Gamma Knife radiosurgery for the management of glomus jugulare tumors: A systematic review and report of the experience of a radioneurosurgery unit in Latin America.

Background: Glomus jugulare tumors (GJTs) are rare and mainly affect women between the 5th and 6th decades of life. Its localization and anatomic relationships make conventional surgical treatment difficult and with a considerable risk of complications. This manuscript aims to describe the results of Gamma Knife radiosurgery (GKR) in patients with GJT treated in a single center in Latin America, as well as to systematically review the literature to determine the clinical and radiological effectiveness of this technique. Methods: A search of information from January 1995 to June 2023 was performed. Twenty-two articles reporting 721 GJT patients treated with GKR were included in the study. Variables such as symptomatic control, control of tumor size, and complications were evaluated. These variables were described using measures of central tendency and proportions. For the institutional experience, 77 patients with GJT tumors were included in the study. Pre-treatment clinical variables and follow-up data were collected from medical charts and phone interviews. The Short Form-36 scale was applied to assess the quality of life. The data were analyzed using the statistical program STATA17.0. Results: A total of 721 patients were considered. The median of patients included in these studies was 18.5. The mean age was 58.4 years. The median of symptom control was 89%, and the median of imaging control was 95.7%. In our institution, 77 patients were included in the study. The mean age was 53.2 years. The median hospital stay was 4.92 hours. For the clinical follow-up, information on 47 patients was obtained. An improvement in pre-treatment symptoms was described in 58%, with general symptomatic control of 97%. The tumor-control rate was 95%, and there were statistically significant differences in six of the nine Short Form-36 scale domains. Conclusion: GKR is an effective, safe, and cost-effective technique that offers a high degree of symptomatic and tumor size control in patients with GJT.

Cross-cultural validation and measurement invariance of anxiety and depression symptoms: A study of the Brief Symptom Inventory (BSI) in 42 countries.

BACKGROUND: Depression and anxiety are among the most prevalent mental health issues experienced worldwide. However, whereas cross-cultural studies utilize psychometrically valid and reliable scales, fewer can meaningfully compare these conditions across different groups. To address this gap, the current study aimed to psychometrically assess the Brief Symptomatology Index (BSI) in 42 countries. METHODS: Using data from the International Sex Survey (N = 82,243; Mage = 32.39; SDage = 12.52; women: n = 46,874; 57 %), we examined the reliability of depression and anxiety symptom scores of the BSI-18, as well as evaluated evidence of construct, invariance, and criterion-related validity in predicting clinically relevant variables across countries, languages, genders, and sexual orientations. RESULTS: Results corroborated an invariant, two-factor structure across all groups tested, exhibiting excellent reliability estimates for both subscales. The 'caseness' criterion effectively discriminated among those at low and high risk of depression and anxiety, yielding differential effects on the clinical criteria examined. LIMITATIONS: The predictive validation was not made against a clinical diagnosis, and the full BSI-18 scale was not examined (excluding the somatization sub-dimension), limiting the validation scope of the BSI-18. Finally, the study was conducted online, mainly by advertisements through social media, ultimately skewing our sample towards women, younger, and highly educated populations. CONCLUSIONS: The results support that the BSI-12 is a valid and reliable assessment tool for assessing depression and anxiety symptoms across countries, languages, genders, and sexual orientations. Further, its caseness criterion can discriminate well between participants at high and low risk of depression and anxiety.

Development of Lyophilized Eukaryotic Cell-Free Protein Expression System Based on Leishmania tarentolae.

Eukaryotic cell-free protein expression systems enable rapid production of recombinant multidomain proteins in their functional form. A cell-free system based on the rapidly growing protozoan Leishmania tarentolae (LTE) has been extensively used for protein engineering and analysis of protein interaction networks. However, like other eukaryotic cell-free systems, LTE deteriorates at ambient temperatures and requires deep freezing for transport and storage. In this study, we report the development of a lyophilized version of LTE. Use of lyoprotectants such as poly(ethylene glycol) and trehalose during the drying process allows retention of 76% of protein expression activity versus nonlyophilized controls. Lyophilized LTE is capable of withstanding storage at room temperature for over 2 weeks. We demonstrated that upon reconstitution the lyophilized LTE could be used for in vitro expression of active enzymes, analysis of protein-protein interactions by AlphaLISA assay, and functional analysis of protein biosensors. Development of lyophilized LTE lowers the barriers to its distribution and opens the door to its application in remote areas.

