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1.
Proc Natl Acad Sci U S A ; 114(6): 1252-1257, 2017 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-28115723

RESUMEN

Enhanced vertical carbon transport (gravitational sinking and subduction) at mesoscale ocean fronts may explain the demonstrated imbalance of new production and sinking particle export in coastal upwelling ecosystems. Based on flux assessments from 238U:234Th disequilibrium and sediment traps, we found 2 to 3 times higher rates of gravitational particle export near a deep-water front (305 mg C⋅m-2⋅d-1) compared with adjacent water or to mean (nonfrontal) regional conditions. Elevated particle flux at the front was mechanistically linked to Fe-stressed diatoms and high mesozooplankton fecal pellet production. Using a data assimilative regional ocean model fit to measured conditions, we estimate that an additional ∼225 mg C⋅m-2⋅d-1 was exported as subduction of particle-rich water at the front, highlighting a transport mechanism that is not captured by sediment traps and is poorly quantified by most models and in situ measurements. Mesoscale fronts may be responsible for over a quarter of total organic carbon sequestration in the California Current and other coastal upwelling ecosystems.

2.
Am J Orthod Dentofacial Orthop ; 149(3): 416-28, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26926030

RESUMEN

INTRODUCTION: The purpose of this study was to present and validate a novel semiautomated method for 3-dimensional evaluation of the temporomandibular joint (TMJ) space and condylar and articular shapes using cone-beam computed tomographic data. METHODS: The protocol for 3-dimensional analysis with the Checkpoint software (Stratovan, Davis, Calif) was established by analyzing cone-beam computed tomographic images of 14 TMJs representing a range of TMJ shape variations. Upon establishment of the novel method, analysis of 5 TMJs was further repeated by several investigators to assess the reliability of the analysis. RESULTS: Principal components analysis identified 3 key components that characterized how the condylar head shape varied among the 14 TMJs. Principal component analysis allowed determination of the minimum number of landmarks or patch density to define the shape variability in this sample. Average errors of landmark placement ranged from 1.15% to 3.65%, and none of the 121 landmarks showed significant average errors equal to or greater than 5%. Thus, the mean intraobserver difference was small and within the clinically accepted margin of error. Interobserver error was not significantly greater than intraobserver error, indicating that this is a reliable methodology. CONCLUSIONS: This novel semiautomatic method is a reliable tool for the 3-dimensional analysis of the TMJ including both the form and the space between the articular eminence and the condylar head.


Asunto(s)
Tomografía Computarizada de Haz Cónico/estadística & datos numéricos , Procesamiento de Imagen Asistido por Computador/estadística & datos numéricos , Imagenología Tridimensional/estadística & datos numéricos , Articulación Temporomandibular/diagnóstico por imagen , Adolescente , Adulto , Puntos Anatómicos de Referencia/diagnóstico por imagen , Variación Anatómica , Niño , Femenino , Humanos , Masculino , Cóndilo Mandibular/diagnóstico por imagen , Variaciones Dependientes del Observador , Análisis de Componente Principal , Intensificación de Imagen Radiográfica/métodos , Reproducibilidad de los Resultados , Hueso Temporal/diagnóstico por imagen , Adulto Joven
3.
J Oral Maxillofac Surg ; 73(12 Suppl): S67-76, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26608156

RESUMEN

PURPOSE: Orthognathic surgery can induce changes in airway volume. The aim of this study was to determine whether there is a correlation of surgical movement of the maxilla or mandible to airway volume changes. MATERIALS AND METHODS: This was a prospective cohort study and the sample was composed of patients undergoing single-jaw orthognathic procedures from 2004 through 2007. Cone-beam computed tomograms were obtained before surgery (T0), immediately after surgery (T1), and at least 6 months after surgery (T2). The airway was segmented from 3-dimensional images and identified as the whole airway, consisting of the naso-, oro-, and hypopharynx. The volumetric percentage of change of the airway between time points was compared and correlated to the surgical movements using paired t test and cubic regression analysis. The level of statistical significance was set at a P value less than or equal to .05. RESULTS: The sample was composed of 33 patients. Sixteen patients underwent maxillary advancement with mean advancement of 5.4 mm (3 to 8 mm), 13 underwent mandibular advancement with mean advancement of 8.0 mm (5 to 15 mm), and 4 underwent mandibular setback of 4.0 mm. For maxillary advancement at T1, volume percentages of change for the whole airway and the naso-, oro-, and hypopharynx were 18.4 (P ≤ .05), 53.8 (P ≤ .05), 26.3, and 5.5%, respectively, and at T2, the changes were 10.0, 46.7 (P ≤ .05), 6.8, and 1.0%, respectively. For mandibular advancement at T1, volume percentages of change were 34.6 (P ≤ .05), 26.1, 54.1 (P ≤ .05), and 17.4%, respectively, and at T2, the changes were 15.0 (P ≤ .05), -3.7, 23.5 (P ≤ .05), and 12.1%, respectively. There were no meaningful long-term airway changes with mandibular setback. CONCLUSION: The study results suggest that there might be an anatomic limit to pharyngeal airway expansion associated with single-jaw orthognathic surgery.


