160 research outputs found
Orthodontic Emergencies and Perspectives During and After the COVID-19 Pandemic: The Italian Experience
Objective: To investigate the types of dental emergencies that occurred during the lockdown period in Italy (12th March—4th May) and to investigate future therapeutic preferences related to the use of different types of appliances. Material and Methods: A questionnaire dedicated to assessing dental emergencies during the lockdown period and surveying the resumption of orthodontic practice was submitted to clinicians in digital form. The first part of the questionnaire, focused on the orthodontic emergencies that were encountered in relation to the different types of orthodontic appliances and how these were resolved. The second part of the questionnaire was devoted to the resumption of clinical practice; in particular, it was designed to assess whether and what percentage of clinicians are willing to change the duration of appointments in relation to the different types of appliance used, asking them whether their approach to orthodontic treatment would change in the coming months as compared to the pre-COVID-19 era. Results: Results show that in most cases (82%), the percentage of patients who experienced a dental emergency was less than 5% and that far fewer emergencies were attributable to removable (5.7%) than to fixed appliances (94.3%). Looking ahead, clinicians expressed a greater preference for using removable (60.8%) rather than fixed appliances (39.2%). Conclusion: During the lockdown, there relatively few orthodontic emergencies, many of which were handled by telephone consultation. However, a far lower percentage of emergencies were generated by removable (e.g., clear aligners) as opposed to fixed appliances (e.g., multibracket equipment), likely influencing the decision of the majority of clinicians to opt for removable appliances in the wake of the COVID-19 pandemic
Orthodontic Emergencies and Perspectives During and After the COVID-19 Pandemic: The Italian Experience
Objective: To investigate the types of dental emergencies that occurred during the lockdown period in Italy (12th March—4th May) and to investigate future therapeutic preferences related to the use of different types of appliances. Material and Methods: A questionnaire dedicated to assessing dental emergencies during the lockdown period and surveying the resumption of orthodontic practice was submitted to clinicians in digital form. The first part of the questionnaire, focused on the orthodontic emergencies that were encountered in relation to the different types of orthodontic appliances and how these were resolved. The second part of the questionnaire was devoted to the resumption of clinical practice; in particular, it was designed to assess whether and what percentage of clinicians are willing to change the duration of appointments in relation to the different types of appliance used, asking them whether their approach to orthodontic treatment would change in the coming months as compared to the pre-COVID-19 era. Results: Results show that in most cases (82%), the percentage of patients who experienced a dental emergency was less than 5% and that far fewer emergencies were attributable to removable (5.7%) than to fixed appliances (94.3%). Looking ahead, clinicians expressed a greater preference for using removable (60.8%) rather than fixed appliances (39.2%). Conclusion: During the lockdown, there relatively few orthodontic emergencies, many of which were handled by telephone consultation. However, a far lower percentage of emergencies were generated by removable (e.g., clear aligners) as opposed to fixed appliances (e.g., multibracket equipment), likely influencing the decision of the majority of clinicians to opt for removable appliances in the wake of the COVID-19 pandemic
Location, quality and choice of hospital: Evidence from England 2002–2013
We investigate (a) how patient choice of hospital for elective hip replacement is influenced by distance, quality and waiting times, (b) differences in choices between patients in urban and rural locations, (c) the relationship between hospitals' elasticities of demand to quality and the number of local rivals, and how these changed after relaxation of constraints on hospital choice in England in 2006. Using a data set on over 500,000 elective hip replacement patients over the period 2002 to 2013 we find that patients became more likely to travel to a provider with higher quality or lower waiting times, the proportion of patients bypassing their nearest provider increased from 25% to almost 50%, and hospital elasticity of demand with respect to own quality increased. By 2013 average hospital demand elasticity with respect to readmission rates and waiting times were −0.2 and −0.04. Providers facing more rivals had demand that was more elastic with respect to quality and waiting times. Patients from rural areas have smaller disutility from distance
Evaluating the Correlation between Overjet and Skeletal Parameters Using DVT
Aim. To evaluate the degree of correlation between a dental parameter of immediate clinical relevance (overjet) with skeletal (ANB angle) and dentoskeletal parameters such as the IMPA angle and upper incisor-bispinal angle. Materials and Methods. A sample of 42 subjects, all in complete permanent dentition and without a history of orthodontic treatment or systemic pathologies, was subdivided into 2 groups: group 1 consisted of 25 subjects with ANB angle 0°–4° (skeletal class I), and group 2 was made up of 17 subjects with ANB angle >4° (skeletal class II). Each subject underwent cone-beam computed tomography (CBCT). For each right and left CBCT, the following parameters were measured: (1) ANB, (2) OJ (overjet), (3) IMPA angle, and (4) upper incisor-bispinal angle (U1/ANS-PNS). Results. Analysis of the entire sample revealed that both right and left overjets were correlated in a statistically significant fashion (<0.001) with ANB. No correlation between overjet and IMPA emerged, while a weak correlation between overjet and the left U1-bispinal plane was ascertained. Conclusions. Overjet may be a reliable predictor of ANB, and to a lesser extent the U1-bispinal plane, particularly in skeletal class II
3D FEM comparison of lingual and labial orthodontics in en masse retraction
