Prediction of hypertensive crisis based on average, variability and approximate entropy of 24-h ambulatory blood pressure monitoring

Approximate entropy (ApEn) of blood pressure (BP) can be easily measured based on software analysing 24-h ambulatory BP monitoring (ABPM), but the clinical value of this measure is unknown. In a prospective study we investigated whether ApEn of BP predicts, in addition to average and variability of BP, the risk of hypertensive crisis. In 57 patients with known hypertension we measured ApEn, average and variability of systolic and diastolic BP based on 24-h ABPM. Eight of these fifty-seven patients developed hypertensive crisis during follow-up (mean follow-up duration 726 days). In bivariate regression analysis, ApEn of systolic BP (P<0.01), average of systolic BP (P=0.02) and average of diastolic BP (P=0.03) were significant predictors of hypertensive crisis. The incidence rate ratio of hypertensive crisis was 14.0 (95% confidence interval (CI) 1.8, 631.5; P<0.01) for high ApEn of systolic BP as compared to low values. In multivariable regression analysis, ApEn of systolic (P=0.01) and average of diastolic BP (P<0.01) were independent predictors of hypertensive crisis. A combination of these two measures had a positive predictive value of 75%, and a negative predictive value of 91%, respectively. ApEn, combined with other measures of 24-h ABPM, is a potentially powerful predictor of hypertensive crisis. If confirmed in independent samples, these findings have major clinical implications since measures predicting the risk of hypertensive crisis define patients requiring intensive follow-up and intensified therapy.

Soft tissue profile changes following mandibular advancement and setback surgery an average of 12 years postoperatively

PURPOSE: The aim of this study was to assess long-term changes in position of soft tissue landmarks following mandibular advancement and setback surgery. MATERIALS AND METHODS: Twenty-seven patients (14 women, 13 men; mean age, 36 years) who had undergone either mandibular advancement (15 patients) or setback surgery (12 patients), were available for a long-term follow-up an average of 12 years postoperatively. In all of these cases, lateral cephalometric radiographs taken immediately before operation, at 1 week, 14 months, and 12 years postoperatively, were studied. RESULTS: During the 14 months postoperatively, soft tissue chin and mentolabial fold followed its underlying hard tissue in all patients. A continuous skeletal relapse was observable 12 years after mandibular advancement, but soft tissue chin moved more in an anterior direction. After mandibular setback, soft and hard tissue landmarks remained almost unchanged. Over the entire observation period, a thickening of soft tissue at pogonion was generally seen, and particularly a thickening of the whole chin in the setback group. All patients showed a significant lengthening and thinning of the upper lip. In all except 2 males, the patient's body weight increased markedly. CONCLUSION: In contrast to the immediate postoperative stage, soft tissue changes observed an average of 12 years after the primary operation do not directly follow the movements of the underlying skeletal structure. The soft tissue profile changes observed over such a long term seem to be influenced not only by the underlying skeletal structure but also by other factors such as weight gain and aging process.

Calculation of the average travel distance in a low-level picker-to-part system considering any distribution function within the aisles

The estimation of the average travel distance in a low-level picker-to-part order picking system can be done by analytical methods in most cases. Often a uniform distribution of the access frequency over all bin locations is assumed in the storage system. This only applies if the bin location assignment is done randomly. If the access frequency of the articles is considered in the bin location assignment to reduce the average total travel distance of the picker, the access frequency over the bin locations of one aisle can be approximated by an exponential density function or any similar density function. All known calculation methods assume that the average number of orderlines per order is greater than the number of aisles of the storage system. In case of small orders this assumption is often invalid. This paper shows a new approach for calculating the average total travel distance taking into account that the average number of orderlines per order is lower than the total number of aisles in the storage system and the access frequency over the bin locations of an aisle can be approximated by any density function.

Cessation of facial growth in subjects with short, average, and long facial types - Implications for the timing of implant placement

Placement of a single-tooth implant should be performed when a patient's facial growth has ceased. In this retrospective observational study, we evaluated if there was a difference in the timing of cessation of craniofacial growth in short, average, and long facial types. Based on the value of the angle between cranial base and mandibular plane (SN/MP angle), three groups comprising 48 subjects with short facial type (SF; SN/MP ≤28°), 77 with average facial type (AF; SN/MP ≥31.5° and ≤34.5°), and 44 with long facial type (LF; SN/MP ≥38°) were selected. Facial growth was assessed on lateral cephalograms taken at 15.4 years of age, and 2, 5, and 10 years later. Variables were considered to be stable when the difference between two successive measurements was less than 1 mm or 1°. We found no difference between facial types in the timing of cessation of facial growth. Depending on the variable, the mean age when variables became stable ranged from 18.0 years (Is-Pal in LF group) to 22.0 years (SN/MP in LF group). However, facial growth continued at the last follow-up in approximately 20% subjects. This study demonstrates that facial type is not associated with the timing of cessation of facial growth.