Association between Anatomical Variations and maxillary canine impaction: A retrospective study in orthodontics

This study aims to evaluate whether or not there is a higher prevalence of skeletal abnormalities in subjects with maxillary canine impaction (MCI). This retrospective study was performed on 67 subjects with maxillary canine impaction (test group) and on 67 patients without dental displacement (control group). Sella turcica bridging (SB), ponticulus posticus (PP), atlas posterior arch deficiency (APAD) and the morphology of sella turcica and pterygopalatine fissure were evaluated on lateral cephalometric radiographs. Statistical analysis was performed using chi-square, Mann-Whitney test and multivariate logistic models; the level of significance was p < 0.05. Results showed that in the test and control groups 87% and 62.7% of patients had SB, respectively. PP was observed in 60% of patients in the test group and in 16.4% of patients in the control group. APAD was observed in 9% of test group and in 4.5% of the control group. Skeletal anomalies were significantly increased (p < 0.05) in subjects with MCI. A significant difference between the groups was observed in regards to the shape of the pterygopalatine fissure, found to be less wide and longer in the test group. SB, PP and APAD were higher in subjects with MCI; furthermore, an elongated pterygopalatine fissure was significantly associated with MCI

Weak proactive cognitive/motor brain control accounts for poor children's behavioral performance in speeded discrimination tasks

Background: Motor and inhibitory control rely on frontal cortex activity, which is known to reach full maturation only in late adolescence. The development of inhibitory control has been studied using event-related potentials (ERP), focusing on reactive processing (i.e. the N2 and the P3 components). Scarce information exists concerning pre-stimulus activity as that represented by the Bereinshafstpotential (BP) and by the prefrontal negativity (pN). Further, no literature exists concerning the post-stimulus components originating within the anterior insula (pN1, pP1, pP2). This study aims at associating children performance with these motor-cognitive processing in frontal brain areas. Methods: High-resolution EEG recordings were employed to measure ERPs from 18 children (12 years old) and 18 adults (28 years old) during a visuo-motor discriminative response task. Response time (RT), commission (CE) and omission errors, and RT variability were compared between groups. At brain level, two pre-stimulus (BP and pN) and seven post-stimulus (P1; pN1; N1; pP1; N2; pP2; P3) ERP components were compared between groups. Results: Children showed slower and more variable RTs and poorer inhibition (higher CEs) than adults. At electrophysiological level, children presented smaller BP and pN. After stimulus onset, children showed lower amplitude of N1, pP1, P3, and pP2 components. The P1, pP1, N2 and P3 were delayed compared to adults. Conclusions: Our results demonstrate that children are characterized by less intense task-related proactive activities in frontal cortex, which may account for subsequent poor and delayed reactive processing and, thus, for inaccurate and slow performance

Oral and craniofacial manifestations of Ellis-Van Creveld syndrome: A systematic review

Aim A systematic literature review on oral and craniofacial manifestations of Ellis-Van Creveld syndrome was performed. Methods From 2 databases were selected 74 articles using as key words "Ellis-Van Creveld" AND "Oral" OR "Craniofacial" OR "Dental" OR "Malocclusion". Prisma protocol was used to create an eligible list for the screening. Data were collected in a table to compare the clinical aspects found. Results From the first research emerged 350 articles, and only 72 of them were selected. Conclusion Through this analysis oral and cranio-facial manifestations of Ellis-Van Creveld syndrome were pointed out. Management of Ellis-Van Creveld syndrome requires a multidisciplinary approach involving different clinicians; dentists play an important role in early diagnosis and treatment of the patients

Hybrid Genetic Bees Algorithm applied to Single Machine Scheduling with Earliness and Tardiness Penalties

