Clinical significance of sleep bruxism on several occlusal and functional parameters.

The aim of this study was to evaluate the association between various functional and occlusal parameters and sleep bruxism. Thirty-nine (39) sleep bruxism patients and 30 controls participated in this investigation. The assessment of sleep bruxism was performed using the Bruxcore Bruxism-Monitoring Device (BBMD) combined with a new computer-based analyzing method. Sixteen functional and/or occlusal parameters were recorded. With a mean slide of 0.95 mm in the sleep bruxism group and a mean slide of 0.42 mm in the control group (Mann Whitney U test; p<0.003), results solely demonstrated a significant group difference regarding the length of a slide from centric occlusion to maximum intercuspation. The results suggest that the slightly pronounced slide could be of clinical importance in the development of increased wear facets in patients with current sleep bruxism activity. Following further evaluation including polysomnographic recordings, the BBMD combined with this new analyzing technique seems to be a clinically feasible instrument that allows the practitioner to quantify abrasion over a short period.

A new analyzing method for quantification of abrasion on the Bruxcore device for sleep bruxism diagnosis.

AIMS: To evaluate a newly developed semi-automatic computer-based method to analyze the objectivity of the Bruxcore Bruxism-Monitoring Device (BBMD) by assessing the interrater reliability. The capability of the BBMD to differentiate between sleep bruxers (SB) and healthy controls was also verified by estimating the sensitivity, specificity, and predictive values. METHODS: Forty-eight SB and 21 controls took part in this investigation. After a detailed clinical dental examination, each participant received a BBMD to be worn for 5 consecutive nights. The BBMDs were then scanned and rated by 2 independent examiners using the new method, which counted the abraded area in pixels. Interrater reliability was assessed by intraclass correlation coefficient (ICC) analyses. RESULTS: The analyses showed a very high interrater reliability of ICC = 0.99, and comparison of the mean pixel scores revealed values that were approximately 8 times higher for the SB than for the controls. With a selected pixel score cutoff point of 2900, a sensitivity of 79.2% and a specificity of 95.2% were found. The clinical diagnosis was correctly predicted in 97.4% of the SB and 66.7% of the controls. CONCLUSION: The results support the assumption that the newly developed analyzing method for the assessment of the BBMD is a clinically suitable, objective, and applicable method that seems to be able to differentiate between SB and a healthy control sample. These data, however, need to be confirmed in further investigations using polysomnographic recordings.

Visual event-related potentials in subjects with alexithymia: modified processing of emotional aversive information?

OBJECTIVE: A modified autonomous response (e.g., electrodermal activity) in subjects with alexithymia (a reduced ability to identify and communicate emotions) while processing emotional information is well known. However, the functional and neurobiological bases of this impairment are unclear. Do subjects with alexithymia suffer from a primary lack of perception ("emotional blindness"), or is alexithymia based on incomplete information processing due to immature undifferentiated cognitive schemes? The study investigates if subjects with alexithymia show a modified central response as a correlate of classifying emotional aversive stimuli. METHOD: Twenty subjects with high alexithymia and 20 with low alexithymia (selected by the 20-item Toronto Alexithymia Scale) were investigated within a modified odd-ball paradigm. Three different stimulus categories were presented: aversive (probes) and affective neutral pictures (nontargets and instructed targets). Visual event-related EEG potentials and subjective data were recorded. RESULTS: All subjects showed elevated positive amplitudes or mean activity after probe presentation in the latency range: 150-260, 280-450, and 600-1500 msec. Subjects with alexithymia displayed increased positive components (especially P2) of visual event-related potentials after probe presentation than subjects without alexithymia. Subjects without alexithymia more frequently verbalized the emotional impact of these aversive pictures than subjects with alexithymia. CONCLUSIONS: These findings do not support the assumption of a primary lack of perception in alexithymia. Subjects with alexithymia show central correlates of perception and classification of aversive pictures. They may need more effort and cognitive recourses to process emotional information. Nevertheless, spontaneous verbal reference to emotional stimulus aspects is reduced.

Predictive value of preoperative digital templating in THA depends on the surgical experience of the performing physician.

Digital preoperative templating is increasingly used to predict the correct component size in total hip arthroplasty (THA). Experienced surgeons could avoid the new technique and rely on a digital template done by a younger colleague. We compared the accuracy of preoperative templating between orthopedic residents (group A) and an experienced orthopedic surgeon (group B). In 106 cases, the software-predicted component sizes of both groups were compared with component sizes placed surgically. An accurate prediction of the acetabular component was achieved in 63% of cases in group A compared with 88% of cases in group B (P=.001). Concerning the femoral component, accurate prediction was achieved in 89% in group A and 97% in group B (P=.021). If performed by an experienced orthopedic surgeon, digital templating is an accurate method to predict the prosthetic component size in THA.