Asunto(s)
Tomografía Computarizada de Haz Cónico/métodos , Procedimientos Quirúrgicos Ortognáticos/métodos , Faringe/diagnóstico por imagen , Adolescente , Adulto , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Hipofaringe/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador/métodos , Imagenología Tridimensional/métodos , Masculino , Mandíbula/cirugía , Avance Mandibular/métodos , Osteotomía Mandibular/métodos , Maxilar/cirugía , Osteotomía Maxilar/métodos , Nasofaringe/diagnóstico por imagen , Tamaño de los Órganos , Orofaringe/diagnóstico por imagen , Estudios Prospectivos , Adulto Joven
4.
J Oral Maxillofac Surg ; 73(3): 499-508, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25488314

RESUMEN

PURPOSE: To examine and compare the skeletal and dental effects of surgically assisted rapid palatal expansion (SARPE) and multipiece Le Fort osteotomy using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: This was a prospective cohort study. Patients underwent SARPE or multipiece Le Fort I osteotomy to address maxillary transverse deficiency. CBCT scans were taken preoperatively, immediately postoperatively or after retention, and at least 6 months postoperatively. Four landmark measurements and ratios of dental-to-skeletal change were used to follow skeletal and dental widths in the posterior and anterior maxillary regions. Wilcoxon signed-rank test and Wilcoxon 2-sample rank-sum test were used to compare the landmark measurements and the ratio of dental-to-skeletal change for the 2 surgeries. A P value less than .05 was statistically significant. RESULTS: Thirteen patients (mean, 28.3 yr old; 7 women) were enrolled: 9 were treated by multipiece Le Fort I osteotomy and 4 were treated by SARPE. The ratios of dental-to-skeletal expansion in the posterior maxilla for the Le Fort procedure and SARPE were 0.70 ± 0.41 and 25.20 ± 15.8, respectively, and the dental-to-skeletal relapses were 1.17 ± 0.80 and -3.63 ± 3.70, respectively. The ratios of dental-to-skeletal expansion in the anterior maxilla for the Le Fort procedure and SARPE were 0.58 ± 0.38 and 31.80 ± 59.4, respectively, and the dental-to-skeletal relapses were 2.25 ± 3.41 and 4.86 ± 8.10, respectively. CONCLUSION: There was greater correlation between dental and skeletal changes in the multipiece Le Fort procedure, indicating bodily separation of the segments, whereas the SARPE showed noteworthy dental and skeletal tipping. Dental relapse was greater than skeletal relapse for these 2 procedures.


Asunto(s)
Tomografía Computarizada de Haz Cónico/métodos , Maxilar/cirugía , Osteotomía Le Fort/métodos , Técnica de Expansión Palatina , Adolescente , Adulto , Puntos Anatómicos de Referencia/diagnóstico por imagen , Cefalometría/métodos , Estudios de Cohortes , Diente Canino/diagnóstico por imagen , Arco Dental/diagnóstico por imagen , Arco Dental/cirugía , Femenino , Estudios de Seguimiento , Humanos , Imagenología Tridimensional/métodos , Estudios Longitudinales , Masculino , Maxilar/diagnóstico por imagen , Persona de Mediana Edad , Diente Molar/diagnóstico por imagen , Osteotomía Le Fort/instrumentación , Técnica de Expansión Palatina/instrumentación , Hueso Paladar/diagnóstico por imagen , Estudios Prospectivos , Recurrencia , Férulas (Fijadores) , Adulto Joven
5.
Am J Orthod Dentofacial Orthop ; 145(5): 579-94, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24785922

RESUMEN

INTRODUCTION: The purpose of this study was to evaluate the concept that the affected and contralateral sides do not grow at the same rate in patients with hemifacial microsomia. Changes in the cranial base, maxilla, mandible, and occlusal plane were evaluated on 3-dimensional images from cone-beam computed tomography data in untreated patients. METHODS: Six patients were classified as having mandibular Pruzansky/Kaban type I, IIA, or IIB hemifacial microsomia. Cone-beam computed tomography (MercuRay; Hitachi, Tokyo, Japan) scans were taken before orthodontic treatment during both growth and postpuberty periods. RESULTS: The cranial base as defined by the position of the mastoid process was in a different position between the affected and contralateral control sides. The nasomaxillary length or height was shorter on the affected side for all 6 patients with hemifacial microsomia regardless of its severity, and it grew less than on the contralateral control side in 5 of the 6 patients. The occlusal plane angle became more inclined in 4 of the 6 patients. The mandibular ramus was shorter on the affected side in all patients and grew less on the affected side in 5 of the 6 patients. The mandibular body grew slower, the same, or faster than on the control side. CONCLUSIONS: The cranial base, position of the condyle, lengths of the condyle and ramus, and positions of the gonial angle and condyle can vary between the affected and contralateral control sides of patients with hemifacial microsomia, with the ramus and nasomaxillary length usually growing slower than they grow on the control side. These results suggest that many factors affect the growth rate of the craniofacial region and, specifically, the mandible in patients with hemifacial microsomia.