This paper presents a hybrid Genetic-Bees Algorithm based optimised solution for the single machine scheduling problem. The enhancement of the Bees Algorithm (BA) is conducted using the Genetic Algorithm's (GA's) operators during the global search stage. The proposed enhancement aims to increase the global search capability of the BA gradually with new additions. Although the BA has very successful implementations on various type of optimisation problems, it has found that the algorithm suffers from weak global search ability which increases the computational complexities on NP-hard type optimisation problems e.g. combinatorial/permutational type optimisation problems. This weakness occurs due to using a simple global random search operation during the search process. To reinforce the global search process in the BA, the proposed enhancement is utilised to increase exploration capability by expanding the number of fittest solutions through the genetical variations of promising solutions. The hybridisation process is realised by including two strategies into the basic BA, named as â\u80\u9creinforced global searchâ\u80\u9d and â\u80\u9cjumping functionâ\u80\u9d strategies. The reinforced global search strategy is the first stage of the hybridisation process and contains the mutation operator of the GA. The second strategy, jumping function strategy, consists of four GA operators as single point crossover, multipoint crossover, mutation and randomisation. To demonstrate the strength of the proposed solution, several experiments were carried out on 280 well-known single machine benchmark instances, and the results are presented by comparing to other well-known heuristic algorithms. According to the experiments, the proposed enhancements provides better capability to basic BA to jump from local minima, and GBA performed better compared to BA in terms of convergence and the quality of results. The convergence time reduced about 60% with about 30% better results for highly constrained jobs

Predicting Gas Solubility in Glassy Polymers through Nonequilibrium EOS

The non-equilibrium thermodynamic approach to describing properties of glassy polymers, earlier applied in the so-called NELF model using Lattice Fluid Theory, is generalized to the use of arbitrary equations of state. Application to Statistical Associating Fluid Theory (SAFT) is discussed in detail and use of this approach to predict opr correlate gas solubility in glassy polymers is presented for the case of low-pressure sorption. Prediction procedures rely on volumetric data for the pure polymer and gaseous species, while for data correlation a temperature independent binary interaction coefficient is used as an adjustable parameter. Results from model calculations are compared with literature data for gas solubility in polycarbonate and polysulfone. Analysis of solubility coefficient variations above and below the glass transition temperature indicates thet the non-equilibrium approach is the proper procedure to extend an EoS description of thermodynamic properties to the glassy state

Effects on sorption and diffusion in PTMSP and TMSP/TMSE copolymers of free volume changes due to polymer ageing

Solubility isotherms for n-pentane and n-hexane were measured in pure poly[1-(trimethylsilyl)-1-propyne] (PTMSP) and in 1-trimethylsilyl-1-propyne/1-trimethylsilyl-1-n-hexyne 70/30 copolymer, using freshly prepared samples as well as aged films, at different temperatures. The experimental values of penetrant diffusivity, mobility and heat of mixing have been reported and discussed, based on direct positron annihilation lifetime spectroscopy information, Dual Mode Sorption Model and Non-Equilibrium Lattice Fluid model. The ageing effect is more pronounced in PTMSP, where it leads to a significant solubility and diffusivity reduction, than in the copolymer where the effect is less important. In the activity range inspected the diffusion coefficient and the heat of mixing are almost concentration independent for PTMSP, while they increase appreciably with concentration in the copolymer, as an effect of the great difference in the free volume present in the two matrices

Chlorhexidine gel used as antiseptic in periodontal pockets

The aim of this study was to evaluate the adjunctive benefit offers by the administration of a chlorhexidine based local drug deliver (Chlo-SITE) into periodontal socket after a full mouth disinfection session. The study design was a randomized, crossover, clinical trial conducted on 60 non-smokers subjects with chronic periodontitis. Each volunteer was subjected to a one-stage full mouth disinfection session and, immediately after that, test product (Chlo-SITE) was inserted in 1 pocket in 2 quadrant. The 1° and 4° quadrant were used for the study with the application of antiseptic (Test); the 2° and 3° as a control. Periodontal probe (PD), bleeding on probing (BOP) and plaque index (PI) was collected at baseline (T0), after 7 days (T1), after 4 weeks (T2). The results of this study suggest that the application of xanthan-based chlorhexidine gel (Xan-CHX) offers a great benefit in improving of the indices in chronic periodontitis

Paediatric orthodontics Part 4: SEC III protocol in class III malocclusion

SEC III protocol: Early treatment of dentoskeletal Class III malocclusions The early treatment of dentoskeletal Class III malocclusion is one of the more challenging situations for orthodontists, mainly for the uncertainty of stable long-term results due to the interaction of both environmental and genetic aetiological factors. Several interceptive protocols have been proposed during the past decades. The SEC III protocol includes two occlusal acrylic Splints combined with Class III elastics and chin cup. The protocol was proposed to facilitate Class III dentoskeletal correction by eliminating the intercuspation and the tongue thrust with clockwise mandibular rotation and minimal dentoalveolar compensation. The main difference with all the other appliances is the vertical control, which is crucial in difficult cases such as hyperdivergent Class III malocclusions