Prognostic significance of the methylation of Wnt pathway antagonists—CXXC4, DACT2, and the inhibitors of sonic hedgehog signaling—ZIC1, ZIC4, and HHIP in head and neck squamous cell carcinomas

Objectives

Aberrations in Wnt and Shh signaling pathways are related to the pathogenesis of head and neck carcinomas, and their activation frequently results from epigenetic alterations. This study aimed to assess the frequency of methylation of negative regulators of Wnt signaling: CXXC4, DACT2, HDPR1, and FBXW11 and Shh signaling: HHIP, PTCH1, SUFU, ZIC1, and ZIC4 and correlate it with clinicopathological features in this group of patients.

Materials and methods

Methylation-specific PCR was used to detect gene promoter methylation, and real-time PCR was used to assess gene expression level.

Results

The analysis of the occurrence of gene promoter methylation in head and neck carcinoma cell lines indicated that CXXC4, DACT2, HHIP, ZIC1, and ZIC4 are methylated in these tumors. These genes were further analyzed in tumor sections from oral and laryngeal cancer patients. Gene methylation rate was higher in laryngeal tumors. The methylation index in tumor samples correlated with the overall survival in a subgroup of oral cancer patients who died of the disease. Moreover, ZIC4 methylation correlated with lymph node involvement in oral cancer patients.

Conclusions

Our findings corroborate that the activation of Wnt signaling in head and neck squamous cell carcinoma (HNSCC) is related to epigenetic silencing of its negative regulators. Moreover, the results indicate that the same mechanism of activation may operate in the case of Shh signaling.

Clinical relevance

The methylation of ZIC4 may be considered a new prognostic marker in oral cavity and oropharyngeal tumors. Further investigations should determine the diagnostic significance of methylation of ZIC4, HHIP, and DACT2 in head and neck carcinomas.

     

Immunohistochemistry evaluation of BMP-2 with β-tricalcium phosphate matrix,polylactic and polyglycolic acid gel,and calcium phosphate cement in rats

Purpose

The installation of implants has become a routine procedure in the clinic. However, it takes time and adequate bone thickness, and for that, tissue engineering has made efforts to develop substitutes for autografts, in view of certain disadvantages of this material. The decision to choose the most suitable graft material for each case is an important step in the success of bone reconstruction. This study was to verify, by means of immunohistochemical study, that the addition of bone morphogenetic protein had some influence on biomaterials commercially available, taking into account the formation of mineralized tissue, bone replacement, and the amount of degradation of biomaterials.

Methods

The sample consisted of 72 rats that were divided into eight treatment groups, in which two defects of 5 mm were made in each animal calvaria. Euthanasia was performed at 5, 15, and 30 days postop.

Results

A histologic and histometric analysis was performed to quantitate the area of mineralized tissue formed, the area of newly formed bone, and the area of degradation of the biomaterials. Data were analyzed with multiple comparisons of means by Tukey contrasts, and significant difference was assigned at the level of P < 0.05. The proteins used for immunohistochemical analysis accounted for the process of formation, mineralization, and bone resorption and was performed using ordinal qualitative analysis, where from assigning scores.

Conclusions

Bone morphogenetic protein 2 was shown to be effective as an inducer of bone formation process independent biomaterial used mainly for accelerating the resorption process of the framework.

     

Dental practitioner’s knowledge,opinions and methods of management of oral premalignancy and malignancy

Objectives

The present study outlines the results of a pilot study to determine the knowledge and awareness of a cohort of dentists in United Arab Emirates (UAE) regarding aetiology, clinical features and appropriate early management of oral premalignant and malignant lesions.

Materials and methods

A self-administered questionnaire was constructed and posted to 300 UAE Dental Practitoners (DPs), selected randomly from the register of Emirates Dental Association. The present report details the responses of this cohort.

Results

182 questionnaires were completed and returned (response rate 60.6%). One hundred and twenty-seven (69.8%) of the responding dentists were male and the median age of the DPs was 40 years (range 24–75 years). The majority (84%) practised or had practised in or around Dubai and Sharjah, 75% had graduated from a dental school after 1980. Eighty-two respondents (45.0%) had attended specific courses on premalignant or malignant oral lesions. During their undergraduate training 70% of DPs had witnessed more than 10 patients with oral SCC. Only 60.4% of respondents indicated that the tobacco and alcohol use were the principle causes of oral SCC while 19.7% suggested that HIV disease was a risk factor for oral SCC. 29% of DPs routinely recorded the tobacco or alcohol use of their patients and only 3.8% offered advice to patients regarding modification of these habits. Eight-three percent of the respondents suggested that clinical screening was an effective means of reducing the frequency of premalignant and malignant oral lesions.

