International Poster Journal of Dentistry and Oral Medicine, 03/2016

Introduction: As angiogenesis is closely associated with the process of carcinogenesis, it was the objective of the study to evaluate histologically quantifiable angiogenesis parameters in association with the aggressiveness and the prognosis of oral squamous cell carcinoma (OSCC). Materials and Methods: There were (1) histological preparations of 49 leukoplakia (Leu), 33 Leu with mild dysplasia (Leu-SIN 1) , 13 Leu-SIN 2 and 36 OSCCs resulting from Leu. In those, microvessel density (MVD), vessel diameter and VEGF expression were analysed to calculate the effect of angiogenesis on degeneracy tendencies. Subsequently, MVD and CD31 staining intensity were correlated in 50 OSCCs with tumour staging and prognosis with a mean follow-up of 54 months (2). Results: (1) For MVD, there were significant differences between Leu and Leu-SIN 2/OSCC (p0.05) and between Leu-SIN 1 and OSCC (p0.05). For OSCC, vessel diameters were significantly increased compared to Leu (p0.05). Expression of VEGF increased significantly gradually from Leu-SIN 1 to OSCC (p0.05). (2) Significantly higher vessel counts were seen > in T3/T4, N>0 and G3-4-OSCCs (all p0.05). Higher MVD values were significantly associated with earlier relapse and earlier metastases as well as reduced overall survival (all p0.05). Discussion: With leukoplakia as a precancerous lesion, the important role of angiongensis in gradual malignant transformation towards OSCC was demonstrated. For manifestation of OSCC, angiogenesis influences both the local and metastatic tumour growth and has a significant correlation to prognostic parameters, wherein the MVD represents a possible parameter for evaluation of prognosis. Keywords: Leukoplakia, oral squamous cell carcinoma, angiogenesis

Background: Despite the use of fluorides, molars are still susceptible to dental caries, and hence additional preventive programs are essential. School-based pit and fissure sealant programs are one such public health initiative to prevent dental caries in molars. Aims and Objectives: 1. To investigate the effectiveness of school-based pit and fissure sealant programs in the prevention of dental caries in children. 2. To find out whether these programs are implementable in India. Methods: A systematic literature survey was carried out in October 2015 in electronic data bases such as PubMed, PubMed central and Google Scholar, with MeSH terms "PIT AND FISSURE SEALANTS" and key words such as "School based pit and fissure sealant programs". Articles in English published between January 2000 to October 2015 were selected. The outcome measure was the incidence of dental caries among sealed verses unsealed teeth. 31 articles were obtained through searches, of which 25 met the inclusion criteria and were selected for study. Results: The first permanent molars that received sealants had less risk of developing new caries at 1 year of follow-up. The total retention of the pit and fissure sealants (1 year) ranged from 50% to 92 %, and the reduction in caries incidence ranged from 36.2% to 82.4 %. Conclusion: School-based pit and fissure sealant programs result in a significant reduction of dental caries and may be economically viable as the cost benefit ratio is also high. Similar programs could be implemented in India if resources were available. Keywords: pit and fissure sealant, dental caries, prevention

Background: Despite a significant decrease in smoking prevalence over the past ten years, cigarette smoking still represents the leading cause of preventable morbidity and mortality. Thus, countries around the world have increasingly adopted pictorial health warning labels (HWLs) for tobacco packages to warn consumers about the risks and make an informed decision. Objectives: 1. To assess perceptions and the impact of health warning labels regarding tobacco habits. 2. To look at the evidence for controlling and preventing tobacco habits. Search methodology: A systematic literature survey was carried out in electronic data bases like PubMed, Google scholar, etc, using "health warning labels and tobacco" and "pictorial warning and tobacco" as keywords looking for biomedical research from the past 5 years. Data collection and analysis: Three authors independently assessed all studies for inclusion criteria and for study quality (SS, MBC, AK). Results were not pooled due to the heterogeneity of the included studies. Main results: 293 articles were extracted, of which 13 articles met the inclusion criteria and were selected for the review. Outcome variables reported were credibility, relevance, warning salience, health risks of smoking and change in behaviour i.e. smoking status, motivational impact, association of HWLs with educational level, comparison between effectiveness of positive versus negative labels, misinterpretation of HWLs and country by time interaction effects for all label effectiveness. Author's conclusion: From the limited number of heterogeneous studie, there is weak evidence that pictorial health warning labels (HWLs) are effective in changing smoking behaviour. Keywords: health warning labels, pictorial warning, tobacco

