A comparative study on the formation of nitrogen-containing organic compounds in cloud droplets and aerosol particles.

Nitrogen-containing organic compounds (NOCs) may potentially contribute to aqueous secondary organic aerosols, yet the different formation of NOCs in aerosol particles and cloud droplets remains unclear. With the in-situ measurements performed at a mountain site (1690 m a.s.l.) in southern China, we investigated the formation of NOCs in the cloud droplets and the cloud-free particles, based on their mixing state information of NOCs-containing particles by single particle mass spectrometry. The relative abundance of NOCs in the cloud-free particles was significantly higher than those in cloud residual (cloud RES) particles. NOCs were highly correlated with carbonyl compounds (including glyoxalate and methylglyoxal) in the cloud-free particles, however, limited correlation was observed for cloud RES particles. Analysis of their mixing state and temporal variations highlights that NOCs was mainly formed from the carbonyl compounds and ammonium in the cloud-free particles, rather than in the cloud RES particles. The results support that the formation of NOCs from carbonyl compounds is facilitated in concentrated solutions in wet aerosols, rather than cloud droplets. In addition, we have identified the transport of biomass burning particles that facilitate the formation of NOCs, and that the observed NOCs is most likely contributed to the light absorption. These findings have implications for the evaluation of NOCs formation and their contribution to light absorption.

Analytical Methods for Comparing Uncontrolled Trials with External Controls from Real-World Data: a Systematic Literature Review and Comparison to European Regulatory and Health Technology Assessment Practice.

OBJECTIVES: To provide an overview of analytical methods in scientific literature for comparing uncontrolled medicine trials to external controls from individual patient-level real-world data (IPD-RWD). In addition, to compare these methods with recommendations made in guidelines from European regulatory and health technology assessment (HTA) organizations and with their evaluations described in assessment reports. METHODS: A systematic literature review (until March 1st 2023) in PubMed and Connected Papers was performed to identify analytical methods for comparing uncontrolled trials with external controls from IPD-RWD. These methods were compared descriptively to methods recommended in method guidelines and encountered in assessment reports of the European Medicines Agency (2015-2020) and four European HTA organizations (2015-2023). RESULTS: Thirty-four identified scientific articles described analytical methods for comparing uncontrolled trial data to IPD-RWD-based external controls. The various methods covered controlling for confounding and/or dependent censoring, correction for missing data; and analytical comparative modelling methods. Seven guidelines also focused on research design, RWD quality and transparency aspects, and four of those recommended analytical methods for comparisons with IPD-RWD. The methods discussed in regulatory (n=15) and HTA (n=35) assessment reports were often based on aggregate data and lacked transparency due to the few details provided. CONCLUSION: Literature and guidelines suggest a methodological approach to comparing uncontrolled trials with external controls from IPD-RWD similar to target trial emulation, using state-of-the-art methods. External controls supporting regulatory and HTA decision-making were rarely in line with this approach. Twelve recommendations are proposed to improve the quality and acceptability of these methods.

Individual and group emotional intelligence measurement of sex differences and invariance for individual (WLEIS-S) and group (WEIP-S) emotional intelligence measurement scales.

Different international research groups focus on the study of socio-emotional resources and tools to facilitate adequate management of daily challenges and demands among teachers. This allows for better personal and professional performance. One of these resources that has attracted most attention in recent decades has been that of emotional intelligence. In this regard, the present study set out to analyse the psychometric properties of trait emotional intelligence as a construct. For this purpose, the study focused on two EI measurement instruments. One of the instruments (WLEIS-S) measures individual emotional intelligence and the other instrument (WEIP-S) measures group emotional intelligence. Against this background, the possible invariance of both scales with respect to the sex variable is analysed, as well as possible differences in the variables measured by the scales between sexes. To this end, 452 primary education teachers from Southern Spain filled in the WLEIS-S and WEIP-S tests. The results found in the factor analyses carried out with both instruments showed an excellent fit, as well as good internal consistency. Moreover, both instruments showed robust invariance, which indicates that both scales measure the emotional intelligence construct consistently for both women and men. No differences were found in the assessed latent variables between sexes. To conclude, this study shows psychometric evidence supporting the suitability of the WLEIS-S and WEIP-S scales for the accurate assessment of individual and group emotional intelligence in women and men in the teacher population.

