Comparative Cephalometric Study of Nasal Cavity Growth Patterns in Seven Animal Models

1994 ◽  
Vol 31 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Albert Losken ◽  
Mark P. Mooney ◽  
Michael I. Siegel
Keyword(s):  
Animal Models ◽  
Nasal Cavity ◽  
Rhesus Monkeys ◽  
Growth Models ◽  
Cavity Growth ◽  
Shape Index ◽  
Growth Patterns ◽  
X Rays ◽  
Cross Sectional ◽  
Somatic Development

Although primates have been the craniofacial growth models of choice, recent circumstances have stimulated the search for nonprimate models. In a series of studies we have described changes in various regions of the craniofacial complex for seven commonly used animal models. The present study examined the bony nasal cavity. One hundred and forty-four serial and cross-sectional lateral head x-rays were obtained for unoperated controls from previous growth studies. The sample consisted of data from 26 rats, 21 rabbits, 21 domestic cats, 23 domestic dogs, 17 baboons, 16 rhesus monkeys, and 20 chimpanzees. Comparative human data was taken from the Bolton Standards. The samples were divided into three age categories based on dental and somatic development. Midsagittal nasal cavity measurements included length, height, shape index, and area. Analysis was based on the percent increase in measures from the Infant condition. Three major shapes were discerned at adulthood (1) vertical quadrangles (humans and cats); (2) triangles (chimpanzees, rhesus monkeys, and baboons), and (3) horizontal quadrangles (rabbits, rats, and dogs). Results showed that overall shape was best modeled by the chimpanzee and, as a nonprimate model, the laboratory cat. Rabbits and rats also showed similar percent changes for length or height dimensions at different ages, suggesting that these animals may be acceptable, inexpensive alternatives to primates in some experimental situations.

X-ray micro tomography in the scanning electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 106-107 ◽  
Author(s):  
W. Brünger
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Target Surface ◽  
The Body ◽  
X Rays ◽  
Cross Sectional ◽  
X Ray ◽  
Micro Tomography ◽  
Scanning Electron

Reconstructive tomography is a new technique in diagnostic radiology for imaging cross-sectional planes of the human body /1/. A collimated beam of X-rays is scanned through a thin slice of the body and the transmitted intensity is recorded by a detector giving a linear shadow graph or projection (see fig. 1). Many of these projections at different angles are used to reconstruct the body-layer, usually with the aid of a computer. The picture element size of present tomographic scanners is approximately 1.1 mm2.Micro tomography can be realized using the very fine X-ray source generated by the focused electron beam of a scanning electron microscope (see fig. 2). The translation of the X-ray source is done by a line scan of the electron beam on a polished target surface /2/. Projections at different angles are produced by rotating the object.During the registration of a single scan the electron beam is deflected in one direction only, while both deflections are operating in the display tube.

Characterization of Rh/Si multilayer structure by HREM and HAADF

1992 ◽  
Vol 50 (1) ◽  
pp. 122-123
Author(s):  
Y. Cheng ◽  
J. Liu ◽  
M.B. Stearns ◽  
D.G. Steams
Keyword(s):  
Normal Incidence ◽  
High Resolution Electron Microscopy ◽  
X Rays ◽  
Beam Direction ◽  
Cross Sectional ◽  
Optical Elements ◽  
Resolution Electron ◽  
Point To Point ◽  
Better Than

The Rh/Si multilayer (ML) thin films are promising optical elements for soft x-rays since they have a calculated normal incidence reflectivity of ∼60% at a x-ray wavelength of ∼13 nm. However, a reflectivity of only 28% has been attained to date for ML fabricated by dc magnetron sputtering. In order to determine the cause of this degraded reflectivity the microstructure of this ML was examined on cross-sectional specimens with two high-resolution electron microscopy (HREM and HAADF) techniques.Cross-sectional specimens were made from an as-prepared ML sample and from the same ML annealed at 298 °C for 1 and 100 hours. The specimens were imaged using a JEM-4000EX TEM operating at 400 kV with a point-to-point resolution of better than 0.17 nm. The specimens were viewed along Si [110] projection of the substrate, with the (001) Si surface plane parallel to the beam direction.