Background and objectives: Orthodontics in Nepal do not have a long history. The first specialised orthodontic service by a Nepalese orthodontist was started in1990. Gradually, the number of orthodontists has increased, and the range of services provided by them has also expanded. The aim of this study was to find out the state of orthodontics in Nepal. Materials and Methods: The prevalence of malocclusion was assessed from past studies. Information regarding Nepalese orthodontists was obtained from the Nepal Medical Council, the Orthodontic and Dentofacial Orthopedic Association of Nepal and through personal contacts. Information of Nepalese living standard was obtained from the World Bank report. Results: Malocclusion is one of the most common dental problems, with high prevalence ranging from 73% to 90.4% at various places in Nepal. More than 50% of those with malocclusion have an extreme or severe need of orthodontic treatment. With only a few orthodontists (74), mostly centered in the capital and major cities, even people with severe and extreme treatment needs are deprived of orthodontic treatment. The minimum cost for orthodontic treatment even in a government hospital is approximately one third of the per capita income of the Nepalese people ($220 minimum cost vs $698.30 per capita income a/c to the World Bank 2014) Conclusion: Although orthodontic services are urgently required, people are unable to afford them due to low socioeconomic status. Also, most of the orthodontists are concentrated in the major cities, with difficult access for people residing in rural areas. Keywords: Orthodontics, malocclusion, per capita income

This retrospective study describes the craniofacial architecture of post-pubertal patients with cleft lip and palate by using DELAIRE whole skull analysis along with the analysis by SEGNER AND HASUND. 177 cephalometric X-ray films from a group of patients (114 male, 63 female) of the former Wolfgang Rosenthal Clinic Thallwitz, Germany, were analyzed. Typical changes in the viscerocranium (mandibular and maxillary retrognathia in a vertical basal open relationship) were accompanied by small yet statistically significant changes to the neurocranium. The study revealed midface deficits in the sagittal plane and a reduced height of the midface in favour of the lower face. Furthermore, a reduced craniofacial base line and cranial height and a reduced angle between the cranial base and craniofacial base line were evident. The angle between the cranial base and the basilar slope was enlarged, suggesting an abnormal posture of the cervical spine in CLP patients. Cleft lip and palate along with late-closure corrective surgery may cause complex effects on the entire craniofacial architecture, including, but not limited to, the facial region. Whole skull analyses - such as the DELAIRE analysis - are beneficial in assessing abnormal dimensions extending beyond the face and oral cavity to the entire viscerocranium and neurocranium in general, as might commonly occur in cleft lip and palate patients. Keywords: Cleft, delaire analysis, segner hasund analysis, whole skull analysis, craniofacial architecture, thallwitz

Introduction: An increase in transverse maxillary width can be facilitated using tooth-borne, bone-borne or combined tooth-bone-borne appliances. The advantage of bone-supported expansion is the direct transfer of the expansion forces on to the bone, thus leading to a reduction in the negative side effects such as buccal tipping of the anchor teeth, root resorption and bone dehiscence associated with dental anchored expansion appliances. Ready-made skeletal anchored distractors are mostly fixed submucosally in the bone. However, this procedure is more invasive, patient comfort is reduced and the activation process complicated. Materials and Methods: A new patient-specific distraction device was developed using a standard Hyrax expansion screw made of titanium and standard titanium locking miniplates. After individual positioning and fixation of the locking plates and the Hyrax screw on the model of the patient's jaw, these components were laser welded. The appliance is fixed intraoperatively using standard-locking mini screws. Results: Treatment with this method was successfully completed in five cases. The activation of the screw by the patient seemed to be similar to standard removable appliances or dental anchored rapid maxillary extension appliances and was therefore very reliable. Removal of the devices is less invasive in comparison to the submucosally fixed appliances due to the epimucosal plate position. Conclusion: This newly described method combines the advantages of the hyrax appliances with skeletal anchored distractors. Patient compliance is increased, and the interdisciplinary treatment of these patients between maxillofacial surgeons and orthodontists is supported. Keywords: rapid palatal expansion, distraction osteogenesis