Catalysing Environmental Action: a Governance Framework for Enhancing Individual Participation in Sub-Saharan Africa's Plastic Circular Economy.

Plastic waste poses a significant challenge to achieving sustainable production and consumption of resources, particularly in sub-Saharan Africa where effective governance and waste management systems are lacking. In this paper, we develop an empirical understanding of the influence of public governance system on promoting circular economy (CE) for plastic actions among individuals. Through a survey of 1475 participants across five sub-Saharan African countries, we tested five hypotheses drawing on New Governance Theory and CE Action Recipe to explore the relationship between governance and individual's actions supporting CE for plastic. We found that a governance system that supports CE practices and exhibits governance efficiency is positively associated with individuals' actions supporting CE for plastic. The awareness of government policies, laws and regulations, institutions, processes, and programmes have a significant impact on individuals' engagement in plastic circularity practices. The paper's theoretical and governance implications highlight the relevance of public governance in shaping action towards a CE for plastic at the individual level.

Familiarity and social relationships in degus (Octodon degus).

Degus (Octodon degus) are a highly gregarious species of caviomorph rodent native to South America. Kinship does not appear to play a role in degu social structure, and alloparenting is often observed between unrelated females. We hypothesize that female degus readily establish new, cooperative peer relationships. Here we examined changes in dyadic behavior as individuals became more familiar, testing the prediction that interactions between female strangers would quickly resemble those of cagemates. Adult degus underwent a several week series of 20 minute "reunion" social exposures, interleaving reunions with initial strangers and, as a control, familiar cagemates. Males showed initially higher levels of interaction with strangers that converged with cagemate levels over experience. Females could be split into two groups: those that consistently interacted more with strangers (SC-HIGH) and those that did not (SC-LOW); however, unlike males, the higher interaction levels observed between strangers did not change with familiarity. Following 10 reunion sessions female strangers were housed together to create "new cagemates". Even after co-housing, SC-HIGH (but not SC-LOW) females continued to interact more with the relatively unfamiliar peer than their prior cagemate, particularly in face-to-face and rear-sniffing interactions. A final set of reunions with new strangers found that individual differences in female responses to social novelty were preserved. These results reveal sex differences in the rules relating familiarization to social relationships in degus, and that female predispositions toward cooperation may be due to inherent responses to new individuals more than to how they negotiate relationships over time.

Parents' and healthcare professionals' experiences with the content of an individual care plan for pediatric palliative care: a mixed-method study.

Background: The Individual Care Plan (ICP) for pediatric palliative care translates the general guideline recommendations into a personalized plan for the child. Various documents exist in pediatrics globally, aimed at facilitating anticipatory care or coordinating end-of-life care. The ICP aims both, but user experiences have not been studied post-development. Objective: The overall aim is to enhance knowledge and understanding of the content of the ICP from the perspectives of parents and healthcare professionals (HCPs). Design and method: We conducted a mixed-method study using a convergent parallel design consisting of questionnaires and individual and focus group interviews among parents and HCPs having user experience with the ICP. The questionnaire and interview data were analyzed separately. Quantitative data were descriptively analyzed using mean, ±SD, and median. Qualitative data were thematically analyzed. A narrative approach and joint display were used to describe the results. Results: In total, 27 parents and 161 HCPs participated. Overall, the content of the ICP was seen as important and complete, but changes and additions were called for on language, structure, and content. The chapter on the needs and wishes of child and parents was considered most important. HCPs would like to see this chapter expanded to incorporate more advance care planning outcomes, and parents wished for this chapter to reflect better who their child is. HCPs mentioned missing a chapter for palliative sedation, mainly to guide other HCPs. The ICP was appraised as not user-friendly and might possibly improve by making the ICP available in a secure digital environment. Conclusion: To meet the needs of parents and HCPs considering importance and completeness of the content of the ICP and its user-friendliness, changes are necessary in the content of the ICP, and preferably the ICP should be made digitally available. Although various documents exist globally to facilitate anticipatory care or coordinating end-of-life care, it appears that the combination of describing the values and preferences of the child and parents, along with medical decisions and life-sustaining treatments, makes the ICP a unique and comprehensive care plan.

