaluation showed difference in maxillomandibular relationship, narrowing of airway space, and inferiorly displaced hyoid. CONCLUSION: OSA is a major public health problem. Obesity is a strong predictor for OSA. Thus, high-risk subjects for sleep apnea could be identified using routine clinical examination, investigations, and anthropometric parameters.

DNA staining in agarose and polyacrylamide gels by methyl green.

Methyl green (MG) is an inexpensive, nonproprietary, traditional histological stain for cell nuclei. When bound to DNA and upon excitation with orange-red light, it fluoresces brightly in the far red region. We compared MG with ethidium bromide (EtBr), the conventional stain for DNA in gels, and Serva DNA stain G™ (SDsG), a proprietary stain marketed as a safer alternative to EtBr for staining of electrophoresed DNA bands in agarose and polyacrylamide gels. DNA-MG fluorescence was recorded and 2.4 µg/ml MG produced crisp images of electrophoresed DNA after incubation for 10 min. Stain solutions were stable and detection limits for faint bands as well as relative densitometric quantitation were equivalent to EtBr. MG, EtBr and SDsG cost 0.0192, 0.024 and 157.5 US cents/test, respectively. MG is an effective stain for visualizing DNA in agarose and polyacrylamide gels. Its major advantages including low cost, comparable quality of staining, storage at room temperature, photo-resistance and low mutagenic profile outweigh its disadvantages such as staining of tracking dye and requirement for a gel documentation system with a red filter.

Assessment of Bracket Surface Morphology and Dimensional Change.

OBJECTIVE: The objective of this study was to compare the surface morphology and dimensional stability of the bracket slot at the onset of treatment and after 12 months of intraoral exposure. The study also compared the amount of calcium at the bracket base which indicates enamel loss among the three orthodontic brackets following debonding after 12 months of intraoral exposure. MATERIALS AND METHODS: The sample consisted of 60 (0.022" MBT) canine brackets. They were divided into three groups: self-ligating, ceramic bracket with metal slot, and stainless steel (SS) brackets. The slot dimensions, micromorphologic characteristics of as-received and retrieved brackets were measured with a stereomicroscope and scanning electron microscope (SEM), respectively. The amount of calcium at the bracket base which indicates enamel damage was quantified using energy-dispersive X-ray spectrometry (EDX). RESULTS: The results showed statistically significant alterations (P < 0.05) in the right vertical dimension, internal tie wing width (cervical), right and left depth of the slot (Kruskal-Wallis test). Multiple comparison using Mann-Whitney test showed that ceramic brackets underwent (P < 0.05) minimal alterations in the right vertical dimension, internal tie wing width (cervical), right and left depth of the slot (0.01 mm, -0.003 mm, 0.006 mm, -0.002 mm, respectively) when compared with the changes seen in SS and self-ligating brackets. SEM analysis revealed an increase in the surface roughness of ceramic with metal slot brackets and self-ligating bracket showed the least irregularity. The presence of calcium was noted on all evaluated brackets under EDX, but ceramic with metal slot brackets showed a significantly greater amount of enamel loss (P = 0.001). CONCLUSION: Ceramic brackets were found to be dimensionally stable when compared to SS and self-ligating. Self-ligating bracket showed minimal surface irregularity. Ceramic with metal slot brackets showed a greater amount of enamel loss following debonding.

Securing an OTL-HNS residency: how competitive is it? Comparing medical student perceptions to actual Canadian statistics.

BACKGROUND: The residency match is an important event in an aspiring physician's career. Otolaryngology - Head and Neck Surgery (OTL-HNS) is a surgical specialty that has enjoyed high numbers of applicants to its residency programs. However, recent trends in Canada show a decline in first-choice applicants to several surgical fields. Factors thought to influence a medical student's choice include role models, career opportunities and work-life balance. The notion of perceived competitiveness is a factor that has not yet been explored. This study sought to compare competitiveness of OTL-HNS, as perceived by Canadian medical students to residency match statistics published yearly by CaRMS (Canadian Residency Matching Service), with the hope of informing future decisions of surgical residency programs. METHODS: An electronic survey was created and distributed to all medical students enrolled in the 17 Canadian medical schools. After gathering demographic information, students were asked to rank what they perceived to be the five most competitive disciplines offered by CaRMS. They were also asked to rank surgical specialties from most to least competitive. Publically available data from CaRMS was then collected and analyzed to determine actual competitiveness of admissions to Canadian OTL-HNS residency programs. RESULTS: 1194 students, from first to fourth year of medical school, completed the survey. CaRMS statistics over the period from 2008 to 2014 demonstrated that the five most competitive specialties were Plastic Surgery, Dermatology, Ophthalmology, Emergency Medicine and OTL-HNS. Among surgical disciplines, OTL-HNS was third most competitive, where on average 72% of students match to their first-choice discipline. When students were questioned, 35% ranked OTL-HNS amongst the top five most competitive. On the other hand 72%, 74% and 80% recognized Opthalmology, Dermatology and Plastic Surgery as being among the five most competitive, respectively. We found that fourth-year medical students were significantly more knowledgeable about the competitiveness of both OTL-HNS and Plastic Surgery compared to first-year students (p < 0.01). CONCLUSION: Overall, Canadian medical students may underestimate the competitiveness of OTL-HNS. Furthermore, competitiveness would appear to be a concept that resonates with medical students during the match process.

