Peri-Implant Mucosal Fenestration and Histologic Observation of Bone Xenograft Material 7-Years After Implant Installation: A Case Report.

Bone augmentation is often required before the installation of dental implants. Here, we report a case for a patient who previously received bone augmentation at the upper right jaw using a xenogenic graft, followed by successful implant installation. Seven years later, the patient presented with mucosal fenestration with bone exposure at the area and gave a history of a recent diagnosis of cutaneous lichen planus. Several attempts were made to manage the situation, and finally, we resorted to connective tissue graft placement at the site. A piece of bone was sent for histologic evaluation, where the results indicated the presence of un-resorbed graft material surrounded by inflammatory cells, with no evidence of bone formation in the area. The case presents histologic evidence for the lack of new bone formation using xenograft over the evaluation period. The case also shows lichen planus, a possible cause for oral complication for patients undergoing augmentation and implant installation.

The effect of various washing methods on pesticide residues, toxic and essential elements removal in rice.

This study examined the effects of various treatments on removing pesticide residues and toxic elements in rice. In parallel, nutritional elements, magnesium (Mg), potassium (K), and phosphorous (P), were measured to investigate the effect of these washing treatments on the nutritional value of rice. A naturally contaminated rice sample containing five widespread used pesticides (azoxystrobin, buprofezin, carbendazim, and propiconazole) and toxic elements, arsenic (As), cadmium (Cd), and essential elements, was washed using several washing agents, including boiling water, 5% sodium bicarbonate (baking soda), 5% acetic acid (vinegar), 5% citric acid, and 5% sodium chloride (salt). The washing method was chosen based on its availability and widespread usage; soaking for 10 min was assumed to be reasonable. Our results showed that using 5% acetic acid significantly reduced azoxystrobin by 63%, buprofezin by 70%, carbendazim by 75%, and propiconazole by 61%. However, As and Cd were significantly reduced in sodium chloride by 57% and 32%, respectively. Furthermore, a significant reduction in essential nutrient elements was found in Mg (42%), K (37%), and P (23%) when rice was treated with 5% citric acid. Overall, washing agents reduced analytes in the following manners pesticides, toxic elements, and essential elements when using acetic acid, sodium chloride, and citric acid separately.

Factors underlying suboptimal diagnostic performance in physicians under time pressure.

CONTEXT: Time pressure has been implicated in the suboptimal diagnostic performance of doctors and in increases in diagnostic errors. However, the reasons underlying these effects are not clear. The aim of this study was to investigate the influence of time pressure on physicians' diagnostic accuracy and to explore the mediating effects of perceived stress (emotional pathway) and number of plausible diagnostic hypotheses (cognitive pathway) on the proposed relationship. METHODS: We conducted a randomised controlled experiment. A total of 75 senior internal medicine residents completed eight written clinical cases under conditions with (n = 40) or without (n = 35) time pressure. They were then asked to: (i) rate the overall stress experienced, and (ii) write down any alternative hypotheses they had thought of when diagnosing the cases. In a post hoc analysis, a mediation path analysis was performed to test the causal relationships between time pressure, perceived stress and number of alternative diagnoses. RESULTS: Participants who were under time pressure spent less time diagnosing the cases (85.54 seconds versus 181.81 seconds; p< 0.001) and had a lower mean diagnostic accuracy score (0.44 versus 0.53; p = 0.01). In addition, they reported more stress (5.80 versus 4.69; p = 0.01) and generated fewer plausible tentative hypotheses (0.37 versus 0.51; p = 0.01). Two path coefficients were found to be statistically significant; the first path coefficient referred to the relationship between time pressure and perceived stress (standardised ß = 0.25, p = 0.029), and the second negative path coefficient referred to the relationship between time pressure and number of plausible alternative hypotheses (standardised ß = -0.32, p< 0.01). CONCLUSIONS: Time pressure adversely influences physicians' diagnostic accuracy by increasing their stress response and reducing the number of plausible hypotheses as mediators.

Measuring dental students' preference: A comparison of light microscopy and virtual microscopy as teaching tools in oral histology and pathology.

OBJECTIVES: Light microscopy used to be the traditional modality of teaching histology and pathology disciplines. Recent advances and innovations in the information technology field have revolutionized the use of hard- and software in medical education. An example of such an innovation is the so-called virtual microscopy. Many schools have started to adopt virtual microscopy as a new method aimed at enhancing student learning. Nonetheless, few reports have described the experiences of introducing virtual microscopy in dental education. We conducted this study to evaluate student perceptions of virtual microscopy use. MATERIALS AND METHODS: A survey of 9 items with a five-point Likert scale was designed to assess student perceptions of different aspects of virtual microscopy use compared with light microscopy. Eighty-seven 2nd year dental students answered the survey for a response rate of 80%. RESULTS: The majority of the students (85.1%) reported positive feedback for the use of virtual slides as a method of learning. Students reported significantly higher scores in virtual microscopy compared with light microscopy (t test: t86 = 9.832, P < 0.0001); however, a few students reported some technical difficulties when using computers to view the virtual slides. CONCLUSIONS: Although light microscopy is the classical tool of teaching histology and pathology, virtual microscopy is a highly preferred substitute. We believe that virtual microscopy is a valuable teaching tool that enhances student educational experiences.