Understanding the shift to compulsion in addiction: insights from personality traits, social factors, and neurobiology.

Compulsion stands as a central symptom of drug addiction; however, only a small fraction of individuals who use drugs exhibit compulsive characteristics. Differences observed in Sign-trackers (ST) and Goal-trackers (GT) during Pavlovian conditioning may shed light on individual variances in drug addiction. Here, we focus on the behavioral attributes, formation processes, and neural mechanisms underlying ST and how they drive addiction toward compulsivity in humans. We will explore addiction from three interconnected levels: individual personality traits, social factors, and neurobiology. Furthermore, we distinguish between the processes of sensitization and habituation within ST. These nuanced distinctions across various aspects of addiction will contribute to our understanding of the addiction development process and the formulation of targeted preventive strategies.

Under the influence: exogenous testosterone influences men's cross-sex perceptions of sexual interest.

The sexual misperception bias is a cognitive bias in which men tend to overestimate sexual interest from women, potentially shaped by evolutionary mating strategies. Testosterone, often linked to mating behaviors, might play a role in sustaining sexual overperceptions. To explore this possibility, we conducted a placebo-controlled study with 190 heterosexual men, administering either 11 mg of testosterone or a placebo. Participants interacted with an attractive female confederate, while naïve raters assessed the confederate's affiliative behaviors. Our findings suggest that exogenous testosterone did not broadly impact sexual overperception. However, we found that affiliative behavior from the confederate was positively correlated with perceived sexual interest among testosterone-treated, but not placebo-treated men. In addition, we found that this effect among testosterone-treated men was contingent on their self-perceived attractiveness. Specifically, the confederate's affiliative behaviors were positively correlated with perceived sexual interest, but only for testosterone-treated men with average or above average self-perceived attractiveness. Furthermore, our data revealed that men's tendency to project their own short-term and long-term mating interests increases as a function of self-perceived attractiveness, and this coupling is enhanced by testosterone for long-term interest. Taken together, these results suggest that testosterone may potentiate existing biases, particularly when sexual motivation is high, and bias perceptions of friendly behavior when engaging in cross-sex mindreading. This study adds to the understanding of the neuroendocrine bases of social cognition, suggesting that testosterone can affect men's perceptions of potential mates.

Sport Participation Trajectories and Loneliness: Evidence From the Longitudinal Study of Australian Children.

BACKGROUND: This study aimed to identify patterns of overall, team, and individual sport participation and examine the prospective associations between these patterns and loneliness in young people. METHODS: We analyzed data from 4241 young people, from waves 3 (8-9 y) to 9 (20-21 y) of the Longitudinal Study of Australian Children. We conducted latent class analyses to identify overall and team versus individual sport participation trajectories and used adjusted log-Poisson regression models to examine the associations between these trajectories and loneliness at wave 9. RESULTS: Latent class analyses identified 4 distinct overall sport participation classes which were labeled: nonparticipants (24%), dropouts (42%), initiators (7%), and consistent participants (27%). Compared with nonparticipants, consistent participants had a lower risk of loneliness (risk ratios = 0.69; 95% CIs, 0.59-0.81). Latent class analyses also identified 4 distinct team versus individual sport participation classes: team and individual sport nonparticipants (38%), individual sport participants (14%), moderate team sport participants (14%), and high team sport participants (34%). Compared with the team and individual sport nonparticipants, the high team sports participants had a lower risk of loneliness (risk ratios = 0.70; 95% CIs, 0.53-0.92). CONCLUSIONS: Young people who continued participating in sport in general, and particularly in team sport, had a reduced risk of loneliness. Continued participation in sports should be promoted to improve a range of physical, mental, and social health benefits. Furthermore, team-based sport can provide additional health and well-being benefits, including reduced loneliness due to the group nature of participation.