Conclusions

In view of the gradual rise in oral malignancy worldwide there is an increased need for DPs to be able to recognize the signs and symptoms of oral malignancy and premalignancy, provide appropriate preventive advice and be aware of the appropriate early management of patients with such oral lesions.     

Phase III,randomized, double-blind,placebo-controlled trial of topical 2 % lidocaine for the prevention and treatment of oral mucosal pain in children

Objectives

The aim of this study was to assess the efficacy in pain reduction of topical 2 % lidocaine compared to a placebo cream in children with oral mucosal lesions due to trauma or aphthous ulcers or in the prevention of clamp placement pain.

Materials and methods

The design was a double-blind, randomized, placebo-controlled, four-center trial on 64 patients. Pain intensity and relief were measured using a 100-mm visual analog scale (VAS). One-tailed Student’s t test and ANOVA were used for statistical analyses.

Results

Independent of the pain origin, application of 2 % lidocaine cream led to a mean reduction in VAS pain intensity of 19.7 mm?±?18.3, which was significantly greater than that obtained with the placebo cream (p?=?.025). Analyses showed a statistically significant efficacy of the 2 % lidocaine cream (p?<?.0001). Its efficacy was not associated to any local or systemic adverse drug reaction, as reported by the patients. As the most important population represented in our patients was children whom a rubber dam clamp was placed, we also specifically analysed this population, and we were able to demonstrate a significantly greater efficacy of the 2 % lidocaine cream on the pain caused by the rubber dam clamp placement in comparison to the placebo cream (p?<?.005).

Conclusions

A significant reduction in pain intensity occurred after application of 2 % lidocaine cream, and the effect was significantly greater than that obtained with the placebo cream. Considering the study’s limitations, this product appears safe for use in children.

Clinical relevance

For painful benign lesions of the oral mucosa (trauma or aphthous ulcers) or for preventing painful iatrogenic procedures such as rubber dam clamp placement, it is essential to treat or prevent pain onset, especially in the pediatric population for whom a painful experience could end in refusal of dental care. Application of a topical anesthetic in this specific situation is of particular interest, as is defining its efficacy and safety.     

Cyclic Fatigue Resistance of One Curve, 2Shape,ProFile Vortex,Vortex Blue,and RaCe Nickel-Titanium Rotary Instruments in Single and Double Curvature Canals

Introduction

The aim of this study was to evaluate and compare the resistance to cyclic fatigue of the new One Curve (OC) instrument in double (S-shaped) and single curvature canals compared with other nickel-titanium rotary instruments.

Mucocele of the glands of Blandin�CNuhn��clinical, pathological, and therapeutical aspects

Purpose

This study aims to review anatomical, clinical, and pathological concepts as well as to discuss the most adequate therapeutic approach to the mucoceles of the glands of Blandin?CNuhn.

Discussion

The glands of Blandin?CNuhn are localized in the ventral part of the tongue, next to the apex in the lingual median plane. Development of a mucocele in this site is rarely seen; besides, as the glands of Blandin?CNuhn are not encapsulated and are directly overlapped to the muscle tissues, their manipulation tends to be different from the other oral mucoceles.

Conclusion

As Blandin?CNuhn mucoceles are uncommon and their clinical appearance could be similar to other lesions, it is important that health professionals know their clinical and histopathological features to avoid having them misdiagnosed.     

Comments on “Salivary 8-hydroxy-2-deoxyguanosine,malondialdehyde, vitamin C,and vitamin E in oral pre-cancer and cancer: diagnostic value and free radical mechanism of action”

Clinical Oral Investigations -     

Interrelations between orthostatic postural deviations and subjects’ age,sex, malocclusion,and specific signs and symptoms of functional pathologies of the temporomandibular system: a preliminary correlation and regression study

Aims:

Studies on the relationships between postural deviations and the temporomandibular system (TS) functional health are controversial and inconclusive. This study stems from the hypothesis that such inconclusiveness is due to authors considering functional pathologies of the TS (FPTS) as a whole, without taking into account subjects’ specific FPTS signs and symptoms.

Methodology:

Based on the author and collaborators’ previous studies, the present study analyzed data on body posture from a sample of 50 subjects with (30) and without (20) FPTS. Correlation analyses were applied, taking as independent variables age, sex, Helkimo anamnestic, occlusal, and dysfunction indices, as well as FPTS specific signs and symptoms. Postural assessments of the head, cervical spine, shoulders, lumbar spine, and hips were the dependent variables. Linear regression equations were built that proved to partially predict the presence and magnitude of body posture deviations by drawing on subjects’ characteristics and specific FPTS symptoms.

Results:

Determination coefficients for these equations ranged from 0·082 to 0·199 in the univariate, and from 0·121 to 0·502 in the multivariate regression analyses.

