Presence of SARS-CoV-2 on the conjunctival mucosa in patients hospitalized due to COVID-19: Pathophysiological considerations and therapeutic implications.

Introduction: Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) resulted in a worldwide pandemic, due to its great capacity to invade the human body. Previous studies have shown that the primary route of invasion of this virus is the human respiratory tract via the co-expression of ACE2 receptor and TMPRSS2, a serine protease on the cellular surface. Interestingly, this condition is present not only on the respiratory epithelium but on the conjunctival mucosa, as well. Thus, we hypothesized that SARS-CoV-2 is present on the conjunctival mucosa. Aim: To prove that SARS-CoV-2 can be detected in the conjunctiva. Methods: Previously nasopharyngeal swab-sample based real-time polymerase chain reaction (PCR) positive COVID-19 infected patients were selected at the COVID Care Centers of Semmelweis University, Budapest, Hungary. The study was approved by the ethical committee of Semmelweis University. During their recovery, both nasopharyngeal and conjunctival swab-samples were taken and PCR method was used to detect the presence of SARS-CoV-2 RNA. Appropriate statistical analysis was performed. Results: The study population consisted of 97 patients, 49 females (50.5%) and 48 males (49.5%), with a mean age of 67.2 ± 11.9 years. During recovery, with nasopharyngeal swabs, the PCR test was positive in 55 cases (56.70%), whereas with conjunctival swabs it was positive in 8 cases (8.25%). Both tests were positive in 5 cases (5.15%). In some patients, ocular symptoms were observed as well. The rest of the patients (29 cases) had negative nasopharyngeal PCR tests during recovery. Conclusions: Although only in few cases, the data of the present study provides a proof of concept that SARS-CoV-2 can be present on the conjunctival mucosa even in nasopharyngeal negative patients, a finding, which can have clinical importance. Also, on the basis of these findings one can hypothesize that - in addition to the respiratory tract - the conjunctiva can be an entrance route for SARS-CoV-2 to the human body. Thus, in high-risk conditions, in addition to covering the mouth and nose with mask, the protection of the eyes is also strongly recommended.

Characterization of a G-quadruplex from hepatitis B virus and its stabilization by binding TMPyP4, BRACO19 and PhenDC3.

Specific guanine rich nucleic acid sequences can form non-canonical structures, like the four stranded G-quadruplex (GQ). We studied the GQ-forming sequence (named HepB) found in the genome of the hepatitis B virus. Fluorescence-, infrared- and CD-spectroscopy were used. HepB shows a hybrid form in presence of K+, but Na+, Li+, and Rb+ induce parallel structure. Higher concentrations of metal ions increase the unfolding temperature, which was explained by a short thermodynamic calculation. Temperature stability of the GQ structure was determined for all these ions. Na+ has stronger stabilizing effect on HepB than K+, which is highly unusual. The transition temperatures were 56.6, 53.8, 58.5 and 54.4 °C for Na+, K+, Li+, and Rb+ respectively. Binding constants for Na+ and K+ were 10.2 mM and 7.1 mM respectively. Study of three ligands designed in cancer research for GQ targeting (TMPyP4, BRACO19 and PhenDC3) showed unequivocally their binding to HepB. Binding was proven by the increased stability of the bound form. The stabilization was higher than 20 °C for TMPyP4 and PhenDC3, while it was considerably lower for BRACO19. These results might have medical importance in the fight against the hepatitis B virus.

In vivo cellular imaging of the retina: present and future / Sejtszintu képalkotás a retina in vivo vizsgálatában: jelen és jövo.