Speech-evoked cortical activities and speech recognition in adult cochlear implant listeners: a review of functional near-infrared spectroscopy studies.

Cochlear implants (CIs) are the most successful neural prostheses, enabling individuals with severe to profound hearing loss to access sounds and understand speech. While CI has demonstrated success, speech perception outcomes vary largely among CI listeners, with significantly reduced performance in noise. This review paper summarizes prior findings on speech-evoked cortical activities in adult CI listeners using functional near-infrared spectroscopy (fNIRS) to understand (a) speech-evoked cortical processing in CI listeners compared to normal-hearing (NH) individuals, (b) the relationship between these activities and behavioral speech recognition scores, (c) the extent to which current fNIRS-measured speech-evoked cortical activities in CI listeners account for their differences in speech perception, and (d) challenges in using fNIRS for CI research. Compared to NH listeners, CI listeners had diminished speech-evoked activation in the middle temporal gyrus (MTG) and in the superior temporal gyrus (STG), except one study reporting an opposite pattern for STG. NH listeners exhibited higher inferior frontal gyrus (IFG) activity when listening to CI-simulated speech compared to natural speech. Among CI listeners, higher speech recognition scores correlated with lower speech-evoked activation in the STG, higher activation in the left IFG and left fusiform gyrus, with mixed findings in the MTG. fNIRS shows promise for enhancing our understanding of cortical processing of speech in CI listeners, though findings are mixed. Challenges include test-retest reliability, managing noise, replicating natural conditions, optimizing montage design, and standardizing methods to establish a strong predictive relationship between fNIRS-based cortical activities and speech perception in CI listeners.

Should workers be physically active after work? Associations of leisure-time physical activity with cardiovascular and all-cause mortality across occupational physical activity levels-An individual participant data meta-analysis.

BACKGROUND: There is insufficient evidence to provide recommendations for leisure-time physical activity among workers across various occupational physical activity levels. This study aimed to assess the association of leisure-time physical activity with cardiovascular and all-cause mortality across occupational physical activity levels. METHODS: This study utilized individual participant data from 21 cohort studies, comprising both published and unpublished data. Eligibility criteria included individual-level data on leisure-time and occupational physical activity (categorized as sedentary, low, moderate, and high) along with data on all-cause and/or cardiovascular mortality. A 2-stage individual participant data meta-analysis was conducted, with separate analysis of each study using Cox proportional hazards models (Stage 1). These results were combined using random-effects models (Stage 2). RESULTS: Higher leisure-time physical activity levels were associated with lower all-cause and cardiovascular mortality risk across most occupational physical activity levels, for both males and females. Among males with sedentary work, high compared to sedentary leisure-time physical activity was associated with lower all-cause (hazard ratios (HR) = 0.77, 95% Confidence interval(95%CI): 0.70-0.85) and cardiovascular mortality (HR = 0.76, 95%CI: 0.66-0.87) risk. Among males with high levels of occupational physical activity, high compared to sedentary leisure-time physical activity was associated with lower all-cause (HR = 0.84, 95%CI: 0.74-0.97) and cardiovascular mortality (HR = 0.79, 95%CI: 0.60-1.04) risk, while HRs for low and moderate levels of leisure-time physical activity ranged between 0.87 and 0.97 and were not statistically significant. Among females, most effects were similar but more imprecise, especially in the higher occupational physical activity levels. CONCLUSION: Higher levels of leisure-time physical activity were generally associated with lower mortality risks. However, results for workers with moderate and high occupational physical activity levels, especially women, were more imprecise. Our findings suggests that workers may benefit from engaging in high levels of leisure-time physical activity, irrespective of their level of occupational physical activity.

