Fracture strength of screw-retained zirconia crowns assembled on zirconia and titanium implants.

PURPOSE: This in vitro study evaluated the fracture strength of screw-retained zirconia crowns connected to zirconia (Zr) and titanium (Ti) implants after undergoing a simulation of 5 years of clinical use. MATERIALS AND METHODS: Forty-eight screw-retained zirconia crowns were fabricated and assembled on four implant systems, with 12 in each group: (1) Zr implant (pure ceramic; Straumann AG) (PZr); (2) Zr implant (NobelPearl; Nobel Biocare) (NPZr); (3) Ti-Zr implant (Bone Level Roxolid; Straumann AG) (RSTiZr); (4) Ti implant (Conical Connection PMC; Nobel Biocare) (NRTi). Crowns were luted to their associated abutments using resin cement and then torqued to their assigned implants at the recommended torque value. Specimens were subjected to dynamic loading for 1,200,000 loading cycles. Fracture strength, measured in Newtons (N), was tested under static compression load using a universal testing machine at an angle of 30°. One-way ANOVA and Tukey's multiple comparisons post hoc test were used to compare the mean fracture values between the groups at a significance level of 0.05. RESULTS: The average fracture strengths for the RSTiZr and NRTi groups were 1207 ± 202 and 1073 ± 217 N, respectively, which was significantly (p < 0.0001) higher than the PZr and NPZr groups (712 ± 76 and 571.6 ± 167 N, respectively). However, no significant difference was found between the fracture strength value of RSTiZr and NRTi (p = 0.260) or PZr and NPZr (p = 0.256) groups. CONCLUSIONS: Zirconia crowns connected to Zr implants have the potential to withstand the average physiological occlusal forces which occur in the anterior and premolar regions.

Accuracy of complete-arch digital implant impression with intraoral optical scanning and stereophotogrammetry: An in vivo prospective comparative study.

OBJECTIVES: To assess accuracy of intraoral optical scanning (IOS) and stereophotogrammetry (SPG), complete-arch digital implant impressions in vivo. MATERIALS AND METHODS: Consecutive patients needing implant-supported screw-retained zirconia complete-arch fixed-dental prostheses (ISZ-FDP) were recruited. For each patient, three impressions were taken: IOS, SPG (tests), and open-tray plaster (reference). Linear (ΔX, ΔY, and ΔZ), three-dimensional (ΔEUC), and angular deviations (ΔANGLE) were evaluated and stratified according to scanning technology for each implant. Potential effects of impression device (IOS and SPG), arch (maxilla and mandible), and implant number (4 and 6) were evaluated through multivariable analysis. Significance level was set at .05. RESULTS: A total of 11 complete arches (5 maxillae, 6 mandibles) in 11 patients were rehabilitated with ISZ-FDPs supported by 4 (n = 8) and 6 implants (n = 3). A total of 50 implants and 100 implant positions were captured by two investigated devices and compared to respective reference (mean ΔEUC IOS 137.2, SPG 87.6 µm; mean ΔANGLE 0.79, 0.38°). Differences between measurements (SPG-IOS) were computed for each implant, with negative values indicating better SPG accuracy. Significant mean ΔEUC difference of -49.60 µm (p = .0143; SD 138.15) and mean ΔANGLE difference of -0.40° (p < .0001; SD 0.65) were observed in favor of SPG. Multivariable analysis showed significant effect on ΔEUC (p = .0162) and ΔANGLE (p = .0001) only for impression devices, with SPG performing better. CONCLUSIONS: SPG experienced significantly higher linear and angular accuracy. No effect of type of arch or implant number was detected. Higher extreme deviations were experienced for IOS. SPG can be feasible for complete-arch digital impressions with caution, and rigid prototype try-in is recommended before screw-retained prosthesis manufacturing.

Histological evaluation following treatment of recession-type defects with coronally advanced flap and a novel human recombinant amelogenin.

