Does Certification as Bariatric Surgery Center and Volume Influence the Outcome in RYGB-Data Analysis of German Bariatric Surgery Registry.

AIM: To examine the association between the certification as bariatric surgery center and volume and patient outcome, data collected in the German Bariatric Surgery Registry were evaluated. All data were registered prospectively in cooperation with the Institute of Quality Assurance in Surgery at Otto-von-Guericke University Magdeburg. METHODS: Data collection began in 2005 for all bariatric procedures in an online database. Participation in the quality assurance study is required for all certified bariatric surgery centers in Germany. Descriptive evaluation and matched pairs analysis were performed. Patients were matched via propensity score taking into account BMI, age, and incidence of comorbidities. RESULTS: During the period from 2005 to 2013, 3083 male and 10,639 female patients were operated on with the RYGB primary approach. In Centers of Competence (77.2 %) and non-accredited hospitals (76.3 %), the proportion of female patients was significantly lower than in Centers of Reference/Excellence (78.7 %; p = 0.002). The mean age in Centers of Reference/Excellence (41.2 years) was significantly lower than in Centers of Competence (43.2 years; p < 0.05). Propensity score analysis was performed to compare matched patients with regard to BMI, age, and incidence of comorbidities. The rate of general and surgical postoperative complications and mortality rate was significantly lower in certified Centers of Reference/Excellence compared to Centers of Competence with 29 and non-certified hospitals. CONCLUSION: There is evidence of improved patient outcome in certified bariatric surgery centers with higher volume. The study supports the concept of certification. There are different factors which can and cannot be preoperatively modified and influence the perioperative outcome.

Risk of thrombosis and thromboembolic prophylaxis in obesity surgery: data analysis from the German Bariatric Surgery Registry.

BACKGROUND: Evidence-based data on optimal approach for prophylaxis of deep venous thrombosis (VTE) and pulmonary embolism (PE) in bariatric operations is discussed. Using antithrombotic prophylaxis, weight adjusted the risk of VTE and its complications have to be balanced with the increased bleeding risk. METHODS: Since 2005, the current situation for bariatric surgery has been examined by quality assurance study in Germany. As a prospective multicenter observational study, data on the type, regimen, and time course of VTE prophylaxis were documented. The incidences of clinically diagnosed VTE or PE were derived during the in-hospital course and follow up. RESULTS: Overall, 31,668 primary bariatric procedures were performed between January 2005 and December 2013. Most performed operations were 3999 gastric banding (GB); 13,722 Roux-en-Y-gastric bypass (RYGBP); and 11,840 sleeve gastrectomies (SG). Gender (p = 0.945), surgical procedure (p = 0.666), or administration of thromboembolic prophylaxis (p = 0.272) had no statistical impact on the DVT incidence. By contrast, BMI (p = 0.116) and the duration of thromboembolic prophylaxis (p = 0.127) did impact the frequency of onset of DVT. CONCLUSION: Age, BMI, male gender, and a previous history of VTE are the most important risk factors. The drug of choice for VTE is heparin. LMWH should be given preference over unfractionated heparins due to their improved pharmacological properties, i.e., better bioavailability and longer half-life as well as ease of use. Despite the low incidence of VTE and PE, there is a lack of evidence. Therefore, prospective randomized studies are necessary to determine the optimal VTE prophylaxis for bariatric surgical patients.

[Current Situation of Antibiotic Prophylaxis in Obesity and Metabolic Surgery - Data Analysis from the Study for Quality Assurance in Operative Treatment of Obesity in Germany]. / Aktueller Stand der Antibiotikaprophylaxe in der Adipositas- und metabolischen Chirurgie - Datenanalyse aus der Studie zur Qualitätskontrolle der operativen Therapie der Adipositas in Deutschland.