Does Time Pressure Have a Negative Effect on Diagnostic Accuracy?

PURPOSE: Studies suggest time pressure has negative effects on physicians' working conditions and may lead to suboptimal patient care and medical errors. Experimental evidence supporting this is lacking, however. This study investigated the effect of time pressure on diagnostic accuracy. METHOD: In 2013, senior internal medicine residents at three hospitals in Saudi Arabia were divided randomly into two groups: a time-pressure condition and a control condition without time pressure. Both groups diagnosed eight written clinical cases presented on computers. In the time-pressure condition, after completing each case, participants received information that they were behind schedule. Response time was recorded, and diagnostic accuracy was scored. RESULTS: The 23 participants in the time-pressure condition spent significantly less time diagnosing the cases (mean = 96.00 seconds) than the 19 control participants (mean = 151.97 seconds) (P < .001). Participants under time pressure had a significantly lower diagnostic accuracy score (mean = 0.33; 95% CI, 0.23-0.43) than participants without time pressure (mean = 0.51; 95% CI, 0.42-0.60) (F[1, 41] = 6.90, P = .012, η = 0.15). This suggests participants in the time-pressure condition made on average 37% more errors than control participants. CONCLUSIONS: Time pressure has a negative impact on diagnostic performance. The authors propose that the effect of time pressure on diagnostic accuracy is moderated by both the case difficulty level and the physician's level of experience. Post hoc analyses demonstrated that time pressure affects diagnostic accuracy only if cases are not too difficult and physicians' expertise level is intermediate.

Epithelioid Osteosarcoma of the Maxilla: A Case Report and Review of the Literature.

Epithelioid osteosarcoma is an uncommon variant; only 4 cases have been reported in the jaw area, 2 of which were in the maxilla. A 22-year-old woman, in the eighth month of pregnancy, presented to the oral surgery clinic with a mass in the right maxilla that had rapidly expanded over the past 3 months. Computed tomography scans showed an ill-defined sclerotic destructive lesion that formed bone matrix in its soft tissue extension. Microscopic examination of the lesion revealed malignant epithelioid cells with osteoid deposits. The tumor cells were shown to have pale cytoplasm, vesicular nuclei, and prominent nucleoli and to undergo frequent mitosis. In addition, the tumor was positive for epithelial membrane antigen and vimentin and negative for AE1/AE3, Melan-A, CD30, synaptophysin, NSE, CD45, CD99, desmin, and myogenin. The final diagnosis was epithelioid osteosarcoma, which is a rare aggressive variant of osteosarcoma. Few cases of epithelioid osteosarcoma have been reported in the literature, and more studies are required to determine the clinical behavior of this tumor.

Assessing learning styles of Saudi dental students using Kolb's Learning Style Inventory.

Experiential learning theory (ELT), a theory developed by David Kolb that considers experience to be very important for learning, classifies learners into four categories: Divergers, Assimilators, Convergers, and Accommodators. Kolb used his Learning Style Inventory (LSI) to validate ELT. Knowing the learning styles of students facilitates their understanding of themselves and thereby increases teaching efficiency. Few studies have been conducted that investigate learning preferences of students in the field of dentistry. This study was designed to distinguish learning styles among Saudi dental students and interns utilizing Kolb's LSI. The survey had a response rate of 62 percent (424 of 685 dental students), but surveys with incomplete answers or errors were excluded, resulting in 291 usable surveys (42 percent of the student population). The independent variables of this study were gender, clinical experience level, academic achievement as measured by grade point average (GPA), and specialty interest. The Diverging learning style was the dominant style among those in the sample. While the students preferred the Assimilating style during their early preclinical years, they preferred the Diverging style during their later clinical years. No associations were found between students' learning style and their gender, GPA, or specialty interest. Further research is needed to support these findings and demonstrate the impact of learning styles on dental students' learning.

Oral leiomyomatous hamartoma of the median maxillary gingiva: a case report and review of the literature.

Oral leiomyomatous hamartoma (OLH) is a rare lesion seen in the oral cavity. It mainly presents on the median maxilla and tongue. In the literature in English, there are only 10 reported cases of OLH of the median maxilla. Most of the cases were found in patients of Japanese and Latin American origin. We report a case of OLH in an 18-month-old boy of Middle Eastern ancestry. The lesion presented as a pedunculated, light pink, soft swelling that was located on the labial gingiva of tooth number 21. Microscopically, it showed proliferative smooth-muscle fascicles dispersed in loose fibrous stroma and multiple small vessels. The lesional cells looked mature and elongated and were deeply eosinophilic spindle cells with basophilic, central "cigar-shaped" nuclei. The diagnosis of OLH was supported by positive immunohistochemical reactivity of smooth-muscle actin and desmin. To our knowledge, this is the first reported case of OLH in a Middle Eastern patient.