scholarly journals Temporary Anchorage Device Stability: Monocortical Versus Bicortical Anchorage Technique

2017 ◽  
Vol 1 ◽  
Author(s):  
Fateen Nur Ain Mohd Azmi ◽  
Lim Shuang Ying ◽  
Wael Ahmed Bayomy Mohamed ◽  
Rozita Hassan
Keyword(s):  
Confidence Interval ◽  
Bovine Bone ◽  
Pull Out ◽  
Device Stability ◽  
Significant Difference ◽  
The Mean ◽  
The Stability ◽  
Temporary Anchorage Device ◽  
Pull Out Strength ◽  
One Way Anova

<p class="AbstractContent"><strong>Objective:</strong> To compare the stability of splinted and non-splinted miniscrew between monocortical and bicortical anchorage techniques.</p><p class="AbstractContent"><strong>Methods:</strong> Thirty-Six AbsoAnchor orthodontic miniscrews (10mm x 1.5mm) were divided into four groups; non-splinted monocortical, non-splinted bicortical, splinted monocortical and splinted bicortical anchorage techniques. The miniscrews were inserted into sectioned bovine bone blocks and the pull-out strength for each group of miniscrews was measured using Instron 8874; a crosshead speed of 2mm/minute was applied. Six readings were taken for each group and the mean reading for each group was obtained. The data was analyzed using one-way ANOVA test with 95% confidence interval (P&lt;0.05).</p><p class="AbstractContent"><strong>Results:</strong> The pull-out strength mean of splinted group was observed to be statistically higher than non-splinted. The mean of the pull-out strength of bicortical was higher than monocortical in both splinted and non-splinted groups, however it is not significant.</p><p class="AbstractContent"><strong>Conclusion</strong>: Both splinted monocortical and bicortical anchorage miniscrews were significantly stable than non-splinted counterpart. However, in monocortical and bicortical anchorage, there was no significant difference of the pull-out strength between splinted and non-splinted miniscrews.</p>

scholarly journals Evaluation of stability of three different mini-implants, based on thread shape factor and numerical analysis of stress around mini-implants with different insertion angle, with relation to en-masse retraction force

2020 ◽  
Vol 25 (6) ◽  
pp. 59-68
Author(s):  
Safiya Sana ◽  
Rekha Reddy ◽  
Ashok Kumar Talapaneni ◽  
Arshad Hussain ◽  
Sayeeda Laegue Bangi ◽  
...  
Keyword(s):  
Shape Factor ◽  
Bone Block ◽  
Mini Implants ◽  
Pull Out ◽  
Significant Difference ◽  
The Stability ◽  
Different Diameters ◽  
Post Hoc ◽  
Retraction Force ◽  
Pull Out Strength

ABSTRACT Objectives: Assess the stability of three different mini-implants, based on thread shape factor (TSF), and evaluate stresses at the mini-implant site and surrounding cortical bone on application of retraction force, at two different insertion angles. Methods: Mini-implants of three different diameters (M1 - Orthoimplant, 1.8mm), (M2 - Tomas, 1.6mm) and (M3 - Vector TAS, 1.4mm) and length of 8mm were used. Using scanning electronic microscopy, the mean thread depth, pitch and relationship between the two (TSF) were calculated. The mini-implants were loaded into a synthetic bone block and the pull-out strength was tested. One way ANOVA and Tukey post-hoc tests were used to compare the pull-out strength of mini-implants. P values < 0.05 were considered statistically significant. Finite element models (FEM) were constructed with insertion angulation at 90° and 60°, with retraction force of 150 g. The results were analyzed using ANSYS software. Results: Statistically significant difference was found among all the three mini-implants for thread depth and pitch (< 0.001). Statistically significant higher pull-out force value was seen for Orthoimplant. The stress distribution level in mini-implant and surrounding bone was observed to be smaller for Orthoimplant. Conclusion: Orthoimplant mini-implants have more favorable geometric characteristics among the three types, and less stress with 90°angulation.

scholarly journals Evaluating Endoscopic Ipsilateral Endonasal Corridor Approaches to the Anterolateral Wall of the Maxillary Sinus: A Computerized Tomography Study