BACKGROUND: Since January 2005, the situation of metabolic and obesity surgery in Germany has been constantly evaluated by the German Bariatric Surgery Registry (GBSR). Data registration is performed using an internet online database with prospective data collection. All registered data were analysed in cooperation with the Institute of Quality Assurance at the Otto-von-Guericke University Magdeburg. METHODS: Data collection includes primary and revision/redo-procedures. A main focus of the current study is the analysis of data regarding the perioperative management, in particular, administration of antibiotics. RESULTS: Since 2005 a significant increase of primary bariatric procedures has been reported. For evaluation of the antibiotic regimen 12 296 primary operations including 684 balloons (BIB), 2950 gastric bandings (GB), 5115 Roux-en-Y-gastric bypasses (RYGBP), 120 Scopinaro's biliopancreatic diversions (BPD), 164 duodenal switches (DS), 3125 sleeve gastrectomies (SG) and 138 other procedures were analysed. In total 77.3 % of the patients with primary procedures received perioperative antibiotics. Patients without concomitant comorbidities received antibiotics significantly less often compared to those with comorbidities. Wound infection rates were comparable for patients who underwent either gastric banding or sleeve gastrectomy. CONCLUSION: Surgery has been accepted step by step as a treatment for morbid obesity and its comorbidities in Germany during the last few years. There is only little experience in the literature regarding antibiotic therapy as well as prophylaxis in bariatric surgery. Based on the results of the current study we recommend rather the selective than the routine use of antibiotics depending on different parameters, e.g., operative time, preoperative BMI and concomitant comorbidities.

Inhibitor recurrence after immune tolerance induction: a multicenter retrospective cohort study.

BACKGROUND: Immune tolerance induction (ITI) in patients with congenital hemophilia A is successful in up to 70%. Although there is growing understanding of predictors of response to ITI, the probability and predictors of inhibitor recurrence after successful ITI are not well understood. OBJECTIVES: To determine the association of clinical characteristics, particularly adherence to factor VIII (FVIII) prophylaxis after ITI, with inhibitor recurrence in patients with hemophilia A who were considered tolerant after ITI. METHODS: In this multicenter retrospective cohort study, 64 subjects with FVIII level < 2% who were considered successfully tolerant after ITI were analyzed to estimate the cumulative probability of inhibitor recurrence using the Kaplan-Meier method. The association of clinical characteristics with inhibitor recurrence was assessed using logistic regression. RESULTS: A recurrent inhibitor titer ≥ 0.6 BU mL(-1) occurred at least once in 19 (29.7%) and more than once in 12 (18.8%). The probability of any recurrent inhibitor at 1 and 5 years was 12.8% and 32.5%, respectively. Having a recurrent inhibitor was associated with having received immune modulation during ITI (odds ratio [OR] 3.8, 95% confidence interval [CI] 1.2-22.4) and FVIII recovery of < 85% at the end of ITI (OR 2.6, 95% CI 1.3-5.9) but was not associated with adherence to post-ITI prophylactic FVIII infusion (OR 0.5, 95% CI 0.06-4.3). CONCLUSIONS: The use of immune modulation therapy during ITI and lower FVIII recovery at the end of ITI appear to be associated with an increased risk of inhibitor recurrence after successful ITI. Adherence to post-ITI prophylactic FVIII infusions is not a major determinant of recurrence.

[Comment on Gender-Specific Aspects in Obesity and Metabolic Surgery--Analysis of Data from the German Bariatric Surgery Registry]. / Kommentar zu genderspezifischen Aspekten in der Adipositas- und metabolischen Chirurgie--Daten der Qualitätssicherungsstudie für operative Therapie der Adipositas.

BACKGROUND: The current situation in obesity and metabolic surgery since January 2005 has been investigated with the help of the quality assurance study on surgical therapy for obesity = German Bariatric Surgery Registry (GBSR). The data were acquired and analysed in cooperation with the Institute for Quality Assurance in Surgical Medicine at the Otto-von-Guericke University. METHODS: Data acquisition was done with the help of an online database. On a voluntary basis, all obesity and metabolic surgical interventions since 2005 have been recorded. In addition to the surgical data, the findings of the yearly follow-up investigations were recorded. RESULTS: Since 2005 there have been 1,263 gastric balloon procedures, 11,840 sleeve gastrectomies, 13,722 Roux-en-Y gastric bypasses and 3999 gastric banding operations. The average age of the male patients in all interventions was significantly higher. The average BMI of female patients who received a gastric banding or a gastric balloon procedure was significantly lower than that of the male patients. Men exhibited a higher incidence of comorbidities than women. CONCLUSION: The number of obesity and metabolic surgical interventions in Germany is continuously increasing. The results of the study on surgical therapy for obesity (GBSR) reveal significant differences in the gender-specific incidence of preoperative comorbidities. postoperative complications and mortality. Further studies on gender-specific aspects are necessary in order to optimise patient selection and reduce the incidence of postoperative complications.

Evaluation of von Willebrand factor phenotypes and genotypes in Hemophilia A patients with and without identified F8 mutations.