BACKGROUND: The aim of this study was to compare displacements and stress after en masse retraction of mandibular dentition with lingual and labial orthodontics using three-dimensional (3D) finite element models (FEM).METHODS: A 3D FEM of each lower tooth was constructed and located as appropriate to Roth's prescription. The 0.018-in. GAC Roth Ovation labial and Ormco 7th Generation lingual brackets were virtually bonded to the lower teeth and threaded with 0.018 × 0.025- and 0.016 × 0.022-in. SS labial (Tru-Arch form, small size) and lingual (mushroom) archwires. En masse retraction was simulated by applying 300 g of distal force from the canine to the second premolar on the 0.016 × 0.022-in. SS labial and lingual archwires. The type of finite element used in the analysis was an eight-noded brick element. The Algor program (Algor Inc., Pittsburgh, PA, USA) was used to calculate the strains and displacements at each nodal point.RESULTS: Lingual tipping and extrusion of the anterior dentition occurred with both archwires. At the premolars and first molars, intrusion, lingual movements, and lingual tipping were seen with the labial archwire, while intrusion was accompanied by labial movements, mesial tipping, and buccal rotation with lingual mechanics.CONCLUSIONS: Lingual vs. labial bracket placement influences the pattern of tooth movement, but the stress that occurs around the teeth can be accurately mapped using a 3D FEM model
Efficacy of swm appliance in the expression of first-, second- and third-order information in Class I and Class II
To assess the efficacy of a multibracket appliance?Straight-wire Mirabella (SWM) prescription?in terms of achieving the ideal first-, second- and third-order values proposed by Andrews. A total sample of 46 Caucasian subjects was divided into two groups: 23 with class I malocclusion (Group 1), and 23 with class II malocclusion (Group 2). The treatment protocol involved fixed multibracket appliances?SWM prescription?for both groups, with the addition of class II elastics for Group 2. Values for ?U1-PP, ?IMPA, in-out, tip and torque were measured on digital scans, and the results obtained were compared with the ideal values proposed by Andrews. Statistically significant differences were revealed between the entire sample and Andrews? values for: in-out on upper lateral incisors and upper canines; tip on the upper first premolars, upper second premolars, upper first molars and upper canines; and torque on the lower central incisors, lower lateral incisors, lower canines and lower first premolars. However, comparison of Groups 1 and 2 revealed statistically significant differences only at the lower lateral incisors. The use of class II elastics influenced ?IMPA values, but not ?U1-PP. The efficacy of the multibracket appliance?SWM prescription?in expressing first- second- and, to a lesser extent, third-order information was demonstrated in both class I and class II malocclusions. Class II elastics only influenced the third-order expression on the lower lateral incisors and the ?IMPA
Linestrength ratio spectroscopy as a new primary thermometer for redefined Kelvin dissemination
Experimental methods for primary thermometry, after Kelvin unit redefinition on May 2019, become based on a known value of the Boltzmann constant rather than by measuring temperature with respect to a reference point. In this frame, we propose Linestrength Ratio Thermometry (LRT) as a candidate method for primary thermometry in the 9-700 K temperature range. Temperature accuracies at the ppm level are prospected for LRT applied to optical transitions of the CO molecule in the range 80-700 K and of a rare-earth-doped crystal in the 9-100 K one. Future implementations of this technique can contribute to measure the calibration- discrepancies in the ITS-90 metrological scale of thermodynamic temperature which can have a measurable impact in applications ranging from fundamental-physics to meteorology and climatology
Heterogeneous effects of patient choice and hospital competition on mortality
We examine whether the relaxation of constraints on patient choice of hospital in the English National Health Service in 2006 led to greater changes in mortality for hospitals which faced more rivals before the choice reform. We use patient level data from 2002 to 2010 for three high volume emergency conditions with high mortality risk: acute myocardial infarction (AMI) (288,279 patients), hip fracture (91,005 patients), stroke (214,103 patients). Since mortality risk varies by sub-diagnoses of AMI and stroke we include indicators for sub-diagnoses in the covariates. We also allow for the effect of covariates on mortality to differ before and after the 2006 choice reform. We find that the choice reform reduced mortality risk for hip fracture patients by 0.62% (95% CI: 1.22%, 0.01%), compared with the 2002/3–2010/11 mean of 3.5%, but had statistically insignificant negative effects for AMI and stroke. The reform also had heterogeneous effects across AMI and stroke sub-diagnoses, reducing mortality for 3% of AMI patients and 21% of stroke patients. The reduction in hip fracture mortality was greater for more deprived patients. Policies to increase competition and give patients greater choice are likely to have heterogeneous effects depending on details of patient case mix and market conditions
Patient choice and the effects of hospital market structure on mortality for AMI, hip fracture and stroke patients
We examine (a) the effect of market structure on the level of mortality for AMI, hip fracture, and stroke between 2002/3 and 2010/11 and (b) whether this effect changed after the introduction of Choice policy in 2006 which gave patients the right to a wider choice of hospital. For AMI and hip fracture, hospitals with more rivals had higher mortality at the beginning of the period but this effect became smaller over the period. We find that the decline in the detrimental effect of market structure predated the introduction of Choice. Market structure had no effect on stroke mortality
Market structure, patient choice and hospital quality for elective patients
We examine the change in the effect of market structure on hospital quality for elective procedures (hip and knee replacements, and coronary artery bypass grafts) following the 2006 loosening of restrictions on patient choice of hospital in England. We allow for time-varying endogeneity due to the effect of unobserved patient characteristics on patient choice of hospital using Two Stage Residual Inclusion. We find that the change in the effect of market structure due to the 2006 choice reforms was to reduce quality by increasing the probability of a post-operative emergency readmission for hip and knee replacement patients. There was no effect of the choice reform on hospital quality for coronary bypass patients. We find no evidence of self-selection of patients into hospitals, suggesting that a rich set of patient-level covariates controls for differences in casemix
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