Asunto(s)
Tomografía Computarizada de Haz Cónico/métodos , Huesos Faciales/crecimiento & desarrollo , Síndrome de Goldenhar/fisiopatología , Imagenología Tridimensional/métodos , Cráneo/crecimiento & desarrollo , Puntos Anatómicos de Referencia/diagnóstico por imagen , Cefalometría/métodos , Niño , Preescolar , Oclusión Dental , Huesos Faciales/diagnóstico por imagen , Femenino , Estudios de Seguimiento , Síndrome de Goldenhar/clasificación , Síndrome de Goldenhar/diagnóstico por imagen , Humanos , Estudios Longitudinales , Masculino , Mandíbula/diagnóstico por imagen , Mandíbula/crecimiento & desarrollo , Cóndilo Mandibular/diagnóstico por imagen , Cóndilo Mandibular/crecimiento & desarrollo , Apófisis Mastoides/diagnóstico por imagen , Apófisis Mastoides/crecimiento & desarrollo , Maxilar/diagnóstico por imagen , Maxilar/crecimiento & desarrollo , Nariz/diagnóstico por imagen , Nariz/crecimiento & desarrollo , Pubertad , Estudios Retrospectivos , Cráneo/diagnóstico por imagen , Base del Cráneo/diagnóstico por imagen , Base del Cráneo/crecimiento & desarrollo , Articulación Temporomandibular/diagnóstico por imagen , Articulación Temporomandibular/crecimiento & desarrollo
6.
Am J Orthod Dentofacial Orthop ; 143(4): 574-85, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23561420

RESUMEN

INTRODUCTION: The goal of this study was to develop a more accurate formula to forecast tooth-size discrepancies in patients based on not only the size of the whole teeth but also functional arch components derived from normal cusp-fossa interdigitation that should be obtained as the final treatment goal. METHODS: A total of 141 dental casts from Dr Larry Andrews' collection of "normal occlusions" that never received orthodontic treatment were scanned with an Ortho Insight 3D Laser Scanner (Motion View Software, Chattanooga, Tenn). Individual tooth sizes and portions of tooth sizes were measured with the Motion View Software. For each set of models, potential tooth-size discrepancies were calculated by using both the original Bolton analysis and the new Johnson/Bailey analysis developed by this team at the University of California at San Francisco (UCSF). Six tooth-size discrepancy ratios were computed and included the Bolton (2) and the new (4) Johnson/Bailey analysis ratios for the anterior arch component, posterior arch component, and overall ratio of the maxillary and mandibular arches. The Johnson/Bailey analysis utilized different landmarks and groups of teeth. It consequently divided the maxillary segment by the mandibular segment, in contrast to the Bolton ratios, which divided the mandibular sums by the maxillary totals. RESULTS: The Bolton anterior segment ratio ranged from 70.68 to 84.81, with a mean of 77.91 (SD, 2.43) (3.1%). The Bolton overall ratio ranged from 86.19 to 96.62, with a mean of 91.64 (SD, ±1.74) (1.8%). The Johnson/Bailey posterior discrepancy ratio ranged from 0.98 to 1.23, with a mean of 1.10 (SD, ±0.04) (3.6%). Its anterior discrepancy ratio ranged from 0.91 to 1.14, with a mean of 1.03 (SD, ±0.04) (3.9%). The Johnson/Bailey overall discrepancy ratio ranged from 0.98 to 1.15, with a mean of 1.06 (SD, ±0.03) (2.8%). CONCLUSIONS: Two methods were used to forecast tooth-size discrepancies between opposing arches in a sample with clinically acceptable occlusions. The new approach provided more specific ratios utilizing more clinically relevant functional arch components derived from dental cusp-fossa interdigitation.