Changes in the parameters of nasal breathing and parameters of the upper respiratory tract during orthognathic operations in patients with II and III skeletal class of jaw anomalies

2020 ◽  
pp. 22-27
Author(s):  
S.Sh. Gammadaeva ◽  
M.I. Misirkhanova ◽  
A.Yu. Drobyshev
Keyword(s):  
Respiratory Tract ◽  
Nasal Cavity ◽  
Nasal Septum ◽  
Cross Sectional Area ◽  
Upper Respiratory Tract ◽  
Sectional Area ◽  
Nasal Breathing ◽  
Cross Sectional ◽  
Skeletal Class ◽  
Upper Respiratory

The study analyzed the functional parameters of nasal breathing, linear parameters of the nasal aperture, nasal cavity and nasopharynx, volumetric parameters of the upper airways in patients with II and III skeletal class of jaw anomalies before and after orthognathic surgery. The respiratory function of the nose was assessed using a rhinomanometric complex. According to rhinoresistometry data, nasal resistance and hydraulic diameter were assessed. According to the data of acoustic rhinometry, the minimum cross-sectional area along the internal valve, the minimum cross-sectional area on the head of the inferior turbinate and nasal septum and related parameters were estimated. According to the CBCT data, the state of the nasal septum, the inferior turbinates, the nasal aperture, the state of the nasal cavity, and the linear values of the upper respiratory tract (nasopharynx) were analyzed. The patients were divided into 4 groups according to the classification of the patency of the nasal passages by

scholarly journals Modelling growth curves of the normal infant’s mandible: 3D measurements using computed tomography

2021 ◽  
Author(s):  
Jan Aart M. Schipper ◽  
Manouk J. S. van Lieshout ◽  
Stefan Böhringer ◽  
Bonnie L. Padwa ◽  
Simon G. F. Robben ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Growth Models ◽  
Normal Growth ◽  
Growth Patterns ◽  
Ct Scans ◽  
Mandibular Ramus ◽  
Linear Measurements ◽  
Mandibular Growth ◽  
Gonial Angle ◽  
Mandibular Body

Abstract Objectives Data on normal mandibular development in the infant is lacking though essential to understand normal growth patterns and to discriminate abnormal growth. The aim of this study was to provide normal linear measurements of the mandible using computed tomography performed in infants from 0 to 2 years of age. Material and methods 3D voxel software was used to calculate mandibular body length, mandibular ramus length, bicondylar width, bigonial width and the gonial angle. Intra- and inter-rater reliability was assessed for these measurements. They were found to be sufficient for all distances; intra-class correlation coefficients were all above 0.9. Regression analysis for growth modelling was performed. Results In this multi-centre retrospective study, 109 CT scans were found eligible that were performed for various reasons (e.g. trauma, craniosynostosis, craniofacial abscesses). Craniosynostosis patients had larger mandibular measurements compared to non-craniosynostosis patients and were therefore excluded. Fifty-one CT scans were analysed. Conclusions Analysis showed that the mandible increases more in size vertically (the mandibular ramus) than horizontally (the mandibular body). Most of the mandibular growth occurs in the first 6 months. Clinical relevance These growth models provide insight into normal mandibular development in the first 2 years of life. This reference data facilitates discrimination between normal and abnormal mandibular growth.

Evaluation of Nasal Passage Patency after Antigen and Histamine Challenge in Guinea Pigs by Acoustic Rhinometry

1997 ◽  
Vol 11 (1) ◽  
pp. 85-90 ◽  
Author(s):  
Setsuo Nakamoto ◽  
Yasuo Sakakura ◽  
Ole F. Pedersen ◽  
Kotaro Ukai
Keyword(s):  
Nasal Cavity ◽  
Guinea Pigs ◽  
Airway Resistance ◽  
Cross Sectional Area ◽  
Nasal Passage ◽  
Nasal Airway ◽  
Sectional Area ◽  
Cross Sectional ◽  
Percent Change ◽  
Nasal Airway Resistance