OBJECTIVES: To histologically evaluate the effects of a novel human recombinant amelogenin (rAmelX) on periodontal wound healing / regeneration in recession-type defects. MATERIALS AND METHODS: A total of 17 gingival recession-type defects were surgically created in the maxilla of three minipigs. The defects were randomly treated with a coronally advanced flap (CAF) and either rAmelX (test), or a CAF and placebo (control). At three months following reconstructive surgery, the animals were euthanized, and the healing outcomes histologically evaluated. RESULTS: The test group yielded statistically significantly (p = 0.047) greater formation of cementum with inserting collagen fibers compared with the control group (i.e., 4.38 mm ± 0.36 mm vs. 3.48 mm ± 1.13 mm). Bone formation measured 2.15 mm ± 0.8 mm in the test group and 2.24 mm ± 1.23 mm in the control group, respectively, without a statistically significant difference (p = 0.94). CONCLUSIONS: The present data have provided for the first-time evidence for the potential of rAmelX to promote regeneration of periodontal ligament and root cementum in recession-type defects, thus warranting further preclinical and clinical testing. CLINICAL RELEVANCE: The present results set the basis for the potential clinical application of rAmelX in reconstructive periodontal surgery.

Root submergence technique as a partial extraction therapy to preserve the alveolar ridge tissues: A systematic review and appraisal of the literature.

STATEMENT OF PROBLEM: As socket grafting with commercially available biomaterials has become popular, reports of the root submergence technique for ridge preservation have decreased. A systematic review of this partial extraction therapy is lacking. PURPOSE: The purpose of this systematic review was to review the root submergence technique as well as critically appraise the available data. MATERIAL AND METHODS: A review was carried out that observed the Participant, Intervention, Comparison, Outcomes (PICO) strategy and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The focused question was "What are the outcomes of the different methods to submerge tooth roots for ridge preservation?" Medical subject headings (MeSH) terms that related to the root submergence technique were searched in PubMed/MEDLINE, Scopus, and the Cochrane Library databases. RESULTS: A total of 7709 abstracts and study titles were individually screened from the initial search results. After reviewing the full-text articles and applying the selection criteria, the final included search results totaled 47 full-text articles for in-depth review. In 10 animal studies, 258 roots were studied in 34 dogs and 7 monkeys. Histological data confirmed that coronal bridging (bone or cementum growth over the cut root) was a common outcome. Of the vital roots submerged, the majority maintained their vitality. In 37 human studies, 475 roots were submerged and reported on. Subjective ridge preservation was often reported. Among the adverse healing outcomes, exposure of the root through the mucosa was the most common. Nonetheless, in animals, 86.8% of roots remained submerged; in humans, 74.7%. CONCLUSIONS: Root submergence is an established technique for ridge preservation. Exposure is a common complication, and correct technique may be key to its prevention. Further research of this partial extraction therapy is encouraged.

The root submergence technique at single tooth sites to short-span edentulous sites: A step-by-step partial extraction therapy protocol.

Submerging roots for ridge preservation was the earliest partial extraction therapy and has been described since the 1970s. Despite the approximately 47 animal and human studies published since, an updated and contemporary step-by-step protocol has not yet been provided. This technique report describes in detail how to manage submerged roots at single tooth sites and at short-span edentulous areas.

Effects of Hydroxypropyl-Beta-Cyclodextrin on Cultured Brain Endothelial Cells.

The application of 2-hydroxypropyl-beta-cyclodextrin (HPBCD) in the treatment of the rare cholesterol and lipid storage disorder Niemann-Pick disease type C opened new perspectives in the development of an efficient therapy. Even if the systemic administration of HPBCD was found to be effective, its low permeability across the blood-brain barrier (BBB) limited the positive neurological effects. Nevertheless, the cellular interactions of HPBCD with brain capillary endothelial cells have not been investigated in detail. In this study, the cytotoxicity, permeability, and cellular internalization of HPBCD on primary rat and immortalized human (hCMEC/D3) brain capillary endothelial cells were investigated. HPBCD shows no cytotoxicity on endothelial cells up to 100 µM, measured by impedance kinetics. Using a fluorescent derivative of HPBCD (FITC-HPBCD) the permeability measurements reveal that on an in vitro triple co-culture BBB model, FITC-HPBCD has low permeability, 0.50 × 10-6 cm/s, while on hCMEC/D3 cell layers, the permeability is higher, 1.86 × 10-5 cm/s. FITC-HPBCD enters brain capillary endothelial cells, is detected in cytoplasmic vesicles and rarely localized in lysosomes. The cellular internalization of HPBCD at the BBB can help to develop new strategies for improved HPBCD effects after systemic administration.