Asunto(s)
Puntos Anatómicos de Referencia/anatomía & histología , Imagenología Tridimensional/métodos , Rayos Láser , Odontometría/métodos , Diente/anatomía & histología , Diente Premolar/anatomía & histología , Diente Canino/anatomía & histología , Arco Dental/anatomía & histología , Predicción , Holografía , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Incisivo/anatomía & histología , Mandíbula/anatomía & histología , Maxilar/anatomía & histología , Modelos Dentales , Diente Molar/anatomía & histología , Estudios Retrospectivos , Corona del Diente/anatomía & histología , Interfaz Usuario-Computador
7.
Sci Rep ; 13(1): 1455, 2023 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-36702914

RESUMEN

The oceanic South Atlantic Convergence Zone (SACZ) has played a major role during South America's 2021/2022 summer extreme rainy season, being responsible for more than 90% of the precipitation in some regions of Southeast Brazil and in some regions of the Southwestern Atlantic Ocean (SWA). The summer of 2021/2022 was unique and rare and considered an abnormally humid season as verified by official Brazilian Institutes. First, the unusual number of cases of SACZ episodes (seven), was the highest recorded in the last decade. Second, all the cases that occurred were oceanic SACZ that assumed characteristics of an Atmospheric River and produced an excessively anomalous amount of precipitation during this period. Excess precipitation along with the regions located in mountainous and very uneven relief, which by orographic effects favors high precipitation volumes, were responsible for amplifying the observed impacts, such as landslides and floods that caused several losses to society. We also showed the main effects of coupling and interaction between the waters of the surface layer of the SWA and the atmosphere. Our learning from this study ends with the unprecedented results of how the marine atmospheric boundary layer (MABL) is locally modulated by the sea surface temperature (SST) that lies just below it. Until the present moment, we emphasize that this important mechanism has not been widely highlighted in the literature, showing that even though the ocean is colder than before oceanic SACZ is established, it is still warmer than the overlying air, thus, the ocean continues to be an active source of heat and moisture for the atmosphere and enhances the MABL instability process.

8.
J Oral Maxillofac Surg ; 69(11): e385-94, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21778015

RESUMEN

PURPOSE: The purpose of the present prospective study was to develop a 3-dimensional analysis of the airway using cone-beam computed tomography (CBCT) and to determine whether changes in the airway before and after orthognathic surgery correlate on 2-dimensional lateral cephalogram and 3-dimensional CBCT images. MATERIALS AND METHODS: Patients requiring orthognathic surgery during 2004 to 2005 were recruited for the present study. Lateral cephalograms and CBCT scans were obtained at 3 points: preoperatively, within 1 month postoperatively, and after 6 months postoperatively. The nasopharynx, oropharynx, and hypopharynx were segmented on both the radiograph and the CBCT scan for each patient in a repeatable manner at each point. For the lateral cephalogram, linear measurements in the middle of each of the 3 segments were obtained. For the CBCT, volumetric measurements of each of the 3 segments were obtained. The intrarater variability was assessed, and Pearson's correlation was used to compare the 2 imaging modalities. RESULTS: A total of 20 patients scheduled for orthognathic surgery were recruited for the present study. Of the 20 patients, 13 were female and 7 were male. The mean age at surgery was 23.85 years (range 14 to 43). Of the 20 patients, 6 underwent maxillary advancement only, 8 underwent mandibular advancement with or without genioplasty, and 6 underwent 2-jaw surgery or mandibular setback. We examined the entire cohort without separation into procedure or examination point and found a weak, but statistically significant, correlation between the linear and volume measurements in the nasopharyngeal and oropharyngeal regions but not in the hypopharyngeal region (r = 0.43, P < .002; r = 0.49, P < .0002; r = 0.16, P = .26, respectively). The maxillary advancement group (n = 6) demonstrated a correlation between the linear and volume measurements in the nasopharyngeal region (r = 0.53, P = .03). The mandibular advancement with or without genioplasty group (n = 8) showed a correlation in the nasopharyngeal and oropharyngeal regions (r = 0.55, P < .02, and r = 0.46, P = .05, respectively). For the combination/setback procedures (n = 6), a correlation was found in the oropharyngeal region (r = 0.64, P < .01). All other comparisons between the linear and volume measurements did not correlate. Additionally, no correlations were found between the linear and volumetric change in airway size between 6 months postoperatively and preoperatively, except for the oropharyngeal region (r = 0.67, P < .01). CONCLUSION: We present a method of measuring the airway that could be used for both 2-dimensional and 3-dimensional images. It includes segmentation of the pharyngeal airway into its nasopharyngeal, oropharyngeal, and hypopharyngeal components. Correlations were found between the linear and volumetric measurements of the segmented airway in patients who had undergone orthognathic surgery; however, the correlations were generally weak.


Asunto(s)
Cefalometría/métodos , Tomografía Computarizada de Haz Cónico/métodos , Procedimientos Quirúrgicos Ortognáticos , Faringe/diagnóstico por imagen , Adolescente , Adulto , Mentón/cirugía , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Foramen Magno/diagnóstico por imagen , Humanos , Hipofaringe/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador/métodos , Imagenología Tridimensional/métodos , Masculino , Mandíbula/cirugía , Avance Mandibular/métodos , Maxilar/cirugía , Hueso Nasal/diagnóstico por imagen , Nasofaringe/diagnóstico por imagen , Orofaringe/diagnóstico por imagen , Osteotomía Le Fort/métodos , Osteotomía Sagital de Rama Mandibular/métodos , Estudios Prospectivos , Silla Turca/diagnóstico por imagen , Adulto Joven
9.
Am J Orthod Dentofacial Orthop ; 140(5): 607-15, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22051480