BACKGROUND: Hemophilia A (HA) is an X-linked bleeding disorder caused by a deficiency in factor VIII (FVIII). von Willebrand disease (VWD) is characterized by a quantitative or qualitative defect in von Willebrand factor (VWF). Patients with VWD with severely low VWF or VWD Type 2N (VWD2N), a VWD subtype distinguished by defective VWF binding to FVIII, may have reduced FVIII levels secondary to their VWD. These patients superficially resemble patients with HA and pose a potential for misdiagnosis. OBJECTIVES: To investigate the unexplained cause of bleeding in HA patients without known FVIII mutations by assessing plasma VWF antigen (VWF:Ag), FVIII binding capacities and VWF genotypes. PATIENTS/METHODS: Thirty-seven of 1027 patients with HA studied as part of the Hemophilia Inhibitor Research Study lacked identifiable F8 mutations. These patients (cases) and 73 patients with identified F8 mutations (controls) were evaluated for VWF:Ag, a patient's VWF capacity to bind FVIII (VWF:FVIIIB) and VWF sequence. RESULTS: Four cases had VWF:Ag < 3 IU dL(-1) and VWF mutations consistent with Type 3 VWD. Six cases and one control were heterozygous for mutations previously reported to cause Type 1 VWD (VWD1) (n = five cases and one control) or predicted to be deleterious by Polyphen2 and SIFT prediction tools (n = 1 case). One control had VWF:Ag < 30 IU dL(-1) and seven patients (four cases and three controls), including two cases who were heterozygous for a known VWD2N mutation, had reduced VWF:FVIIIB. CONCLUSIONS: These data emphasize that some patients diagnosed with HA require VWF assessments in order to achieve a comprehensive diagnosis and an optimal treatment strategy.

One versus two-step Roux-en-Y gastric bypass after gastric banding­data analysis of the German Bariatric Surgery Registry.

BACKGROUND: Bariatric surgery outcomes have been examined in Germany since January 1, 2005. All data were registered prospectively in cooperation with the Institute of Quality Assurance in Surgery at the Otto-von-Guericke University Magdeburg. METHODS: The data were collected from an online data bank. Data collection began in 2005 for gastric banding (GB) and Roux-en-Y gastric bypass (RYGB) results. In addition to primary bariatric operations, data regarding the complications of revision procedures and redo operations were analyzed. Participation in the quality assurance study was required for all certified centers in Germany. RESULTS: RYGBs are a popular redo operation after failed gastric banding. In the German Bariatric Surgery Registry (GBSR), we analyzed data from 263 RYGB operations that used a one-step approach after GB and 116 operations that used a two-step approach. The leakage rates for primary RYGB decreased to 1.8%. The incidence of leakage after a one-step RYGB after GB was lower (1.9%) than after the two-step procedure (2.6%). CONCLUSION: RYGBs are popular procedures after failed GB in Germany. The multivariable analysis for overall intraoperative complications revealed a significant difference between the two-step and the one-step procedure. In an unadjusted and multivariate assessment, the one-step procedure had statistically lower general postoperative complications than the two-step approach. Therefore, we suggest performing band removal and RYGB as a one-step procedure. Further analysis is necessary to evaluate the risk factors for the one-step procedure. Follow-up investigations must be performed to determine whether RYGB is an effective and safe option after GB.

[Revisional surgery and reoperations in obesity and metabolic surgery : Data analysis of the German bariatric surgery registry 2005-2012]. / Revisions- und "Redo"-Eingriffe in der Adipositas- und metabolischen Chirurgie : Datenanalyse des German Bariatric Surgery Registry 2005-2012.