Prognostic factors in post-prostatectomy salvage radiotherapy setting with and without hormonotherapy: An individual patient data analysis of randomized trials from ICECaP database.

BACKGROUND: Early salvage radiotherapy (SRT) is the standard of care for biochemical recurrence post-prostatectomy but outcomes are heterogeneous. OBJECTIVE: To develop a risk scoring system based on relevant standard-of-care clinico-pathological prognostic factors for patients treated with SRT with and without hormonal therapy (HT). DESIGN, SETTING, AND PARTICIPANTS: The Intermediate Clinical Endpoints in Cancer of the Prostate (ICECaP) database included three randomized trials (Individual patients' data from 1647 subjects) assessing SRT (GETUG-AFU-16; NRG/RTOG-9601, and a subset of EORTC-22911). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Outcomes were clinical progression (CP). metastasis free-survival (MFS) and overall survival (OS). Clinico-pathological factors, including pathological Gleason Score (GS), PSA at SRT start, margin status, persistent PSA post-RP and time from RP to SRT were evaluated by multivariable models stratified by type of treatment. RESULTS AND LIMITATIONS: On multivariable analysis PSA ≥ 0.5 ng/mL at SRT start, GS ≥ 8 and negative margin status were the three strongest prognostic factors. Three prognostic groups defined by number of these risk features (high risk: 2 or 3; intermediate risk: 1 and low risk: 0) were strongly associated with OS, MFS and CP outcomes with SRT alone or with HT. This prognostic group definition was also relevant for patients with persistent PSA post RP and for patients treated < 1 year from RP to SRT and with and without HT. CONCLUSION: A risk score for patients receiving SRT with or without HT, using three standard-of-care clinico-pathological risk factors provides refined prognostic information for individual patient counselling. PATIENT SUMMARY: By using a composite score of pathology grading (Gleason Score), PSA at start of salvage radiation and margin status data, physicians can provide patients with more refined information on the risk of a second relapse after receiving radiation to the prostate bed after a prostatectomy for a rising or persistent PSA, both with and without hormonal therapy.

An open dataset for individual tree detection in UAV LiDAR point clouds and RGB orthophotos in dense mixed forests.

We present an open access dataset for development, evaluation, and comparison of algorithms for individual tree detection in dense mixed forests. The dataset consists of a detailed field inventory and overlapping UAV LiDAR and RGB orthophoto, which make it possible to develop algorithms that fuse multimodal data to improve detection results. Along with the dataset, we describe and implement a basic local maxima filtering baseline and an algorithm for automatically matching detection results to the ground truth trees for detection algorithm evaluation.

The effect of individual differences on Pavlovian conditioning in specific Internet-use disorders.

The I-PACE model suggests that Internet-use disorders result from the interplay of individual vulnerabilities and cognitive and affective processes. As in substance use disorders, Pavlovian conditioning processes are attributed a key role. However, and despite progress in identifying individual vulnerabilities, factors influencing appetitive conditioning remain poorly understood. We therefore conducted a Pavlovian conditioning experiment in which individuals with risky as well as non-problematic use of either gaming or buying-shopping applications learned to associate different abstract stimuli with either gaming or buying-shopping. Regression analyses were used to identify individual characteristics influencing awareness of the experimental contingencies, speed of acquisition of awareness and the magnitude of the conditioned emotional responses regarding pleasantness and arousal ratings of the stimuli. Results demonstrated successful Pavlovian conditioning and an attentional bias towards reward-predicting cues. Awareness of the experimental contingencies was linked solely to cognitive abilities, while the speed of acquisition of awareness and the magnitude of conditioned responses was influenced by specific personality characteristics, experiences of compensation from using the application and severity of problematic use. Importantly, certain characteristics specifically predicted the magnitude of the conditioned response towards gaming, while others specifically predicted the response towards buying-shopping, highlighting differing vulnerabilities. These findings underscore the importance of targeted interventions and prevention strategies tailored to these specific vulnerability factors. Further implications and limitations are discussed.

