Antimicrobial use and antimicrobial resistance monitoring in pig production in the United States of America.

Monitoring antimicrobial use (AMU) and antimicrobial resistance (AMR) on farms is recognised as an important component of antimicrobial stewardship, yet the process can be resource intensive. This paper describes a subset of findings from the first year of a collaboration across government, academia and a private sector veterinary practice focused on swine production in the Midwestern United States. The work is supported by participating farmers and the greater swine industry. Twice-annual collection of samples from pigs along with AMU monitoring occurred on 138 swine farms. Detection and resistance of Escherichia coli from pig tissues was assessed, and associations between AMU and AMR were evaluated. This paper describes the methods utilised and the first-year E. coli-related results from this project. Higher minimum inhibitory concentrations (MIC) for enrofloxacin and danofloxacin in E. coli from swine tissues were associated with the purchase of fluoroquinolones. There were no other significant associations between MIC and AMU combinations in E. coli isolated from pig tissues. This project represents one of the first attempts to monitor AMU as well as AMR in E. coli in a large-scale commercial swine system in the United States of America.

Alors même que la surveillance exercée sur l'utilisation des agents antimicrobiens (UAM) et sur la résistance aux agents antimicrobiens (RAM) dans les élevages est une composante majeure reconnue de la gestion des antimicrobiens, le processus en lui-même exige une mobilisation intensive de ressources. Les auteurs décrivent un sous-ensemble de résultats obtenus au cours de la première année d'une collaboration entre les pouvoirs publics, les universités et une clinique vétérinaire privée, axée sur la production porcine dans le Midwest des états-Unis d'Amérique. Ce travail est soutenu par les éleveurs participants et par le secteur porcin au sens large. Une collecte d'échantillons porcins a été effectuée deux fois par an, parallèlement à la surveillance de l'UAM dans 138 élevages. Il a été procédé à une recherche des Escherichia coli présents dans les tissus porcins prélevés puis à la détermination de la résistance aux antimicrobiens chez les microorganismes détectés ; les corrélations éventuelles entre l'UAM et la RAM ont ensuite été évaluées. Les auteurs décrivent les méthodes utilisées dans la cadre de ce projet ainsi que les résultats en lien avec les E. coli obtenus au cours de la première année. Une corrélation a été constatée entre l'augmentation des concentrations minimales inhibitrices (CMI) recueillies pour l'enrofloxacine et la danofloxacine vis-à-vis d'E. coli dans les tissus porcins analysés, d'une part, et l'achat de fluoroquinolones, d'autre part. Aucune autre corrélation significative n'a été décelée entre les CMI recueillies et les profils d'UAM concernant les E. coli isolés à partir des tissus porcins. Ce projet représente l'une des premières tentatives conduites aux états-Unis d'Amérique pour surveiller parallèlement l'UAM et la RAM chez les E. coli dans un système commercial de production porcine à grande échelle.

Aunque se tiene por sabido que la vigilancia en las explotaciones del uso de agentes antimicrobianos (UAM) y de la resistencia a los antimicrobianos (RAM) es un importante componente de la gestión de estos fármacos, no es menos cierto que el proceso puede consumir cuantiosos recursos. Los autores exponen un ubconjunto de observaciones realizadas durante el primer año de un proyecto de colaboración entre la administración pública, el mundo universitario y una clínica veterinaria privada que tenía por objeto de estudio la producción porcina en la zona del medio oeste de los Estados Unidos de América. Respaldaban el proyecto los productores que participaban en él y el sector de la industria porcina en general. Dos veces al año se obtuvieron muestras en 138 explotaciones porcinas, en las que también se seguía de cerca el UAM. Tras realizar pruebas de detección de Escherichia coli en tejidos porcinos y analizar la resistencia de esos microorganismos a antimicrobianos, se buscaron correlaciones entre el uso de estos fármacos y la presencia de eventuales resistencias. Los autores describen los métodos empleados y los resultados obtenidos el primer año del proyecto en relación con E. coli. Se observó una correlación entre la compra de fluoroquinolonas y el aumento de la concentración inhibitoria mínima (MIC) de enrofloxacina y de danofloxacina en los E. coli analizados. No se constató ninguna otra asociación significativa entre las MIC y el uso de diferentes antimicrobianos en los E. coli aislados a partir de tejido porcino. Este proyecto constituye una de las primeras tentativas de hacer seguimiento y balance del uso de agentes antimicrobianos y de la resistencia de E. coli a estos fármacos en el sistema de producción porcina industrial de los Estados Unidos de América.

