Analysis of Dental Supportive Structures in Orthodontic Therapy

The purpose was to define the impact of orthodontic appliances on the density of the underlying dental bone tissue. Radiographic images of teeth were made in 27 study subjects before and twelve months after fixed orthodontic appliances were carried. The radiographs were digitalized and the levels of gray at sites where the greatest bone resorption was expected were transformed into optic density. In the standardization and comparison of values from the first and the second measurements the copper calibration wedge – a stepwedge – was used. Optic densities in the observed sites were compared with optic densities of the calibration wedge and expressed as their thickness equivalent. The study results showed no statistically significant difference in bone densities, indicating that the orthodontic therapy was properly planned and carried out and that excessive forces were not used in the applied correctional procedures

Laparoscopic versus open liver resection for intrahepatic cholangiocarcinoma: a multicenter propensity score-matched study

Background: The role of laparoscopy in the treatment of intrahepatic cholangiocarcinoma (ICC) remains unclear. This multicenter study examined the outcomes of laparoscopic liver resection for ICC. Methods: Patients with ICC who had undergone laparoscopic or open liver resection between 2012 and 2019 at four European expert centers were included in the study. Laparoscopic and open approaches were compared in terms of surgical and oncological outcomes. Propensity score matching was used for minimizing treatment selection bias and adjusting for confounders (age, ASA grade, tumor size, location, number of tumors and underlying liver disease). Results: Of 136 patients, 50 (36.7%) underwent laparoscopic resection, whereas 86 (63.3%) had open surgery. Median tumor size was larger (73.6 vs 55.1 mm, p¼ 0.01) and the incidence of bi-lobar tumors was higher (36.6 vs 6%, p< 0.01) in patients undergoing open surgery. After propensity score matching baseline characteristics were comparable although open surgery was associated with a larger fraction of major liver resections (74 vs 38%, p< 0.01), lymphadenectomy (60 vs 20%, p< 0.01) and longer operative time (294 vs 209 min, p< 0.01). Tumor characteristics were similar. Laparoscopic resection resulted in less complications (30 vs 52%, p¼ 0.025), fewer reoperations (4 vs 16%, p¼ 0.046) and shorter hospital stay (5 vs 8 days, p< 0.01). No differences were found in terms of recurrence, recurrence-free and overall survival. Conclusion: Laparoscopic resection seems to be associated with improved short-term and with similar long-term outcomes compared with open surgery in patients with ICC. However, possible selection criteria for laparoscopic surgery are yet to be defined

Ranking as a Procedure for Selecting a Replacement Variable in the Score Predicting the Survival of Patients Treated with Curative Intent for Colorectal Liver Metastases

Background and Objectives: The issue of a missing variable precludes the external validation of many prognostic models. For example, the Liverpool score predicts the survival of patients undergoing surgical therapy for colorectal liver metastases, but it includes the neutrophil–lymphocyte ratio, which cannot be measured retrospectively. Materials and Methods: We aimed to find the most appropriate replacement for the neutrophil–lymphocyte ratio. Survival analysis was performed on data representing 632 liver resections for colorectal liver metastases from 2000 to 2020. Variables associated with the Liverpool score, C-reactive protein, albumins, and fibrinogen were ranked. The rankings were performed in four ways: The first two were based on the Kaplan-Meier method (log-rank statistics and the definite integral IS between two survival curves). The next method of ranking was based on univariate and multivariate Cox regression analyses. Results: The ranks were as follows: the radicality of liver resection (rank 1), lymph node infiltration of primary colorectal cancer (rank 2), elevated C-reactive protein (rank 3), the American Society of Anesthesiologists Classification grade (rank 4), the right-sidedness of primary colorectal cancer (rank 5), the multiplicity of colorectal liver metastases (rank 6), the size of colorectal liver metastases (rank 7), albumins (rank 8), and fibrinogen (rank 9). Conclusions: The ranking methodologies resulted in almost the same ranking order of the variables. Elevated C-reactive protein was ranked highly and can be considered a relevant replacement for the neutrophil–lymphocyte ratio in the Liverpool score. These methods are suitable for ranking variables in similar models for medical research