On the lasting impact of mild traumatic brain injury on working memory: Behavioural and electrophysiological evidence.

Despite increasing recognition of the significance of mild traumatic brain injury (mTBI), the long-term cognitive consequences of the injury remain unclear. More sensitive measures that can detect subtle cognitive changes and consideration of individual variability are needed to properly characterise cognitive outcomes following mTBI. Here, we used complex behavioural tasks, individual differences approaches, and electrophysiology to investigate the long-term cognitive effects of a history of mTBI. In Experiment 1, participants with self-reported mTBI history (n=82) showed poorer verbal working memory performance on the operation span task compared to control participants (n=88), but there were no group differences in visual working memory, multitasking, cognitive flexibility, attentional control, visuospatial ability, or information processing speed. Individual differences analyses revealed that time since injury and presence of memory loss predicted visual working memory capacity and visuospatial ability, respectively, in those with mTBI history. In Experiment 2, participants with mTBI history (n=20) again demonstrated poorer verbal working memory on the operation span task compared to control participants (n=38), but no group differences were revealed on a visuospatial complex span task or simpler visual working memory measures. We also explored the electrophysiological indices of visual working memory using EEG during a change detection task. No differences were observed in early sensory event-related potentials (P1, N1) or the later negative slow wave associated with visual working memory capacity. Together, these findings suggest that mTBI history may be associated with a lasting, isolated disruption in the subsystem underlying verbal working memory storage. The results emphasize the importance of sensitive cognitive measures and accounting for individual variability in injury characteristics when assessing mTBI outcomes.

Information sampling differences supporting superior face identity processing ability.

Face recognition in humans is often cited as a model example of perceptual expertise that is characterized by an increased tendency to process faces as holistic percepts. However emerging evidence across different domains of expertise points to a critical role of feature-based processing strategies during the initial encoding of information. Here, we examined the eye-movement patterns of super-recognisers-individuals with extremely high face identification ability compared with the average person-using gaze-contingent "spotlight" apertures that restrict visual face information in real time around their point of fixation. As an additional contrast, we also compared their performance with that of facial examiners-highly trained individuals whose superiority has been shown to rely heavily on featural processing. Super-recognisers and facial examiners showed equivalent face matching accuracy in both spotlight aperture and natural viewing conditions, suggesting that they were equally adept at using featural information for face identity processing. Further, both groups sampled more information across the face than controls. Together, these results show that the active exploration of facial features is an important determinant of face recognition ability that generalizes across different types of experts.

Differential impact of adolescent or adult stress on behavior and cortical parvalbumin interneurons and perineuronal nets in male and female mice.

BACKGROUND: Stress has become a prevalent public health concern, contributing to the rising prevalence of psychiatric disorders. Understanding stress impact considering critical variables, such as age, sex, and individual differences, is of utmost importance for developing effective intervention strategies. METHODS: Stress effects (daily footshocks for ten days) during adolescence (postnatal day, PND31-40) and adulthood (PND65-74) were investigated on behavioral outcomes and parvalbumin (PV)-expressing GABAergic interneurons and their associated perineuronal nets (PNNs) in the prefrontal cortex (PFC) of male and female mice five weeks post-stress. RESULTS: In adulthood, adolescent stress induced behavioral alterations in male mice, including anxiety-like behaviors, social deficits, cognitive impairments, and altered dopamine system responsivity. Applying integrated behavioral z-score analysis, we identified sex-specific differences in response to adolescent stress, with males displaying greater vulnerability than females. Furthermore, adolescent-stressed male mice showed a decrease PV+ and PNN+ cell numbers and PV+/PNN+ colocalization, while in females, adolescent stress reduced prefrontal PV+/PNN+ colocalization in the PFC. Further analysis identified distinct behavioral clusters, with certain females demonstrating resilience to adolescent stress-induced deficits in sociability and PV+ cell number. Adult stress in male and female mice did not cause long-lasting changes in behavior and PV+ and PNN+ cell number. CONCLUSION: Our findings indicate that the timing of stress, sex and individual variabilities seem to be determinants for the development of behavioral changes associated with psychiatric disorders, particularly in male mice during adolescence.