Alexithymia in the German general population.

The Toronto-Alexithymia-Scale (TAS-20) is used worldwide as a valid measurement of alexithymia. Until now, population-based standardization and cut-off values of the German TAS-20 version have not been available. This study provides these by means of a representative German sample and by investigating the factorial structure of the TAS-20. Data were generated from a representative random sample of the German general population (1,859 subjects aged between 20 and 69). The TAS-20 sum score was normally distributed. The mean value was 49.5 (SD=9.3) in men and 48.2 (SD=9.2) in women. Divorce, single and low social status were associated with enhanced sum scores. Ten percent of the population exceeded the TAS-20 sum score threshold of >or=61. The 66th percentile reached 53 for men and 52 for women. Factor analysis identified three factors that match the scales of the English original version. An additional fourth factor ("importance of emotional introspection") was extracted. Total explanation of variance by these four factors was 52.27%. The sum score of the German TAS-20 version is suited for the standardized measure of alexithymia. For selecting alexithymic individuals in experimental studies, the cut-off >or=61 is possibly too restrictive. Therefore, we propose the 66th percentile for the identification of high alexithymics. The TAS-20 sum score is associated with important socio-demographic variables. The factorial structure is reliable; the fourth factor ("importance of emotional introspection") provides differentiation of content and allows for enhanced explanation of variance.

Maladaptive coping strategies in patients with bruxism compared to non-bruxing controls.

BACKGROUND: Sleep bruxism is the non-functional grinding or clenching of teeth during sleep. It may lead to tooth damage and myofascial pain. Although stress is discussed as a main causal agent, there is a lack of studies concerning coping strategies in patients with sleep bruxism. PURPOSE: The aim of the present study was to investigate whether bruxers, compared to non-bruxing individuals, apply maladaptive coping strategies. METHOD: Seventy-five sleep bruxers and 38 non-bruxers were selected by dental examination and tested by a German coping questionnaire (SVF78). RESULTS: A significant difference in positive coping strategies was observed between the two groups. Bruxers reported less positive coping strategies, mainly less "reaction control" and "positive self-instructions." In general, males reported less negative coping strategies. CONCLUSION: The reported effects demonstrate a deficit of functional coping strategies in bruxers, whereas strategies that enhance stress do not seem to be associated with sleep bruxism. Findings do not admit the conclusion that there is a causal association of maladaptive coping and bruxism. However, they support the approach of a multidisciplinary therapy involving psychological treatment.

Characteristics of hypotension-prone haemodialysis patients: is there a critical relative blood volume?

BACKGROUND: Intradialytic morbid events (IME, mostly hypotension) mainly due to ultrafiltration-induced hypovolaemia still are the most frequent complication during haemodialysis (HD). This study was performed to test the hypothesis that there is an individual critical relative blood volume (RBV(crit)) in IME-prone HD patients. METHODS: In this prospective international multicentre study, 60 IME-prone patients from nine dialysis centres were observed during up to 21 standard HD sessions without trial-specific intervention. The RBV was monitored continuously by an ultrasonic method (BVM; blood volume monitor). Also, the ultrafiltration rate was registered continuously. Blood pressure was measured at regular intervals, and more frequently during IME. All IME and specific therapeutic interventions were noted. RESULTS: In total, 537 IME, some with more than one symptom, were documented during 585 HD sessions. The occurrence of IME increased up to 10-fold from the start to the end of the HD session. RBV(crit) showed a wide inter-individual range, varying from 71 to 98%. However, the intra-individual RBV limit was relatively stable, with an SD of <5% in three-quarters of the patients. In patients with congestive heart failure, cardiac arrhythmia, advanced age, low ultrafiltration volume and low diastolic blood pressure, higher values of RBV(crit) were observed. While all correlations between RBV(crit) and patient characteristics alone were found to be of weak or medium strength, the combination of diastolic blood pressure, ultrafiltration volume and age resulted in a strong correlation with RBV(crit): the linear equation with these parameters allows an estimation of RBV(crit) in patients not yet monitored with a BVM. CONCLUSIONS: An individual RBV limit exists for nearly all patients. In most IME-prone patients, these RBV values were stable with only narrow variability, thus making it a useful indicator to mark the individual window of haemodynamic instabilities.