Dynamic susceptibility of Fe3O4 nanotubes.

In this work we performed a detailed numerical analysis to investigate the dynamic susceptibility of 1000 nm long Fe3O4 nanotubes by varying the diameter, the tube wall thickness and the magnitude of the external magnetic field applied along the tube axis. We found two well-defined modes, one of low frequency associated with the caps of the nanotubes, and another of high frequency associated with the central area of the nanotubes, which can be controlled by varying the geometry of the tubes or the external magnetic field to which they are subjected. These results allow us to suggest the use of these nanotubes in applications that require controlling the resonant frequency in the GHz range.

Transferring the tooth preparation finish line on intraoral digital scans to dental software programs: A dental technique.

Intraoral scanner software programs allow the clinician to draw the tooth preparation finish lines. However, this information may be lost when importing the digital file into different computer-aided design (CAD) dental software programs. A technique for transferring the marked tooth preparation finish line into an intraoral digital scan is described. The intraoral digital scan of the tooth preparation is duplicated and used to draw the finish line. Subsequently, the tooth preparation geometry is erased while maintaining the finish line border, which will be used as a reference when designing the definitive restoration in the CAD software program.

Synthesis and Characterization of Iridium(III) Complexes with Substituted Phenylimidazo(4,5-f)1,10-phenanthroline Ancillary Ligands and Their Application in LEC Devices.

In this work, we report on the synthesis and characterization of six new iridium(III) complexes of the type [Ir(C^N)2(N^N)]+ using 2-phenylpyridine (C1-3) and its fluorinated derivative (C4-6) as cyclometalating ligands (C^N) and R-phenylimidazo(4,5-f)1,10-phenanthroline (R = H, CH3, F) as the ancillary ligand (N^N). These luminescent complexes have been fully characterized through optical and electrochemical studies. In solution, the C4-6 series exhibits quantum yields (Ф) twice as high as the C1-3 series, exceeding 60% in dichloromethane and where 3MLCT/3LLCT and 3LC emissions participate in the phenomenon. These complexes were employed in the active layer of light-emitting electrochemical cells (LECs). Device performance of maximum luminance values of up to 21.7 Lx at 14.7 V were observed for the C2 complex and long lifetimes for the C1-3 series. These values are counterintuitive to the quantum yields observed in solution. Thus, we established that the rigidity of the system and the structure of the solid matrix dramatically affect the electronic properties of the complex. This research contributes to understanding the effects of the modifications in the ancillary and cyclometalating ligands, the photophysics of the complexes, and their performance in LEC devices.

Hollow Iron Oxide Nanospheres Obtained through a Combination of Atomic Layer Deposition and Electrospraying Technologies.

In the present study, we report on the successful synthesis of hollow iron oxide nanospheres. The hollow Fe3O4 nanospheres were synthesized following a four-step procedure: electrospraying spherical PVP particles, coating these particles with alumina (Al2O3) and hematite (Fe2O3) through atomic layer deposition and, finally, a thermal reduction process to degrade the polymer (PVP) and convert hematite (Fe2O3) into magnetite (Fe3O4). A structural analysis using X-ray diffraction (XRD) confirmed the effectiveness of the thermal reduction process. A morphological analysis confirmed that the four-step procedure allowed for the obtainment of hollow iron oxide nanospheres, even though the reduction process caused a contraction in the diameter of the particles of almost 300 nm, but did not affect the thickness of the walls of the hollow spheres that remained at approximately 15 nm. Magnetic properties of the hollow iron oxide nanospheres enable their use in applications where the agglomeration of magnetic nanostructures in liquid media is commonly not allowed, such as in drug encapsulation and delivery.

Gamma Knife radiosurgery - 12 years of experience in a high-complexity center of a middle-income country.