2021 ◽  
Author(s):  
Navarat Vatcharayothin ◽  
Pornthep Kasemsiri ◽  
Sanguansak Thanaviratananich ◽  
Cattleya Thongrong
Keyword(s):  
Confidence Interval ◽  
Maxillary Sinus ◽  
Inferior Turbinate ◽  
Radial Access ◽  
Sinus Wall ◽  
Nasal Floor ◽  
Significant Difference ◽  
Anterolateral Wall ◽  
The Mean ◽  
Maxillary Sinuses

Abstract Introduction The endoscopic access to lesions in the anterolateral wall of the maxillary sinus is a challenging issue; therefore, the evaluation of access should be performed. Objective To assess the accessibility of three endoscopic ipsilateral endonasal corridors. Methods Three corridors were created in each of the 30 maxillary sinuses from 19 head cadavers. Accessing the anterolateral wall of the maxillary sinus was documented with a straight stereotactic navigator probe at the level of the nasal floor and of the axilla of the inferior turbinate. Results At level of the nasal floor, the prelacrimal approach, the modified endoscopic Denker approach, and the endoscopic Denker approach allowed mean radial access to the anterolateral maxillary sinus wall of 42.6 ± 7.3 (95% confidence interval [CI]: 39.9–45.3), 56.0 ± 6.1 (95%CI: 53.7–58.3), and 60.1 ± 6.2 (95%CI: 57.8–62.4), respectively. Furthermore, these approaches provided more lateral access to the maxillary sinus at the level of the axilla of the inferior turbinate, with mean radial access of 45.8 ± 6.9 (95%CI: 43.3–48.4) for the prelacrimal approach, 59.8 ± 4.7 (95% CI:58.1–61.6) for the modified endoscopic Denker approach, and 63.6 ± 5.5 (95%CI: 61.6–65.7) for the endoscopic Denker approach. The mean radial access in each corridor, either at the level of the nasal floor or the axilla of the inferior turbinate, showed a statistically significant difference in all comparison approaches (p < 0.05). Conclusions The prelacrimal approach provided a narrow radial access, which allows access to anteromedial lesions of the maxillary sinus, whereas the modified endoscopic Denker and the endoscopic Denker approaches provided more lateral radial access and improved operational feasibility on far anterolateral maxillary sinus lesions.

scholarly journals Confidence interval approach for evaluating bias in laboratory methods

1988 ◽  
Vol 10 (3) ◽  
pp. 144-146 ◽  
Author(s):  
K. F. Yee
Keyword(s):  
Confidence Interval ◽  
Statistical Tests ◽  
Laboratory Methods ◽  
Mean Values ◽  
Practical Concern ◽  
Alternative Approach ◽  
Interval Approach ◽  
Significant Difference ◽  
The Mean

A statistically significant difference in mean values between two laboratory quantitation methods is interpreted as a bias. Sometimes such a difference is so minute that it does not constitute any practical concern. An alternative approach is to test statistically whether the two methods are close enough, not for equality. This is to look at the confidence interval of the mean method difference and does not entail any additional statistical tests.

scholarly journals Assessment of decrease in renal function associated with hypothyroidism

2021 ◽  
Vol 12 (1) ◽  
pp. 275-286
Author(s):  
Ayesha Ammar ◽  
Kahkashan Bashir Mir ◽  
Sadaf Batool ◽  
Noreen Marwat ◽  
Maryam Saeed ◽  
...  
Keyword(s):  
Renal Function ◽  
Confidence Interval ◽  
Creatinine Clearance ◽  
Confidence Intervals ◽  
Standard Error ◽  
Radioactive Iodine ◽  
T Test ◽  
Euthyroid State ◽  
Significant Difference ◽  
The Mean

