The purpose of this study was to monitor the setting behaviour and elastic modulus of luting cements using an ultrasonic device. The ultrasonic equipment comprised a pulser-receiver, transducers and an oscilloscope. The transit time through the cement disk was multiplied by the thickness of the specimen, and the sonic velocity within the material was then calculated. The sonic velocities of the longitudinal and shear waves were used to determine the elastic modulus. Analysis of variance and the Tukey HSD test were used to compare the elastic moduli of the set cements. In the earliest stages of the setting process, most of the ultrasound energy was absorbed by the cements and the sound waves were relatively weak. As the cements hardened, the sound velocities increased and this tendency differed among the luting cements used. The mean elastic moduli of the specimens ranged from 2.9 to 9.9 GPa after 15 min, from 14.4 to 20.3 GPa after 24 h and from 12.1 to 15.9 GPa after 1 month. The setting processes of the luting cements were thus clearly defined by using the present ultrasonic method. (J. Oral Sci. 50, 117-121, 2008)
The purpose of this study was to up-date the records concerning oral clefts (OCs) encountered at the Child Hospital of the Maternal Infantile Institute of the State of México, and to examine the association of predisposing factors. A retrospective study of the medical records of patients generated over a 5-year period was carried out. A total of 835 files were reviewed, representing 504 boys and 331 girls. The studied variables were the type of oral clefts and predisposing factors. Kendal correlations at P ≤ 0.05 and chi-squared at P ≤ 0.05 were used to find any associations between variables. The distribution of oral cleft was: cleft lip and palate (CLP) 70%, cleft palate (CP) 21%, cleft lip (CL) 8%, separate cleft lip and cleft palate 1%. The sex ratios were 1.7 for CLP, 1.7 for CL, and 1 for CP. Municipalities with ethnic groups as well as industrial, agricultural and pottery activities showed a high rate of prevalence. Although there was no significant association with birth weight, familial history of clefting, consanguinity, medication usage during pregnancy, or paternal occupational risk, the results suggested that the most severe clefts were proportionally related to these factors. A significant association with maternal and paternal age, abortion rate, and parity was found. Additionally, maternal agricultural activities suggested that pesticide exposure might be a factor. (J. Oral Sci. 50, 123-129, 2008)
This study investigated the influence of ceramic thickness and curing unit on light transmission through leucite-reinforced material and polymerization of a dual-cured resin luting agent. Discs of Empress Esthetic (Ivoclar Vivadent) of 0.7-, 1.4- and 2-mm thickness were prepared. Variolink II (Ivoclar Vivadent) was placed in a 1-mm-thick cylindrical mold, and light-activated through ceramic for 40 s, using QTH or LED units. The samples were divided into dual, light, and chemically-polymerized control groups. Knoop hardness indentations were made on the top and bottom surfaces. Data were subjected to split-plot design three-way ANOVA and Tukey's test (P < 0.05). The light spectrum transmitted through ceramic was obtained using a spectrometer. Samples activated through 1.4-and 2-mm-thick discs showed lower hardness than all others groups, except for the chemical control group. Dual and light-polymerized control samples showed similar hardness to those activated through the 0.7-mm ceramic, whereas chemically polymerized control samples showed similar hardness to those activated through 1.4- and 2-mm ceramics. No significant differences in hardness were detected between the curing units or between the top and bottom layers. No significant alteration in the light spectrum profile was observed for both units, irrespective of the ceramic thickness. (J. Oral Sci. 50, 131-136, 2008)
The aim of this study was to determine the effect of different types of composites (Filtek Z250, Esthet X and Filtek Supreme) and dentin thicknesses (0.5 or 1.0 mm) on the generation of heat during photoactivation by QTH (conventional halogen light), LED (light emitting diode), and PAC (xenon plasma light) light-curing units. Temperature changes were recorded with a thermocouple type K connected to a digital thermometer. Twenty chemically polymerized acrylic resin bases were prepared in order to guide the thermocouple and to support the dentin disks. On the acrylic resin base, elastomer molds of 2.0-mm thickness were adapted. The temperature increase was measured after composite photoactivation and the matrix was stored at 37°C. After 24 hours, photoactivation was performed again and the temperature increase was measured. Obtained data were analyzed by ANOVA and Tukey's test (α= 0.05). The mean temperature increase produced by QTH was significantly lower than that of the other photoactivating units (P < 0.05), due to its low radiant exposure. There were no significant differences among the samples with regard to dentin thickness and type of composites (P > 0.05). The immediate temperature rise was statistically higher when compared to the increase after additional polymerization (24 h), in all groups (P < 0.05). Light intensity and exposure time appeared to be the most important factors causing temperature change. (J. Oral Sci. 50, 137-142, 2008)
