1,721,127 research outputs found
Short-term variation in the subgingival microbiota in two groups of patients treated with clear aligners and vestibular fixed appliances: A longitudinal study
Full text linkObjective: To evaluate the subgingival microbiological changes during the first six months of therapy with clear aligners (CAs) and fixed appliances (FAs). The null hypothesis was that there would be no microbiological differences between the two. Setting/Sample: Two groups of patients to be treated, respectively, with CAs (14 patients; 9 females and 5 males; mean age 21 years ± 0.25) and FAs (13 patients; 8 females and 5 males; mean 14 years ± 0.75) were consecutively recruited. Materials and Methods: Subgingival microbiological samples were obtained at the right upper central incisor and right first molar at four different time points: before appliance fitting (T0), and at 1 month (T1), 3 months (T3) and 6 months (T6) thereafter. Total bacterial load (TBL) and counts of the bacteria Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Fusobacterium nucleatum, Campylobacter rectus, Treponema denticola and Tannerella forsythia were determined using real-time PCR. Results: Total bacterial load did not vary in the CA group, while a significant increase was detected after 3 and 6 months of treatment in the FA group. Unlike red complex species, C rectus and F nucleatum were often detected: levels remained stable in the CA group but increased progressively in the FA group. Conclusion: The type of orthodontic appliance influences the subgingival microbiota. TBL increased in the FA group but not in the CA group, although the levels of the individual periodontal pathogenic bacteria species did not significantly increase during the observation period
MICROSATELLITE DNA AS A MARKER FOR MAPPING OF LOCI LINKED TO CRANIOFACIAL MALFORMATIONS
No full textCleft Lip with or without cleft palate (CL +/- P) is one of most common congenital orofacial anomaly, with a frequency of 1/700-1/1,000 live births among Caucasians. This embryopathy is due to a failure of nasal processes and palatal shelves fusion. Approximately 20 % of patients have a positive family history of CL +/- P, and thus genetic factors are thought to be important in its etiology. Four different chromosomal regions, 6p23-25, 2p13, 17q21.1 and 1q21, have been claimed to contain a CL +/- P locus. In our study we investigated the possible CL +/- P locus of chromosome 6p23. To this purpose we selected a group of markers, which map on this chromosome region, to analyse a large sample of families. Twentyone families characterized by the presence of at least two affected CL +/- P individuals, arising from north-eastern Italy, were enrolled in this study. DNA was analyzed with five highly informative PCR markers close to the putative CL +/- P locus: 1 VNTR factor 13A, and 4 dinucleotide repeats at loci EDN1, D6S89, D6S109, D6S105. Our results demonstrate that nonsyndromic familiar CL +/- P is heterogeneous; these data are in agreement with the idea of a model of a dominant major gene modified by additional genetic and/or enviromental factors. So it is possible that different chromosomal region are involved in etiology of the disease. Our linked families showed an autosomal dominant inheritance with incomplete penetrance. Finally, CL +/- P locus maps on 6p23 very close to, or at the microsatellite marker D6S89
Non-syndromic Cleft Palate: An Overview on Human Genetic and Environmental Risk Factors
No full textThe epithelial and mesenchymal cells involved in early embryonic facial development are guided by complex regulatory mechanisms. Any factor perturbing the growth, approach and fusion of the frontonasal and maxillary processes could result in orofacial clefts that represent the most common craniofacial malformations in humans. The rarest and, probably for this reason, the least studied form of cleft involves only the secondary palate, which is posterior to the incisive foramen. The etiology of cleft palate only is multifactorial and involves both genetic and environmental risk factors. The intention of this review is to give the reader an overview of the efforts made by researchers to shed light on the underlying causes of this birth defect. Most of the scientific papers suggesting potential environmental and genetic causes of non-syndromic cleft palate are summarized in this review, including genome-wide association and gene–environment interaction studies
Human genetic factors in nonsyndromic cleft lip and palate: An update
No full textNonsyndromic cleft lip and/or palate (or orofacial cleft, OFC) is a malformation characterized by an incomplete separation between nasal and oral cavities without any associated anomalies. The last point defines the distinction between syndromic and nonsyndromic OFC. Nonsyndromic OFC is one of the most common malformations among live births and is composed of two separate entities: cleft lip with or without cleft palate (CL+/-P) and cleft palate isolated (CPI). Because of the complex etiology of nonsyndromic OFC, which is due to the differences between CL+/-P and CPI, and the heterogeneity of each group, caused by the number of genes involved, the type of inheritance, and the interaction with environmental factors, we reviewed those genes and available loci in the literature whose involvement in the onset of nonsyndromic OFC has more sound scientific evidence. Genetic studies on human populations have demonstrated that CL+/-P and CPI have distinct genetic backgrounds and, therefore, environmental factors probably disclose only these malformations. In CL+/-P several loci, OFC from 1 to 10 have been identified. The first locus, OFC1, has been mapped to chromosome 6p24. Other CL+/-P loci have been mapped to 2p13 (OFC2), 19q13.2 (OFC3) and 4q (OFC4). OFC5-8 are identified by mutations in the MSX1, IRF6, PVRL1, and TP73L gene, respectively. OFC9 maps to 13q33.1-q34, whereas OFC10 is associated with haploinsufficiency of the SUMO1 gene. In addition, MTHFR, TGF-beta3, and RARalpha play a role in cleft onset. In CPI one gene has been identified (TBX22) at present, but others are probably involved. Greater efforts are necessary in order to have a complete picture of the main factors involved in lip and palate formation. These elements will permit us to better understand and better treat patients affected by OFC