Background: Gamma Knife radiosurgery (GKR) is a technique that consists of the release of a high dose of ionizing radiation onto a therapeutic target, which has been previously delimited. This technique was described by Lars Leksell and Borje Larsson in 1951. In Colombia, there is only one GKR unit functioning machine nowadays. The objective of this study is to describe the institutional experience of a single institution with Gamma Knife Perfexion over 12 years. Methods: We conducted a retrospective observational study. A total of 1906 medical records, taken from the period between May 4, 2010, and May 4, 2022, were included in the study. Descriptive analysis was performed through STATA 17 as statistic tool. Measures of central tendency were calculated depending on the distribution of the continuous data and proportions were taken into account in the case of qualitative variables. Results: A total of 1906 procedures were performed. Patients from 1 year to 99 years old were treated, with a median age of 51 years. The most frequent diagnoses were meningioma (20.8%), arteriovenous malformation (AVM) (17%), vestibular schwannoma (15.6%), metastases (9.81%), and trigeminal neuralgia (9.12%). At 3-year posttreatment, in meningiomas, tumor size stability was observed in 57.3%, size decrease in 36%, and disappearance in 1.3%. In AVM, complete obliteration of the lesion was described in 36.8% and a decrease in size in 52.6%. Intracranial hemorrhage occurred in 5.2% during the follow-up period and 3.5% of all treated patients required a new procedure due to residual malformation. In vestibular schwannomas, tumor size remained stable in 62.2% and decreased in 28.8%. No new cases of facial paralysis after the procedure were described. At 1-year posttreatment, in metastasis, the size of the lesions remained stable in 40% of the patients, decreased in 47.5%, and disappeared in 2.5%. In trigeminal neuralgia, 88.4% of patients had pain relief and recurrences occurred in 16.6%. Acute complications were generally uncommon, the main ones being headache, pain at frame fixation points, and nausea. Conclusion: Our experience suggests that GKR is a noninvasive procedure with a broad spectrum of clinical applications, low frequency of complications, feasible, with good enough control size of tumor and vascular lesions in images, and good clinical results in the medium and long term.

Effects of Photobiomodulation on the Upper First Molar Intrusion Movement Using Mini-Screws Anchorage: A Randomized Controlled Trial.

Objective: The aim of this study was to quantify the changes obtained when the molar intrusion movement is complemented by photobiomodulation (PBM). Background: A common problem in adult patients is the super-eruption of maxillary molars caused by the loss of the antagonist tooth. Super-erupted molars impair oral rehabilitation and can cause both occlusal and functional problems. There is increasing research confirming the benefits of adjunctive PBM during orthodontic treatment. Methods: Twenty patients with indication of a maxillary first molar intrusion for oral rehabilitation were selected. Patients were randomized into two groups to receive orthodontic intrusion (control group) or the same treatment complemented by PBM (PBM group) in repeated doses (days 0, 1, 2, 3, 4, and 7 from the start of the intrusion and in each monthly follow-up) by using a low-power red laser diode (670 nm, 150 mW, 12 min around the molar). Plaque index (PI), probing depth (PD), and bleeding of probing (BOP) were assessed at 0, 1, 2, 3, and 6 months. Stereolithography models generated from an intraoral scanner were taken at 0, 3, and 6 months and cone beam computed tomography (CBCT) records were taken at 0 and 6 months. Mean intrusion distance, mean intrusion velocity, and volumetric resorption were calculated. Results: Periodontal clinical assessments (PI, PD, and BOP) and mean intrusion distance or mean intrusion velocity yielded no differences (p > 0.05) between groups. However, PBM group showed lower values of all these scores during the first 3 months. Intraoral scanner and CBCT were equally effective in accurately monitoring the intrusion distance (p > 0.05). CBCT records allowed volumetric evaluation of the root resorption process, being lesser in the PBM group, but not significantly (p > 0.05). Conclusions: During orthodontic intrusion process, the adjunctive application of PBM may provide better periodontal records and lower progression of root resorption at the expense of a little lower intrusion distance and velocity.

Stabilization of Magnetic Skyrmions on Arrays of Self-Assembled Hexagonal Nanodomes for Magnetic Recording Applications.