We investigated the effects of antigen and histamine on the nasal passage patency in guinea pigs with or without nasal allergy. The change of nasal patency was measured by acoustic rhinometry and nasal airway resistance. Acoustic reflections have been used in adult humans to determine nasal cavity dimensions in terms of cross-sectional areas as a function of the distance from the nostril. In order to measure nasal cavity dimensions in guinea pigs, we modified equipment for use in humans by decreasing sound tube dimensions, increasing sampling frequency, and applying a special nosepiece. The percent change of volume, minimum cross-sectional area, and nasal airway resistance showed the largest changes at 10 minutes after antigen challenge in sensitized guinea pigs. There was a significant correlation between the individual percent change of nasal airway resistance and volume or minimum cross-sectional area. Histamine, 102 to 105 μg/mL, caused a dose-dependent reduction in percent change of volume in the challenged side of nonsensitized guinea pigs, but not in the opposite side. These results indicate that the noninvasive acoustic reflections technique is useful in small experimental animals, especially to assess the effect of nasal cavity dimensions after the challenge of antigen or nonspecific stimuli.

An investigation into the extent of Lodox imaging usage in South Africa: Radiographer’s perspective

2021 ◽  
Author(s):  
Julius Muchui Thambura ◽  
Jeanette G.E du Plessis ◽  
Cheryl M E McCrindle ◽  
Tanita Cronje
Keyword(s):  
South Africa ◽  
Waiting Times ◽  
Cross Sectional Study ◽  
Trauma Patients ◽  
X Rays ◽  
Online Questionnaire ◽  
Cross Sectional ◽  
Imaging Protocol ◽  
X Ray ◽  
X Ray Imaging

Abstract Introduction Anecdotal evidence suggests that medical professionals in trauma units are requesting additional regional images using conventional x-ray systems, even after trauma patients have undergone full-body Lodox scans. Patients are then exposed to additional radiation, additional waiting times and an increased medical bill. This study aimed at investigating the extent to which Lodox systems were used in trauma units (n=28) in South Africa. Method In this descriptive cross-sectional study, the researcher invited one radiographer from the 28 hospitals in South Africa that use Lodox systems. Radiographers who were most experienced in using the Lodox system completed an online questionnaire. Results Twenty (71.43% n=20) out of twenty-eight radiographers responded. Most hospitals (90%, n=18) were referring patients for additional conventional x-ray images. Radiographers indicated that conventional x-rays were requested for the chest (27.80%, 10/36), the abdomen (16.67%, 6/36), the spine (13.89%, 5/36) and the extremities and skull (19.44%, 7/36). Additionally, radiographers reported using Lodox to perform procedures and examinations usually performed on conventional x-ray systems when conventional x-ray systems were not operational. Conclusion Currently, it is not clear if the use of conventional x-ray imaging following Lodox is necessary, but the results suggest that the practice is commonplace, with healthcare workers in most hospitals (90%, n=18) requesting additional x-ray imaging. The researcher thus recommends that an imaging protocol for Lodox imaging systems should be developed to guide the referral of the patients for further imaging.

Clinical and epidemiological features of community-acquired pneumonia during an epidemic of respiratory viral infection

2021 ◽  
Vol 31 (4) ◽  
pp. 490-498
Author(s):  
N. I. Izmozherova ◽  
A. A. Popov ◽  
E. R. Prokopeva ◽  
A. A. Kuryndina ◽  
E. I. Gavrilova ◽  
...  
Keyword(s):  
Risk Factors ◽  
Streptococcus Pneumoniae ◽  
Causative Agent ◽  
Community Acquired Pneumonia ◽  
Influenza Viruses ◽  
X Rays ◽  
Imaging Data ◽  
Cross Sectional ◽  
Epidemiological Features ◽  
Working Age