Objective: Study was aimed to see the effects of hypothyroidism on GFR as a renal function. Material and methods: Total of Fifty-eight patients were included in the study. Out of those forty-eight patients were female and the rest were male. Out of fifty eight patients, fifty three patients were of thyroid cancer in which hypothyroidism was due to discontinuation of thyroxine before the administration of radioactive iodine for Differentiated thyroid cancer.Moreover, remaining five patients were post radioactive iodine treatment (for hyperthyroidism) hypothyroid. All of the patients were above eighteen years of age with TSH value > 30µIU/ml. Pregnant and lactating females were excluded.Renal function tests (urea/creatinine, creatinine clearance) and serum electrolytes followed by Tc-99m-DTPA renal scan for GFR assessment (GATES’ method) were carried out in all subjects twice during the study, One study during hypothyroid state (TSH > 30 µIU/ml) and other during euthyroid state (TSH between 0.4 to 4µ IU/ml). The results of Student’s t-test showed significant difference in renal functions (Urea, creatinine, creatinine clearance, GFR values) in euthyroid state and hypothyroid state (p-value <0.05). RESULTS: In case of creatinine the paired t test reveal the mean 1.014±0.428, with standard error of 0.669 within 95% confidence interval, for creatinine clearance 80.11±14.12 with standard error of 1.94 within 95% confidence intervals, for urea the mean 28±12.13 with standard error of 1.607 within 95% confidence intervals and for GFR for individual kidney is 38.056±8.56 with standard error of 1.3717 within 95% confidence interval. There was no difference in the outcome of the 2 groups. Conclusion: Hypothyroidism impairs renal function to a significant level and hence needs to be prevented and corrected as early as possible.

scholarly journals Effects of prophylactic ketamine and pethidine to control postanesthetic shivering: A comparative study

2018 ◽  
Vol 5 (12) ◽  
pp. 2898-2903 ◽  
Author(s):  
Masoum Khoshfetrat ◽  
Ali Rosom Jalali ◽  
Gholamreza Komeili ◽  
Aliakbar Keykha
Keyword(s):  
Normal Saline ◽  
Pearson Correlation ◽  
Saline Group ◽  
Normal Saline Group ◽  
Chi Square ◽  
Double Blind ◽  
Postanesthetic Shivering ◽  
Significant Difference ◽  
The Mean ◽  
One Way Anova

Background: Shivering is an undesirable complication following general anesthesia and spinal anesthesia, whose early control can reduce postoperative metabolic and respiratory complications. Therefore, this study aims to compare the effects of prophylactic injection of ketamine and pethidine on postoperative shivering. Methods: This double-blind clinical trial was performed on 105 patients with short-term orthopedic and ENT surgery. The patients were randomly divided into three groups; 20 minutes before the end of the surgery, 0.4 mg/kg of pethidine was injected to the first group, 0.5 mg/kg of ketamine was injected to the second group, and normal saline was injected to the third group. After the surgery, the tympanic membrane temperature was measured at 0, 10, 20, and 30 minutes. The shivering was also measured by a four-point grading from zero (no shivering) to four (severe shivering). Data were analyzed by one-way ANOVA, Kruskal Wallis, Chi-square and Pearson correlation. Results: The mean age of patients was 35.8+/-11.45 years in the ketamine group, 34.8+/-11.64 years in the normal saline group, and 33.11+/-10.5 years in the pethidine group. The one-way ANOVA showed no significant difference in the mean age between the three groups (P=0.645). The incidence and intensity of shivering were significantly higher in the normal saline group than in the ketamine and pethidine groups (p=0.001). However, there was no significant difference in the incidence and the intensity of shivering between the ketamine and the pethidine groups (p=0.936). Conclusion: The results showed that the 0.5 mg/kg of ketamine could control the post-anesthetic shivering.  

scholarly journals Comparison of electrocardiographic parameters of racing and non-racing horses in Sokoto Nigeria

2020 ◽  
Vol 18 (1) ◽  
pp. 33-38
Author(s):  
B. Saidu ◽  
A.J. Ishaq ◽  
H.M. Ibrahim ◽  
A. Dahiru ◽  
A.M. Abdullahi ◽  
...  
Keyword(s):  
Standing Position ◽  
P Wave ◽  
Average Weight ◽  
T Wave ◽  
Qt Intervals ◽  
Significant Difference ◽  
The Mean ◽  
Electrocardiographic Parameters ◽  
Electrical Activities ◽  
One Way Anova