Összefoglaló. A látószerv különbözo betegségei, valamint egyes szisztémás megbetegedések részben vagy kifejezetten az ideghártya károsodásával járnak. A patológia segítségével ma már tudjuk, hogy ezek a betegségek a retina mely rétegének vagy rétegeinek elváltozásait okozzák: míg az idoskori maculadegeneratio a külso retinában található fotoreceptorokat érinti kifejezetten a fovea centralis területén, addig a glaucoma a belso retina ganglionsejtjeinek pusztulásával, valamint e sejtek opticusrostjainak károsodásával jár a stratum ganglionaréban és a stratum neurofibrarumban. Az emberi retina sejtjei azonban egyelore nem maradéktalanul karakterizáltak, az egyes sejttípusok számát csak becsülni tudjuk, így nem írhatók le az egyes sejtszintu elváltozások sem kello pontossággal. A szövettani feldolgozás és vizsgálat megfelelo részletességgel tájékoztat a diagnózisról és az elváltozás súlyosságáról, értelemszeruen azonban ez a módszer in vivo nem használható a mindennapi klinikai gyakorlatban. A sejtszintu elváltozások ismerete az egyes kórképekben felvetette és szükségessé tette olyan in vivo, a klinikumban is alkalmazható vizsgálómódszerek kifejlesztését, amelyek lehetoséget nyújtanak a retina neurális és egyéb sejtjeinek celluláris és szubcelluláris szintu vizsgálatára, ideértve a vér alakos elemeit is, amelyek egészséges vagy neovascularis eredetu erekben áramlanak. A jelenleg is használt klinikai vizsgálatok mellett ezek a képalkotó módszerek segítségül szolgálhatnak a diagnózis megerosítésében vagy elvetésében, emellett az elváltozás súlyosságának megítélésében, valamint a progresszió vagy remisszió monitorozásában. Orv Hetil. 2021; 162(22): 851-860. Summary. Diseases of the visual system as well as many systemic illnesses are usually associated with retinal damage. With the help of pathology, we can clearly identify the affected layer(s): while age-related macular degeneration mostly damages the photoreceptors in the outer retina at the central fovea, glaucoma promotes ganglion cell death in the ganglion cell layer and damages respective neural fibers. However, the diverse cell types of the human retina have not been fully characterized yet, thus in most cases our knowledge on cellular pathologies is not precise enough. While histopathological preparation and examination of the retinal tissue provide more detailed information about the diagnosis and the severity of the condition, unfortunately, it cannot be used in vivo in everyday clinical practice. Our understanding of the cellular changes in different diseases has revealed a need for new everyday clinical examination methods that can be used in vivo to asses cellular and subcellular changes in neural and other cells of the retina, such as blood cells flowing in healthy vessels or in vessels of neovascular origin. In addition to the currently used clinical examination methods, these imaging methods could help confirm or dismiss diagnoses, assess the severity of a condition, and monitor disease progression or remission. Orv Hetil. 2021; 162(22): 851-860.

The ways of using machine learning in dentistry.

Innovative computer techniques are starting to be employed not only in academic research, but also in commercial production, finding use in many areas of dentistry. This is conducive to the digitalization of dentistry and its increasing treatment and diagnostic demands. In many areas of dentistry, such as orthodontics and maxillofacial surgery, but also periodontics or prosthetics, only a correct diagnosis ensures the correct treatment plan, which is the only way to restore the patient's health. The diagnosis and treatment plan is based on the specialist's knowledge, but is subject to a large, multi-factorial risk of error. Therefore, the introduction of multiparametric pattern recognition methods (statistics, machine learning and artificial intelligence (AI)) is a great hope for both the physicians and the patients. However, the general use of clinical decision support systems (CDSS) in a dental clinic is not yet realistic and requires work in many aspects - methodical, technological and business. The article presents a review of the latest attempts to apply AI, such as CDSS or genetic algorithms (GAs) in research and clinical dentistry, taking under consideration all of the main dental specialties. Work on the introduction of public CDSS has been continued for years. The article presents the latest achievements in this field, analyzing their real-life application and credibility.

Comparative evaluation of the effectiveness of the implantation in the lateral part of the mandible between short tissue level (TE) and bone level (BL) implant systems.

Short dental implants can be an alternative method of treatment to a vertical bone augmentation procedure at sites of reduced alveolar height. However, for successful treatment, an implant system that causes a minimal marginal bone loss (MBL) should be taken into consideration. The aim of the study has been to evaluate implantation effectiveness for bone level and tissue level short implants provided in lateral aspects of partially edentulous mandible and limited alveolar ridge height. The MBL and primary as well as secondary implant stability were determined in the study. Patients were randomly divided into two groups according to the method of treatment provided. Sixteen short Bone Level Implants (OsseoSpeed TX, Astra tech) and 16 short Tissue Level Implants (RN SLActive®, Straumann) were successfully placed in the edentulous part of the mandible. The determination of the marginal bone level was based on radiographic evaluation after 12 and 36 weeks. Implant stability was measured immediately after insertion and after 12 weeks. The marginal bone level of Bone Level Implants was significantly lower compared to Tissue Level Implants. Furthermore, the Bone Level Implants had greater primary and secondary stability in comparison with Tissue Level Implants (Primary: 77.8 ISQ versus 66.5 ISQ; Secondary: 78.9 ISQ versus 73.9 ISQ, respectively). Since short Bone Level Implants showed a significantly decreased MBL 12 and 36 weeks after implantation as well as better results for the primary stability compared to Tissue Level Implants, they should preferentially be used for this mentioned indication.