Cellular Effects of Cyclodextrins: Studies on HeLa Cells.

Cyclodextrins are high molecular weight, hydrophilic, cyclic, non-reducing oligosaccharides, applied as excipients for the improvement of the solubility and permeability of insoluble active pharmaceutical ingredients. On the other hand, beta-cyclodextrins are used as cholesterol sequestering agents in life sciences. Recently, we demonstrated the cellular internalization and intracellular effects of cyclodextrins on Caco-2 cells. In this study, we aimed to further investigate the endocytosis of (2-hydroxylpropyl)-beta-(HPBCD) and random methylated-beta-cyclodextrin (RAMEB) to test their cytotoxicity, NF-kappa B pathway induction, autophagy, and lysosome formation on HeLa cells. These derivatives were able to enter the cells; however, major differences were revealed in the inhibition of their endocytosis compared to Caco-2 cells. NF-kappa B p65 translocation was not detected in the cell nuclei after HPBCD or RAMEB pre-treatment and cyclodextrin treatment did not enhance the formation of autophagosomes. These cyclodextrin derivates were partially localized in lysosomes after internalization.

Assessing the risk of rapid radiographic progression in Hungarian rheumatoid arthritis patients.

BACKGROUND: The outcome of rheumatoid arthritis (RA) should be determined early. Rapid radiological progression (RRP) is > or = 5 units increase according to the van der Heijde-Sharp score within a year. The risk of RRP can be estimated by a matrix model using non-radiographic indicators, such as C-reactive protein (CRP), rheumatoid factor (RF) and swollen joint count (SJC). PATIENTS AND METHODS: A non-interventional, cross-sectional, retrospective study was conducted in eleven Hungarian arthritis centres. We assessed RRP risk in biologic-naïve RA patients with the prevalence of high RRP risk as primary endpoint. RRP was calculated according to this matrix model. As a secondary endpoint, we compared RRP in methotrexate (MTX) responders vs non-responders. RESULTS: We analyzed data from 1356 patients. Mean CRP was 17.7 mg/l, RF was 139.3 IU/ml, mean 28-joint disease activity score (DAS28) was 5.00 and mean SJC was 6.56. Altogether 18.2% of patients had high risk (≥40%) of RRP. RA patients with high RRP risk of RRP (n = 247) had significantly lower age compared to those with RRP < 40% (n = 1109). MTX non-response (OR: 16.84), male gender (OR: 1.67), erosions at baseline (OR: 1.50) and ACPA seropositivity (OR: 2.18) were independent predictors of high-risk RRP. Male gender (OR: 5.20), ACPA seropositivity (OR: 4.67) and erosions (OR: 7.98) were independent predictors of high RRP risk in MTX responders. CONCLUSIONS: In this Hungarian study, high RRP risk occurred in 18% of RA patients. These patients differ from others in various parameters. RRP was associated with non-response to MTX.

Digital three-dimensional visualization of intrabony periodontal defects for regenerative surgical treatment planning.

