Gingival neoplasms: a multicenter collaborative study of 888 patients in Brazil.

BACKGROUND: To evaluate the prevalence and clinicopathological features of a large series of gingival neoplasms in Brazil. MATERIAL AND METHODS:  All gingival benign and malignant neoplasms were retrieved from the records of six Oral Pathology Services in Brazil, during a 41-year period. Clinical and demographic data, clinical diagnosis, and histopathological data were collected from the patients' clinical charts. For statistical analysis, the chi-square, median test of independent samples and the U Mann-Whitney tests were used, considering a significance of 5%. RESULTS:  From 100,026 oral lesions, 888 (0.9%) were gingival neoplasms. There were 496 (55.9%) males, with a mean age of 54.2 years. Most cases (70.3%) were malignant neoplasms. Nodules (46.2%) and ulcers (38.9%) were the most common clinical appearance for benign and malignant neoplasms, respectively. Squamous cell carcinoma (55.6%) was the most common gingival neoplasm, followed by squamous cell papilloma (19.6%). In 69 (11.1%) malignant neoplasms, the lesions were clinically considered to be inflammatory or of infectious origin. Malignant neoplasms were more common in older men, appeared with larger size, and with a time of complaint shorter than benign neoplasms (p<0.001). CONCLUSIONS:  Benign and malignant tumors may appear as nodules in gingival tissue. In addition, malignant neoplasms, especially squamous cell carcinoma, should be considered in the differential diagnosis of persistent single gingival ulcers.

Awareness on oral cancer among patients attending dental school clinics in Brazil.

BACKGROUND: Oral cancer is considered a public health problem worldwide. Dental schools may play an important role in educating patients about oral cancer. This study aimed at evaluating the knowledge of patients attending clinics at two dental schools in Brazil. MATERIAL AND METHODS: From March 2017 to April 2017, 251 patients who were attending clinics at two dental schools in Recife, Brazil, were included in the study. Patients were contacted in the waiting rooms of the clinic. Each participant completed a self-administered questionnaire, which consists of 21 questions, including socio-demographic and specific information on the disease. Data were analyzed using descriptive statistics, and a chi-square test (with a 5% significance level) was used to assess the correlation between the variables, education and family income and other variables. RESULTS: Most participants were women (64.9%) with a mean age of 42.72 years. Most participants were knowledgeable about oral cancer and identified tobacco use (48.6%), alcohol consumption (25.1%), and solar radiation (12%) as the primary risk factors for the disease. Only 36.7% of the participants reported having received counselling on oral cancer, of which 18.3% received the information from a dentist. All patients with an income higher than six minimum wages were aware about oral cancer (p = 0.001). CONCLUSIONS: These findings emphasize the importance of educational programs in dental schools as well providing integrated services for patients seeking care at school clinics, including population's awareness on oral cancer.

Intraoral lipomas: A clinicopathological study of 43 cases, including four cases of spindle cell/pleomorphic subtype.

BACKGROUND: The aim of this study was to describe the clinicopathological characteristics of 43 intraoral lipomas and classify them according to their microscopic variants. MATERIAL AND METHODS: All the cases of intraoral lipomas diagnosed at an Oral Pathology service were selected for the study. Clinical data, such as age, gender, location, time of evolution, clinical presentation, clinical hypothesis of diagnosis, and treatment, were collected from the clinical files. RESULTS: Of the 43 cases analyzed, 24 (55.8%) occurred in women. The mean age was 77.4 years. The most affected site was the buccal mucosa (22 cases, 51.1%). The mean lesion size was 1.7 cm. Twenty-three cases (53.5%) were classified as simple lipoma, 14 (32.6%) as fibrolipoma, four (9.3%) as spindle cell/pleomorphic lipoma (SC/PL), one (2.3%) as lipoma of the salivary glands, and one (2.3%) as intramuscular lipoma. In one case of SC/PLs, lipoblasts were observed. No atypical lipoblasts or mitoses were noted. Lipoma was considered more often than other tumor histological subtypes among the clinical hypotheses of diagnosis when the final diagnosis was simple lipoma (p=0.01). CONCLUSIONS: Intraoral lipomas present different clinical presentation depending on the histological subtype. In SC/PLs, lipoblasts with vacuolated cytoplasm may be found and the presence of mature adipocytes is essential for diagnosis.

Recording different geometries of 2D hexagonal photonic crystals by choosing the phase between two-beam interference exposures.

2D hexagonal patterns can be generated by the superimposition of two or three fringe patterns that have been formed by two-wave interference and that have rotations of 60 degrees between them. Superimposing three exposures solves the problem of asymmetry in the cross section of structures, which is caused by double exposure. The resulting structure, however, depends on the phase shift of the third fringe pattern in relation to the previous two. We propose a method for controlling the phase shift, and we demonstrate that three different lattice geometries of hexagonal photonic crystals can be recorded when the phase is chosen.