Hypodontia of permanent teeth was evaluated from orthopantomograms of 2072 apparently healthy pediatric patients at The Hospital of Nihon University School of Dentistry at Matsudo. The prevalence of congenitally missing teeth (CMT) was 8.7% in boys and 10.8% in girls, and 9.4% for both sexes combined. Most cases (67.8%) involved either one or two missing teeth. There were in total 574 CMT, and on average 2.8 teeth were missing per child. The most commonly absent tooth was the mandibular second premolar. On the other hand, no first molars were missing in any case. A high frequency of CMT mandibular incisors (18.82%) was observed, and this seems to be a characteristic peculiar to individuals of Asian ethnicity. Oligodontia (6 or more CMT excluding the third molar) ranged from 6 to 14 teeth, with a prevalence of 1.4% in general: 1.8% for girls and 0.9% for boys. Symmetry of CMT was predominant: 214 pairs for bilateral symmetry and 107 pairs for symmetry between two antagonistic quadrants. The distribution of CMT between maxillary and mandibular hypodontia in the right and left quadrants for boys and girls no had significant association (P < 0.05). (J. Oral Sci. 50, 143-150, 2008)
Localized aggressive periodontitis (LAgP) is a complex multifactorial periodontal disease to which genetic factors are thought to predispose individuals. Interleukin-1 (IL-1) and tumor necrosis factor-α (TNF-α) are potent immunomodulators and proinflammatory cytokines that have been implicated in the pathogenesis of autoimmune and infectious diseases and proposed to be risk factors for LAgP. Our aim was to investigate IL-1 α +4845, IL-1 β +3954, and TNF-α -308 gene polymorphisms in Turkish LAgP patients. We genotyped 31 LAgP patients and 31 healthy controls for IL-1α+4845, IL-1β+3954, and TNF-α-308 using standard PCR amplification followed by restriction enzyme digestion and gel electrophoresis. Higher prevalence of heterozygosity for IL-1α+4845 was found in cases (65%) when compared to controls (35%) (P < 0.05). While homozygous allele 1 of IL-1β+3954 was the most frequent genotype in cases (62%), no controls were homozygous for this allele (P < 0.001). Homozygous allele 1 was the most common TNF-α genotype in both groups, however no significant difference in TNF-α genotypes was found between groups. In conclusion, in this Turkish population, susceptibility to LAgP is increased by heterozygosity for allele 1 of IL-1α+4845 or homozygosity for allele 1 of IL-1β+3954. Moreover, IL-1 gene polymorphisms appear to have a role in susceptibility to LAgP, and the above-mentioned genotypes could be an important risk factor for LAgP in the Turkish population. (J. Oral Sci. 50, 151-159, 2008)
The present cross-sectional study was conducted to assess the prevalence of caries and treatment needs among 127 institutionalized subjects aged 5-22 years attending a special school for students with hearing impairment in Udaipur City, Rajasthan, India. The data were collected using the methods and standards recommended by the WHO for oral health surveys, 1997. Dentition status and treatment needs along with DMFT, DMFS, dmft, dmfs were recorded using a Type III examination procedure. ANOVA, chi-squared test and multiple regression analysis were conducted using the SPSS software package (version 11.0). The mean DMFT was 2.61. Of the 127 subjects, 111 (87.4 %) needed treatment. Filling of one tooth surface was necessary for 79.5% of the subjects. Pulp treatment was needed in less than 7%. There was a high prevalence (83.92%) of decayed teeth, whereas only 7.14% of subjects had filled teeth. Multiple regression analysis showed that DMFT had a close association with age. Linear regression analysis revealed that age explained a variance of 32% and 25.4% for DMFT and dmft respectively The findings of this study demonstrate that young people with impaired hearing in this region have a high prevalence of dental caries, poor oral hygiene, and extensive unmet needs for dental treatment. This highly alarming situation requires immediate attention. (J. Oral Sci. 50, 161-165, 2008)
We investigated sex and age group differences in attitudes to oral health among school-age children using an Oral Self-Care Appraisal (OSCA) to systematically determine changes in oral health knowledge, attitude, and behavior across developmental stages. The subjects (n = 1584) were stratified after random sampling so that each school grade analyzed contained 88 boys and 88 girls. Factor analysis was undertaken to identify a set of underlying factors, with 10 factors considered in the cross-sectional study. Our results showed that the factors toothbrushing, persistence, and sociability were more predominant in primary school children than in junior high and senior high school students. Furthermore, postponement of visiting the dentist and resignation to one's own dental cavities became more predominant in proportion to the level of school education. Girls had significantly higher scores than boys for desire to improve oral care, dental anxiety, dependency on snacks, toothbrushing, concern over number of cavities, and sociability. Together, the results indicated that the oral health care behavior of girls was better than that of boys, and that the tendency to postpone visiting the dentist and resignation to one's own dental cavities increased markedly with age. (J. Oral Sci. 50, 167-174, 2008)