BACKGROUND: In the regenerative treatment of intrabony periodontal defects, surgical strategies are primarily determined by defect morphologies. In certain cases, however, direct clinical measurements and intraoral radiographs do not provide sufficient information on defect morphologies. Therefore, the application of cone-beam computed tomography (CBCT) has been proposed in specific cases. 3D virtual models reconstructed with automatic thresholding algorithms have already been used for diagnostic purposes. The aim of this study was to utilize 3D virtual models, generated with a semi-automatic segmentation method, for the treatment planning of minimally invasive periodontal surgeries and to evaluate the accuracy of the virtual models, by comparing digital measurements to direct intrasurgical measurements. METHODS: Four patients with a total of six intrabony periodontal defects were enrolled in the present study. Two months following initial periodontal treatment, a CBCT scan was taken. The novel semi-automatic segmentation method was performed in an open-source medical image processing software (3D Slicer) to acquire virtual 3D models of alveolar and dental structures. Intrasurgical and digital measurements were taken, and results were compared to validate the accuracy of the digital models. Defect characteristics were determined prior to surgery with conventional diagnostic methods and 3D virtual models. Diagnostic assessments were compared to the actual defect morphology during surgery. RESULTS: Differences between intrasurgical and digital measurements in depth and width of intrabony components of periodontal defects averaged 0.31 ± 0.21 mm and 0.41 ± 0.44 mm, respectively. In five out of six cases, defect characteristics could not be assessed precisely with direct clinical measurements and intraoral radiographs. 3D models generated with the presented semi-automatic segmentation method depicted the defect characteristics correctly in all six cases. CONCLUSION: It can be concluded that 3D virtual models acquired with the described semi-automatic segmentation method provide accurate information on intrabony periodontal defect morphologies, thus influencing the treatment strategy. Within the limitations of this study, models were found to be accurate; however, further investigation with a standardized validation process on a large number of participants has to be conducted.

Prosthetic management of implants placed with the socket-shield technique.

Partial extraction therapies, such as the socket-shield technique, use the patient's tooth tissues and periodontium to preserve the alveolar ridge and limit postextraction resorption. Internal exposure through the overlying peri-implant mucosa has been reported as the most common complication, suggesting that the preparation technique requires modification. This technique report describes the prosthetic management of the socket-shield technique, emphasizing preparation of the socket-shield to the bone crest, and the creation of an S-shape prosthetic emergence profile to support maximal soft tissue infill.

The socket-shield technique at molar sites: A proof-of-principle technique report.

The socket-shield technique for avoiding postextraction tissue alteration was first described in 2010. The technique was developed for hopeless teeth in anterior esthetic sites but has not yet been described for molar sites. Managing postextractive ridge changes in the posterior region by prevention or regeneration remains a challenge. The socket shield aims to offset these ridge changes wherever possible, preserving the patient's residual tissues at immediate implants. This technique report describes the molar socket-shield step by step.

[A clinicopathological retrospective epidemiological analysis of benign tumors and tumor-like lesions in the oral and maxillofacial region, diagnosed at the University of Szeged, Department of Oral Medicine (1960-2014)]. / A szegedi Fogászati és Szájsebészeti Klinikán diagnosztizált, az orofacialis régiót érinto jóindulatú daganatok és daganatszeru laesiók klinikopatológiai retrospektív epidemiológiai analízise (1960­2014).

INTRODUCTION: In a clinicopathological retrospective epidemiological study we investigated benign tumors and tumor-like lesions located in the orofacial region, diagnosed at the Universiy of Szeged, Department of Oral Medicine. METHOD: During a 54-year period (1960-2014), 14 661 biopsies were taken. The included subjects were 7491 patients diagnosed with benign tumors and tumor-like lesions. RESULTS: The average age of patients was 55.3 years, 2823 (37.7%) patients were male and 4668 (62.3%) female. The male : female ratio was 1 : 1.65. Most of the patients included in the study were aged 51-60 (1280, 17.1%). The number of children was 1014 (13.6%) and the number of adults was 6477 (86.3%). The number of non-neoplasms was 6420 (85.7%), being significantly higher than the number of neoplasms (1071, 14.3%). Most of the lesions were of mesenchymal origin (5574, 77.4%); the number of lesions of non-mesenchymal origin was 982 (13.1%). The most prevalent type of lesions was traumatic fibroma (fibrosis): 1806 (32.4%). The most common lesion type in the group of lesions of infectious/inflammational origin was pyogenic granuloma, the number of which was 465 (8.3%). The most common cystic lesion was mucocele (805, 10.7%). Hemangioma was the most frequent lesion type among developmental anomalies with the number of 815 (14.6%). The most common location of the lesions was the lip in 2081 cases (27.8%), followed by the gingiva in 2024 cases (27.0%), bucca in 1069 cases (14.3%), tongue in 981 cases (13.1%), and the facial skin in 695 cases (9.3%). After taking biopsy, the majority of benign lesions were treated with cryo-, laser-, or combined (cryo and laser) surgery. CONCLUSION: The present computer-aided study showed that irritational fibroma was the most common orofacial benign tumor, and the lip was the most frequent location. The diagnostic classification and the methodology are considerably different in the majority of the studies, which may hinder the exact comparison with other surveys from different regions of the world. Orv Hetil. 2018; 159(37): 1516-1524.