The study was conducted due to the economic importance of horses and shortage of information on electrocardiographic parameters of horses in Sokoto, Nigeria. This study established the normal electrocardiographic parameters of racing and non-racing horses in Sokoto and statistically compared the values. The study used forty horses comprising of 20 racing and 20 non-racing horses with mean age of 8 ± 0.5 years and average weight of 200 ± 2.0 kg. ECG was recorded using the base apex system with the animals in standing position using single lead channel ECG recorder (EDAN VE-100 manufactured by Edan instruments China). The paper speed was set at 25mm/s while the sensitivity of the machine was adjusted to 10 mm/mV. The durations and amplitudes of P, R and T, the durations of Q and S and the durations of PR, QRS and QT intervals were all determined. These parameters were determined for the three standard limb leads (I, II and III) as well as the augmented limb leads (aVR, aVL and aVF). Descriptive statistics using SPSS version 16 was used to calculate the means and standard error of mean at 95 % confidence interval. One-way ANOVA was used to compare between the values of the racing and non-racing horses. The highest values of P amplitude, R amplitude, Q amplitude, QRS complex and P-R interval were recorded in racing horses, while highest T wave amplitude was recorded in non-racing horses. Highest duration of P wave, T wave and QRS was recorded in racing horses while highest duration of Q wave was recorded in non-racing horses. Significant difference was found in the T amplitude in racing horses in lead aVF. The mean heart rate for the racing and non-racing horses was 80.3 ± 8.4 and 63.1 ± 9.2 beats/minute respectively. Higher values recorded in racing horses indicates that exercise has influence on electrical activities in horses. Keywords: Electrocardiograph, Non-racing horses, Parameters, Racing horses, Sokoto

scholarly journals Effects of placement angle and direction of orthopedic force application on the stability of orthodontic miniscrews

2012 ◽  
Vol 83 (4) ◽  
pp. 667-673 ◽  
Author(s):  
Jihye Lee ◽  
Ji Young Kim ◽  
Yoon Jeong Choi ◽  
Kyung-Ho Kim ◽  
Chooryung J. Chung
Keyword(s):  
Cortical Bone ◽  
Lateral Force ◽  
Von Mises Stress ◽  
Biomechanical Stability ◽  
Element Analysis ◽  
Force Application ◽  
Pull Out ◽  
The Stability ◽  
Von Mises ◽  
Pull Out Strength

ABSTRACT Objectives: To evaluate the influence of placement angle and direction of orthopedic force application on the stability of miniscrews. Materials and Methods: Finite element analysis was performed using miniscrews inserted into supporting bone at angles of 90°, 60°, and 30° (P90°, P60°, and P30°). An orthopedic heavy force of 800 gf was applied to the heads of the miniscrews in four upward (U0°, U30°, U60°, U90°) or lateral (L0°, L30°, L60°, L90°) directions. In addition, pull-out strength of the miniscrews was measured with various force directions and cortical bone thicknesses. Results: Miniscrews with a placement angle of 30° (P30°) and 60° (P60°) showed a significant increase in maximum von Mises stress following the increase in lateral force vectors (U30°, U60°, U90°) compared to those with a placement angle of 90° (P90°). In accordance, the pull-out strength was higher with the axial upward force when compared to the upward force with lateral vectors. Maximum von Mises stress and displacement of the miniscrew increased as the angle of lateral force increased (L30°, L60°, L90°). However, a more dramatic increase in maximum von Mises stress was noted in P30° than in P60° and P90°. Conclusion: Placement of the miniscrew perpendicular to the cortical bone is advantageous in terms of biomechanical stability. Placement angles of less than 60° can reduce the stability of miniscrews when orthopedic forces are applied in various directions.

Pull-out strength of orthopaedic screws in polymethylmethacrylate filled medullary cavities of foal third metacarpal bones

2004 ◽  
Vol 17 (03) ◽  
pp. 136-140
Author(s):  
G. S. Martin ◽  
M. S. Gill ◽  
G. A. Sod
Keyword(s):  
Fracture Site ◽  
Medullary Cavity ◽  
Pull Out ◽  
Metacarpal Bones ◽  
Cavity Filling ◽  
The Mean ◽  
Stable Internal Fixation ◽  
Empty Control ◽  
Pull Out Strength

SummaryThe purpose of this study was to determine the in vitro pull-out force and strength of 4.5-mm and 5.5-mm cortical screws inserted in the diaphysis of foal third metacarpal bones with and without polymethylmethacrylate (PMMA) filling the medullary cavity. Filling the medullary cavity with PMMA significantly increased the pull-out force of 4.5-mm screws by 2.0-fold, and 5.5-mm screws by 2.2-fold, compared to controls (p < 0.001). Also the mean pull-out strength per mm of bones filled with PMMA was significantly greater (p < 0.001) than empty control bones. Our results suggest that filling the medullary cavity with PMMA at sites of greater stress, such as the ends of the plate and near the fracture site, may result in a more stable internal fixation.