Magnetic skyrmions are nontrivial spin textures that resist external perturbations, being promising candidates for the next-generation recording devices. Nevertheless, a major challenge in realizing skyrmion-based devices is the stabilization of ordered arrays of these spin textures under ambient conditions and zero applied field. Here, we demonstrate for the first time the formation and stabilization of magnetic skyrmions on the arrays of self-assembled hexagonal nanodomes taking advantage of the intrinsic properties of its curved geometry. Magnetic force microscopy images from the arrays of 100 nm nanodomes showed stable skyrmions at the zero field that are arranged following the topography of the nanostructure. Micromagnetic simulations are compared to the experiments to determine the correlation of the domain textures with the topography of the samples. We propose a simple method to nucleate and annihilate skyrmions, opening the possibility for an ultradense data storage based on the high stability and low energy consumption of the skyrmionic textures.

Controlled dispersion of ZnO nanoparticles produced by basic precipitation in solvothermal processes.

Zinc oxide nanoparticles were successfully synthesized under precipitation processes, using ZnSO4·7H2O as a Zn2+ precursor and K2CO3 used as a basic source, and hydrozincite was obtained as an intermediary, which was treated under two procedures; first procedure involved multiple stages to get final precipitated with NaOH, and in the second procedure the hydrozincite was straightforwardly dried at 220 °C. By both processes ZnO structures were obtained, which were turned into nanoparticles by a solvothermal treatment, for four hours in ethylene glycol at 200 °C. The final products for the first procedure was conglomerate of spherical nanoparticles with sizes ranged between 5-10 nm and dispersed ellipsoidal nanoparticles for the second procedure. Apart off the two procedures mentioned above, another synthesis was carried out with the same Zn2+ precursor but now using NaOH, and the solvothermal treatment produced ZnO mixed micro-structures which under ultrasonic cavitation disaggregated on mesoporous ZnO nanoplates of hexagonal shapes with nanopore sizes of approximately 0.35 nm. All ZnOs synthesized were structurally characterized with XRD, TEM and FT-IR techniques, and electronically with UV-Vis absorption and diffuse reflectance spectroscopies.

Impact of photodynamic therapy versus ultrasonic scaler on gingival health during treatment with orthodontic fixed appliances.

OBJECTIVES: Poor oral hygiene during treatment with fixed appliances results in plaque accumulation. The presence of bacteria in the gingival crevice triggers an inflammatory reaction in the gingival tissues. The aim of this study was to compare the impact of two preventive treatments, photodynamic therapy (PDT), and ultrasonic scaler (US), on gingival health in patients under fixed orthodontic treatment. METHODS: Twenty orthodontic patients were randomly allocated to two groups: PDT or US. Each group received seven sessions [days 0, 15, 30, 45, 90 (3-months follow-up), 180 (6-months follow-up), 270 (9-months follow-up)] of experimental interventions, and clinical parameters [Plaque index(PI); gingival index(GI); probing depth(PD)], periodontopathogens [Agreggatibacter actinomycetemcomitans; Porphyromonas gingivalis; Prevotella intermedia; Micromonas micros; Fusobacterium nucleatum; Tannerella forsythia; Campylobacter rectus; Eikenella corrodens; Capnocytopaga sp.] and protein markers [IL-1ß;IL-1ra;IL-6;IL-10;TNF-α;FGF-2/FGF basic] were monitored at baseline and at 3, 6, and 9 months. ANOVA, Student's t-test with Bonferroni correction and ANOVA with multiple rank test were used to identify differences between groups (P < 0.05). RESULTS: Clinical assessments [PI, GI, and PD] yielded no differences (P > 0.05) between groups, which showed a major decrease at the start of the trial. Reductions in total colony forming units (log CFU reduction) were observed with both treatments, although to a greater extent in the PDT group, but with no differences between groups (P > 0.05). Similar reductions in log CFU counts of P. gingivalis, P. intermedia, and F. nucleatum were observed in both groups (P > 0.05). The two groups also showed similar trends for inflammatory mediators with decreased levels of IL-1ß, IL-10, and TNF-α, whereas IL-6 and IL-1ra levels remained stable and those of FGF-2 were increased after both interventions, with no differences (P > 0.05) between groups. CONCLUSION: Both PDT and US methods proved similar effectiveness for the treatment of gingival inflammation induced by fixed orthodontic appliances. Lasers Surg. Med. 51:256-267, 2019. © 2018 Wiley Periodicals, Inc.