[Odontogenic foci and systemic diseases. A review]. / Az odontogén góc és a szisztémás betegségek. Irodalmi áttekintés.

The aim of the present review is to provide an up-to-date picture of what we know about the connection between odontogenic foci and non-oral diseases. After a brief historical summary, we give an overview on how the odontogenic focus causes disease in distant areas of the body in general, and then we start the discussion of the particular conditions, such as cardiovascular diseases, pneumonia, diabetes mellitus, metabolic syndrome, rheumatoid arthritis and adverse pregnancy outcomes. The review is centered around the two main odontogenic foci: periodontitis and periapical periodontitis, the latter being a widely recognized but rarely discussed oral focus. Finally, we offer a few considerations that the practicing dentist may find useful when dealing with odontogenic foci. Orv Hetil. 2018; 159(11): 415-422.

[Paradigm shift in conservative dentistry: the end of the amalgam era]. / Paradigmaváltás a fogmegtartó kezelésben: az amalgámkorszak vége.

Dental amalgam has been used for more than 150 years due to its beneficial mechanical properties and durability in dentistry. In the past and to date, many questions about amalgam restorations have arisen, especially regarding the mercury content, which has been the subject of global disputes. By presenting the past and present of the 'amalgam issue', the aim of our paper is to display the current position of international literature. This summary is based on the publications in the PubMed database, the guidelines of the Council of European Dentists. Although the use of dental amalgam is widespread, concerns have been raised about the adverse effect on human health and the environment, focusing on its heavy metal pollution during waste treatment. In 2017, the European Union (EU) adopted the so-called Mercury Regulation, based on the United Nations Minamata Convention on Mercury, the recommendations of which are presented in the present review. This Regulation includes the requirement for EU Member States to develop a national action plan for the phase-down of amalgam. The feasibility plan for complete phase-out may be guaranteed by 2030. The authors discuss the advantages and disadvantages of possible amalgam alternatives by presenting glass-ionomers and resin-based composites. In the future, more material research programmes and long-term follow-up studies are necessary. In addition to several global health organizations, the Council of European Dentists also draws attention to prevent dental caries, expecting to reduce the number of restorations. Orv Hetil. 2018; 159(42): 1700-1709.

Stressors alter intercellular communication and exosome profile of nasopharyngeal carcinoma cells.

BACKGROUND: Head and neck cancers comprise the sixth most common cancer type worldwide. One of the most remarkable malignancies of the head and neck is the cancer of the nasopharynx, with a strong metastatic tendency already in the early stage. Besides the conventional pathways of metastasis formation, the information content of exosomes produced by the cancer cells may play a key role in metastatic transformation. The aim of this study was to investigate how stressors alter the characteristic of tumor derived exosomes. METHODS: In our experimental model, we compared the quantity and content of exosomes produced by a nasopharyngeal carcinoma cell line (5-8F) under conventional (chemotherapy) and alternative (Ag-TiO2 -catalyzed reactive oxygen species generation) cytostatic treatment. After isolation, exosomes were identified by atomic force microscopy and quantified with Nanosight NS500 device. MicroRNA content of them was analyzed using SOLiD 5500xl technology. The sequences were annotated in CLC Genomics Workbench version 5.5.1. RESULTS: Beyond the classic chemotherapeutic agent (doxorubicin), Ag-TiO2 in a photo-catalytic process also showed cytostatic activity. Tumor cell damage induced by the cytostatic treatments significantly altered the number of released exosomes and led to the predominance of tumor suppressors in the exosomal miRNA profile. CONCLUSIONS: Our results suggest that the intercellular communication between tumor cells and surrounding stroma cells can be altered by microenvironment which increased quantity of exosomes and diversity of miRNAs in this study. Imbalance of oncogenic and tumor suppressor miRNAs caused by cytostatic treatments may influence the antiproliferative and metastasis inhibitory effect of cytostatic agents.