Recent animal studies have demonstrated that many trigeminal ganglion neurons co-express TRPV1 and TRPA1 receptors following peripheral inflammation. In the present study, we examined whether cold receptors were sensitized by capsaicin in awake monkeys. Two monkeys were trained to detect a change in cold stimulus temperature (30°C to 0.5, 1.0, 1.5 or 2.0°C) applied to the facial skin. A total of 589 trials were studied, and the number of escape and hold-through trials and detection latency were measured. The number of escape trials was increased after capsaicin treatment, whereas that of hold-through trials was decreased. Detection latency was significantly decreased after capsaicin treatment. The present findings suggest that topical application of capsaicin to the facial skin induces reversible hypersensitivity to a facial cold stimulus in behaving monkeys. (J. Oral Sci. 50, 175-179, 2008)
Single-step self-etch adhesive systems have been developed to simplify and shorten bonding procedures. With the gain in popularity of these simplified systems, their reliability has become a focus of interest. The purpose of this study was to determine the effect of adhesive application method on enamel bond strength. Two commercial single-step self-etch adhesive systems, Clearfil tri-S Bond, and G-Bond, were used. Bovine mandibular incisors were mounted in self-curing resin and the facial enamel surfaces were ground wet on 600-grit SiC paper. Adhesives were only applied without agitation (inactive) or were agitated by a brush (active), and resin composites were condensed into the mold on the enamel surface and light-activated. Ten specimens per test group were stored in water at 37°C for 24 h, then shear-tested at a cross-head speed of 1.0 mm/min. Two-way ANOVA followed by the Tukey HSD test were used. The bond strengths for active application were higher than those for inactive application. Significant differences were found for both adhesive systems. From the results of this study, active application of single-step self-etch adhesive may help to ensure the creation of a roughened enamel surface and enhance the penetration of resin monomer into the subsurface demineralized enamel. (J. Oral Sci. 50, 181-186, 2008)
Odontogenic myxoma is a benign neoplasm, which presents local invasiveness and tendency for recurrence. Matrix metalloproteinases (MMPs) 2 and 9 are involved in tumor invasion. Thus, the aim of this study was to analyze the expression and activity of these MMPs in odontogenic myxoma in vivo and in vitro. Three cases of odontogenic myxoma and cultured cells derived from this tumor (Mix1 cell line) were used. The detection and activity of two MMPs (2 and 9) were performed by immunohistochemistry in formalin-fixed, paraffin-embedded sections of odontogenic myxoma and immunofluorescence of the cultured cells and, by gelatin zymographic analysis of Mix1 conditioned media, respectively. MMPs 2 and 9 were detected in vivo and in vitro. The zymographic assay detected latent MMP-2 as well as latent and active MMP-9. Based on our findings, we suggest that MMPs may be involved in local invasiveness of the odontogenic myxoma. MMP-9 is not only secreted by odontogenic myxoma but also has enzyme activity with no further stimulation. Other MMPs were not analyzed; however, our results suggest that the invasive behaviour of odontogenic myxoma could be related at least to MMP-9. (J. Oral Sci. 50, 187-192, 2008)
Susceptibility to and development of periodontal disease have been associated with psychological conditions. Previous studies have associated the presence of polymorphism in the promoter region of the serotonin transporter with several behavioral traits and psychological conditions such as depression, anxiety, and stress. The short allele S has a reduced transcriptional efficiency and is associated with lowered serotonin expression and uptake. The purpose of the present study was to investigate the association between 5-HTTLPR polymorphism and aggressive periodontitis in a sample of Brazilian individuals. This study involved 61 individuals affected by aggressive periodontitis and 71 without periodontitis. Genomic DNA was obtained from oral swabs, amplified by polymerase chain reaction (PCR), and genotyped at 5-HTTLPR. The Chi-square test and multivariate logistic regression were used for statistical analysis. The aggressive periodontitis group displayed a significantly higher occurrence of genotype SS (P < 0.01) and of allele S (P < 0.01). After adjustment for gender and age, it was observed that genotype SS occurred 8 times more frequently in this group. Our findings suggest that 5-HTTLPR polymorphism might be associated with aggressive periodontitis in the Brazilian population. (J. Oral Sci. 50, 193-198, 2008)
A study was conducted to observe the surface morphological changes of human dentinal pulpal walls in specific areas of the tooth at various ages. Thirty-two extracted human non-carious teeth with single root canals were used. The teeth were divided longitudinally in the bucco-lingual plane and prepared for scanning electron microscopy (SEM). The specimens were divided into two groups (younger and older) according to age. Four central sites of the dentinal pulpal wall, including coronal, cervical, mid-root and apical sections, were selected as specific locations. Under the conditions of this study, six basic types of SEM appearance at dentinal pulpal wall surfaces were identified on the basis of calcospherite shape and mineralization. The appearance of the calcospherites varied according to tooth age and location along the dentinal pulpal walls. (J. Oral Sci. 50, 199-203, 2008)
