Temporalis Muscle Changes Following Botulinum Toxin A Injections in Masseter Hypertrophy Patients: A Randomized Triple-Blinded Trial.

BACKGROUND: This study aimed to elucidate the effects of botulinum toxin A (BoNT-A) treatment for patients diagnosed with masseter hypertrophy on the temporalis muscle, with a particular focus on assessing alterations in muscle thickness, electromyographic (EMG) activity, and the development of muscle pain. METHODS: The present randomized triple-blinded clinical trial enrolled 26 female participants aged between 25 and 50 years complaining about masseter hypertrophy. Participants received 75U of BoNT-A (abobotulinumtoxinA) in both masseter muscles and after three months were randomized to receive a second treatment session of saline solution (S-BoNT-A) or BoNT-A (M-BoNT-A). Longitudinal assessments included temporalis muscle thickness through ultrasound, EMG activity, subjective pain, and masseter prominence severity after one, three, and six months of the first injection session. Muscle thickness, EMG, and subjective pain were analysed using two-way ANOVA with repeated measures and post hoc Sidak test, and for masseter prominence severity, Friedman and Mann-Whitney tests were used. RESULTS: Regarding inter-group comparisons, a higher muscle thickness (p < 0.02) and a higher EMG activity (p < 0.01) were found in the M-BoNT-A group at the 6-month follow-up. For subjective pain assessments, inter-group comparisons showed a higher prevalence of painful regions in M-BoNT-A group at the 6-month follow-up (p < 0.02). No significant differences were found in masseter prominence severity at the 6 months assessment between groups. CONCLUSION: BoNT-A treatment for masseter hypertrophy lead to structural and functional changes in the temporalis muscle, presenting higher changes after multiple injections of this treatment. LEVEL OF EVIDENCE I: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Comparison of the Effectiveness of Different Methods for Pain Reduction During Injection Procedures in the Frontalis Muscle.

BACKGROUND: Forehead aesthetic injections are a well-known source of discomfort, and many analgesic non-invasive techniques have been proposed to ameliorate pain. However, no study has compared all these techniques for aesthetic purposes. Therefore, this study aimed to compare the effectiveness of topical cream anesthesia, vibratory stimulus, cryotherapy, pressure, and even no intervention, on pain during and immediately after injection, when considering aesthetic injections in the forehead. METHODS: Seventy patients were selected and had their foreheads divided into 5 parts, which received four different analgesic techniques, and one control zone was added. A numeric rating scale was used to assess pain, two direct questions were asked to evaluate patients' preference and discomfort with the techniques, and the adverse events were quantified. The injections were performed in the same sequence, with three minutes of rest between them and in a single session. Comparisons among analgesic methods for pain relief were performed by the one-way analysis of variance (ANOVA), considering a significance level of 5%. RESULTS: No significant differences were found among the analgesic methods, and between the methods and the control zone, both during and immediately after the injections (p > 0.05). The preferred method for pain relief was the use of topical anesthetic cream (47%), while the most uncomfortable technique was manual distraction (pressure) (36%). Only one patient reported an adverse event. CONCLUSIONS: No analgesic method to diminish pain was superior to the others or was better than no method. Nevertheless, the topical anesthetic cream was the preferred technique, causing less discomfort. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Effect of frozen storage on preservation of a silicone-based test food material

Aim: This study aimed to evaluate the effect of frozen storage on the physical properties of a silicone-based test food material, highly used to evaluate the masticatory performance in research settings. Methods: A total of 1,666 silicone cubes of Optosil Comfort® with 5.6-mm edges were shaped and stored at -18°C. The cubes were subsequently tested for flexural strength (maximum force, displacement, stress, and strain) before breaking (n = 136), changes in weight and size (n = 170), and masticatory performance (n = 1360) at eight timepoints: immediately after cube preparation (baseline, no freezing), and 1, 2, 3 and 4 weeks, and 2, 4 and 6 months after frozen storage. The cubes were thawed 8 h before each assessment. Results: The maximum force, stress, maximum displacement, and deformation values for the cubes were not affected by freezing (P > 0.05). At all of the time points, the cubes exhibited similar weight (P = 0.366) and size (identical values). The masticatory performance for the cubes also showed no differences from baseline through 6 months (P = 0.061). Conclusion: Freezing Optosil Comfort® silicone cubes did not alter the physical and mechanical properties of the material, being suitable to optimize the assessment of masticatory parameters for research purposes

Academic perspectives and psychosocial aspects of final-year dental students during COVID-19 pandemic

Aim: This cross-sectional observational study aimed to evaluate the influence of the Universities lockdown measures on academic perspectives and psychosocial aspects of Brazilian finalyear dental students. Methods: 268 undergraduate students regularly enrolled in a Dentistry course at public universities were asked about anxiety, depression, stress sensitivity, and their academic perspectives by using an online survey. The Hospital Anxiety and Depression Scale (HADS) was used to measure anxiety and depression, while the Perceived Stress Scale (PSS) evaluated stress levels. The academic perspective was evaluated by five affirmatives regarding possible difficulties that will be faced when school reopens and after graduation. The possible association between fear of having COVID-19 with psychosocial outcomes and COVID-19 association with academic perspectives were analyzed by ANOVA and chisquare tests, respectively, considering a significance level of 5%. Results: Considering possible associations between the fear of having COVID-19 and psychosocial aspects, significant values were found for anxiety (P = 0.018) and stress sensitivity (P = 0.002). Regarding students' academic perspectives, COVID-19 had significant impact on less opportunity to perform procedures (P = 0.023), additional expenses with personal protective equipment (P = 0.007), and concerns of consulting elderly people (P = 0.012). Conclusion: The COVID-19 pandemic led to increased psychological impairments and enlarged concerns with learning and biosecurity, which might impact academic perspectives. Thus, being aware of these apprehensions, university professors and staff can improve the clinical training of final-year dental students in an empathetic way