Efficacy of photodynamic therapy vs ultrasonic scaler for preventing gingival inflammation and white spot lesions during orthodontic treatment.

INTRODUCTION: The complex designs of fixed orthodontic appliances hinder proper access for cleaning, favouring the development of gingival inflammation and white spot lesions around brackets. The aim of this study was to evaluate the effectiveness to avoid these undesirable effects by using two prophylactic methods: Photodynamic Therapy (PDT) and conventional ultrasonic scaler (US), in patients during fixed orthodontic treatment. MATERIALS AND METHODS: Twenty patients under orthodontic treatment for at least 15 months were randomly divided into two groups: PDT mediated by methylene blue (MB) and US. Both treatments were applied in repeated doses (four times in intervals of 2 weeks in the beginning of the study (T0), with booster doses at 3, 6 and 9 months, T1, T2 and T3, respectively). Periodontal clinical parameters (full-mouth plaque score (FMPS), full-mouth bleeding score (FMBS) and probing depth (PD)) were recorded as well as the International Caries Detection and Assessment System (ICDAS) index. Samples of subgingival plaque and saliva (for determination of 4 periodontopathogens and mutans streptococci, respectively), were collected at T0 and at the follow-ups of T1, T2 and T3. RESULTS: The evolution of FMPS, FMBS, PD, ICDAS scores as well as the counts of periodontopathogens and salivary mutans streptococci was similar after US or PDT implementation. Greatest periodontal scores reduction took place at T1 for FMBS and PD and at T2 for FMPS. Main microbial reduction took place at T1. ICDAS index began to increase from T2. No statistically significant intergroup differences were observed. CONCLUSIONS: Additional treatment of PDT or US in repeated doses delayed undesired side effects during fixed orthodontic treatment in young patients with low caries risk and signs of gingival inflammation.

Magnetic properties of Fe3O4 antidot arrays synthesized by AFIR: atomic layer deposition, focused ion beam and thermal reduction.

Magnetic films of magnetite (Fe3O4) with controlled defects, so-called antidot arrays, were synthesized by a new technique called AFIR. AFIR consists of the deposition of a thin film by atomic layer deposition, the generation of square and hexagonal arrays of holes using focused ion beam milling, and the subsequent thermal reduction of the antidot arrays. Magnetic characterizations were carried out by magneto-optic Kerr effect measurements, showing the enhancement of the coercivity for the antidot arrays. AFIR opens a new route to manufacture ordered antidot arrays of magnetic oxides with variable lattice parameters.

Novel Antimicrobial Titanium Dioxide Nanotubes Obtained through a Combination of Atomic Layer Deposition and Electrospinning Technologies.

The search for new antimicrobial substances has increased in recent years. Antimicrobial nanostructures are one of the most promising alternatives. In this work, titanium dioxide nanotubes were obtained by an atomic layer deposition (ALD) process over electrospun polyvinyl alcohol nanofibers (PVN) at different temperatures with the purpose of obtaining antimicrobial nanostructures with a high specific area. Electrospinning and ALD parameters were studied in order to obtain PVN with smallest diameter and highest deposition rate, respectively. Chamber temperature was a key factor during ALD process and an appropriate titanium dioxide deposition performance was achieved at 200 °C. Subsequently, thermal and morphological analysis by SEM and TEM microscopies revealed hollow nanotubes were obtained after calcination process at 600 °C. This temperature allowed complete polymer removal and influenced the resulting anatase crystallographic structure of titanium dioxide that positively affected their antimicrobial activities. X-ray analysis confirmed the change of titanium dioxide crystallographic structure from amorphous phase of deposited PVN to anatase crystalline structure of nanotubes. These new nanostructures with very large surface areas resulted in interesting antimicrobial properties against Gram-positive and Gram-negative bacteria. Titanium dioxide nanotubes presented the highest activity against Escherichia coli with 5 log cycles reduction at 200 µg/mL concentration.

Clinical and microbiological effects of the use of a cetylpyridinium chloride dentifrice and mouth rinse in orthodontic patients: a 3-month randomized clinical trial.