RESUMEN

INTRODUCTION: In this study, using a cone-beam computed tomography system, we evaluated the airways of 30 adults. METHODS: The shapes of the 3-dimensional volume of the airway were analyzed and compared among the subjects by using surface superimposition software techniques. RESULTS: The airway had the greatest variability in the hypopharynx, in the region below the epiglottis, and above the vocal folds. Moderate variation was apparent at the nares, behind the soft palate, and at the base of the tongue. Conservation of form was seen at the central portion of the nasal airway surrounding the inferior turbinate. CONCLUSIONS: The potential for comparing the shape of the airway among subjects is possible.


Asunto(s)
Tomografía Computarizada de Haz Cónico/métodos , Imagenología Tridimensional/métodos , Faringe/diagnóstico por imagen , Adulto , Puntos Anatómicos de Referencia/diagnóstico por imagen , Cefalometría/métodos , Epiglotis/diagnóstico por imagen , Femenino , Humanos , Hipofaringe/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador/métodos , Masculino , Cartílagos Nasales/diagnóstico por imagen , Nasofaringe/diagnóstico por imagen , Nariz/diagnóstico por imagen , Orofaringe/diagnóstico por imagen , Paladar Blando/diagnóstico por imagen , Programas Informáticos , Lengua/diagnóstico por imagen , Cornetes Nasales/diagnóstico por imagen , Pliegues Vocales/diagnóstico por imagen , Adulto Joven
10.
Am J Orthod Dentofacial Orthop ; 139(4 Suppl): e377-89, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21435546

RESUMEN

INTRODUCTION: The goal of this study was to look at mandibular cortical bone in live patients using cone-beam computed tomography (CBCT) to determine differences in cortical plate thicknesses and mandibular cross-sectional height and width in patients with different vertical facial dimensions. METHODS: A total of 111 scanned patients were used. Of these subjects, 43 were included in the average vertical facial dimension group (average face), 34 in the high vertical facial group (long face), and 34 in the low vertical facial group (square short face). Cross-sectional slices of the mandible were developed with the cone-beam scans to evaluate the cortical bone between the dentition at 13 locations. Each section was then measured at 8 sites, which included 1 height and 2 width measures of the cross-sectional area and 5 cortical plate thicknesses. An analysis of variance (ANOVA) with a posthoc Bonferroni statistical analysis was used with a significance level of P  ≤0.0167. RESULTS: The long-face group had slightly more narrow cortical bone than the other 2 facial groups at a few selected sites of the mandible. The height of the cross-sectional area of the mandible in the long-face group was shorter posteriorly than in the other 2 groups and became greater toward the symphysis. CONCLUSIONS: Mandibular height and width differed more than cortical bone thickness among the 3 types of subjects with different vertical facial dimensions, but statistically significant differences were evident is some sites for cortical bone thickness.


Asunto(s)
Cara/anatomía & histología , Mandíbula/anatomía & histología , Mandíbula/diagnóstico por imagen , Desarrollo Maxilofacial , Adolescente , Adulto , Anciano , Análisis de Varianza , Anatomía Transversal , Densidad Ósea , Cefalometría , Niño , Tomografía Computarizada de Haz Cónico , Femenino , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Caracteres Sexuales , Estadísticas no Paramétricas , Dimensión Vertical , Adulto Joven
11.
Sci Rep ; 11(1): 10648, 2021 05 20.
Artículo en Inglés | MEDLINE | ID: mdl-34017014

RESUMEN

Sea surface temperature (SST) anomalies caused by a warm core eddy (WCE) in the Southwestern Atlantic Ocean (SWA) rendered a crucial influence on modifying the marine atmospheric boundary layer (MABL). During the first cruise to support the Antarctic Modeling and Observation System (ATMOS) project, a WCE that was shed from the Brazil Current was sampled. Apart from traditional meteorological measurements, we used the Eddy Covariance method to directly measure the ocean-atmosphere sensible heat, latent heat, momentum, and carbon dioxide (CO2) fluxes. The mechanisms of pressure adjustment and vertical mixing that can make the MABL unstable were both identified. The WCE also acted to increase the surface winds and heat fluxes from the ocean to the atmosphere. Oceanic regions at middle and high latitudes are expected to absorb atmospheric CO2, and are thereby considered as sinks, due to their cold waters. Instead, the presence of this WCE in midlatitudes, surrounded by predominantly cold waters, caused the ocean to locally act as a CO2 source. The contribution to the atmosphere was estimated as 0.3 ± 0.04 mmol m-2 day-1, averaged over the sampling period. The CO2 transfer velocity coefficient (K) was determined using a quadratic fit and showed an adequate representation of ocean-atmosphere fluxes. The ocean-atmosphere CO2, momentum, and heat fluxes were each closely correlated with the SST. The increase of SST inside the WCE clearly resulted in larger magnitudes of all of the ocean-atmosphere fluxes studied here. This study adds to our understanding of how oceanic mesoscale structures, such as this WCE, affect the overlying atmosphere.