Community-acquired pneumonia (CAP) is one of the most common lower respiratory tract diseases. An increase in the CAP incidence has been reported to be associated with epidemics of acute respiratory viral infections (ARVI).Aim. Аssess clinical and epidemiological features of CAP in patients admitted to hospital during an ARVI epidemic.Methods. A cross-sectional study included 208 patient records. Medical history, physical examination, laboratory and imaging data were analyzed. CAP severity was assessed by CRB-65 scale and the systemic inflammatory response syndrome (SIRS) criteria.Results. Most CAP patients (75%) were of active working age; all presented signs of ARVI upon admission. Nasal mucosa diagnostic smears have revealed type A influenza viruses: H1N1 – 5 (83.3%) and H3N2 – 1 (16.7%) cases. 195 (93.8%) patients were not vaccinated against influenza. X-rays showed that unilateral (81.7%) and lobular pneumonia (55.8%) were the most common CAP types. 93.2% patients had nonsevere CAP, according to CRB-65. But 88 (42.3%) subjects qualified for SIRS upon admission. Concomitant conditions as risk factors of an adverse course of CAP were present in 89 patients (42.8%). Sputum analysis, if available, most frequently identified Streptococcus pneumoniae (23 cases or 38.9%) as a causative agent. Antibacterial drugs (ABD) used to treat CAP were ceftriaxone 206 (99%), macrolides 188 (90.4%), and fluoroquinolones 94 (45.2%). The initial antibacterial treatment regimens were: 186 (89.4%) prescriptions of ceftriaxone + macrolides, 16 (7.7%) prescriptions of ceftriaxone alone, and 6 (2.9%) prescriptions of levofloxacin. A switch between ABDs was reported in 78 (37.5%) cases, including 61 switches to fluoroquinolones. The median ABD administration duration was 10 (8 – 13) days.Conclusion. Most of the hospitalized CAP patients were of working age and not vaccinated against influenza. Streptococcus pneumoniae was the most common causative agent. PCR (polymerase chain reaction) smear analysis was performed only in 6 patients with ARVI, which does not allow us to assess the role of viruses and viral-bacterial associations in the etiology of CAP. In spite of non-severe CAP, all hospitalizations were justified, due to multiple risk factors of unfavorable prognosis of CAP and epidemiological factors. Most patients received a combination of generation 3 cephalosporins and macrolides as the initial therapy for CAP.

scholarly journals Determination of Sagittal Skeletal Discrepancy through Beta Angle: A Lateral Cephalometric Study

2020 ◽  
Vol 10 (3) ◽  
pp. 40-43
Author(s):  
Farah Saleem ◽  
Zubair H Awiasi
Keyword(s):  
Correct Diagnosis ◽  
Cross Sectional Study ◽  
X Rays ◽  
Class Iii ◽  
Cross Sectional ◽  
Skeletal Class ◽  
Skeletal Class Ii ◽  
Beta Angle ◽  
Third Line ◽  
Cephalometric Study

Introduction: Accurate classification and treatment planning relies on correct diagnosis of skeletal and dentalrelationships. Commonly used measurements used to classify sagittal relationship ANB and Wit’s appraisal are not without potential inherent problems which might lead to less accurate classification of sagittal dysplasia. To avoid these problems, a new approach Beta angle was introduced by Baik in 2004. Beta angle as it involves different landmarks of classifying anterior-posterior relationships is said to be devoid of those problems thus more reliable. We conducted a cross sectional study to measure the angle among patients presenting in Nishtar Institute of Dentistry Multan Pakistan. Materials and Method: Ninety pretreatment cephalometric x-rays of patients between ages 12 to 30 years were selected and studied. They were divided into three classes based on ANB angle and Wit’s appraisal. For the measurement of Beta angle, a line was drawn from the center of condyle (C) to point A and other to point B. A third line joining A to B was drawn. A line from point A perpendicular to line C-B was drawn and angle was measured between this perpendicular and line joining A-B. ANOVA was used to compare means of three groups. Pearson correlational coefficient was used to correlate relationship between Beta angle and ANB angle. Result: The results showed Beta angle ranged between 27° and 34° for class I. Subjects having angle less than 27° can be classified as skeletal class II and those with angles larger than 34° as skeletal class III subjects. Conclusion: Beta angle is reliable method for assessing and classifying sagittal skeletal discrepancies 

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