Conclusions:

Results show that factors intrinsic to the subjects or the TS may potentially interfere in results of studies that analyze relationships between FPTS and body posture. Furthermore, a trend to specificity was found, e.g. the degree of cervical lordosis was found to correlate to age and FPTS degree of severity, suggesting that some TS pathological features, or malocclusion, age or sex, may be more strongly correlated than others with specific posture patterns.     

Evaluation of translucency,Marten’s hardness,biaxial flexural strength and fracture toughness of 3Y-TZP, 4Y-TZP and 5Y-TZP materials

ObjectivesTesting and comparing of different non-shaded zirconia materials (3Y-TZP, 4Y-TZP and 5Y-TZP) on optical and mechanical properties.Materials and methodsZirconia materials (N = 320, Opaque O, Translucent T, Extra Translucent ET, High Translucent HT) were investigated on translucency, Martens parameter, biaxial flexural strength, Chevron-Notch-Beam (CNB) fracture toughness (K_IC) and grain size. The grain size was analyzed using a scanning electron microcopy (SEM). Univariate ANOVA, post-hoc Scheffé, partial eta-squared, Kolmogorov-Smirnov-, Kruskal-Wallis- and Mann-Whitney-U-tests (p < 0.05) were performed. The reliability of flexural strength was calculated with two-parametric Weibull analysis and 95 % confidence level.ResultsThe translucency of ET and HT increased with the thermo-mechanical aging (p < 0.001). The zirconia material and aging had no impact on the Martens hardness and the indentation modulus. ET showed the highest flexural strength values after initial and thermo-mechanical aging (p < 0.001 – 0.683). All four materials showed the highest flexural strength after thermo-mechanical aging after 1.2 Mio cycles. Thermo-mechanically (1.2 Mio cycles) aged HT presented the highest Weibull modulus (m = 15.0) regardless of aging. Within initial groups, T (p ≤ 0.001) showed the highest fracture toughness, followed by O (p ≤ 0.001), ET (p < 0.003) and HT (p ≤ 0.001).SignificanceTranslucency of ET and HT increases with thermo-mechanical aging. Chevron-Notch-Beam (CNB) is a valid alternative to the single-edge-V-notched beam (SEVNB) method for testing fracture toughness.     

Dental imaging—2D to 3D: a historic,current, and future view of projection radiography

Projection radiography, developed over 100 years ago, has helped transform Dentistry into a sophisticated evidence-based healthcare profession. It has been an international collaboration of research that created the technology we now use. The following essay reviews the history behind the technology and provides examples of its current endodontic applications. The dangers of ionizing radiation have pushed the science of imaging into new frontiers. New imaging processes that use magnetic resonance, ultrasound, and infrared technology may supersede the need to use x-rays. Change is a constant in imaging. Future applications will go beyond the imagination of the inventors.     

Clinical evaluation of chemomechanical and mechanical caries removal: status of the restorations at 3, 6, 9 and 12 months

In this study, the clinical efficacy of Carisolv™ system and the hand excavation method in the removal of occlusal dentine caries of primary molar teeth was evaluated. Both Carisolv system and hand excavation method were applied for the removal of caries on different teeth of the same children. After the removal of the caries, Dyract AP materials were used to restore the teeth. The clinical follow-up was made every 3 months within a year. The clinical evaluations of restorations were carried out in accordance with US Public Health Service (USPHS) criteria. To determine whether there was any statistical difference between the groups, chi-square analysis was used. During both excavation methods, pain occurrence and the need for anesthesia and the time spent were all recorded. The time spent for the removal of caries in Carisolv system and in hand excavation method was 9.03±4.14 min (mean±SD) and 7.34±3.41 min (mean±SD), respectively (P>0.05). At the end of 1 year, differences between Carisolv and hand excavation groups in terms of marginal adaptation and secondary caries were found to be statistically insignificant (P>0.05). During the removal of caries, certain children complained about pain both in Carisolv system and hand excavation method (7.1 and 35.7%, respectively). As a result, it can be argued that Carisolv system is effective in the removal of caries and causes minimum level pain occurrence. Compared to hand excavation, Carisolv system seems to be a promising restorative approach to remove occlusal caries in primary molar teeth. Studies of longer duration are needed to confirm these findings.     