12.
Dysphagia ; 25(4): 323-33, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20814803

RESUMEN

Over the past 20 years, research on the physiology of swallowing has confirmed that the oropharyngeal swallowing process can be modulated, both volitionally and in response to different sensory stimuli. In this review we identify what is known regarding the sensory pathways and mechanisms that are now thought to influence swallowing motor control and evoke its response. By synthesizing the current state of research evidence and knowledge, we identify continuing gaps in our knowledge of these mechanisms and pose questions for future research.


Asunto(s)
Trastornos de Deglución/diagnóstico , Deglución/fisiología , Corteza Motora/fisiología , Vías Olfatorias/fisiología , Sensación/fisiología , Trastornos de Deglución/patología , Esófago/anatomía & histología , Esófago/patología , Esófago/fisiología , Humanos , Faringe/anatomía & histología , Faringe/patología , Faringe/fisiología , Estimulación Luminosa , Salivación , Olfato/fisiología
13.
J Prosthet Dent ; 104(3): 191-8, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20813233

RESUMEN

STATEMENT OF PROBLEM: Composite mandibular resection resulting in mandibular discontinuity can alter jaw motion, occlusal forces, and mastication, whether or not the jaw is reconstructed. The biomechanical events associated with these changes are difficult to assess clinically and, therefore, are not well documented or researched. PURPOSE: The purpose of this study was to model movements of a mandible with a discontinuity defect, and to compare them to movements of a mandible with its continuity restored by alloplastic reconstruction. MATERIAL AND METHODS: Computational models were created with a novel simulation platform. The variables designed into the models included gravity, external forces, and jaw muscle activity. Each jaw was observed at rest, when opened by external force or by muscle drive, and during the generation of unilateral occlusal force on the nonoperated side. Scarring was simulated with springlike forces. Outputs included individual muscle forces and torques, as well as mandibular incisor and condylar motions. RESULTS: Both models displayed plausible resting postures, and jaw opening with deviation toward the defect side when scarring was simulated. Opening caused by downward force on the incisors differed from that due to muscle activation. Jaw rotations during unilateral molar contact on the unaffected side were muscle specific and influenced by mandibular discontinuity. CONCLUSIONS: Plausible jaw movements after hemimandibulectomy and/or alloplastic reconstruction could be predicted by dynamic modeling. The effect of soft tissue forces on jaw posture and movements varied with the condylar support available. In both models, different opening trajectories were produced by external force on the jaw and by jaw muscle activation. Mandibular rotation during unilateral molar contact depended on which muscles were activated, and the availability of bilateral condylar support.


Asunto(s)
Sustitutos de Huesos , Simulación por Computador , Mandíbula/fisiopatología , Mandíbula/cirugía , Modelos Biológicos , Fenómenos Biomecánicos , Fuerza de la Mordida , Placas Óseas , Humanos , Cóndilo Mandibular/fisiología , Músculos Masticadores/fisiología , Movimiento/fisiología
14.
Am J Orthod Dentofacial Orthop ; 137(4 Suppl): S58-70, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20381763

RESUMEN

INTRODUCTION: The purpose of this research was to examine methods for assessing the shape and growth of the mandible 3 dimensionally. Furthermore, 1 method was defined and applied. METHODS: Thirty mandibles were assessed. An average or mean shape was determined, and the mandibles were ranked quantitatively, by using the root mean square (RMS), according to their variation from the mean. The rankings ranged from mandibles that were small, short, and narrow at the minus-RMS end, to large, tall, and broad at the plus-RMS end. A second analysis provided a method to superimpose a mandible over the average mandible and determine the differences from the average-derived mandible by using a spectrum of colors to indicate changes in a region. RESULTS: Variations in the mandible were greatest in the condylar heads, coronoid tips, canine-incisor dentoalveolar segment, and chin point. CONCLUSIONS: The visual images of the 30 segmented mandibles suggest that a new method of classification needs to be developed that extends the original 2-dimensional lateral evaluation to a total 3-dimensional view that provides new relationships, such as the direction of the condylar heads to the ramus and the ratio of the intergonial angle length to the intercondylar head length to define the narrowness of a mandible.