BACKGROUND: Increasing numbers of interventions for obesity and metabolic surgery have led to an increase of primary bariatric operations as well as redo operations and revisional surgery after various primary bariatric procedures. Evidence-based guidelines for indications and choice of procedure for revisional surgery do not currently exist. AIM: The spectrum of various revisional and redo operations following standard operative procedures for obesity and metabolic surgery is presented based on current data from the German bariatric surgery registry (GBSR, German nationwide survey on quality assurance in bariatric surgery) and a literature search. MATERIAL AND METHODS: Since 1 January 2005, the current situation of bariatric surgery has been examined using the GBSR. All data are registered prospectively in cooperation with the Institute of Quality Assurance in Surgery at the Otto-von-Guericke University Magdeburg. Since 2005 a total of 24,070 primary bariatric procedures, 2070 revisional procedures and 1124 redo operations were analyzed. The study evaluated 1021 revisional and 491 redo operations after gastric banding (GB), 443 redo operations after sleeve gastrectomy (SG) and 306 revisional procedures and 10 redo operations after a Roux-en-Y gastric bypass (RYGBP). RESULTS: Reoperations of GB to SG were performed in 240 cases. The complication rate for GB removal and SG showed a significantly higher leakage rate for one step operations than for two step procedures of 3.3% vs. 0.0%. Conversion of GB to RYGBP was performed in 402 operations without any significant differences between one and two step approaches (1.9% vs. 2.2%). The specific complication rate in the 443 interventions in patients for conversion from SG to RYGBP was 10.8% which is higher than for primary SG (4.9%) and RYGBP (5.3%). CONCLUSION: Compared with the primary surgical procedures redo operations and revisional procedures have significantly higher complication rates. The data evaluated show that strong and differentiated indications are necessary for revisional and redo operations particularly in cases of therapy or metabolic failure.

Influences of gender on complication rate and outcome after Roux-en-Y gastric bypass: data analysis of more than 10,000 operations from the German Bariatric Surgery Registry.

BACKGROUND: Since 1 January 2005, bariatric surgery has been monitored in Germany. All related data are registered prospectively in cooperation with the Institute of Quality Assurance in Surgery at the Otto-von-Guericke University Magdeburg. METHODS: Data collection regarding obesity and metabolic surgery was started in an online database in 2005. Follow-up data are collected once a year. Participation in the quality assurance study is voluntary. RESULTS: Since 2005, 10,330 Roux-en-Y gastric bypass (RYGB) procedures have been performed in Germany. In total, 8,013 patients were female and 2,317 were male. Male patients suffered significantly more comorbidities than female patients. The men also had higher body mass indexes (BMIs) and ages than the women at the time of operation. Data on the gender-specific aspects of RYGB from the Nationwide Survey of Bariatric Surgery in Germany (GBSR) showed a significant difference in anastomotic insufficiency at the gastro-entero-anastomosis. The leakage rate was 2.37 % (55/2,317) in men and 1.68 % (135/8,013) in women. Additionally, specific complication and mortality rates were significantly higher in male than in female patients. CONCLUSIONS: Metabolic and obesity surgery is becoming increasingly popular in Germany. Data from the GBSR show significant differences in preoperative comorbidities and postoperative complication and mortality rates between male and female patients. There is a need for further evaluation of gender-specific aspects to optimize patient selection and reduce specific postoperative complications.

Is a one-step sleeve gastrectomy indicated as a revision procedure after gastric banding? Data analysis from a quality assurance study of the surgical treatment of obesity in Germany.

BACKGROUND: Since 1 January 2005, the outcomes of bariatric surgeries have been examined in Germany. All data are registered prospectively in cooperation with the Institute of Quality Assurance in Surgery at Otto-von-Guericke University Magdeburg. METHODS: Data are collected in an online data bank. Data collection began in 2005 for the results of gastric banding (GB) and in 2006 for sleeve gastrectomies (SGs). In addition to primary bariatric operations, data regarding the complications of revision procedures and redo operations have been analyzed. Participation in the quality assurance study is required for all certified centers in Germany. RESULTS: SGs are a popular redo operation after failed gastric banding. Using the German Bariatric Surgery Registry, we analyzed data from 137 SGs that were used in a one-step approach after GB and 37 SGs that were used in a two-step approach. Leakage rates for primary SGs dropped to 1.9 %. The incidence of leakage after a one-step SG after GB is significantly higher (4.4 %) than for a two-step approach (0 %). CONCLUSION: SGs are popular procedures after failed GB in Germany, but the complication rates for one-step band removal are higher than for a two-step approach. After examining the data, we suggest performing band removal and SG as a two-step procedure. Further analysis is necessary to evaluate the optimal time period between band removal and SG. Follow-up investigations must be performed to determine if SG is an effective and safe option after GB.

Bariatric surgery in adolescents and young adults--safety and effectiveness in a cohort of 345 patients.