The distribution of osteocytic lacunar–canalicular system,and immunolocalization of FGF23 and sclerostin in osteocytes

Osteocytes build up functional syncytia, i.e., the osteocytic lacunar–canalicular system (OLCS). The sites of active bone remodeling revealed the irregularly arranged OLCS, while those of slow remodeling featured well arranged OLCS. This implies that the speed of bone deposition during bone remodeling would affect the regularity of OLCS. Recently, osteocytes were shown to regulate phosphorus serum levels and osteoblastic activity through the expression of fibroblast growth factor (FGF) 23 and sclerostin. In our observations, FGF23 and sclerostin synthesis seemed to be associated with the spatial regularity of the OLCS: both proteins were consistently expressed by osteocytes in epiphyses and cortical bones showing regularly arranged OLCS. In contrast, osteoprotegerin-deficient (OPG^?/?) mice revealed rapid bone remodeling with irregular OLCS. Sclerostin-immunoreactivity was markedly diminished in OPG^?/? bones. However, sclerostin expression seemed to be a function of osteoclastic and osteoblastic activities rather than being influenced by the regularity of OLCS. This review will introduce our recent studies on the regularity of OLCS and the synthesis of osteocyte-derived FGF23 and sclerostin.     

Sweets consumption of preschool children—extent, context, and consumption patterns

Objectives

Sweets consumption is one of the risk factors of caries, especially among children. The aim of our study was to explore the extent and context of preschoolers’ sweets consumption and to identify high-risk groups.

Materials and methods

The baseline cross-sectional data used originated from a nutritional intervention study encompassing 879 parental surveys, which were obtained in 52 kindergartens in Baden-Württemberg—the third largest federal state in Germany—between September and March 2009. Our outcome variable “sweets consumption” was operationalized using food-frequency items and analyzed by testing the influence of sociodemographic, educational, cultural, and family context covariates.

Results

Most preschoolers consumed sweets every day—on average 9.7?±?6.2 times per week. Most popular were cookies, gummy bears, and chocolate. Sweets consumption did not correlate significantly with sociodemographic factors like age and sex but rather was associated with cultural and contextual factors such as immigrant background, parental education, specific nutritional knowledge levels, and access arrangements in the home.

Conclusions

The consumption patterns identified are a result of high availability and parental influence (factors such as parents’ knowledge levels, interest in, and habits regarding their child’s nutrition).

Clinical relevance

Dental practitioners should place more emphasis on gathering information from young patients regarding excessive and frequent consumption of sweets and consequently on trying to educate the children and their parents on oral health risks associated with such consumption. Particular attention is to be paid to children of Turkish and Arabic decent, as they have been shown to consume above-average amounts of sweets.     

Buffer capacity, pH, and flow rate in saliva of children aged 2–60 months with Down syndrome

This study measured the flow rate, pH, and buffer capacity of saliva from children with Down syndrome aged 2–60 months. We compared 25 children with Down syndrome with 21 children without Down syndrome. The whole saliva was collected under slight suction and the pH and the buffer capacity were determined using a digital pHmeter. The buffer capacity was measured by titration with 0.01 N HCl. The Down syndrome group demonstrated higher buffer capacity than the control group in the pH ranges of 6.9–6.0, 5.9–5.0, and 4.9–4.0. The flow rate was low in the Down syndrome group. Boys from the Down syndrome group demonstrated higher buffer capacity in the pH ranges 6.9–6.0, 5.9–5.0, and 4.9–4.0 than controls, while girls from the Down syndrome group showed no difference compared with controls. Girls with Down syndrome demonstrated significant difference only in the range of pHi–pH 7.0. Conclusion. These data suggest that the Down syndrome persons present a better buffer capacity, supporting the results observed in several studies which found the low dental caries in persons with Down syndrome.     

A clinical, radiographic, and microbiologic comparison of Astra Tech and Brånemark single tooth implants

Background: The soft tissues around single tooth implants differ fundamentally from the gingiva around natural teeth. There are very limited data comparing soft tissues around different implant systems. Aim: To assess whether the design characteristics of dental implants, particularly the implant‐abutment junction, may affect the dimensions and health of the peri‐implant soft tissues and radiographic bone levels. Subjects and Method: Fifteen Astra Tech and 15 Brånemark single tooth implants that had been in function for a minimum of 2 years in 30 partially dentate subjects were examined for plaque accumulation, probing depth, and bleeding on probing and compared to contralateral healthy teeth. Standardized radiographs were taken to measure the most coronal bone to implant contact on the mesial and distal surfaces. In addition, samples of subgingival plaque were taken on paper points and examined by darkfield microscopy. Results: Significantly higher mean probing depths (p < .001) and higher mean percentage of spirochetes (p= .003) were found at implants compared to teeth. In this sample, the Brånemark implants had significantly higher probing depths than the Astra Tech implants (median and interquartile range: Astra Tech 2.7 mm [2–3], Brånemark 3.3 mm [3–3.7] p= .026) and the most coronal bone to implant contact was closer to the implant–abutment junction in the Astra Tech implants (Astra Tech 0.6 mm [0.2–0.9], Brånemark 1.6 mm [1.4–2.0]. p < .001). Conclusion: Although there were statistically significant differences between the two implant systems, the clinical differences were small and probably reflect differences in the biologic width in relation to the location and design of the implant‐abutment junction.