Aim: Integration of biostatistics content in the orthodontic treatment curriculum (9th semester) through practical exercises by the students. Materials and Methods: This dental-undergraduate curriculum includes the evaluation of the students' own dentition models. The models were 3D-scanned (ZirkonZahn AR600, ZirkonZahn, Gais, Italy) and virtually measured (Onyx Ceph® 3, Image Instruments GmbH, Chemnitz, Germany). Following a 60-minute lecture in selected basics of biostatistics, the students analysed the data they had obtained (R Project for Statistical Computing 3.1.0). Before and after the course, a questionnaire was filled out to evaluate the students' biostatistical knowledge and their personal attitudes towards the importance of biostatistics for dental research theses and future clinical work (10 questions, 5-point scale, "disagree" to "I agree completely"). A total of 68 questionnaires were analysed. To compare between the students' answers before and after the course, a Kruskal-Wallis rank-sum test was performed. Results: Students assessed their knowledge of biostatistics heterogeneously: while 61% claimed to know sufficient basics, 25% reported having no understanding of biostatistics at all. However, 91% of the students believed that statistics are very important for dental research. A stronger inclusion of statistical topics into the curriculum of dental undergraduate education was assessed rather negatively, but the agreement increased after this course. The comparison of questionnaires filled out before and after the seminar showed no significant difference, except in one question: a more extensive lecture in biostatistics knowledge was favoured by significantly (p = 0.04) fewer students after the course than before. Conclusion: Students' biostatistical knowledge is very dissimilar. A one-day course in medical statistics can only convey fragmentary knowledge, but demonstrates the importance for dental research and clinical work. The desire to learn more about statistics is low and was not increased by the seminar. Keywords: basic biostatistics, orthodontic, students, one-day course, medical statistics

Purpose: The aim of this split-mouth study was to evaluate the behaviour of soft and hard tissue around implants with two different surface treatments. Materials and methods: 10 patients (5 men, 5 women) were treated with fixed partial dentures supported by implants. Each patient received at least 2 implants (1 control, 1 test) into an edentulous quadrant. The control implants (Osseotite, OSS) had a dual acid-etched (DAE) surface in the apical portion and a machined coronal part; test implants (Full Osseotite, FOSS) had a completely DAE surface. Machined healing abutments were placed on control implants and DAE abutments on test ones. After 3 months from surgery, a mini-invasive sample of soft tissue was collected from the first 7 patients recruited for the study (4 women and 3 men). The samples were analysed by microRNA (miRNA) microarray. Standardised periapical radiographs were taken to investigate interproximal bone levels at baseline (immediately after implant insertion), 2 months, 6 months, and 1 year post-implant placement. Plaque index (PI), bleeding on probing (BOP) and periodontal depth (PD) were recorded at 3 and 6 weeks, and at 2, 3, 6 and 12 months post-implant placement. Differences in bone resorption over time were evaluated with the Friedman test followed by post-hoc Wilcoxon signed ranks tests. Differences in bone resorption, PI, BOP and PD between the two types of implant over time were assessed by the repeated measures ANOVA test for ranked data. A p ≤0.05 was considered statistically significant. Statistical analyses were carried out with SPSS v.20. Microarray data were processed by GeneSpring® software and their overall variability was examined by box-plot analysis, scatter-plot analysis, hierarchical cluster analysis (HC) and principal component analysis (PCA). Individual miRNAs modulated by the experimental treatments were identified by volcano-plot (thresholds 2-fold and P0.05), support vector machine and k-nearest neighbour analyses. The results of miRNA microarray were compared with measured clinical parameters. Results: Control implants showed greater bone resorption compared to test ones; however, the difference was not statistically significant. Greater plaque accumulation was found for test surfaces, but the difference was not statistically significant. No statistically significant differences in BOP and PD were found. miRNA microarray analysis led to the following findings: - Implant sites with low plaque accumulation and absence of BOP had a gene expression profile similar to those with plaque deposits and an absence of BOP; sites with both high PI and high BOP had a completely different profile. - Implant sites with BOP present presented similar gene expression profiles independently from the type of implant surface. - Implant sites with high PI and normal bone resorption had a different expression profile from the other experimental conditions. - Implant sites with normal bone resorption despite high BOP differed from the other experimental conditions. This gene expression profile resembled that of FOSS implants. - Implant surface affected bone resorption: groups having similar bone resorption characteristics (normal vs. increased) clustered differently according to the implant type. Conclusions: DAE surfaces showed more plaque accumulation than machined ones; however, this did not affect the health of soft peri-implant tissue. In fact, BOP values did not differ between test and control implants. Furthermore, DAE surfaces induced lower bone resorption compared with machined ones. miRNA analysis suggested that soft tissue inflammation is more related to a specific host characteristic (gene expression profile) rather than to the presence of plaque or to a given implant surface. Some specific miRNA profile might be able to protect implant sites from bleeding and bone resorption irrespective of plaque accumulation. Possible future applications of the present findings include the use of the identified biomarkers for diagnosis and as drugs or coatings for implant surfaces in order to improve the health of peri-implant tissues. Keywords: dental implants, peri-implant tissue, microRNA, titanium surfaces