OBJECTIVE: To examine the safety and effectiveness of adolescent bariatric surgery and to improve treatment recommendations for this age group. DESIGN: Prospective longitudinal registry. Since January 2005, patients undergoing bariatric surgery in Germany are enlisted in an online registry called 'study for quality assurance in obesity surgeries'. SUBJECTS: Adolescents and young adults up to the age of 21 years, operated from January 2005 to December 2010. MEASUREMENTS: Weight, BMI, comorbidities, complication rates. RESULTS: N=345 primary procedures were recorded by 58 hospitals. N=51 patients were under the age of 18 years. Follow-up information was available for 48% (n=167) of patients, with an average observation period of 544±412 days (median: 388 days). The most common surgical techniques were gastric banding (n=118, 34.2%), gastric bypass (n=116, 33.6%) and sleeve gastrectomy (n=78, 22.6%). Short-term complications (intra-operative; general postoperative; specific postoperative) were slightly lower for gastric banding (0.8%; 2.5%; 0.8%) than for gastric bypass (2.6%; 5.2%; 1.7%) or sleeve gastrectomy (0%; 9.0%; 7.7%). In accordance with published findings, weight and BMI reduction were lower for gastric banding (-28 kg; -9.5 kg m(-2)) compared to gastric bypass (-50 kg; -16.4 kg m(-2)) P< 0.001 or sleeve gastrectomy (-46 kg; -15.4 kg m(-2)) P< 0.001. Outcomes did not differ between the <18 and ≥18-year-old patients. CONCLUSION: Like in adults, bariatric surgery has low short-term complication rates and results in sustained weight loss in adolescents. However, the missing long-term observations prohibit a final conclusion about lasting effectiveness and safety. Clinical trials with structured follow-up programs and mechanisms to ascertain patient adherences are needed.

Actual situation of thromboembolic prophylaxis in obesity surgery: data of quality assurance in bariatric surgery in Germany.

Background. Evidence-based data on optimal approach for prophylaxis of deep venous thrombosis (VTE) and pulmonary embolism (PE) in bariatric operations is discussed. Using antithrombotic prophylaxis weight adjusted the risk of VTE and its complications have to be balanced with the increased bleeding risk. Methods. Since 2005 the current situation for bariatric surgery has been examined by quality assurance study in Germany. As a prospective multicenter observational study, data on the type, regimen, and time course of VTE prophylaxis were documented. The incidences of clinically diagnosed VTE or PE were derived during the in-hospital course and follow up. Results. Overall, 11,835 bariatric procedures were performed between January 2005 and December 2010. Most performed procedures were 2730 gastric banding (GB); 4901 Roux-en-Y-gastric bypass (RYGBP) procedures, and 3026 sleeve gastrectomies (SG). Study collective includes 72.5% (mean BMI 48.1 kg/m(2)) female and 27.5% (mean BMI 50.5 kg/m(2)) male patients. Incidence of VTE was 0.06% and of PE 0.08%. Conclusion. VTE prophylaxis regimen depends on BMI and the type of procedure. Despite the low incidence of VTE and PE there is a lack of evidence. Therefore, prospective randomized studies are necessary to determine the optimal VTE prophylaxis for bariatric surgical patients.

CXCL9 induces chemotaxis, chemorepulsion and endothelial barrier disruption through CXCR3-mediated activation of melanoma cells.

BACKGROUND: Metastasis is associated with poor prognosis for melanoma. The formation of metastases is a multi-step process, in which cancer cells can subsequently acquire the potential to intravasate into the blood or lymph vessels, disseminate through the circulation, extravasate through the endothelium and invade the connective tissue. There is increasing evidence that chemokines have a pivotal role in the dissemination and establishment of melanoma metastasis. METHODS: We isolated melanoma cells from melanoma metastasis and performed different migration assays and transendothelial resistance measurements of endothelial monolayers co-cultured with melanoma cells, in order to monitor barrier function and diapedesis and confirmed these results by confocal microscopy. RESULTS: We observed that tumour endothelial cells (ECs) secrete high levels of CXCL9 in all, and CXCL10 in most melanoma metastases. Migration studies revealed that low concentrations of these chemokines induce chemotaxis, whereas high concentrations induce spontaneous migration of melanoma cells (chemokinesis/chemorepulsion) and the disruption of the endothelial barrier, resulting in an accelerated transendothelial migration (TEM). Addition of anti-CXCL9 or anti-CXCR3 antibodies to the co-cultures delayed the TEM of melanoma cells. CONCLUSION: Our data represent novel mechanisms by which tumour cells in melanoma metastases might use the chemokine-expressing endothelium to leave the tumour and eventually to form additional metastases at distinct sites.

Comparison of eating disorders and body image disturbances between Eastern and Western countries.