Socioeconomic status, individual behaviors and risk of anxiety disorders: A Mendelian randomization study.

BACKGROUND: The association between socioeconomic status and individual behaviors (SES/IB) and anxiety disorders has garnered increasing attention, yet the impact of SES/IB on anxiety disorders remains unclear. Therefore, we employed a Mendelian randomization (MR) design to evaluate the causal relationship between SES/IB and anxiety disorders. METHODS: We conducted a two-sample MR study to assess the causal effects of SES and IB (smoking behaviors, drinking behaviors, sleeping behaviors, habitual physical activity, leisure sedentary behaviors, and reproductive behaviors) on anxiety disorders. A series of filtering steps were taken to select eligible genetic instruments robustly associated with each of the traits. The inverse variance weighted was used for preliminary analysis, and multiple methods were used for sensitivity testing. RESULTS: After Bonferroni correction and rigorous quality control, we found that educational attainment (odds ratio [OR]:0.75; 95 % confidence interval [CI]:0.69-0.81; P = 9.21E-12), alcohol consumption per week (OR: 1.62; 95 % CI: 1.33-1.97; P = 1.80E-06), insomnia (OR: 1.68; 95 % CI: 1.43-1.97; P = 1.45E-10),age at first birth (OR: 0.59; 95 % CI: 0.50-0.68; P = 1.31E-11),and number of sexual partners (OR: 2.19; 95 % CI: 1.71-2.80; P = 6.64E-10) were causally associated with anxiety disorders. LIMITATIONS: The subjects included in this study were all of European descent, and whether this finding can be generalized to other populations needs to be further demonstrated. CONCLUSIONS: The MR Study provides strong evidence that some factors influence anxiety disorders.

The preliminary study of the effects of individual musculoskeletally stable position in the treatment of temporomandibular disorders.

BACKGROUND: Temporomandibular Disorders (TMD) is the dysfunction of group of muscles and bones in the joint area, the main symptoms of TMD are the pain of the chewing muscles and (or) the temporomandibular joints, mandibular movement disorders and joint noise. This study was designed to explore the therapeutic effects following Individual Musculoskeletally Stable (IMS) position stabilization splint therapy for TMD patients using Fricton index, cone beam computed tomography (CBCT) and surface-Electromyogram (sEMG). METHODS: In this study, we enrolled 31 TMD patients (ranging from 18 to 26 years old, including 7 males and 24 females), first Fricton index was used to evaluate the clinical curative effect of TMD with the treatment of IMS stabilization splint; then CBCT was used to observe the TMJ condylar position changes of TMD before and after the treatment of IMS stabilization splint; finally sEMG was used to observe the changes of electromyography of anterior temporalis (AT) and masseter muscles (MM) of TMD before and after the treatment of IMS stabilization splint. RESULTS: The course of treatment was 6-8 months, with an average of 7.6 months. After the IMS stabilization splint treatment, TMD symptoms relieved, especially in pain, mandibular movement disorder, but still slightly inferior in the treatment of joint noise. And there was a statistically significant difference in the anterior and inner joint space, the condyle had the tendency of moving forward and outward. AT presented reduction significantly of EMG value at rest position after treatment. CONCLUSIONS: IMS stabilization splint is a therapeutic reversible treatment for TMD, especially for pain and mandibular movement disorder; it produces effects of forward and outward condylar movement and elimination of the masticatory muscles antagonism.