Radiographic Study of the Prevalence and Distribution of Hypodontia Associated with Unilateral and Bilateral Clef Lip and Palate in a Hungarian Population.

BACKGROUND Cleft defects are one of the most frequent birth-deformities of the orofacial region and they are commonly associated with anomalies of the tooth structure, size, shape, formation, eruption, and tooth number. The aim of our study was to evaluate the prevalence, distribution, and potential association of combined hypodontia in cleft-affected patients with regard to all types of teeth in both jaws in the permanent dentition. MATERIAL AND METHODS This retrospective radiographic analysis included patients with various types of clefts treated orthodontically in the Department of Orofacial Orthopedics and Orthodontics at Heim Pàl Children's Hospital, Budapest. There were 150 patients (84 males, 66 females) with non-syndromic unilateral (UCLP; n=120 patients) or bilateral (BCLP; n=30 patients) cleft formation (lip, alveolus and palate) who met the inclusion criteria. Statistical analysis was performed using the chi-square test and Fisher's exact test (significance level p<0.05). RESULTS Hypodontia was significantly more frequent in patients with cleft-sided lateral incisor (104 patients, 69%), with a total of 235 missing teeth, followed by the second premolars of the upper and lower jaw. A significant correlation of congenital missing teeth was observed in left-sided clefts between the upper and lower second premolar in the cleft area CONCLUSIONS Hypodontia inside and outside the cleft area was frequently observed. This should affect the therapy plans, especially if the cleft-sided premolar is also absent. Further comprehensive research including numerous random samples is necessary for better estimating other possible associations.

Physical properties of root cementum: Part 25. Extent of root resorption after the application of light and heavy buccopalatal jiggling forces for 12 weeks: A microcomputed tomography study.

INTRODUCTION: The aims of this study were to evaluate with microcomputed tomography the orthodontically induced inflammatory root resorption in premolars caused by buccopalatal jiggling movement with light and heavy forces and to compare it with the resorption caused by equivalent but continuous buccal forces. METHODS: The sample consisted of 60 maxillary first premolars collected from 30 patients (15 girls, 15 boys; ages, 13-18 years) who required orthodontic treatment with extractions. They were divided into 3 groups of 10 patients. Light (25 g) or heavy (225 g) buccal tipping orthodontic forces were randomly assigned on the maxillary right or left quadrant with either continuous buccal (positive controls) or buccopalatal jiggling forces for 12 weeks. At the end of the experimental period, the teeth were carefully extracted and processed for 3-dimensional imaging and volumetric evaluations of resorption craters. Data were analyzed with Wilcoxon signed rank tests. RESULTS: There was no statistically significant difference between positive control light (P = 0.0173) and heavy (P = 0.0173) continuous forces and jiggling forces for both force magnitudes. However, statistically significant differences were observed between heavy and light jiggling forces (P = 0.038), with heavy jiggling forces causing greater total root resorption than light jiggling forces. CONCLUSIONS: Light and heavy jiggling forces in the buccopalatal direction did not cause significantly different amounts of root resorption when compared with continuous forces of the same magnitude. On the other hand, light jiggling forces resulted in less root resorption than heavy jiggling forces.

Mapping chemical elements on the surface of orthodontic appliance by SEM-EDX.

BACKGROUND: During orthodontic treatment, the various elements that constitute the fixed appliance undergo different processes. As a result of a change of the surface, elution/coverage of metals on the surface can be observed in the process of corrosion/passivation. MATERIAL AND METHODS: Scanning electron microscopy with an energy-dispersive X-ray analytical system (SEM-EDX) was used to analyze the composition of stainless steel elements of orthodontic fixed appliances (before and after orthodontic treatment), to obtain the composition of the surface of the elements. The analyzed elements were: brackets (Victory Series APC PLUS 022, 3M Unitek, Monrovia, CA, USA); wires (0.017×0.025, 3M Unitek, Monrovia, CA, USA); and bands (37+, 3M Unitek, Monrovia, CA, USA). RESULTS: The results showed a decrease of chromium and iron contribution to the surface, with increase of oxygen content in used vs. new elements of the appliance. CONCLUSIONS: Our results confirm the formation of oxides (passivation layer) on the surface of stainless steel as a result of the presence of the orthodontic appliance in patients' oral cavities.