Introduction: Through food and drink, various acids reach the oral cavity. In biofilms, lactic acid is produced, and gastric acid secretion leads to an extremely strong lowering of the pH. These changes in pH can influence corrosion processes in the oral cavity. The aim of this study was to simulate such pH conditions and to compare the electrochemical corrosion behaviour of 2 experimental CoCr alloys with same pitting resistance equivalent (PRE) value in 0.9% saline solution (pH 6.3) which was additionally adjusted with 2 different acids (0.02 M HCl and lactic acid) to the pH-values of 5, 4, 3 and 2. Material & Methods: The experimental dental alloys Co-28Cr-5Mo-1.5Si-Mn and Co-28Cr-10W-1.5Si-Mn with PRE=44.5 were used. From each alloy, 6 specimens were prepared. 0.9% saline solution was used as a reference electrolyte. With the use of a pH-meter (691, Metrohm), the pH-values of the saline solution were adjusted to pH 2, 3, 4 and5 either with 0.02 M HCl or lactic acid. With each alloy and electrolyte, electrochemical corrosion measurements according to ISO 10271 were performed, which consist of an open-circuit-potential measurement over 2 h followed by anodic polarisation (-150 mV~Ecorr to 1 V, speed 1 mV/sec). From each measurement, the parameters Ecorr after 2 h, Ez, Ep, ip, i(300 mV), i(300mV+Ez), icorr, Rp, E(-6) and E(-5) were determined. Results: Generally, the corrosion behaviour was different for both alloys and the acids used. With the exception of the calculated parameter Rp, higher corrosion resistance could be determined with decreasing pH in a clear ranking for Co-28Cr-5Mo-1.5Si-Mn with 0.02 M HCl; however, in lactic acid only to pH 3. For Co-28Cr-10W-1.5Si-Mn, decreasing corrosion could be measured in both acids only to pH 3; a clear ranking was found only for the calculated potential parameters. The most prominent differences could be seen at pH 2 adjusted with lactic acid: The icorr value was 71 ± 25 in lactic acid and 24 ± 5 nA/cm² in 0.02M HCl for Co-28Cr-5Mo-1.5Si-Mn, and respectively 2556 ± 1698 and 55 ± 28 nA/cm² for Co-28Cr-10W-1.5Si-Mn. Conclusion: The Mo-containing alloy showed good acidic corrosion resistance for all pH values used which were adjusted with 0.02 M HCl. This alloy is superior at a low pH-value adjusted with lactic acid compared to Co-28Cr-10W-1.5Si-Mn. Acknowledgement: Special thanks to Dentaurum (Ispringen, Germany) for casting the specimens. Keywords: electrochemical corrosion measurements, experimental nonprecious alloys, pitting resistance equivalent (PRE), organic and anorganic acids

Background: One of the problems encountered with the immediate implant placement is insufficient soft tissue that could achieve a tension-free primary closure. In this case report, a simple approach was recently performed to provide sufficient primary closure at the time of immediate implant placement. Patient and intervention: A 38-year-old non-smoking medically fit female patient presented to the Prosthodontics Department, Faculty of Dentistry - Cairo University with a history of endodontic treatment in the maxillary left lateral incisor and repeated post fracture. The condition resulted in insufficient tooth structure to support a post core restoration. Hence, it was decided to replace the tooth with an endosseous implant. Oral examination revealed that the remaining supra-gingival portion of the broken lateral incisor could hinder adequate primary closure at the time of immediate implant placement. Therefore, it was decided to reduce the root to 2mm below gingiva and leave it for 3 weeks to allow for growth of soft tissue in the exposed area, thereby providing adequate soft tissue for primary closure after implant placement. Conclusion: This approach provides a tension-free primary closure of the socket after immediate implant placement. This protects the healing site from the oral environment. Keywords: Immediate implant placement, soft tissue coverage, case report