Effect of a new xenograft material in mandibular post-extraction sites: a case series
No full textThe alveolus bone is a tooth-dependent tissue. The extraction of the dental element determines the resorption of the alveolar crest, which trophism is linked to the presence of the periodontal ligament. Several materials have been used to improve alveolar bone healing and maintain alveolar ridge. The aim of the study is to evaluate the effects of a new matrix of bovine bone processed at low temperature in association with a membrane of the bovine pericardium in post-extraction sites using histological analysis comparing treated and untreated alveoli. Five patients with non-recoverable teeth were enrolled in the present study for teeth extraction. In treated sites, the alveolus was packed with Decellularized and Antigen-free Bovine Bone (RE-BONE® Ubgen, Padova, Italy) and subsequently covered with a bovine-derived pericardium membrane (SHELTER® FAST Ubgen, Padova, Italy). Four alveoli of two patients were left to heal spontaneously as control sites. The tissue sampling was performed during the implant site preparation four months after extraction. Specimens were decalcified, and sections were stained with hematoxylin and eosin. Bone histomorphometry of regeneration tissues from treated sites showed an average increase of 2.9% in bone tissue. However, no statistically significant differences can be detected since standard deviations are very high. Generally, the alveolar preservation technique is a valuable method to guarantee alveolar volume stability. The material studied here showed a slight increase in bone production after 4 months from a tooth extraction in treated sites, which is an expression of a good healing process. However, since the limited number of cases analyzed, additional studies are needed to verify the bone gain in alveolar bone healing
Focus on periodontal disease and colorectal carcinoma
No full textDiagnosis of focal disease, the theory that the human oral microbial (HOM) could affect the onset and development of systemic diseases, was very popular in the past, but the lack of scientific evidence has led to the abandonment of this idea. Interestingly, increasing evidence over the past 3 or so decades suggests that HOM can indeed serve as a reservoir for systemic dissemination of pathogenic bacteria and their toxins in distant body sites, favouring the developments of malignant tumours. Malignant tumours are complex communities of oncogenically transformed cells with aberrant genomes, associated nonneoplastic cells including immune and stromal cells, and sometimes HOM, including bacteria and viruses. Recent data suggest that HOM and periodontal disease play an active role in the pathogenesis of colorectal cancer, in fact HOM has been found within the colorectal cancer microenvironment, and the composition of the HOM was different from that of adjacent non- neoplastic tissue. An association of fusobacterium nucleatum with the colonic mucosa of colorectal cancer has been proven. Several questions thus arise. Is periodontal disease a risk factor for colorectal carcinoma? Given the connectivity of the digestive tract, could fusubacterium nucleatum or other HOM be involved in additional gastrointestinal disorders? Furthermore, based on the âmobilityâ of Fusubacterium nucleatum and the omnipresence of cadherins, could this organism be involved in cancers beyond the gastrointestinal tract? Answers to these questions will shed new lights on the role of the HOM in onset of diseases
Classification of oral clefts by affection site and laterality : A genotype - Phenotype correlation study
No full textOrthod Craniofac Res. 2002 Aug;5(3):185-91.
Classification of oral clefts by affection site and laterality: a genotype-phenotype correlation study.
Farina A, Wyszynski DF, Pezzetti F, Scapoli L, Martinelli M, Carinci F, Carls F, Nardelli GB, Tognon M, Carinci P.
SourceInstitute of Embryology, University of Bologna-Centre of Molecular Genetics CARISBO Foundation, Bologna, Italy.
Abstract
OBJECTIVES: The aim of this study was to classify the phenotypes found in a series of patients with non-syndromic cleft lip (CL) with or without cleft palate (CP) and isolated cleft palate. Additionally, the frequency distribution of cases belonging to families linked to markers on chromosomes 6 and 2 within these phenotypic patterns were estimated.
DESIGN: A retrospective examination of all the available affected cases collected in Italy.
SETTING AND SAMPLE POPULATION: Ninety-seven affected subjects aged 5-18 years belonging to 38 families were considered. Patterns were identified by variance of the cleft (lip, primary palate, secondary palate) and stratified according to the side of occurrence (right, left, or bilateral). Latent class analysis was used as main statistical tool for carrying out the results.
RESULTS: Three homogenous classes were identified (P < 0.0001) by means of latent class analysis. Individuals were assigned to the most suited class. All three variables (lip, primary and secondary cleft palate) generated a specific class. Optimal findings were reported in cases having 'any isolated cleft lip' (class 1); 'secondary CP with or without bilateral/right primary cleft palate + bilateral/right cleft lip' (class 2); and 'left primary cleft palate + left/bilateral cleft lip with or without secondary CP' (class 3). Correspondence to the evidence of linkage to chromosome 6 showed that 9 of 10 cases presenting with 'right primary CP + right CL with secondary cleft palate' (class 2) belonged to a linked family. The same combination, but occurring on the left side (class 3), revealed that only three of nine cases belong to families linked to chromosome 6 (P-value = 0.02). The two patterns (right and left) never occurred in the same family. Three reliable groups were identified based on laterality and the presence of a cleft. A single right sided pattern displayed a statistically different distribution of linkage to chromosome 6 when compared with the homologous left side.
CONCLUSION: Non-syndromic CL with/without CP can be classified according to laterality that can be under genetic control
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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