Early treatment of posterior crossbite--a randomised clinical trial.

BACKGROUND: The aim of this randomised clinical trial was to assess the effect of early orthodontic treatment in contrast to normal growth effects for functional unilateral posterior crossbite in the late deciduous and early mixed dentition by means of three-dimensional digital model analysis. METHODS: This randomised clinical trial was assessed to analyse the orthodontic treatment effects for patients with functional unilateral posterior crossbite in the late deciduous and early mixed dentition using a two-step procedure: initial maxillary expansion followed by a U-bow activator therapy. In the treatment group 31 patients and in the control group 35 patients with a mean age of 7.3 years (SD 2.1) were monitored. The time between the initial assessment (T1) and the follow-up (T2) was one year. The orthodontic analysis was done by a three-dimensional digital model analysis. Using the 'Digimodel' software, the orthodontic measurements in the maxilla and mandible and for the midline deviation, the overjet and overbite were recorded. RESULTS: Significant differences between the control and the therapy group at T2 were detected for the anterior, median and posterior transversal dimensions of the maxilla, the palatal depth, the palatal base arch length, the maxillary arch length and inclination, the midline deviation, the overjet and the overbite. CONCLUSIONS: Orthodontic treatment of a functional unilateral posterior crossbite with a bonded maxillary expansion device followed by U-bow activator therapy in the late deciduous and early mixed dentition is an effective therapeutic method, as evidenced by the results of this RCT. It leads to three-dimensional therapeutically induced maxillary growth effects. Dental occlusion is significantly improved, and the prognosis for normal craniofacial growth is enhanced. TRIAL REGISTRATION: Registration trial DRKS00003497 on DRKS.

Mandibular midline distraction osteogenesis.

In orthodontics, bone structure, its density and dimensions play an essential role by explaining limitations in magnitude, size and extent of tooth movement. Severe anterior crowding is one of the most frequently encountered dental malocclusions. Its therapy is mostly limited by lack of basal and alveolar bone and it often involves tooth extractions. Mandibular midline distraction osteogenesis is a method of natural bone generation and also a treatment option to achieve space regaining in a much-reduced lower jaw with distinctive frontal place deficit and severe anterior crowding, without sacrificing permanent teeth. McCarthy and Guerrero were of the first researchers reporting on this method applied on human lower jaws and they increased clinical interest in this approach. Although this method has been clinically used ever since, many questions concerning effects on bone regeneration speed, bone quality, tooth movement into regenerated area, periodontal health and long-time stability of treatment outcomes have not been sufficiently investigated. This overview should present the current clinical and biological state of knowledge about bone gain and tooth movement through regenerate bone. Furthermore it should encourage interest in further research on this topic.

Tooth movement using palatal implant supported anchorage compared to conventional dental anchorage.

Tooth stability is one of the most changing parameters in age. The aim of the present study has been to clarify the therapeutic benefit of the osseointegrated palatal implant (PI) supported anchorage in adolescents compared with conventional dental anchorage (DA) in extraction cases requiring 'maximum anchorage' in growing patients following the post pubertal growth spurt. Thirty patients (14.22±1.37 years) selected with homogeneous facial skeletal characteristics were divided in two groups. In the PI group, Orthosystem(®) implants were placed into the palate for anchorage and the transpalatal arch (TPA) was fixed to the implant and to the molar bands. In the DA group maximal anchorage was provided by a TPA and a utility arch. Super-elastic spring was used for canine- and contraction arch for incisor retraction. An insignificant difference was observed between the groups as to the duration of the canine retraction. In the PI group, the duration of the front retraction and the total treatment time was shorter compared to the DA group (P<0.05). No significant difference in molar mesial movement was found during canine retraction, but during front retraction, there was significantly less mesial molar movement in the PI group compared to the DA group (P<0.05). The use of palatal implant-based anchorage does not offer a shorter canine retraction period, but resulted in a significant shortening of the front-retraction phase and a total treatment time shortened by 5 months on average. The tooth stability in adolescent patients is adequate for tooth movements using both methods.