Asunto(s)
Cefalometría/métodos , Tomografía Computarizada de Haz Cónico , Imagenología Tridimensional/métodos , Mandíbula/diagnóstico por imagen , Adolescente , Adulto , Niño , Femenino , Humanos , Masculino , Mandíbula/anatomía & histología , Mandíbula/crecimiento & desarrollo , Persona de Mediana Edad , Distribución Normal , Adulto Joven
15.
Am J Orthod Dentofacial Orthop ; 137(5): 590-7, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20451777

RESUMEN

INTRODUCTION: In this prospective study, we compared differences in the diagnosis and treatment planning of impacted maxillary canines between 2 imaging modalities. METHODS: Twenty-five consecutive impacted maxillary canines were identified from the pool of patients seeking orthodontic treatment. The first set of radiographs consisted of traditional 2-dimensional (2D) images including panoramic, occlusal, and 2 periapical radiographs. The second set comprised prints of 3-dimensional (3D) volumetric dentition images obtained from a cone-beam computed tomography (CBCT) scan. Seven faculty member completed a questionnaire for every impacted canine and diagnostic radiographic modality (2D and 3D). RESULTS: The data show that the judges produced different decisions regarding localization depending on the x-ray method. There were 21% disagreement (or discordance) in the perceived mesiodistal cusp tip position and 16% difference in the perceived labiopalatal position. In the perception of root resorption of adjacent teeth, there was 36% lack of congruence. Twenty-seven percent of the teeth that were planned to be left, recovered, or extracted with the 2D radiographs had different treatment plans when the judges viewed the 3D CBCT images (McNemar test, chi-square, 4.45; P = 0.035). The clinicians' confidence of the accuracy of diagnosis and treatment plan was statistically higher for CBCT images (P <0.001). CONCLUSIONS: These results showed that 2D and 3D images of impacted maxillary canines can produce different diagnoses and treatment plans.


Asunto(s)
Tomografía Computarizada de Haz Cónico , Diente Canino/diagnóstico por imagen , Maxilar/diagnóstico por imagen , Planificación de Atención al Paciente , Radiografía Dental , Diente Impactado/diagnóstico por imagen , Adolescente , Adulto , Niño , Tomografía Computarizada de Haz Cónico/estadística & datos numéricos , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/estadística & datos numéricos , Imagenología Tridimensional/estadística & datos numéricos , Masculino , Variaciones Dependientes del Observador , Estudios Prospectivos , Radiografía de Mordida Lateral/estadística & datos numéricos , Radiografía Dental/estadística & datos numéricos , Radiografía Panorámica/estadística & datos numéricos , Resorción Radicular/diagnóstico por imagen , Corona del Diente/diagnóstico por imagen , Extracción Dental/estadística & datos numéricos , Técnicas de Movimiento Dental/estadística & datos numéricos , Adulto Joven
16.
Am J Speech Lang Pathol ; 29(2S): 1030-1043, 2020 07 10.
Artículo en Inglés | MEDLINE | ID: mdl-32650664

RESUMEN

Purpose Swallowing is a complex process, mediated by a broad bilateral neural network that spans from the brainstem to subcortical and cortical brain structures. Although the cortex's role in swallowing was historically neglected, we now understand, especially through clinical observations and research of patients with stroke, that it substantially contributes to swallowing control. Neuroimaging techniques (e.g., magnetic resonance imaging) have helped significantly to elucidate the role of cortical and subcortical brain areas, in general, and the importance of specific areas in swallowing control in healthy individuals and patients with stroke. We will review recent discoveries in cortical and subcortical neuroimaging research studies and their generalizability across patients to discuss their potential implications and translation to dysphagia diagnosis and treatment in clinical practice. Conclusions Stroke lesion locations have been identified that are commonly associated across patients with the occurrence and recovery of dysphagia, suggesting that clinical brain scans provide useful information for improving the diagnosis and treatment of patients with stroke. However, individual differences in brain structure and function limit the generalizability of these relationships and emphasize that the extent of the motor and sensory pathology in swallowing, and how the patient recovers, also depends on a patient's individual brain constitution. The involvement of the damaged brain tissue in swallowing control before the stroke and the health of the residual, undamaged brain tissue are crucial factors that can differ between individuals.


Asunto(s)
Trastornos de Deglución , Accidente Cerebrovascular , Encéfalo/diagnóstico por imagen , Deglución , Trastornos de Deglución/diagnóstico , Trastornos de Deglución/terapia , Humanos , Imagen por Resonancia Magnética , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/diagnóstico por imagen
17.
Nat Commun ; 11(1): 1903, 2020 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-32313028

RESUMEN

Summer 2019 observations show a rapid resurgence of the Blob-like warm sea surface temperature (SST) anomalies that produced devastating marine impacts in the Northeast Pacific during winter 2013/2014. Unlike the original Blob, Blob 2.0 peaked in the summer, a season when little is known about the physical drivers of such events. We show that Blob 2.0 primarily results from a prolonged weakening of the North Pacific High-Pressure System. This reduces surface winds and decreases evaporative cooling and wind-driven upper ocean mixing. Warmer ocean conditions then reduce low-cloud fraction, reinforcing the marine heatwave through a positive low-cloud feedback. Using an atmospheric model forced with observed SSTs, we also find that remote SST forcing from the central equatorial and, surprisingly, the subtropical North Pacific Ocean contribute to the weakened North Pacific High. Our multi-faceted analysis sheds light on the physical drivers governing the intensity and longevity of summertime North Pacific marine heatwaves.

