Missing facial parts computed by a morphable model and transferred directly to a polyamide laser-sintered prosthesis: an innovation study.

Mirroring of missing facial parts and rapid prototyping of templates have become widely used in the manufacture of prostheses. However, mirroring is not applicable for central facial defects, and the manufacture of a template still requires labour-intensive transformation into the final facial prosthesis. We have explored innovative techniques to meet these remaining challenges. We used a morphable model of a face for the reconstruction of missing facial parts that did not have mirror images, and skin-coloured polyamide laser sintering for direct manufacture of the prosthesis. From the knowledge gleaned from a data set of 200 coloured, three-dimensional scans, we generated a missing nose that was statistically compatible with the remaining parts of the patient's face. The planned prosthesis was manufactured directly from biocompatible skin-coloured polyamide powder by selective laser sintering, and the prosthesis planning system produced a normal-looking reconstruction. The polyamide will need adjustable colouring, and we must be able to combine it with a self-curing resin to fulfil the requirements of realistic permanent use.

Facial acquisition by dynamic optical tracked laser imaging: a new approach.

Three-dimensional capture of the surface of soft tissue is a desirable support for documentation and therapy planning in plastic and reconstructive surgery concerning the complex anatomy of the face, particularly cleft lip and palate (CLP). Different scanning systems are used for capturing facial surfaces. These systems are mostly based on a static linear measuring arrangement. Established systems work on the basis of coded white light or linear laser triangulation and digital stereophotogrammetric approaches. Shadowing effects occur with these devices. These effects may be avoided by a radical new approach first used in automotive industries that employs a mobile, flexible handheld laser scanner with simultaneous registration by optical tracking. The aim of this study was to assess the suitability of this scanner for surgical procedures on the human face in operating theatre. Five babies aged about 3 months with cleft deformities (one CLP, one bilateral CLP, three isolated cleft lips) were captured directly: twice preoperatively, twice postoperatively and twice after 7 days. An industrial standard specimen and two plaster cast masks of CLP babies were taken and subsequently measured to assess reliability and validity of the device. Masks were measured to reflect the complex surface of the cleft deformity. Data evaluation was done with respect to completeness of the data sets, as well as reliability and validity of the system. Missing data caused by shadowing could be avoided in all images. Even complex areas with undercuts could be reproduced completely and precisely with an accuracy in the sub-millimetre range.

3D surface measurement for medical application--technical comparison of two established industrial surface scanning systems.

In 3D mapping of flexible surfaces (e.g. human faces) measurement errors due to movement or positioning occur. Aggravated by equipment- or researcher-caused mistakes considerable deviations can result. Therefore first the appliances' precision handling and reliability in clinical environment must be established. Aim of this study was to investigate accuracy and precision of two contact-free 3D measurement systems (white light vs. laser). Standard specimens of known diameter for sphere deviation, touch deviation and plane deviation were tested. Both systems are appropriate for medical application acquiring solid data (

A sensitive and specific PCR/Southern blot assay for detection of bovine herpesvirus 4 in calves infected experimentally.

A PCR/Southern blot assay for detection of bovine herpesvirus 4 (BHV-4) in the background of bovine cellular DNA was developed. A BHV-4 specific sequence within the gene coding for the glycoprotein B (gB) was selected for primer sequences to guarantee the specificity of the assay. With a detection limit of six molecules BHV-4 DNA in the background of 1 microg of cellular DNA (equals about 150,000 bovine cells) this PCR/Southern blot assay represents a highly sensitive method for detection of BHV-4 DNA. At low concentrations of BHV-4 genomes, this assay also allows to estimate the copy number of BHV-4: a distinction between fewer than 6, 6-59 and more than 60 BHV-4 genomes/100 microl DNA suspension was possible. Tissue and blood samples of two calves, infected experimentally with BHV-4 were examined for the prevalence of BHV-4 DNA 130 days post infection. Ten days before taking samples, one of the calves was immuno-suppressed with dexamethasone. In both calves, BHV-4 DNA was detected in the leucocyte fraction of the blood, and beyond that in lower quantities in the spleen and the kidney of the immuno-suppressed calf. It is assumed that a latent BHV-4 infection was activated after application of dexamethasone and that the leucocyte fraction of the blood represents one site of latency of BHV-4 in cattle.

Trona and sodium bicarbonate in beef cattle diets: effects on pH and volatile fatty acid concentrations.

A study was conducted to evaluate the effectiveness of NaHCO3 and trona in beef cattle diets. Trace element (n = 28) analysis revealed no toxicological or safety concerns with the use of trona. Trona was more (P less than .05) soluble in ruminal fluid than Na2CO3, and NaHCO3 and had greater (P less than .05) buffering capacity (9.6 meq/g) than NaHCO3 (6.1 meq/g) but less (P less than .05) than Na2CO3 (11.1 meq/g). Calcium carbonate was insoluble and did not buffer ruminal fluid. Six yearling (avg 272 kg) Hereford X Angus steers, each with ruminal, duodenal and ileal cannulas, were fed 50:50 (cracked corn-based concentrate:cottonseed hulls) or 90:10 concentrate diets with no buffer, 1% NaHCO3 or with 1% trona. Intake, across all treatments, averaged 2.4% of body weight. Propionate (mmol/liter) increased (17.6 vs 13.5; P less than .05) and butyrate decreased (3.5 vs 5.2; P less than .05) with trona in the 90:10 diet as compared with no buffer. Propionate (16.8) increased (P less than .05) with NaHCO3 in the 90:10 diet. Average ruminal pH was greater (P less than .05) in 90:10 diets with trona or NaHCO3 than with no buffer (5.61, 5.61 vs 5.55); duodenal pH was greater (P less than .01) with trona than with no buffer (2.66 vs 2.55). Trona reduced ruminal pH-hours (P less than .05) and pH-area (P less than .12; time and area below mean pH of control) below control for both concentrate levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Trona and sodium bicarbonate in beef cattle diets: effects on site and extent of digestion.

Six yearling Hereford X Angus steers (avg 272 kg), each with ruminal, duodenal and ileal cannulas were used in a 6 X 6 Latin-square metabolism trial to evaluate the impact of NaHCO3 and trona (a ground, nonrefined ore with chemical composition NaHCO3-Na2CO3-2H2O) on site and extent of digestion of nutrients in the digestive tract. The diets were 50:50 or 90:10 (cracked corn-based concentrate:cottonseed hulls) with no buffer, 1% NaHCO3, or 1% trona. Intake, across all treatments, averaged 2.4% of body weight. Dry matter (DM) and starch digestibility (via indigestible acid detergent fiber) before the duodenum was decreased (P less than .10) with trona in the 50:50 diet. Digestibility of DM, crude protein and starch before the ileum were greater (P less than .05) in the 90:10 diet vs 50:50 diet. Total tract digestibility was similar across buffer treatments in the 90:10 diet. Addition of NaHCO3 increased (P less than .05) digestibility of dry matter and cell solubles in the 50:50 diet. Organic matter and crude protein digestibility were also increased (P less than .10) with NaHCO3. Apparent crude protein and cell solubles digestibility were greater (P less than .10) with trona than NaHCO3 in the 50:50 diet. This trial indicates that buffers provide overall enhancement of diet digestibility in mixed grain/roughage diets.