Finite element analysis of the effects of thermal obturation in maxillary canine teeth.

OBJECTIVE: The purpose of the present study was to determine the distribution and level of temperature, in a model of a maxillary canine, the surrounding periodontal tissues, and the bones, during a System B heat obturation technique simulation. STUDY DESIGN: The temperature distribution was determined by using a three-dimensional finite element analysis. The tooth was assumed to have undergone an endodontic treatment before the application. Heat applications of 200 degrees C and 100 degrees C were considered. RESULTS: By using the virtual model and the simulation technique, the maximum temperature in the periodontal ligament was found to be 43.5 degrees C. CONCLUSIONS: Within the assumptions and the limitations of the study, it was determined that the simulation of System B technique created no potentially harmful levels of temperature throughout the maxillary canine model.     

Primary spinal column sarcomas

Summary Five cases of primary spinal column sarcomas are presented. Sarcomas primarily originating from paravertebral soft tissues were excluded. Patients' age ranged from 1 to 14 years (mean 8.4 years). The male: female ratio was 23. Two patients had Ewing's sarcoma (ES) originating from L5-S1 and L4-5 pedicles, respectively; two patients had mesenchymal chondrosarcoma (MCS) originating from L1-2 pedicles and L5 body, respectively; and one patient had osteogenic sarcoma (OS) of C4 body. All patients clinically presented with pain and progressive weakness of the extremities. The time that elapsed between the onset of symptoms and diagnoses ranged from one to five months. All cases were treated with chemotherapy, radiotherapy and subtotal tumour resection with spinal canal decompression. Two cases received posterior spinal fusion operations. Three patients were alive 10 to 98 months following diagnosis. Only the case with ES of L5-S1 pedicles was in complete remission and off therapy at the 98th postoperative month. The two MCS cases were in partial remission, and were receiving chemoterapy at the time of analysis. These tumours caused similar clinical findings and prognoses, and required combined treatment, which consisted of surgery, radiotherapy and chemotherapy; histologically three different types of malignant tumours are presented in the same category. We preferred surgical decompression and stabilization procedures especially for neurologically symptomatic patients, even if they had extensive tumours with high grades. By spinal canal decompression and stabilisation, we did not intend to cure the disease; however, we intended to provide neurological improvement, spinal stabilisation, improved quality of life, early mobilisation of the patient, and cytoreduction by means of surgical tumour ablation, which could render the chemotherapy more effective.     

Discriminating performance of macular ganglion cell-inner plexiform layer thicknesses at different stages of glaucoma

AIM: To determine the discriminating performance of the macular ganglion cell-inner plexiform layer (GC-IPL) parameters between all the consecutive stages of glaucoma (from healthy to moderate-to-severe glaucoma), and to compare it with the discriminating performances of the peripapillary retinal nerve fiber layer (RNFL) parameters and optic nerve head (ONH) parameters. METHODS: Totally 147 eyes (40 healthy, 40 glaucoma suspects, 40 early glaucoma, and 27 moderate-to-severe glaucoma) of 133 subjects were included. Optical coherence tomography (OCT) was obtained using Cirrus HD-OCT 5000. The diagnostic performances of GC-IPL, RNFL, and ONH parameters were evaluated by determining the area under the curve (AUC) of the receiver operating characteristics. RESULTS: All GC-IPL parameters discriminated glaucoma suspect patients from subjects with healthy eyes and moderate-to-severe glaucoma from early glaucoma patients (P<0.017, for all). Also, minimum, inferotemporal and inferonasal GC-IPL parameters discriminated early glaucoma patients from glaucoma suspects, whereas no RNFL or ONH parameter could discriminate between the two. The best parameters to discriminate glaucoma suspects from subjects with healthy eyes were superonasal GC-IPL, superior RNFL and average c/d ratio (AUC=0.746, 0.810 and 0.746, respectively). Discriminating performances of all the parameters for early glaucoma vs glaucoma suspect comparison were lower than that of the other consecutive group comparisons, with the best GC-IPL parameters being minimum and inferotemporal (AUC=0.669 and 0.662, respectively). Moreover, minimum GC-IPL, average RNFL, and rim area (AUC=0.900, 0.858, 0.768, respectively) were the best parameters for discriminating moderate-to-severe glaucoma patients from early glaucoma patients. CONCLUSION: GC-IPL parameters can discriminate glaucoma suspect patients from subjects with healthy eyes, and also all the consecutive stages of glaucoma from each other (from glaucoma suspect to moderate-to-severe glaucoma). Further, the discriminating performance of GC-IPL thicknesses is comparable to that.     

Long‐Term Exposure to Biomass Fuel and Its Relation to Systolic and Diastolic Biventricular Performance in Addition to Obstructive and Restrictive Lung Diseases

Background: Previous studies have demonstrated an increased risk for cardiovascular events and pulmonary disease in patients with biomass fuel exposure (BFE). However, biventricular heart function has yet to be investigated in these patients. Left ventricular (LV) myocardial performance index (LVMPI), which is an index of global ventricular function, incorporates ejection, isovolumic relaxation, and contraction times. In this study, pulmonary function and biventricular heart function were investigated in nonsmoking female patients with BFE. Methods: Our study population consisted of 46 female patients with BFE (group 1) and 31 control subjects (group 2). Pulmonary function tests and transthoracic echocardiographic examination were performed. Right ventricular myocardial performance index (RVMPI) and LVMPI were obtained by tissue Doppler imaging echocardiography (TDI). Results: BFE caused obstructive and restrictive spirometric impairments. RVMPI was higher in group 1 (0.55 ± 0.07) than group 2 (0.46 ± 0.06) (P = 0.042) and LVMPI was higher in group 1 (0.54 ± 0.08) than group 2 (0.47 ± 0.05) (P = 0.032). Also, pulmonary artery systolic pressure was higher in group 1 than group 2 (P = 0.02). Conclusions: BFE causes both obstructive and/or restrictive lung disease and systolic and diastolic biventricular dysfunction. Nonetheless, long‐term studies are needed to understand on BFE‐related ventricular dysfunctions and to document subsequent cardiovascular events. (Echocardiography 2011;28:52‐61)     

Is Premature Thelarche in the First Two Years of Life Transient?

Objective: Premature thelarche (PT) refers to isolated onset of thelarche in girls younger than 8 years of age. Most cases have an onset under 2 years of age. We aimed to establish whether the onset of thelarche under 2 years of age certifies a transient clinical course, as suggested by several authors.Methods: Sixty-seven girls with an onset of PT under 2 years of age were classified as having early puberty (EP) or classical PT after one year of follow-up. Progression of pubertal findings or absolute growth velocity (GV) standard deviation score (SDS) above 1 SDS constituted the criteria for a diagnosis of EP. Results: Twenty (29.1%) girls were classified as having EP and 47 (70.1%) girls as having classical PT. Basal serum luteinizing hormone (LH; ICMA) values at a cut-off level of 0.3 IU/L were found to be a significant risk factor for having an atypical course [OR=7.8; CI (95%): 2.04– 30.4, p=0.003]. Conclusions: Onset of thelarche under 2 years of age does not assure a transient course in a remarkable proportion of girls with PT. An absolute GV value of >1 SDS or a basal LH level ≥0.3 IU/L are suggested as indicators for close follow-up. Conflict of interest:None declared.