Time-frequency analysis of rhythmic masticatory muscle activity

The aim of this study was to develop and validate under laboratory conditions an algorithm for a time-frequency analysis of rhythmic masticatory muscle activity (RMMA). The algorithm baseband demodulated the electromyographic (EMG) signal to provide a frequency versus time representation. Using appropriate thresholds for frequency and power parameters, it was possible to automatically assess the features of RMMA without examiner interaction. The algorithm was first tested using synthetic EMG signals and then using real EMG signals obtained from the masticatory muscles of 11 human subjects who underwent well-defined rhythmic, static, and possible confounding oral tasks. The accuracy of detection was quantified by receiver operating characteristics (ROC) curves. Sensitivity and specificity values were >/=90% and >/=96%, respectively. The areas under the ROC curves were >/=95% (standard error +/-0.1%). The proposed approach represents a promising tool to effectively investigate rhythmical contractions of the masticatory muscles. Muscle Nerve, 2009

Incidence of temporomandibular joint clicking in adolescents with and without unilateral posterior cross-bite: a 10-year follow-up study

Among different malocclusions, posterior cross-bite is thought to have a strong impact on the correct functioning of the masticatory system. The association between unilateral posterior cross-bite (UPCB) and temporomandibular joint (TMJ) clicking, however, remains still controversial. The aim of this study was to investigate whether the presence of UCPB during early adolescence increases the risk of reporting TMJ clicking after a long-term follow-up. A longitudinal survey design was carried out in a group of 12-year-old young adolescents, who were examined at baseline for TMJ clicking sounds and unilateral posterior cross-bite. After 10 years, 519 subjects could be reached by a telephone survey. Standardised questions were used to collect self-reported TMJ sounds and to determine whether participants had received an orthodontic treatment. Logistic regression analysis revealed a significant association between unilateral posterior cross-bite and subjectively reported TMJ clicking (odds ratio = 6·0; 95% confidence limits = 3·4-10·8; P < 0·0001). The incidence of TMJ clicking was 12%. At a ten-year follow-up, self-reports of TMJ clicking were significantly associated with the presence of UPCB at baseline, but not with the report of having received an orthodontic treatment. Within the limitation of this study, the presence of unilateral posterior cross-bite in young adolescents may increase the risk of reporting TMJ sounds at a 10-year follow-up. The provision of an orthodontic treatment, however, does not appear to reduce the risk of reporting TMJ sounds

Knowledge and valorization of historical sites through 3D documentation and modeling

The paper presents the first results of an interdisciplinary project related to the 3D documentation, dissemination, valorization and digital access of archeological sites. Beside the mere 3D documentation aim, the project has two goals: (i) to easily explore and share via web references and results of the interdisciplinary work, including the interpretative process and the final reconstruction of the remains; (ii) to promote and valorize archaeological areas using reality-based 3D data and Virtual Reality devices. This method has been verified on the ruins of the archeological site of Pausilypon, a maritime villa of Roman period (Naples, Italy). Using Unity3D, the virtual tour of the heritage site was integrated and enriched with the surveyed 3D data, text documents, CAAD reconstruction hypotheses, drawings, photos, etc. In this way, starting from the actual appearance of the ruins (panoramic images), passing through the 3D digital surveying models and several other historical information, the user is able to access virtual contents and reconstructed scenarios, all in a single virtual, interactive and immersive environment. These contents and scenarios allow to derive documentation and geometrical information, understand the site, perform analyses, see interpretative processes, communicate historical information and valorize the heritage location

Effect of weather on temporal pain patterns in patients with temporomandibular disorders and migraine

Patients with masticatory muscle pain and migraine typically report that the intensity of pain fluctuates over time and is affected by weather changes. Weather variables, such as ambient temperature and humidity, may vary significantly depending on whether the individual is outdoor or indoor. It is, therefore, important to assess these variables at the individual level using portable monitors, during everyday life. This study aimed to determine and compare the temporal patterns of pain in individuals affected with facial and head pain and to investigate its relation with weather changes. Eleven patients (27·3 ± 7·4 years) with chronic masticatory muscle pain (MP) and twenty (33·1 ± 8·7 years) with migraine headache (MH) were asked to report their current pain level on a visual analogue scale (VAS) every hour over fourteen consecutive days. The VAS scores were collected using portable data-loggers, which were also used to record temperature, atmospheric pressure and relative humidity. VAS scores varied markedly over time in both groups. Pain VAS scores fluctuate less in the MP group than in the MH group, but their mean, minimum and maximum values were higher than those of migraine patients (all P < 0·05). Pain scores <2 cm were more common in the MH than in the MP group (P < 0·001). Perceived intensity of pain was negatively associated with atmospheric pressure in the MP group and positively associated with temperature and atmospheric in the MH group. Our results reveal that patients with masticatory muscle pain and patients with migraine present typical temporal pain patterns that are influenced in a different way by weather changes