Factors associated with the development of eating disorders in countries with non-Western cultures have not been adequately investigated in relation to Westernized countries. We therefore studied 243 girls [age =16.5+/-1.2 (SD)], recruited from schools in India, Tibet, the US and France. They completed the Figure Rating Scale (FRS), the Eating Attitudes Test (EAT), and the Beck Depression Inventory (BDI). The Tibetan group had a lower body mass index (BMI) than the other groups (p<0.0001), which did not differ from each other. All groups differed significantly on socio-economic status (SES), with those living in India having the highest (p<0.0001). Prior to controlling for age, SES, and BMI, there were no significant differences on any psychological measure between the individual countries, or when collapsed by East vs. West. However, after controlling for the same covariates, the Tibetan group selected a significantly larger current (p<0.0001) and ideal body size (p=0.03), compared to all the other countries, and had more body image discrepancy than the American group (p=0.04). After controlling only for BMI, the girls from the East had a larger current and ideal, but no difference on body image discrepancy. Body image discrepancy scores were best predicted by EAT scores and BMI, accounting for 35% of the variance (p<0.0001). EAT scores themselves were best predicted by mother's education, BDI, body image discrepancy, and drug and tobacco use, accounting for 33% of the variance (p<0.0001). Unlike some other studies, we did not observe greater body image discrepancy and eating pathology in Western cultures, whether or not controlling for age, SES, and BMI. There were no differences in eating and depression pathology between those in the US, France, or India. Indeed, the Tibetans, after controlling for their low BMI and SES, had the greatest body image discrepancy.

Automatic localization of cephalometric Landmarks.

A system for automatic detection of cephalometric landmarks is presented. Landmark detection is carried out in two steps: a line detection module searches for significant, well-contrasted lines of the image, such as the jaw line or the nasal spine. The landmark detection module uses the lines located in the first module to determine the search areas and then applies a pattern detection algorithm, based on mathematical morphology techniques. Relations between landmarks and lines are determined by means of a training process. The system has been tested for the detection of 17 landmarks on 20 images: more than 90% of the landmarks are accurately identified.

The invasion front of human colorectal adenocarcinomas shows co-localization of nuclear beta-catenin, cyclin D1, and p16INK4A and is a region of low proliferation.

At the invasion front of well-differentiated colorectal adenocarcinomas, the oncogene beta-catenin is found in the nuclear compartment of tumor cells. Under these conditions, beta-catenin can function as a transcription factor and thus activate target genes. One of these target genes, cyclin D1, is known to induce proliferation. However, invasion front of well-differentiated colorectal adenocarcinomas are known to be zones of low proliferation and express the cell cycle inhibitor p16INK4A. Therefore, we investigated the expression profiles of nuclear beta-catenin, cyclin D1, p16INK4A, and the Ki-67 antigen, a marker for proliferation, in serial sections of well-differentiated colorectal adenocarcinomas. Invasion fronts with nuclear beta-catenin were compared with areas from central parts of the tumors without nuclear beta-catenin, for the expression of cyclin D1, p16INK4A, and Ki-67. It was observed that expression of nuclear beta-catenin, cyclin D1, and p16INK4A at the invasion front are significantly correlated. Such areas exhibit low Ki-67 expression indicating a low rate of proliferation. Thus, in colorectal carcinogenesis the function of beta-catenin and its target gene cyclin D1 does not appear to be the induction of tumor cell proliferation. In particular, the function of cyclin D1 should be reconsidered in view of these observations.

Multiresolution segmentation of three-dimensional medical images using mathematical morphology techniques.

A semi-automatic method for three-dimensional segmentation of medical images is proposed. A multiresolution representation is achieved through the application of morphological filters, which assures causality for image extrema. This allows for a compact scale space representation, in which each extremum is assigned a scale value. Interactive selection of the interesting extrema of the image is carried out, aided by this scale information and other relevant features. Extrema selected are then used as markers in three-dimensional watersheds calculation. The system has been developed and tested under low cost platforms, and can be the base for totally automatic, knowledge based segmentation systems.

Computer-aided periodontal disease diagnosis using computer vision.

Periodontal diseases are the major cause of tooth loss. The study of the evolution of these diseases is crucial to achieve adequate planning and treatment. Depth probing is essential to know the periodontal disease stage. In this paper we present a new system for Computer-Aided Periodontal Disease Diagnosis using computer vision. The system automates the depth probing and incorporates a colour camera fitted together with a plastic probe that automatically and exactly obtains the depth probing measure. The system has been tested by several periodontists and with 125 teeth of different patients. The differences between the values taken by the system and two periodontists have not been significant.