The use of facial anthropometrics in aesthetic assessment.

OBJECTIVE: To identify a valid method for scoring facial aesthetics, correlating clinicians' assessments with measurements taken from 3D facial photographs. DESIGN: Album assessment of facial images, using a visual analog scale of attractiveness and the scores ranked. Facial ratios, obtained following digitization of the images compared with control group mean data, obtained from the Farkas growth study and the differences from the matched mean calculated. Ranked scores compared according to the inclusion of surface as well as caliper (shortest distance) measurements and whether the ranked scores, representing difference to the mean, were weighted. PATIENTS, PARTICIPANTS: Eleven facial images were presented. Seven clinicians provided clinical judgment. MAIN OUTCOME MEASURES: Correlation coefficients between mean attractiveness rankings and summed differences between patients' facial proportions and matched control data from the Farkas growth study. RESULTS: The highest correlation was obtained with the use of the difference accommodating the mean of the Farkas proportion index (r = -.76, p = .006), followed by standard deviation (r = -.65, p = .032), using data in which the difference is weighted according to the magnitude of the linear measurement involved. Repeatability of the clinicians' assessments and operator digitization were validated. CONCLUSIONS: There appears to be potential in the use of the mean as aesthetic ideal as a principle in aesthetic assessment and perhaps as an objective means of outcome assessment after facial surgery. The most appropriate scoring method would seem to include use of both surface and caliper measurements and incorporate weighting.

Efficacy of immunising pigs against porcine circovirus type 2 at three or six weeks of age.

The efficacy of a porcine circovirus type 2 (pcv-2) vaccine was tested in pigs vaccinated at three or six weeks of age. A total of 1106 weaned pigs were randomly allocated to one of three treatment groups: vaccinated at three weeks of age, vaccinated at six weeks of age, or not vaccinated. Each pig was weighed at three, 10 and 22 weeks of age, and 48 pigs selected at random from each treatment group were serially blood sampled at three, six, 10, 14, 18 and 22 weeks of age. The mean weight of the vaccinated pigs was 6.1 kg heavier at 22 weeks than the unvaccinated pigs. The combined mortality and cull rates of the unvaccinated pigs during the growing/finishing period was 14.1 per cent compared with 3.6 per cent and 3.1 per cent for the pigs vaccinated at three weeks and six weeks, respectively. The vaccinated pigs also had a significantly higher mean daily weight gain and a smaller load of humoral pcv-2 than the unvaccinated pigs.

Comparison of three methods of facial measurement.

The aims of this study were to assess the accuracy of measurements recorded by 3D stereophotogrammetry and to compare three methods of facial measurement: manual anthropometry, 3D stereophotogrammetry and 2D photography. Measurements were taken from 14 landmarks on each of six volunteers and compared. In addition, the variability of the methods was assessed. Three-dimensional measurements were shown to compare well with manual measurements on volunteers as well as test objects for which the mean difference was 0.23 mm (shortest distance) and 0.13 mm (surface). All the three methods of measurement were found to have good levels of repeatability. Two-dimensional measurements were more variable than manual measurements (P=0.021). Three-dimensional stereophotogrammetric measurements were shown to compare well with manual measurements although the values obtained were mostly slightly larger. Stereophotogrammetry allows images to be taken in a Medical Photography Department, facilitating the accurate measurement of facial morphology from digitized data, including changes associated with treatment or growth. There are clear potential benefits of using 3D measurements in the assessment of facial deformity.