Web-based randomised controlled trials in orthodontics

Randomised controlled trials (RCT) are considered the best source of scientific evidence--the gold standard--when evaluating the efficacy of orthodontic treatments. Frequently, RCT are planned as multicentre trials, with the intention of increasing statistical power and raising the precision of outcome estimates. The management of large-scale RCT, however, requires even more thorough organisation than conventional RCT. Indeed, the need for high accuracy and standardisation in data collection, research aids, secretarial skills, staff and patient training, and organisational meetings, make these studies time-consuming, expensive and, in general, relatively complex to carry out well. A website was developed to support a large scale-orthodontic RCT which aimed to evaluate the efficacy of a functional appliance(www.ortodonzia.unina.it). Websites such as this can increase the quality of data collection, simplify the randomisation process, speed up data collection, and improve trial monitoring. Web-based RCT have the potential to help globalise orthodontic research and also increase our rate of acquisition of evidence in orthodontics

The difficult alliance between vegan parents and pediatrician: A case report

The number of children on a vegetarian or vegan diet is gradually increasing. If not balanced and adequately supplemented, these dietary regimes can seriously impact the growth of children. Often the pediatrician is not perceived as a figure to rely on in the event of parents’ willingness to follow an alternative diet for their child. The feeling of distrust of parents towards the pediatrician can be dangerous for the health of the child. We present a 22-month-old boy with failure to thrive probably induced by an unbalanced vegetarian diet. The acquisition of the anamnestic data concerning the child’s diet was difficult because initially omitted by the parents. The poor compliance and the difficult follow-up highlights the difficulty in establishing a therapeutic alliance between parents who follow alternative regimens and the pediatrician

Predictability of lower incisor tip using clear aligner therapy

Background: Uprighting incisors is particularly important with clear aligner therapy as incisor tip determines the mesio-distal space needed in the arch, and consequently the fit of the aligner. The objective of this study was to investigate the accuracy of ClinCheck (R) software to predict lower incisor tip by comparing digitally prescribed movements with actual clinical outcomes and to determine whether the presence of a vertically orientated rectangular composite attachment influences the efficacy of incisor tip.Methodology: This retrospective study included 66 lower incisors from 42 non-extraction adult patients treated using the Invisalign (R) appliance. Twenty-one incisors had vertical attachments, while 45 incisors did not have any attachments. Lower incisor tip was measured at T0 (pre-treatment),T1 (predicted post-treatment) and T2 (achieved post-treatment) on digital models using metrology software. The change in position from T0 to T1 and T0 to T2 was measured from the estimated centre of resistance (C-Res) of each tooth. The estimated centre of rotation was plotted relative to the C(Res )to describe the type of orthodontic tooth movement (OTM) predicted and achieved.Results: Predicted incisor tip and achieved incisor tip were positively correlated (R-2 = 0.55; p &lt; 0.001). For every degree of tip planned 0.4 degrees of tip was achieved. The presence of an attachment resulted in 1.2 degrees greater tip (F=3.7; p= 0.062) and 0.5 mm greater movement of the predicted apex of the tooth (F=4.3; p= 0.042) compared with the no attachment group. The type of OTM achieved differed from the type predicted. Sixty-seven percent of incisors investigated were predicted to move by root movement, while 46% achieved this type of movement.Conclusions: The amount of lower incisor tip achieved was on average substantially less than the ClinCheck (R) displayed. Vertically orientated rectangular attachments are recommended where large root movement is planned, and their presence slightly improves apex movement

Immersive Virtual Reality for Cultural Heritage Exploration

Virtual Reality can provide an immersive experience that allows cultural heritage to be experienced in a more realistic and immersive way than traditional showcasing techniques. The objective of this paper is to provide a software pipeline that can be adopted for the realization of immersive experiences in cultural heritage sites. This work has been realized within the 3DLab-Sicilia project, which includes the realization of immersive virtual tours of UNESCO World Heritage sites located in the Sicily area (Italy)

Effect of orthodontic appliances on masticatory muscle activity

There is limited and conflicting evidence regarding the impact of orthodontic appliances on masticatory muscle activity (MMA), jaw function, and oral parafunctional behaviours. Investigations in this field frequently utilise surface electromyography (sEMG) to analyse changes in muscle contractile activity. Fixed orthodontics appliances have been associated with significant reductions in MMA post archwire activation. Conversely, elevations in masseter and digastric muscle activity have been reported in response to removable functional appliances. Research into the effect of clear aligner therapy (CAT) on MMA is still in its infancy with few studies published. There is a lack of agreement on whether MMA increases or diminishes in response to CAT though there is evidence this relationship may change over time due to muscle adaptation. The impact of CAT on temporomandibular disorder (TMD) symptoms is unclear, particularly how pre-existing risk factors for TMD may alter and individual's response