Botulinum toxin type A and acupuncture for masticatory myofascial pain: a randomized clinical trial

Abstract BoNT-A has been widely used for TMD therapy. However, the potential benefits compared to dry needling techniques are not clear. Objective this study aimed to compare the immediate effects of botulinum toxin type A (BoNT-A) injections and Acupuncture in myofascial temporomandibular disorders (TMD) patients. Methodology 54 women were divided into three groups (n=18). AC patients received four sessions of traditional acupuncture, being one session/week during 20-min. BoNT-A patients were bilaterally injected with 30U and 10U in masseter and anterior temporal muscles, respectively. Moreover, a control group received saline solution (SS) in the same muscles. Self-perceived pain was assessed by visual analog scale, while pressure pain threshold (PPT) was verified by a digital algometer. Electromyographic evaluations (EMG) of anterior temporal and masseter muscles were also measured. All variables were assessed before and 1-month after therapies. The mixed-design two-way repeated measures ANOVA and Tukey's post-hoc tests were used for analysis, considering a=0.05. Results Self-perceived pain decreased in all groups after one month of therapy (P<.001). BoNT-A was not better than AC in pain reduction (P=0.05), but both therapies were more effective in reducing pain than SS (P<0.05). BoNT-A was the only treatment able to improve PPT values (P<0.05); however, a severe decrease of EMG activity was also found in this group, which is considered an adverse effect. Conclusion after one month of follow-up, all therapies reduced the self-perceived pain in myofascial TMD patients, but only BoNT-A enhanced PPT yet decreased EMG.

Mandibular single-implant overdenture as an alternative for full arch rehabilitations: a literature review

Oral rehabilitation with mandibular single-implant overdentures (SIO) has been characterized as a solution to improve retention and stability of conventional complete dentures (CD). Among the benefits of this therapy, it can be mentioned minimally invasive surgery, simple prosthetic technique, better retention, and significantly reduced costs. However, the application of this protocol in daily clinic is still not widespread. Aim: Thus, this study aimed to perform a literature review to address the clinical characteristics of this rehabilitation, when compared to two-implant mandibular overdentures and CD. Methods: For this, a search was conducted in the PubMed database, considering articles published in English language, without date limitation. Results: It was found 243 manuscripts, of which 20 were compatible with the aim of this study after title/abstract reading. The selected papers focused on masticatory muscles function, satisfaction levels and self-reported quality of life, as well as surgical and prosthetic outcomes, such as maintenance, repair and implant failure rates. All evaluated manuscripts showed similar masticatory function and patient's satisfaction with SIO and two-implant overdenture, while results for a SIO were greater when compared to rehabilitations with CD. In addition, SIO have proven to do not damage the implant, being implant loss close to zero. However, the prosthesis fracture adjacent to the implant was a recurrent clinical outcome, which requires further studies to solve this impairment. Conclusion: Thus, it can be concluded that SIO represents an alternative treatment for frail elders or low-income patients, leading to higher masticatory function, as well as improved quality of life

Sensitivity and specificity of different indexes used to diagnose Temporomandibular Disorders / Sensibilidade e especificidade de diferentes índices utilizados para o diagnóstico de disfunções temporomandibulares

Objective: To verify the level of agreement among different indexes used to achieve the prevalence of Temporomandibular Disorders (TMD). Material and Methods: One hundred one dental students were selected by a randomized process. TMD were evaluated by the Fonseca's Anamnestic Index (FAI), Helkimo's Clinical Index (HCI), and the Research Diagnostic Criteria for TMD (RDC/TMD). Data was analyzed using Chi-square and Kappa tests, considering a significance level of 5%. Results: HCI showed the highest prevalence of TMD, and the comparison between RDC/TMD, FAI, and HCI showed low agreement (k=0.17 and k=0.35 respectively). Most individuals presented mild TMD for both FAI and HCI indexes. A moderate correlation for TMD severity was obtained (kw=0.53) between FAI and HCI, and a high sensitivity and low specificity were observed for both diagnosis when compared to RDC/TMD. Conclusion: The prevalence of TMD may vary significantly depending on the index used for its diagnosis, which may lead to a large number of false positives and overtreatments. (AU)

Objetivo: Verificar o nível de concordância entre diferentes índices utilizados para avaliar a prevalência de disfunções temporomandibulares (DTMs). Material e Métodos: Cento e um estudantes de odontologia foram selecionados por um processo randomizado. As DTMs foram avaliadas pelo Índice Anamnéstico de Fonseca (IAF), pelo Índice Clínico de Helkimo (ICH) e pelo Research Diagnostic Criteria for TMD (RDC / TMD). Os dados foram analisados pelos testes Qui-quadrado e Kappa, considerando um nível de significância de 5%. Resultados: A aplicação do ICH levou a uma maior prevalência de DTM, e a comparação entre o RDC/TMD, IAF e ICH mostrou baixa concordância (k = 0,17 e k = 0,35, respectivamente). A maioria dos indivíduos apresentou DTM leve para os índices FAI e ICH. Uma correlação moderada para a gravidade da DTM foi obtida (kw = 0,53) entre FAI e HCI, e uma alta sensibilidade e baixa especificidade foram observadas para ambos os diagnósticos quando comparados com o RDC/TMD. Conclusão: A prevalência de DTM pode variar significativamente, dependendo do índice usado para o seu diagnóstico, o que pode levar a um grande número de falsos positivos e sobretratamentos. (AU)