Spine deviations and orthodontic treatment of asymmetric malocclusions in children.

BACKGROUND: The aim of this randomized clinical trial was to assess the effect of early orthodontic treatment for unilateral posterior cross bite in the late deciduous and early mixed dentition using orthopedic parameters. METHODS: Early orthodontic treatment was performed by initial maxillary expansion and subsequent activator therapy (Münster treatment concept). The patient sample was initially comprised of 80 patients with unilateral posterior cross bite (mean age 7.3 years, SD 2.1 years). After randomization, 77 children attended the initial examination appointment (therapy = 37, control = 40); 31 children in the therapy group and 35 children in the control group were monitored at the follow-up examination (T2). The mean interval between T1 and T2 was 1.1 years (SD 0.2 years). Rasterstereography was used for back shape analysis at T1 and T2. Using the profile, the kyphotic and lordotic angle, the surface rotation, the lateral deviation, pelvic tilt and pelvic torsion, statistical differences at T1 and T2 between the therapy and control groups were calculated (t-test).Our working hypothesis was, that early orthodontic treatment can induce negative therapeutic changes in body posture through thoracic and lumbar position changes in preadolescents with uniltaral cross bite. RESULTS: No clinically relevant differences between the control and the therapy groups at T1 and T2 were found for the parameters of kyphotic and lordotic angle, the surface rotation, lateral deviation, pelvic tilt, and pelvic torsion. CONCLUSIONS: Our working hypothesis was tested to be not correct (within the limitations of this study). This randomized clinical trial demonstrates that in a juvenile population with unilateral posterior cross bite the selected early orthodontic treatment protocol does not affect negatively the postural parameters. TRIAL REGISTRATION: DRKS00003497 on DRKS.

Orofacial characteristics of adolescents with diagnosed spinal disorders.

The objective of the current epidemiological study is to show the correlation of various postural abnormalities and spinal deformities and the clinically identifiable dentofacial anomalies by orthodontic examination. Twenty-three children with Scheuermann's disease [mean age: 14 years 8 months; standard deviation (SD): 1 year 8 months] and 28 with scoliosis (mean age: 14 years 7 months; SD: 2 years 3 months) participated in the study. Standardized orthodontic screening protocols were used to map the occlusal relations in the sagittal, vertical, and horizontal dimensions; the space relations of the maxillary and mandibular frontal segment; the temporomandibular joint (TMJ) status; and the facial asymmetries. Statistically significant differences (p<0.05) were found between the values of the examined groups of patients for the following measurements: incisal overjet and overbite, upper and lower midline deviation, mandibular frontal spacing, TMJ pathological symptoms and functional characteristics, and frequency of facial asymmetries. A large percentage of patients with pre-pubertal developments of spinal deformities have various dentofacial anomalies. The majority of these anomalies are present in patients with Scheuermann's disease. Early treatment of the malocclusions closely correlated to postural disorders should minimize the progression of the dentofacial anomalies, making necessary performing orthodontic screening of these patients as early as possible.

Elution characteristics of residual monomers in different light- and auto-curing resins.

The aim of this in vitro study was to assess different auto-curing resins based on methylmethacrylate (MMA) and new light-curing resins based on urethane dimethacrylate (UDMA) regarding the residual monomers remaining in the resin and their elution over time. Specimens from three auto-curing and three light-curing resins were produced following the manufacturer's instructions. The concentration of residual MMA and UDMA monomers present in the resins as well as the quantity of the residual monomers released into artificial saliva solution after immersion times of 1, 3, and 7 days were analyzed by high-performance liquid chromatography (HPLC). Data were statistically analyzed using ANOVA and the post hoc Student-Newman-Keuls test. The highest and lowest amounts of residual monomers were found in the group of light-curing resins (p<0.05). The light-curing resins Triad Trans Sheet (0.06 wt%) and Primosplint (0.06 wt%) released over the entire immersion time of 7 days the smallest (p<0.05) quantity of UDMA. These two light-curing resins based on UDMA exhibited lower elution of residual monomers than auto-curing resins (MMA). The elution characteristics of the residual monomers do not seem to correlate with the residual monomer concentration in resins. These observations demonstrate that the quantitative determination of residual monomers alone - as required by the ISO specification 20795-1 - does not seem to be sufficient for an assessment of the biological properties of different resins. Instead, the evaluation of elution characteristics appears to be of higher clinical relevance.

