Masticatory muscle activity during deliberately performed oral tasks.

The aim of this study was to investigate masticatory muscle activity during deliberately performed functional and non-functional oral tasks. Electromyographic (EMG) surface activity was recorded unilaterally from the masseter, anterior temporalis and suprahyoid muscles in 11 subjects (5 men, 6 women; age = 34.6 +/- 10.8 years), who were accurately instructed to perform 30 different oral tasks under computer guidance using task markers. Data were analyzed by descriptive statistics, repeated measurements analysis of variance (ANOVA) and hierarchical cluster analysis. The maximum EMG amplitude of the masseter and anterior temporalis muscles was more often found during hard chewing tasks than during maximum clenching tasks. The relative contribution of masseter and anterior temporalis changed across the tasks examined (F 5.2; p < or = 0.001). The masseter muscle was significantly (p < or = 0.05) more active than the anterior temporalis muscle during tasks involving incisal biting, jaw protrusion, laterotrusion and jaw cupping, the difference being statistically significant (p < or = 0.05). The anterior temporalis muscle was significantly (p < or = 0.01) more active than the masseter muscle during tasks performed in intercuspal position, during tooth grinding, and during hard chewing on the working side. Based upon the relative contribution of the masseter, anterior temporalis, and suprahyoid muscles, the investigated oral tasks could be grouped into six separate clusters. The findings provided further insight into muscle- and task-specific EMG patterns during functional and non-functional oral behaviors.

Alloplastic total temporomandibular joint replacements: do they perform like natural joints? Prospective cohort study with a historical control.

The aim of this study was to qualitatively and quantitatively describe the biomechanics of existing total alloplastic reconstructions of temporomandibular joints (TMJ). Fifteen patients with unilateral or bilateral TMJ total joint replacements and 15 healthy controls were evaluated via dynamic stereometry technology. This non-invasive method combines three-dimensional imaging of the subject's anatomy with jaw tracking. It provides an insight into the patient's jaw joint movements in real time and provides a quantitative evaluation. The patients were also evaluated clinically for jaw opening, protrusive and laterotrusive movements, pain, interference with eating, and satisfaction with the joint replacements. The qualitative assessment revealed that condyles of bilateral total joint replacements displayed similar basic motion patterns to those of unilateral prostheses. Quantitatively, mandibular movements of artificial joints during opening, protrusion, and laterotrusion were all significantly shorter than those of controls. A significantly restricted mandibular range of motion in replaced joints was also observed clinically. Fifty-three percent of patients suffered from chronic pain at rest and 67% reported reduced chewing function. Nonetheless, patients declared a high level of satisfaction with the replacement. This study shows that in order to gain a comprehensive understanding of complex therapeutic measures, a multidisciplinary approach is needed.

Novel approach to the study of jaw kinematics in an alloplastic TMJ reconstruction.

Total alloplastic temporomandibular joint (TMJ) reconstruction is a reliable treatment modality in patients with severely diseased TMJ with good clinical behaviour. TMJ mandibular function after alloplastic reconstruction has scarcely been analysed as a biomechanical parameter and investigation has generally been limited to interincisal measurements without deeper insight into joint kinematics. Dynamic stereometry to assess condylar movements relative to the fossa was performed at the 5 year follow-up of a patient who underwent condylar resection of the right TMJ followed by total alloplastic joint reconstruction to treat pigmented villonodular synovitis. The patient could achieve wide mouth opening, but overall mandibular kinematics showed a strong deviation towards the prosthetic side due to the lack of mandibular translation caused by the absence of the lateral pterygoid attachment. Possible overloading of the joint contralateral to the TMJ prosthesis might be prevented by optimizing replacement joint design.

Long-term follow-up of thoracoscopic talc pleurodesis for primary spontaneous pneumothorax.

The aim of the present study was to evaluate the long-term outcome of patients with primary spontaneous pneumothorax treated with talc pleurodesis. A follow-up study was undertaken in all patients with primary spontaneous pneumothorax who underwent talc pleurodesis for prolonged air leak or recurrence using thoracoscopy. In total, 112 patients underwent pleurodesis and follow-up data was obtained in 63 (56%) patients: 45 patients were available for clinical follow-up, 14 for telephone follow-up and four were dead. The causes of death were unrelated to the pleurodesis. There were no episodes of acute respiratory failure following pleurodesis. A total of 56 (95%) out of the cohort of 59 patients had a successful pleurodesis. Surgical pleurectomy was required in three (5%) patients for persistent air leak. Median duration of follow-up after talc pleurodesis was 118 months. Long-term success was observed in 53 (95%) out of 56 patients. Recurrent pneumothorax was observed in three (5%) out of 56 patients. Patients with successful talc pleurodesis had a median forced vital capacity (FVC) of 102% and median total lung capacity of 99% at follow-up. Comparing smokers and nonsmokers, the forced expiratory volume in one second (FEV(1)) was significantly lower in smokers and there was a tendency for the FEV(1)/FVC ratio to be lower in smokers. Talc pleurodesis in patients with primary spontaneous pneumothorax via thoracoscopy is an effective procedure associated with normal lung function in patients who do not smoke.

[Antibiotics, purpura and ulcers: a leukocytoclastic vasculitis after clarithromycin]. / Antibiotika, Purpura und Ulzera: Eine leukozytoklastische Vaskulitis nach Clarithromycin.

HISTORY AND CLINICAL FINDINGS: A 47- year-old woman presented with palpable purpura of both lower limbs after taking six tablets of clarithromycin for pneumonia. INVESTIGATIONS: Apart from mild microhematuria there were no other signs of organ involvement. Histology of a skin biopsy revealed a hypersensitivity vasculitis. TREATMENT AND COURSE: A hypersensitivity vasculitis due to clarithromycin was the cause of the purpura. The course of this hypersensitivity vasculitis was severe and protracted over weeks with formation of deep ulcerative skin lesions. CONCLUSION: Clarithromycin may be the cause of a hypersensitivity vasculitis: often the course of the disease is mild, but it may also lead to severe local complications. The diagnosis of hypersensitivity vasculitis can be made in a patient over 16 years of age if there is the combination of a triggering substance, purpura and leukocytoclastic vasculitis. The most important step is immediate withdrawal of the causative agent. A beneficial effect of treatment with steroids on prognosis is not proven.