[The effect of smoking on the quality of life enhancement following prosthetic rehabilitation in head and neck cancer patients who underwent surgical treatment]. / A dohányzás hatása a fej-nyak régió daganata miatt sebészi terápiában részesült betegek protetikai rehabilitációt követo életminoség-javulására.

INTRODUCTION: It is known that the quality of life (QoL) of patients surgically treated for head and neck cancer (HNC) is significantly enhanced by rehabilitation. It is also known that some of these patients will not quit smoking. AIM: To assess if smoking hampers rehabilitation-related QoL enhancement after surgery. METHOD: Applying the H&N 35 questionnaire of EORTC, we assessed the QoL of 38 smoking and non-smoking patients who underwent surgical therapy for HNC and subsequent rehabilitation. QoL was assessed after surgery (after the healing period) and 6 months after rehabilitation. RESULTS: While the QoL enhancement of nonsmokers was significant in almost all aspects, that of smoking patients did not reach the level of significance on a number of scales. The results suggest that smoking does not hamper rehabilitation directly, rather, it prevents rehabilitation from exerting its beneficial effects through its own effects. CONCLUSIONS: Smoking is a factor that measurably acts against the efforts to enhance the QoL of the surgically treated HNC patient. Therefore, it is essential that emphasis is put on smoking cessation right from the cancer diagnosis also for this reason. Orv. Hetil., 2017, 158(5), 172-177.

[Hungarian Heart Failure Registry 2015-2016. Preliminary results]. / Magyar Szívelégtelenség Regiszter 2015­2016. Kezdeti eredmények.

Heart failure is associated with a poor prognosis despite significant advances in the pharmacological and device therapy and incurs very high cost because of frequent hospitalizations. Therefore, professional high-quality care is essential for both patients and the healthcare system. The best way to evaluate the quality of care for a particular disease is the use of disease-specific registries. Until now, there has not been a registry evaluating characteristics and management of heart failure patients in Hungary. For that reason, the Hungarian Society of Cardiology initiated the set-up of the Hungarian Heart Failure Registry. The Aim of this paper is to present the goals, methods and first year results of the Hungarian Heart Failure Registry. The goal of the Registry is to create a modern, web-based database that summarizes the data of large number of patients who are currently or were previously admitted to hospital or who are currently or were previously patients in an outpatient department due to severe heart failure (NYHA III-IV). Currently 17 cardiology departments participate in the development of the Registry. The planned number of patients is 2000. Initially follow-up was planned for one year (pilot study). After the evaluation of the relevant experiences of the pilot study, long-term follow-up is planned. The Registry collects information about the type of heart failure (heart failure with reduced - LVEF≤45% - vs. preserved - LVEF>45% - ejection fraction), etiology, co-morbidities, diagnostic methods, treatment as well as morbidity and mortality. After the first year, assessing the baseline parameters of 698 patients enrolled in the Registry we found that the majority of patients (87.8%) has heart failure with reduced ejection fraction and in 39.8% of the patients heart failure has an ischaemic origin. The most frequent co-morbidity was hypertension followed by diabetes, renal insufficiency and COPD. The patients were treated with ACE inhibitors or ARBs in 94.4%, with beta blockers in 95.9%, and mineralocorticoid receptor antagonists in 73.9%. The mean dose of neurohormonal antagonists was higher than half of the target dose defined by current guidelines. The use of cardiac resynchronisation therapy was 11.7% and implantable cardioverter defibrillator was 25.8%. The pharmacological and device therapy of patients who were enrolled in the Registry until now was fit the current guidelines' recommendations. This, however, does not mean that the management of heart failure is without problems in our country but that high quality patient care is available with adequate heart failure treatment in cardiology departments dedicated to heart failure care. Orv. Hetil., 2017, 158(3), 94-100.