Sagittal back contour and craniofacial morphology in preadolescents.

The aim of this study was to analyze the correlation ratios between the sagittal back contour (flèche cervicale and lombaire, trunk inclination) and selected parameters of craniofacial morphology in children. The patient sample consisted of 66 healthy children with a mean age of 11.2 years (SD 1.6 years), of which 34 were male (mean age 11.5 years, SD 1.3 years) and 32 were females (mean age 10.9 years, SD 1.9 years). The children were recruited during the preparation of the initial orthodontic treatment records. Craniofacial morphology was analyzed by six angular measurements: facial axis, mandibular plane angle, inner gonial angle, lower facial height, facial depth and maxilla position. Rasterstereography was used for reconstruction of the spinal back sagittal profile. From the profile flèche cervicale, flèche lombaire and trunk inclination were determined and the correlations with the craniofacial morphology were calculated (Pearson and Mann-Whitney U test). Significant correlations were found with respect to the inner gonial angle and the flèche cervicale, the mandibular plane angle and the flèche lombaire, the inner gonial angle and the flèche lombaire, and the angular lower facial height and the flèche lombaire, as well as the inner gonial angle and the trunk inclination. The craniofacial vertical growth pattern, presented by mandibular plane angle, inner gonial angle and the angular lower facial height, and the correlation to flèche cervicale and lombaire as well as trunk inclination reveal correlations between growth pattern and sagittal back contour.

Craniofacial features of children with spinal deformities.

BACKGROUND: The objective of this epidemiological study is to map the dentofacial anomalies that can be correlated to the two most frequent spinal diseases responsible for postural abnormalities and that can be clinically identified by the orthodontic examination. METHODS: Twenty-three children with Scheuermann's disease participated in the study (mean age: 14Y8M; SD: 1Y8M), 28 with Scoliosis (mean age: 14Y7M; SD: 2Y3M) and a control group of 68 orthopedically healthy children (mean age: 14Y8M; SD: 0Y11M). Standardized orthodontic screening protocols were used to map the occlusal relations in the sagittal, vertical, and transversal dimensions, space relations of the maxillary and mandibular frontal segment, and the TMJ status and function. The examinations for the children with orthopedic disorders were supplemented by the evaluation of routine orthodontic radiograms - lateral cephalograms and panoramic X-rays. RESULTS: The majority of the dentofacial features examined revealed more and greater abnormalities among patients in the Scheuermann's disease group than in the scoliosis group. In the latter group the proportion of the TMJ symptoms and the consecutive functional deviations were greater. When comparing the values of the two spinal-disorder groups and the control group, statistically significant differences (p < .05) occurred for the following measurements: frequency of unilateral Cl.II. molar occlusion, overjet and extreme overjet mean value (Scheuermann's disease group), as well as the frequency of TMJ pathological symptoms (scoliosis group). The evaluation of the panoramic X-rays showed significant differences among the mandibular measurements of the two spinal-disorder groups. Within the framework of the evaluation of the cephalograms significant differences (p < .05) were found only in the case of dental relations. However, several values differed significantly from the Ricketts' norms, none of the indices strictly characterized any of the groups with spinal disorders. CONCLUSION: The more extended treatment of the malocclusions closely correlated to postural disorders draws attention to the indicators of a higher frequency and severity occurring in the case of the dentofacial deviations in the patients of the MSCH group who had previously been less examined.

Immediate loading of palatal implants in still-growing patients: a prospective, comparative, clinical pilot study.