Are Internal Medicine Residents Meeting the Bar? Comparing Resident Knowledge and Self-Efficacy to Published Palliative Care Competencies

2020 ◽  
pp. 104990912095480
Author(s):  
Kristen M. Moyer ◽  
Matthew S. Ellman ◽  
John Encandela ◽  
Laura J. Morrison
Keyword(s):  
Internal Medicine ◽  
Palliative Care ◽  
Self Efficacy ◽  
Rank Analysis ◽  
Cultural Aspects ◽  
Internal Medicine Residents ◽  
Significant Difference ◽  
New Instrument ◽  
The Mean ◽  
One Way Anova

Background: There is a need for improved primary palliative care (PC) education and resident comfort with providing end-of-life care. Objective: Utilize a new instrument derived from published PC competencies to assess baseline Internal Medicine (IM) resident knowledge and self-efficacy in PC to identify educational gaps and create new PC curricula. Design: We created a 2-part instrument including a Knowledge Test (KT) and a Self-Efficacy Inventory (SEI) addressing 18 PC resident competencies across 5 domains: Pain and Symptom Management (PSM), Communication (COMM), Psychosocial, Spiritual, and Cultural Aspects of Care (PSC), Terminal Care and Bereavement (TCB), and Palliative Care Principles and Practice (PCPP). Setting/Subjects: The instrument was emailed to IM residents at our institution during academic years 2015-2016 and 2016-2017. Measurements: Basic descriptive statistics were performed for the KT and SEI. Mean Rank Analysis and One-way ANOVA were utilized for the KT and SEI, respectively. Congruence was calculated between knowledge and self-efficacy. Results: The mean score on the KT was 73% (range 33-80%). There was no significant difference in knowledge among post-graduate year cohorts. Self-efficacy scores were lower for interns overall and in PCPP, TCB, and COMM domains. Knowledge was concordant with self-efficacy in 42% of participants, higher than self-efficacy in 10% of participants, and lower than self-efficacy in 48% of participants. Conclusions: For approximately half of respondents, high self-efficacy in PC did not correlate with high PC knowledge. A more focused curriculum is needed to help IM residents facilitate mastery of PC competencies by graduation.

The Effect of Thermoforming on Tear Strength of Ethylene Vinyl Acetate Mouthguard Material in Various Thicknesses

2017 ◽  
Vol 751 ◽  
pp. 657-662
Author(s):  
Phakphum Srinuan ◽  
Jeerapatr O. Baiyokvichit ◽  
Rasana Boonpeng ◽  
Tanapol Wongwisatekit ◽  
Pacharaporn Pattanasukwasan ◽  
...  
Keyword(s):  
Vinyl Acetate ◽  
Testing Machine ◽  
Ethylene Vinyl Acetate ◽  
Strength Test ◽  
Tear Strength ◽  
Universal Testing ◽  
Significant Difference ◽  
The Mean ◽  
Thermoforming Process ◽  
One Way Anova

The effect of thermoforming on the tear strength of ethylene vinyl acetate (EVA) mouthguard material (Bioplast®) has not been widely investigated. The present study compared the tear strengths of non-processed and processed EVA specimens in various thicknesses. Two groups of EVA sheet (non-processed and processed) in three different thicknesses of 3, 4 and 5 mm were used in specimen fabrication. The processed EVA sheets were achieved by forming the EVA sheet on the cylindrical stone model with the pressure-molding device (Biostar®). Twelve of tear strength specimens of non-processed and processed group in each thickness were prepared following the modified ASTM D 624-00 guideline. The tear strength test was conducted using universal testing machine (Lloyd® 1K series) with the speed of 500 mm/min. The mean thickness and tear strength of the non-processed and processed specimens in each thickness were compared using independent T-test. The differences in the mean tear strength for each thickness of non-processed and process specimens were determined using one-way ANOVA. The mean tear strength and mean thickness of processed EVA specimens was significantly lower than the non-processed EVA specimens for every thickness (P ≤ 0.05). There was no significant difference in the mean tear strength of EVA specimens among each thickness in both non-processed and processed groups. It can be concluded that the thermoforming process has the significant effect on the tear strength of the EVA mouthguard material formed by pressure molding device in every thicknesses. The tear strength of processed specimens were significant lower than the non-processed. Thus, it is more relevant for testing properties of the processed mouthguard material that the mouthguard material before processing.

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