18.
J Oral Maxillofac Surg ; 67(3): 491-500, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19231771

RESUMEN

PURPOSE: The purpose of this study is to assess cortical thickness, height, and width with cone-beam computed tomography (CBCT), and determine the relationship of these parameters with age. PATIENTS AND METHODS: A total of 113 subjects from the University of California at San Francisco Orthodontic Clinic with a CBCT scan were enrolled. Subjects were stratified by age in decades. Thickness of buccal and lingual cortices and mandibular height and width were evaluated in 5 regions (13 sites). A single factorial ANOVA was used to compare the parameters among age groups. P less than or equal to .05 was statistically significant. RESULTS: There were 44 (38.9%) males; 69 females. For all groups, the thickest to the least thick cortical plates were: base of the mandible, lower buccal one third, upper lingual one third, upper buccal one third, and lower lingual one third. In all groups, the mandible increased in height as the midline was approached, and the width of the upper third of the mandible decreased from the second molar to the symphysis whereas the reverse occurred in the lower third. Comparison of the age groups showed that subjects 10 to 19 years old had thinner cortical plates than other age groups (P

Asunto(s)
Mandíbula/anatomía & histología , Mandíbula/diagnóstico por imagen , Adolescente , Adulto , Factores de Edad , Anciano , Anatomía Transversal , Densidad Ósea , Cefalometría/métodos , Niño , Tomografía Computarizada de Haz Cónico , Estudios Transversales , Femenino , Humanos , Masculino , Mandíbula/crecimiento & desarrollo , Persona de Mediana Edad , Tamaño de los Órganos , Estudios Prospectivos , Valores de Referencia , Adulto Joven
19.
Am J Orthod Dentofacial Orthop ; 135(4): 468-79, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19361733

RESUMEN

INTRODUCTION: Changes in the normal pattern of nasal respiration can profoundly affect the development of the craniofacial skeleton in both humans and experimental animals. The orthodontist is often the first clinician to notice that a child is breathing primarily through the mouth, either at the initial examination or later during treatment. The lateral headfilm, part of the patient's normal records, might show increased adenoid masses, suggesting that these could be part of the problem. Previous studies have, however, questioned the validity of the information from lateral headfilm. METHODS: Our aim was to compare imaging information about nasopharyngeal airway size between a lateral cephalometric headfilm and a 3-dimensional cone-beam computed tomography scan in adolescent subjects. The nasopharyngeal airway area and volume were measured in 35 subjects (8 boys, 27 girls; average age, 14 years). RESULTS: Volumetric measurement errors ranged from 0% to 5% compared with known physical airway phantoms used to calibrate. A moderately high (r = 0.75) correlation was found between airway area and volume; the larger the area, the larger the volume. However, there was considerable variability in the airway volumes of patients with relatively similar airways on the lateral headfilms. Nine of the 35 patients had over 25% of the potential nasopharyngeal airway volume occupied by inferior turbinate protuberances, leading to significant airway restriction in some patients. CONCLUSIONS: The cone-beam 3-dimensional scan is a simple and effective method to accurately analyze the airway.


Asunto(s)
Cefalometría/métodos , Tomografía Computarizada de Haz Cónico , Imagenología Tridimensional , Nasofaringe/anatomía & histología , Radiografía Dental/métodos , Adolescente , Cefalometría/instrumentación , Niño , Femenino , Humanos , Masculino , Nasofaringe/diagnóstico por imagen , Tamaño de los Órganos , Radiografía Dental/instrumentación , Valores de Referencia
20.
Sci Rep ; 9(1): 10993, 2019 07 29.
Artículo en Inglés | MEDLINE | ID: mdl-31358814

RESUMEN

The causes of the extreme and persistent warming in the Northeast Pacific from the winter of 2013/14 to that of 2014/15 are still not fully understood. While global warming may have contributed, natural influences may also have played a role. El Niño events are often implicated in anomalously warm conditions along the US West Coast (USWC). However, the tropical Pacific sea surface temperature (SST) anomalies were generally weak during 2014, calling into question their role in the USWC warming. In this study, we identify tropical Pacific "sensitivity patterns" that optimally force USWC warming at a later time. We find that such sensitivity patterns do not coincide with the mature SST anomaly patterns usually associated with ENSO, but instead include elements associated with ENSO SST precursors and SST anomalies in the central/western equatorial Pacific. El Niño events that produce large USWC warming, irrespective of their magnitude, do project on the sensitivity pattern and are characterized by a distinct evolution of the North Pacific atmospheric and oceanic fields. However, even weak tropical SST anomalies in the right location, and not necessarily associated with ENSO, can significantly influence USWC conditions and enhance their predictability.

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