OBJECTIVE: The objective of this prospective, comparative study was to evaluate the potential of allowing immediate (within 72 hours) loading of palatal implants used for maximum orthodontic anchorage. This is in contrast to the standard protocol calling for a healing period of 12 weeks. MATERIALS AND METHODS: Sixteen patients with a mean age of 14.22+/-1.37 years for whom orthodontic treatment with maximum anchorage was indicated were randomized into two groups. In the SB (immediate loading) group (n=8, mean age 14.15+/-1.2 years), the implants were employed to provide maximum anchorage for a 1.2 x 1.2 mm TPA wire in combination with a molar band within 72 hours of insertion. In the KB (conventional loading) group (n=8, mean age 14.30+/-1.57 years), the implants were not used for maximum anchorage until a 12-week healing period had elapsed. Patients in both groups with implants that were clinically unstable after insertion were excluded from the study. After conclusion of the treatment, the implants were explanted and embedded using the sawing-grinding technique after Donath. Bone-implant contact (KIK) was analyzed using Bioquant Osteo software version 7.10.10. RESULTS: The objective of the orthodontic treatment, to achieve maximum anchorage of the first molars, was achieved in both groups. In the SB group, the mean bone-implant contact was 55.0%+/-21.6. In the KB group, the mean bone-implant contact was 73.1%+/-19.8. With a p-value of 0.1661, the difference between the bone-implant contact values was not statistically significant. CONCLUSION: The results of our clinical study demonstrate that when implants are clinically stable following insertion, it seems that a 12-week healing phase during which the implants are not loaded leads to a non-statistically significant improvement in osseointegration.

Gains and losses of adhesion molecules (CD44, E-cadherin, and beta-catenin) during oral carcinogenesis and tumour progression.

The aim of this study was to define whether or not the impaired expression of CD44, E-cadherin (E-cad), and beta-catenin (beta-cat) correlates with the clinical evolution and prognosis of oral cancer. Ninety-three primary oral squamous cell carcinomas (OSCCs) with tumour-adjacent normal and/or dysplastic mucosa, 30 associated metastases, and 12 recurrences were immunostained for CD44s, -v3, -v4, -v5, -v6, -v7, -v9, E-cad, and beta-cat. In non-neoplastic epithelium, all molecules investigated were constitutively expressed in the basal layers. In the majority of dysplasias, immunoreactivity for all adhesion molecules was increased, but there was restricted loss for CD44s, E-cad, and beta-cat in a few cases. In carcinomas, a striking accumulation of CD44s, v3, v4, v9 and a loss of E-cad/beta-cat were observed at the invasive tumour front. In metastases and recurrences, besides a loss of CD44s, v4, v7, and E-cad, a significant increase of v9 was recorded, whereas CD44v5 and v6 remained unchanged. Clinically, reduced expression of CD44v3, E-cad, and changes of CD44v9 phenotype within the primary tumours correlated significantly with poor prognosis; decreased beta-cat expression was a predictive marker for nodal metastases. These findings indicate that there is some perturbed expression of adhesion molecules during the stepwise course of oral carcinogenesis and tumour progression. Distinct phenotypic alterations project poor prognosis, while others predict metastasis. Some of these restricted molecular changes may serve as potential targets for future antibody-based tumour therapy.

Deranged expression of the E-cadherin/beta-catenin complex and the epidermal growth factor receptor in the clinical evolution and progression of oral squamous cell carcinomas.

BACKGROUND: Deranged expression and function of the E-cadherin/beta-catenin (E-cad/beta-cat) complex and the epidermal growth factor receptor (EGFR) have been implicated in the development and progression of carcinomas. METHODS: To estimate the role of these molecules in oral cancer, we investigated 75 primary oral squamous cell carcinomas (OSCCs) with adjacent normal and/or dysplastic mucosa, 30 paired metastases and 12 recurrences by immunohistochemistry. RESULTS: All three molecules were constitutionally expressed in the basal/parabasal layers of tumour adjacent 'normal' epithelium, in contrast to a significant increase of EGFR and heterogeneous expression of E-cad/beta-cat in dysplasia. In OSCCs, over-expression of EGFR correlated significantly with lower tumour grade and poor prognosis, loss of E-cad was a significant marker for shortened survival, reduced beta-cat staining was a predictive marker for lymph node metastasis. CONCLUSIONS: There is a perturbance in intercellular adhesion molecules and EGFR expression/function in oral cancer with major clinical impact. E-cad and beta-cat seem to inhibit EGFR to enhance the progression of OSCCs.

[Diagnosis of Helicobacter pylori infection from dental plaque]. / A Helicobacter pylori infekció kimutatása foglepedékból.

The key role of Helicobacter pylori (Hp) in gastric inflammations is discussed extensively in the literature. In the present study in 140 school-children aged 12 years, Hp was traced in dental plaque by use of the polymerase chain reaction (PCR). Oral Hp was detected in the case of 11 children, where subsequent UBT did not confirm gastric Hp infection, however during family research in 8 of the 11 families at least one of the parents was found Hp positive. It was concluded that the non-invasive dental plaque PCR may play a significant role in the early indication of Hp infection.