Objective: To assess the clinical, microbiological, and patient-based effects of using a cetylpyridinium chloride (CPC) toothpaste and mouth rinse in orthodontic patients. Design: Parallel randomized controlled, triple-blinded trial (participants, examiners, outcomes' assessors). A computer-generated list was used to allocate treatments. Central allocation was used for concealment. Participants: Thirty-one placebo (10 males, 21 females; mean age 15.2 ± 2.1) and 32 test patients (15 males, 17 females; mean age 15.0 ± 1.8) with fixed orthodontic appliance were included in the study. Interventions: Patients were randomly assigned to both brush and rinse with placebo or with CPC-based products. Products were purposely prepared in white opaque bottles. After screening and professional prophylaxis, patients received a baseline examination, and started to use the assigned products. Patients were monthly assessed during a 3-month period. Main outcome measures: Plaque (PlI) and gingival (GI) indexes. Secondary outcome variables: Calculus index, tooth staining, subgingival microbiological samples, patient-based variables (questionnaire, compliance, and remaining mouth rinse), side-effects (debonded braces or mucosal injuries). Results: Sixty-three patients were randomized, 13 patients were excluded from analysis because of early dropout, leaving 50 patients for intention to treat analysis. PlI in the upper jaw diminished (0.18; SD = 0.82) after 1 month in the test group, while it increased (0.26; SD = 0.62) in the placebo group (P = 0.024). Statistically significant higher GI values were observed in the placebo group at 1 month (mean increase = 0.05; SD = 0.33 versus mean decrease = 0.03; SD = 0.38) and 3 months (mean = 0.05; SD = 0.43 versus mean = 0.02; SD = 0.34). The taste of the test product was rated higher than the placebo at 2- and 3-month visits (P < 0.05). Non-significant changes were observed in microbiological parameters, overgrowth of opportunistic species or remaining secondary outcome variables, including side-effects. Conclusion: The use of CPC-based toothpaste and mouth rinse in orthodontic patients had limited effect in reducing plaque accumulation and gingival inflammation. Effects were little and highly variable. The use of the test products was not associated with relevant adverse effects. Trial registration: Trial registration: Local internal reference: P07/133.

On-line laser radiation controlled to the removal of adhesive on teeth after bracket debonding.

BACKGROUND AND AIMS: After bracket debonding a correct removal of the adhesive from tooth surfaces without causing any iatrogenic damage to the enamel is needed. However, conventional techniques do not allow a selective removal process. The present article focuses on the removal of adhesive on teeth after bracket debonding by using laser radiation at 355 nm (third harmonic wavelength of a Q-switched Nd:YAG). MATERIAL AND METHODS: Brackets were bonded to 10 extracted human premolars from young patients and removed after a storage period of 2 months. As real-time diagnostic technique, laser-induced breakdown spectroscopy (LIBS) elemental analysis was applied for precisely controlling the removal of the adhesive and morphological analysis of the etched surfaces was carried out by scanning electron microscopy (SEM). RESULTS: LIBS technique allowed an on-line precise control in the adhesive removal process. SEM analysis revealed the capability of the 355 nm UV laser radiation to complete the removal of the adhesive on the tooth with no signs of damage on the enamel. CONCLUSION: Laser ablation process at 355 nm monitored by the LIBS technique allows to carry out efficient removal of the adhesive on teeth.

Impact of delayed gratification on oral health and caries status in the primary dentition.

OBJECTIVE: The ability to delay gratification (ATDG) is naturally linked to key regulatory psychological traits involved in self-discipline/regulation. The aim of this study was to ascertain the normalized impact of ATDG as an early predictor of oral health, on the primary dentition. METHODS: 404 subjects [202 children (4-6 years old) and 202 mothers] were enrolled in a case-control study. Systematic data collection included: i) extraoral diagnostic parameters; ii) intraoral health status; iii) behavioral aspects; iv) baseline socio-demographic data. The ICC, the paired Student's t-test and kappa statistic were used to evaluate intra-observer reliability. Distributions were explored with the chi-squared test [Odds ratio;95%CI;p<0.05]. Conditional logistic regression was used to evaluate associations between all clinical diagnostic data and ATDG. RESULTS: Overweight/obese children and those diagnosed with ADHD are more prone to lack ATDG (p<0.001). Higher deft values were observed in children who lacked ATDG, who were also strongly associated with higher sugar consumption and more impulsive personalities (p<0.001;OR:.107/0.031;95%CI:036-0.316/0.008-0.115). By contrast, children with responsible personality traits were associated with this skill (p<0.028;OR:3.33;95%CI:1.1-9.7) and obtained the lowest deft (p<0.306;OR:0.539;95%CI:0.165-0.176) and gingival index values (p<0.001;OR:10.44;95%CI:2.6-40.9), which are clear indicators of better current and future oral health. CONCLUSIONS: These data provide insights into a novel predictor for identifying individuals at a higher risk of dental caries in early childhood. CLINICAL SIGNIFICANCE: The present study offers a new hypothesis for identifying individuals with poor oral health status. Early tools to detect the most vulnerable population sectors are critically important to reduce the global burden of caries and other oral diseases.

