Relationship between occlusal curvatures and bite force in humans

PurposeIt is clinically believed that humans with a broad and rounded dental arch accompanied by a shallow curve of Spee have good masticatory function. However, the relationship between them has not been elucidated fully. The purpose of this study was to quantitatively examine the relationship between occlusal curvatures and bite force.Materials and methodsBite force was measured and analyzed in 20 young adults with healthy permanent dentition and normal stomatognathic function using a bite force recording system. Study models of the mandibular dental arch were scanned with CCD cameras, and X, Y and Z coordinates of the cusp tips of the molars were recorded. Their occlusal curvatures were analyzed using a three-dimensional measurement system.ResultsBite force showed significant positive correlations (0.52 < R < 0.57) with the radius of the anteroposterior occlusal arc of the molar region and the radii of the translateral occlusal arcs in the second premolar, first molar and second molar regions, and showed significant positive correlation (R = 0.71) with the radius of the occlusal sphere of the molar region.ConclusionsIt was suggested that occlusal curvatures is related with the magnitude of bite force, and that the three dimensional spherical analysis of occlusal curvatures is useful predictor of the masticatory function.     

A recommendation on the basis of long-term follow-up resultsof our microvascular decompression operation for hemifacial spasm

Background

Microvascular decompression (MVD) for hemifacial spasm (HFS) has been popular, but it may take enough time to master this special operative technique and procedure. This may induce uneven distribution of the number of MVD operations in each institute, possibly resulting in an overall unsatisfactory quality of MVD surgeons. Nakanishi’s approach to MVD operations has the feature of using a, “supine, no retractor” technique, which would achieve various benefits for patients and medical professionals. We would like to recommend this approach for MVD surgeons on the basis of our follow-up outcomes.

Methods

A questionnaire, which was based on the method of evaluation for the long-term results of post-MVD operation as recommended by the Japanese Society of MVD, was sent by mail to the 154 HFS patients who had received Nakanishi’s approach at our hospital.

Results

Except for 42 patients who had changed their residences, 89 patients (79.5 % of 112) fully answered. The mean postoperative follow-up term was 13.0 years. The 76.4 % of the patients was estimated as excellent. Postoperative deafness was not present. The average value of satisfaction degree for the results of the MVD operation was 87.9 %.

Conclusions

This study revealed that Nakanishi’s approach produced good results equivalent of other approaches for HFS patients. This approach is considered to have many advantages comparing to the other approaches. Therefore, we would like to recommend that Nakanishi’s approach would contribute to overall advancement of the level of MVD surgeons.     

Risk factors for major morbidity after liver resection for hepatocellular carcinoma

Background:

Bile leakage, and organ and/or space surgical‐site infection (SSI) are common causes of major morbidity after partial hepatectomy for hepatocellular carcinoma (HCC). The purpose of this study was to analyse risk factors for major morbidity and to explore strategies for its reduction after partial hepatectomy for HCC.

Methods:

Risk factors for bile leakage and organ/space SSI were analysed in patients who underwent partial hepatectomy for HCC between 2001 and 2010. The causes, management and outcomes of intractable bile leakage requiring endoscopic therapy or percutaneous transhepatic biliary drainage were analysed. In addition, causative bacteria, outcomes and characteristics of organ/space SSI were investigated. Risk factors were identified using multivariable analysis.

Results:

Some 359 patients were included in the analysis. The prevalence of bile leakage and organ/space SSI was 12·8 and 8·6 per cent respectively. Repeat hepatectomy and an operating time of at least 300 min were identified as independent risk factors for bile leakage. The main causes of intractable bile leakage were latent strictures of the biliary system caused by previous treatments for HCC and intraoperative injury of the hepatic duct during repeat hepatectomy. Independent risk factors for organ/space SSI were repeat hepatectomy and bile leakage. Methicillin‐resistant Staphylococcus aureus was detected more frequently in organ/space SSI after repeat hepatectomy than after initial partial hepatectomy.

Conclusion:

Repeat hepatectomy and prolonged surgery were identified as risk factors for bile leakage after liver resection for HCC. Bile leakage and repeat hepatectomy increased the risk of organ/space SSI. Copyright © 2012 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.     

Fish to meat intake ratio and cooking oils are associated with hepatitis C virus carriers with persistently normal alanine aminotransferase levels

Aim: Dietary habits are involved in the development of chronic inflammation; however, the impact of dietary profiles of hepatitis C virus carriers with persistently normal alanine transaminase levels (HCV‐PNALT) remains unclear. The decision‐tree algorithm is a data‐mining statistical technique, which uncovers meaningful profiles of factors from a data collection. We aimed to investigate dietary profiles associated with HCV‐PNALT using a decision‐tree algorithm. Methods: Twenty‐seven HCV‐PNALT and 41 patients with chronic hepatitis C were enrolled in this study. Dietary habit was assessed using a validated semiquantitative food frequency questionnaire. A decision‐tree algorithm was created by dietary variables, and was evaluated by area under the receiver operating characteristic curve analysis (AUROC). Results: In multivariate analysis, fish to meat ratio, dairy product and cooking oils were identified as independent variables associated with HCV‐PNALT. The decision‐tree algorithm was created with two variables: a fish to meat ratio and cooking oils/ideal bodyweight. When subjects showed a fish to meat ratio of 1.24 or more, 68.8% of the subjects were HCV‐PNALT. On the other hand, 11.5% of the subjects were HCV‐PNALT when subjects showed a fish to meat ratio of less than 1.24 and cooking oil/ideal bodyweight of less than 0.23 g/kg. The difference in the proportion of HCV‐PNALT between these groups are significant (odds ratio 16.87, 95% CI 3.40–83.67, P = 0.0005). Fivefold cross‐validation of the decision‐tree algorithm showed an AUROC of 0.6947 (95% CI 0.5656–0.8238, P = 0.0067). Conclusion: The decision‐tree algorithm disclosed that fish to meat ratio and cooking oil/ideal bodyweight were associated with HCV‐PNALT.     

New Surgical Approach to Large Splenorenal Shunt in Living Donor Liver Transplantation: Diversion of SMV and SPV Blood Flow

Introduction

The management of a large splenorenal shunt is important because it affects recipient outcome, particularly in living donor liver transplantation.

Methods

To manage large splenorenal shunts in living donor liver transplantation, we diverted superior mesenteric vein and splenic portal vein blood flow by ligation at the root of the splenic portal vein.

Result

This procedure was applied for five patients in whom superior mesenteric vein blood flow had been completely stolen by a splenorenal shunt preoperatively. Postoperative course was excellent in all cases.

Conclusion

This technique completely prevents morbidity related to large splenorenal shunts after living donor liver transplantation.