In 2005, the WHO Working Group considered odontogenic keratocyst (OKC) to be a tumor and recommended the term keratocystic odontogenic tumor (KCOT), separating the lesion from the orthokeratinizing variant, which is now considered an odontogenic cyst. We analyzed the clinicopathological features of KCOTs encountered over a period of 28 years at Meikai University Hospital. The diagnosis was confirmed by reevaluation of hematoxylin and eosin-stained slides on the basis of the 2005 WHO Classification. Clinical history was also taken into consideration. A total of 183 KCOTs were found, and the two genders were affected almost evenly (51.3% male; 48.7% female; male to female ratio 1.05 to 1). Patient age at the time of diagnosis ranged from 6 to 78 years, with a peak in the third decade of life (mean age: 32.8 years). The mandible was the site of occurrence of 70.5% of tumors; 16.4% occurred in the maxilla and 13.1% in both. Association with the nevoid basal cell carcinoma syndrome (NBCCS) was found in 6.0% of all tumors, and recurrence was found in 13.1% of patients. We found that tumors that initially appeared in the maxilla alone had a higher recurrence rate than those that first appeared in the mandible alone. Pathological examination of KCOT is important to avoid misdiagnosis and provide appropriate treatment and follow-up. (J. Oral Sci. 50, 205-212, 2008)
This article presents the original description of Nikolskiy's sign given by Piotr Vasiliyevich Nikolskiy in 1894, along with various different interpretations of Nikolskiy's sign and numerous terminologies used in the literature by a number of clinicians. (J. Oral Sci. 50, 213-214, 2008)
Leiomyosarcoma is a relatively uncommon malignant lesion that exhibits smooth muscle differentiation. Occurrence of this tumor in the oral cavity is exceedingly rare, reflecting the paucity of smooth muscle in this region. This article presents a rare case of leiomyosarcoma of the buccal mucosa, which was confirmed by immunohistochemical staining. (J. Oral Sci. 50, 215-218, 2008)
Epithelioid hemangioendothelioma is a rare vascular neoplasm which exhibits the potential for malignancy and recurrence as well as the ability to metastasize. Although numerous sites of involvement are possible, these tumors most commonly arise in soft tissues, lung, liver, bone, and lymph nodes. In this report, we describe a case of oral epithelioid hemangioendothelioma in a child. This tumor appeared as exophytic ulcerated painless masses in the maxillary and mandibular gingiva. Histologically, the tumor was composed of a proliferation of tumor cells arranged in nests, cords, and short strands. Epithelioid cells exhibited abundant eosinophilic cytoplasm with nuclear and cellular pleomorphism and intra-cytoplasmic vacuoles. (J. Oral Sci. 50, 219-223, 2008)
This case report describes a rare and unusual lesion found in a 12-year-old boy, which was diagnosed as pleomorphic adenoma of the minor salivary glands in the upper lip. The tumor was a circumscribed, submucosal nodule, about 2.0 cm in diameter and characterized by slow growth and a rubbery consistency. Complete excision was performed and the histopathological analysis showed an epithelial salivary gland tumor with islands of plasmacytoid cells, duct-like structures, in a variable stroma with chondroid, fibrous and myxoid appearance. The tumor did not recur. A brief review of the relevant literature is also presented. (J. Oral Sci. 50, 225-228, 2008)
Bone exostosis has long been described in the literature, appearing in most cases as a torus palatinus or mandibularis. These two variations are relatively common and affect approximately 30% of the world's population. Incidence is even higher when human skulls are examined post mortem, indicating that in some cases the exostosis is small and cannot be seen under the soft tissue. Removal of an exostosis is usually associated with the construction of a prothesis, but in rare cases such as the present, the lesion enlarges enough to affect speech and feeding. Few studies have reported the removal of such a large exostosis, and all were conducted in a hospital environment. In this case, complete removal was successfully conducted in an ambulatory clinic under local anesthesia. (J. Oral Sci. 50, 229-231, 2008)
Hemangiopericytoma, initially described by Stout and Murray in 1942 (1), is a rare vascular tumor arising from mesenchymal cells with pericytic differentiation. Hemangiopericytomas usually occur in the 5th decade of life and account for 3-5% of all soft tissue sarcomas and 1% of all vascular tumors (2). The tumor usually occurs in the limbs, pelvis, or head and neck region; 15-30% of all hemangiopericytomas occur in the head and neck (2,3). Here we present a case of hemangiopericytoma of the submandibular region with keratocystic odontogenic tumors in an adolescent patient. (J. Oral Sci. 50, 233-237, 2008)
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