Vortex-dislodged cells from bone marrow trephine biopsy yield satisfactory results for flow cytometric immunophenotyping.

INTRODUCTION: A good bone marrow (BM) sample is essential in evaluating many hematologic disorders. An unsuccessful BM aspiration (BMA) procedure precludes a successful flow cytometric immunophenotyping (FCI) in most hematologic malignancies. Apart from FCI, most ancillary diagnostic techniques in hematology are less informative. We describe the feasibility of FCI in vortex-dislodged cell preparation obtained from unfixed trephine biopsy (TB) specimens. METHODS: In pancytopenic patients and dry tap cases, routine diagnostic BMA and TB samples were complemented by additional trephine biopsies. These supplementary cores were immediately transferred into sterile tubes filled with phosphate-buffered saline, vortexed, and centrifuged. The cell pellet obtained was used for flow cytometric immunophenotyping. RESULTS: Of 7955 BMAs performed in 42 months, 34 dry tap cases were eligible for the study. Vortexing rendered a cell pellet in 94% of the cases (32 of 34), and FCI rendered a rapid diagnosis in 100% of the cases (32 of 32) where cell pellets were available. CONCLUSION: We describe an efficient procedure which could be effectively utilized in resource-limited centers and reduce the frequency of repeat BMA procedures.

Reliability performance of titanium sputter coated Ni-Ti arch wires: mechanical performance and nickel release evaluation.

The present research was aimed at developing surface coatings on NiTi archwires capable of protection against nickel release and to investigate the stability, mechanical performance and prevention of nickel release of titanium sputter coated NiTi arch wires. Coated and uncoated specimens immersed in artificial saliva were subjected to critical evaluation of parameters such as surface analysis, mechanical testing, element release, friction coefficient and adhesion of the coating. Titanium coatings exhibited high reliability on exposure even for a prolonged period of 30 days in artificial saliva. The coatings were found to be relatively stable on linear scratch test with reduced frictional coefficient compared to uncoated samples. Titanium sputtering adhered well with the Ni-Ti substrates at the molecular level, this was further confirmed by Inductive coupled plasma emission spectroscopy (ICPE) analysis which showed no dissolution of nickel in the artificial saliva. Titanium sputter coatings seem to be promising for nickel sensitive patients. The study confirmed the superior nature of the coating, evident as reduced surface roughness, friction coefficient, good adhesion and minimal hardness and elastic modulus variations in artificial saliva over a given time period.

Efficacy of custom made oral appliance for treatment of obstructive sleep apnea.

INTRODUCTION: oral appliance for the treatment of OSA is considered as an effective, low-risk alternative to CPAP. Demand for oral appliance increases as an alternative for those who cannot tolerate CPAP and refuse surgery. Oral appliances uses the traditional methods to advance the mandible thus modify the posture and their by enlarge the airway or otherwise reduce the collapsibility. AIMS AND OBJECTIVES: The main objective of this study was to evaluate the efficacy of custom made oral appliance on sleep characteristics of OSA patients. MATERIALS AND METHODS: Polysomnography was done on 15 patients of 24-60 years of age before (T1), and after the delivery of the custom made oral appliance (T2). STATISTICAL ANALYSIS: Paired t tests were performed to determine the significance of change in the polysomnographic and cephalometric variables. P < 0.05 was considered as significant. RESULTS: All patients with oral appliance showed an improvement in sleep parameters with an increase in sleep efficiency, and desaturation index with the use of oral appliance. ESS and cephalometric findings showed improvement in the sleep apnea in concordance with the sleep parameters. CONCLUSIONS: Custom made oral appliance is a useful treatment option for improving quality of sleep and can be considered as an alternative treatment modality.

Improving operation notes and postoperative care: an audit of current practice.

The operation note is the single most important document in surgical practice. Ninety one operation notes were assessed on their adherence to guidelines, as well as their legibility and ability to inform postoperative care; as judged by five different healthcare professionals. Results showed a deficiency in essential information and poor legibility overall. Re-audit of 103 operation notes after intervention showed an improvement in nearly all criteria measured. The results indicate that education about current guidelines and an increase in word processing of operation notes improves quality of documentation, and therefore of postoperative care.