Detection and Phylogenetic Analysis of Torque Teno Virus in Salivary and Tumor Biopsy Samples from Head and Neck Carcinoma Patients.

OBJECTIVES: Because torque teno virus (TTV) has been implicated in tumorigenesis as a cocarcinogen, we studied TTV prevalence in saliva and biopsy samples from head and neck cancer (HNCC) patients, patients with premalignant lesions of oral cancer, and controls. We also wished to determine the TTV genotypes in HNCC patients. METHODS: A seminested polymerase chain reaction (PCR) amplifying the N22 region of the TTV genome, as well as direct sequencing of PCR fragments, was used. RESULTS: TTV prevalence was higher in HNCC patients (saliva: 27/71, 38%; tumor biopsy: 22/74, 30%) than in controls (saliva: 8/56, 14%; oral mucosa: 1/19, 5%). TTV prevalence was also high in patients with premalignant lesions of oral carcinoma (saliva: 9/18, 50%; biopsy: 5/21, 24%). By phylogenetic analysis, TTV belonging mostly to genotypes 1 and 2 was found in HNCC patients. In most of the cases, identical TTV strains were present in the biopsy and salivary sample of the same HNCC patient. In addition, the same TTV strain was detected in 2 laryngeal carcinoma biopsies obtained from 2 independent patients. CONCLUSIONS: Our data are compatible with the idea that TTV might act as a cocarcinogen in certain cases of HNCC. Alternatively, HNCC may facilitate either TTV replication or TTV entry into the saliva.

Infectious Agents Associated with Head and Neck Carcinomas.

In addition to traditional risk factors such as smoking habits and alcohol consumption, certain microbes also play an important role in the generation of head and neck carcinomas. Infection with high-risk human papillomavirus types is strongly associated with the development of oropharyngeal carcinoma, and Epstein-Barr virus appears to be indispensable for the development of non-keratinizing squamous cell carcinoma of the nasopharynx. Other viruses including torque teno virus and hepatitis C virus may act as co-carcinogens, increasing the risk of malignant transformation. A shift in the composition of the oral microbiome was associated with the development of oral squamous cell carcinoma, although the causal or casual role of oral bacteria remains to be clarified. Conversion of ethanol to acetaldehyde, a mutagenic compound, by members of the oral microflora as well as by fungi including Candida albicans and others is a potential mechanism that may increase oral cancer risk. In addition, distinct Candida spp. also produce NBMA (N-nitrosobenzylmethylamine), a potent carcinogen. Inflammatory processes elicited by microbes may also facilitate tumorigenesis in the head and neck region.

[Role of cone-beam computed tomography in diagnostic otorhinolaryngological imaging]. / A cone-beam komputertomográfia alkalmazása a fül-orr-gégészeti képalkotásban.

Accurate diagnosis and preoperative planning in modern otorhinolaryngology is strongly supported by imaging with enhanced visualization. Computed tomography is often used to examine structures within bone frameworks. Given the hazards of ionizing radiation, repetitive imaging studies exponentially increase the risk of damages to radiosensitive tissues. The authors compare multislice and cone-beam computed tomography and determine the role, advantages and disadvantages of cone-beam computed tomography in otorhinolaryngological imaging. They summarize the knowledge from the international literature and their individual imaging studies. They conclude that cone-beam computed tomography enables high-resolution imaging and reconstruction in any optional plane and in space with considerably lower effective radiation dose. Cone-beam computed tomography with appropriate indications proved to be an excellent diagnostic tool in otorhinolaryngological imaging. It makes an alternative to multislice computed tomography and it is an effective tool in perioperative and postoperative follow-up, especially in those cases which necessitate repetitive imaging with computed tomography.