Dental and skeletal ages in hypopituitary patients.

Skeletal and dental ages were radiographically determined in 14 cases of confirmed growth hormone deficiency. The cases were in the 6.5- to 12-year-age group, and were receiving hormone therapy. Delay in skeletal age ranged from 24.8 to 32.3%, the average being 27.9%. There was very much less delay in dental age, ranging from only 4.3 to 19.7%; the average delay being approximately 9%. Most cases thus fell within normal limits. Seven patients had dental ages assessed before therapy and their dental age delays were comparable to those of the group as a whole. The four patients in the 12-year-old group showed a greater dental age delay then did the others. This could have been simply due to individual variation, or this delay could possibly support the view that dental development does become androgen dependent at puberty. None of the radiographs examined revealed any defects in dental development as has been reported elsewhere. While the small normal patient followed the general trend, the three low birth weight patients did not and it would not be instructive to measure the dental ages of larger numbers of these cases.

The use of vacuum-formed splints for temporary intermaxillary fixation in the management of unilateral condylar fractures.

We report a simple, effective method of managing displaced unilateral condylar fractures with occlusal disruption using vacuum-formed thermoplastic foil splints with bonded wire cleats. The cleats enable intermaxillary fixation in the form of orthodontic elastics to be used, which guide then maintain the occlusion in centric relation. A case is presented in which this technique was used successfully.

Efficacy and stability of the alar base cinch suture.

The alar base cinch suture is designed to prevent excessive flaring of the nose after Le Fort 1 osteotomy of the maxilla. However, it is difficult to measure the effect of the suture on nasal width during the operation in the presence of a nasal endotracheal tube, and the long-term stability of the manoeuvre has not been well-documented. We have investigated the efficacy and stability of the alar base cinch suture by measuring nasal width in 36 patients before, during, and 12 months after, bimaxillary surgery with submental intubation. The use of submental intubation facilitated accurate measurement of the changes in nasal width produced by the osteotomy and the cinch suture. Intraoperative measurements showed that there was a mean increase in the width of the base of the nose of 3.0 mm, 9% (right and left alar points, al-al) and 3.6 mm, 11% (right and left alar curvature points, ac-ac) after the osteotomy, and that the cinch suture produced a reduction in these increases of 1.6 mm, 53% (al-al), and 2.1 mm, 58% (ac-ac). Measurements taken after the operation at 3, 6, and 12 months showed no significant changes. This indicates that our method of cinch suturing is effective in mitigating the increase in nasal width that is produced by the osteotomy, and that this effect is stable in the medium term.

Quantitative use of photography in orthognathic outcome assessment.

This study reports an independent audit of two aspects of orthognathic surgery, namely control of inter-alar width and mandibular outline asymmetry. Measurements were taken from standardized photographs of a consecutive series of 27 patients, using an on-screen digitizing program (IPTool). All patients had undergone bimaxillary osteotomies involving maxillary impaction and/or advancement, by one surgeon, using a cinch suture for nasal width control. Nine-twelve months after surgery, inter-alar width had increased by just 0.08 cm mean (SD 0.3). Four patients showed an increase of just over 2mm, whilst six showed a small reduction. Based on ratios of size (area) and shape (compactness) of the right and left mandibular segments, there was a small overall improvement in mandibular symmetry (0.019 and 0.005 respectively). Whilst in most of the patients the need for surgery was primarily the correction of antero-posterior and vertical discrepancies, five patients with demonstrable asymmetry showed a clear improvement. In three patients whose asymmetry scores were very mild pre-treatment, there was a small, measured increase in asymmetry, but not to a degree that would be clinically noticeable. At a time when 3D imaging is still unavailable to many clinicians, the results of this study suggest that appropriate measurements taken from carefully standardized conventional photographs can provide a valid and objective means of assessing treatment outcome.

Problems in the orthodontic management of orthognathic cases.