Impact of iron deficiency on hemoglobin A2% in obligate ß-thalassemia heterozygotes.

INTRODUCTION: The potential impact of concomitant iron deficiency on hemoglobin A2 (HbA2)-based identification of ß-thalassemia trait (ßTT) is a worrisome issue for screening laboratories. This is especially true for resource-constrained settings where iron deficiency is widespread and molecular confirmatory tests for borderline low HbA2 values may be unavailable. METHODS: Obligate ßTT carrier individuals (n = 752) were identified during screening studies on the parents of thalassemia major patients. HbA2%, complete blood counts and serum iron, ferritin and transferrin saturation were studied. Iron-deficient individuals (n = 135) with normal range HbA2% were taken as controls. RESULTS: Concomitant iron deficiency (defined as ferritin ≤15 ng/mL and/or transferrin saturation ≤15%) was present in 20.7% (156/752) ßTT cases, that is, 33.3% females (122/366) and 8.8% males with ßTT (34/386). Mean HbA2 in iron-replete ßTT was 5.4 ± 0.8 (range 3.1-7.9) and in iron-deficient ßTT was 5.4 ± 0.9 (range 3.3-7.6). HbA2 < 4.0% was found in 23/752 (3.1%) ßTT: 13/595 iron-replete (2.2%) and 10/157 (6.4%) iron-deficient ßTT individuals. However, five of the 10 iron-deficient ßTT cases carried the silent CAP+1 (A>C) ß-thalassemia allele accounting for the borderline HbA2%. On a separate analysis, all five severely anemic ßTT (Hb < 80 g/L) and 16/17 ßTT with severe hypoferritinemia (<5 ng/mL) had HbA2 > 4.5%. The single case with serum ferritin 4.8 ng/mL and HbA2 3.3% showed a CAP+1 (A>C) mutation. CONCLUSIONS: Iron deficiency was prevalent among north Indian ßTT individuals, especially women. After adjusting for other causes of low HbA2 in ßTT, iron deficiency, even when very severe, was very unlikely to interfere significantly with HbA2-based identification of ßTT.

Effect of rapid maxillary expansion on sleep characteristics in children.

INTRODUCTION: Rapid maxillary expansion (RME) is an orthopedic treatment procedure routinely used to treat constricted maxillary arches and also a potential additional treatment in children presenting with sleep-disordered breathing (SDB). AIMS AND OBJECTIVES: The main objective of this study was to evaluate the effects of RME on sleep characteristics in children. MATERIALS AND METHODS: Polysomnography was done on children of 8-13 years of age before expansion (T0), after expansion (T1) and after a period of 3 months after retention (T2). Bonded rapid maxillary expander was cemented in all children. Inter-molar distance was also measured at T0 and T2. STATISTICAL ANALYSIS: Nonparametric Friedman test was used for comparing the averages of sleep parameters at different time period (T0, T1, T2). Wilcoxon signed ranks test was used for comparing the averages of inter-molar width (T0-T2). P < 0.05 were considered as significant. RESULTS: All children showed an improvement in sleep parameters with an increase in sleep efficiency, decreased in arousal and desaturation index after expansion. Total sleep time showed a statistically significant increase after expansion. A statistically significant increase in inter-molar distance was obtained after expansion. CONCLUSIONS: Rapid maxillary expansion is a useful treatment option for improving quality of sleep even in normal children without SDB. It also induces widening of the maxilla, corrects posterior crossbites and improves maxillary and mandibular dental arch coordination.

1-[3-(2-Benz-yloxy-6-hy-droxy-4-methyl-phen-yl)-5-[3,5-bis-(tri-fluoro-meth-yl)phen-yl]-4,5-di-hydro-1H-pyrazol-1-yl]propane-1-one.

In the title compound, C28H24F6N2O3, the mean plane of the central pyrazoline ring forms dihedral angles of 2.08 (9) and 69.02 (16)° with the 2-benz-yloxy-6-hy-droxy-4-methyl-phenyl and 3,5-bis-(tri-fluoro-meth-yl)phenyl rings, respectively. The dihedral angle between the mean planes of the pyrazoline and 3,5-bis-(tri-fluoro-meth-yl)phenyl rings is 68.97 (9)°. An intra-molecular O-H⋯N hydrogen bond is observed, which forms an S(6) graph-set motif. In the crystal, pairs of weak C-H⋯F halogen inter-actions link the mol-ecules into inversion dimers while molecular chains along [100] are formed by C-H⋯O contacts.