Improvement of Polylactide Properties through Cellulose Nanocrystals Embedded in Poly(Vinyl Alcohol) Electrospun Nanofibers.

Electrospun nanofibers of poly (vinyl alcohol) (PV) were obtained to improve dispersion of cellulose nanocrystals (CNC) within hydrophobic biopolymeric matrices, such as poly(lactic acid) (PLA). Electrospun nanofibers (PV/CNC)n were successfully obtained with a final concentration of 23% (w/w) of CNC. Morphological, structural and thermal properties of developed CNC and electrospun nanofibers were characterized. X-ray diffraction and thermal analysis revealed that the crystallinity of PV was reduced by the electrospinning process, and the incorporation of CNC increased the thermal stability of biodegradable nanofibers. Interactions between CNC and PV polymer also enhanced the thermal stability of CNC and improved the dispersion of CNC within the PLA matrix. PLA materials with CNC lyophilized were also casted in order to compare the properties with materials based on CNC containing nanofibers. Nanofibers and CNC were incorporated into PLA at three concentrations: 0.5%, 1% and 3% (CNC respect to polymer weight) and nanocomposites were fully characterized. Overall, nanofibers containing CNC positively modified the physical properties of PLA materials, such as the crystallinity degree of PLA which was greatly enhanced. Specifically, materials with 1% nanofiber 1PLA(PV/CNC)n presented highest improvements related to mechanical and barrier properties; elongation at break was enhanced almost four times and the permeation of oxygen was reduced by approximately 30%.

Electromyographic activity of the jaw muscles and mandibular kinematics in young adults with theoretically ideal dental occlusion: Reference values

BACKGROUND: A necessary step to use neuromuscular analysis as diagnostic tool is to establish normal reference values for the physiological range in a healthy population. Surface electromyographic (sEMG) activity of the jaw muscles and mandibular kinematics were measured in young adults with theoretically ideal dental occlusion to determine normal reference values during different tasks. Differences between the sexes were evaluated. MATERIAL AND METHODS: Forty young adults (20 men, 20 women; mean age 22.8 ± 3.9 years) with theoretically ideal dental occlusion were selected using very restrictive criteria. sEMG activity of the anterior temporalis (AT), posterior temporalis, masseter (MA), and suprahyoid muscles were evaluated in the rest position and during swallowing, mastication, and clenching. Mandibular kinematics in the rest position and during maximum excursions were assessed. Asymmetry, activity, and torque indices and MA/AT ratios were calculated. RESULTS: For all muscles, sEMG values were 1.01-3.57 miV at rest, 3.50-10.85 miV during swallowing, and 41.04- 86.59 miV during mastication. During clenching, values were 230.08-243.55 miV for the AT and MA muscles. Mean total asymmetry, activity, and torque indices at rest were 20.34 %, -15.04 %, and 19.02 %, respectively; during clenching, these values were 6.14 %, -2.62 %, and 4.46 %. MA/AT ratios were near 1. Kinematic measurements during lateral excursion, protrusive and maximum opening were 7.54, 8.44, and 37.38 mm respectively; lateral mandibular shift was 1.41 mm; freeway and lateral displacement at rest were 1.40 and 0.26 mm. Right MA activity during mastication and clenching was higher in men than women. CONCLUSIONS: Reference values for sEMG activity and mandibular kinematics were determined. Some muscular asymmetry and torque were observed