The planning and management of orthodontic treatment for patients requiring surgery is considered in the light of a variety of problems that occur commonly, but have not received much attention in the literature. These problems can be categorized into dental, skeletal, and soft tissue varieties, and some cases are presented in illustration. The occasional need for compromise in treatment planning is suggested and the limitations of an excessive dependence on cephalometrics are discussed.

Background considerations to facial aesthetics.

This paper examines the nature of our objectives in attempting to improve facial appearance. Questions are addressed concerning the basis for any collective agreement on "improvement" and the nature of an agreed "ideal", including an exploration of the reasons for its existence. The discussion focuses on the concept of "averageness", as well as supplementary hypotheses. Finally, the origins and validity of contemporary clinical guidelines are addressed.

Long-term stability of the lower labial segment relative to the A-Pog line.

Cephalometric records of 47 cases treated with the Begg technique were examined with a view to assessing both the effects of treatment and long-term change. The cases were treated by a single operator (Dr H. Brouwer) whose long-term records were taken on average over 10 years out of retention. Special reference was made of the use of A-Pog line as a guide to lower incisor stability. There was marked individual variation in both response to treatment and long-term change. Though all the results were clinically stable the A-Pog line was not found to be a reliable guide to lower incisor stability. In 62 per cent of the cases examined, the lower incisors tended to return towards their original positions after retention, whilst in the remaining cases the changes were extremely variable.

Clinical and computerized assessment of mandibular asymmetry.

The aim of this study was to investigate assessment of mandibular asymmetry by clinicians and to evaluate a new computerized system. Eight experienced clinicians (four maxillofacial surgeons and four orthodontists) assessed 12 standardized facial photographs of patients selected to provide a range, from normality to marked mandibular asymmetry. Photographs were taken under standardized conditions; analysis of photographs repeated after one month showed close agreement. The computerized system used four different methods for quantifying asymmetry based on right/left differences in perimeter, area, compactness, and centre of area ratios. Good agreement (kappa = 0.77) was achieved by the clinicians in assessing the likelihood of treatment need; however, when assessing an 'acceptable' level of asymmetry, agreement was moderate (kappa = 0.46). Differences in perimeter ratios did not compare well with clinical assessment, but those for both area and compactness showed 100 per cent sensitivity and specificity to clinical assessment at ratio differences of 0.05 and 0.03 (deviation from 1), respectively. A centre of area difference ratio greater than 1 showed 75 per cent sensitivity and 85 per cent specificity to clinical assessment. These parameters could prove useful in quantifying change in asymmetries brought about by growth, treatment, or any subsequent relapse.

Natural head posture--considerations of reproducibility.

This three-part study investigated the reproducibility of natural head posture (NHP) using radiographs and photographs. In part 1, reproducibility of cephalograms 1 year after the introduction of NHP was investigated and found to be less favourable (Dahlberg coefficient of 2.99 degrees) than most other previous investigations. In order to minimize radiation exposure of patients, reproducibility of photographs and method agreement between photographs and cephalograms were investigated in part 2. Reproducibility of the two photographs was poor (2.71 degrees). However, method agreement between cephalograms and the photographs taken at the same time was good (1.39 degrees). Replacement of the radiographic method with the photographic method for assessing NHP reproducibility appeared justified. Changing the protocol for achieving NHP in part 3 of the study improved reproducibility substantially (1.41 degrees). Various statistical methods were used to assess reproducibility and method agreement. Bland and Altman's graphical representation was found to be the most appropriate for method agreement. The Dahlberg coefficient, commonly used to assess NHP repeatability/reproducibility, does not provide an extreme enough interval to allow a sufficient clinical assessment of a method to be undertaken, compared with the reproducibility coefficient. That is, the latter provides a 95 per cent range, compared with 52 per cent with Dahlberg.

Task Group for Orthodontics Report.

The UK Specialist Review Group of the General Dental Council's Education Committee has been charged with taking forward the recommendations in the Chief Dental Officer's report 'UK Specialist Dental Training'. The Specialist Review Group has, in turn, established a number of specialty task groups. This report is from the Task Group for Orthodontics. It was submitted in May 1996.