Does cannula's size alter rheological properties of hyaluronic acid filler?

This study evaluated the rheological properties of various hyaluronic acid (HA) gels after passing through different-sized cannulas (22-G and 25-G). Five commercial brands of highly crosslinked HA fillers were analyzed: (A) Rennova® Ultra Deep, (B) Restylane® Lyft, (C) Hialurox® - Ultra Lift, (D) Belotero® Volume, and (E) E.P.T.Q S500. Rheological characterization was conducted using an automated controlled stress rheometer. The rheological properties of the fillers were assessed both before and after passing through the cannulas. Each filler brand and cannula size was tested three times by a researcher who was blinded to the commercial brands. For data analysis, frequencies of 0.1, 0.5, and 2 Hz were employed. The rheological properties (storage modulus [G'] and loss modulus [G"]) of the high-crosslink HA fillers did not change after being passed through cannulas of different sizes (22-G and 25-G) (p > 0.109) compared to baseline measurements (no cannula). Furthermore, all fillers displayed desirable solid-like, volumizing behavior at low frequencies and strain amplitudes (<10 %). Under physiologically relevant conditions for skin and facial applications, the cannula size did not alter the rheological properties of high crosslink HA fillers.

Effect of poly-L-lactic acid and polydioxanone biostimulators on type I and III collagen biosynthesis.

OBJECTIVE: Safe, effective, and biocompatible minimally invasive procedures with the potential to stimulate collagen production have been made to recover dermal thickness and skin quality. The main of this animal model experiment was to observe the effect of poly-L-lactic acid (PLLA) and polydioxanone (PDO) biostimulators in collagen I and III after hypodermal injection. METHODOLOGY: Sixteen adult female rats (Wistar) were randomized into four groups and had dorsal treatment with: G1: hypodermic subcision (HS) only; G2: HS and PLLA hypodermic injection (HI), G3: HS and PDO HI; G4: Control, with no treatment. RESULTS: In histochemical, it was observed hypodermal and dermal tissue in more organized thickness in G3 and in G4 when compared to G1 and G2. There was few difference in G1 compared to G4. The tissue of G2 showed irregularities in the arrangement of collagen fibers, less defined structure and lower distribution of type I collagen compared to the other groups. There is a greater tendency for the proportions of type III collagen among tissues treated with both biostimulators (G2 and G3). PLLA and PDO had relatively similar percentages of collagen when compared to G4. The amount of type I collagen was higher in tissues treated with subcision, while type III collagen was higher in tissues treated with both biostimulators. CONCLUSION: G3 showed better performance in collagen production, although small, when compared with G2.

Influence of botulinum toxin A in pain perception and condyle-fossa relationship after the management of temporomandibular dysfunction: a randomized controlled clinical trial.

OBJECTIVES: To investigate the pain perception (PP) and condyle-fossa relationship (CFR) after botulinum toxin A (BoNTA) injection in the masseter muscles of painful muscular temporomandibular dysfunction (TMD) patients. MATERIALS AND METHODS: Fourteen women (aged 29.7 ± 5.4 years) diagnosed with myogenic TMD were randomized in the BoNTA-treated group (TG) and control group (CG). TG masseter muscles (n = 7) were bilaterally injected with 30 U. The CG (n = 7) were injected with saline injections. Condyle-fossa relationship (CFR) spaces were measured in sagittal (SP) and frontal planes (FP) of images of cone-beam computed tomography (CBCT) done before (T0) and after 30 days' interventions (T1). Visual analogue scale (VAS) measured the patients' TMD pain perception (PP). Data were compared by generalized linear models considering the results over time (α = .05). RESULTS: There were no statistical differences in CFR in the SP or FP for TG and CG over time (p ˃ .05), except for frontal lateral space CFR (p < .05). In both groups, the condyle was positioned medially after interventions. Frontal lateral space increased in TG for both, left and right sides, over time (p < .05), as well as PP decreased over time (p < .05) for TG and CG. CONCLUSIONS: The results depicted that there was no significant association with BoNTA injection in TMD masseter muscles in PP and CFR, except considering the frontal lateral space of CFR. CLINICAL RELEVANCE: BoNTA injection in the masseter muscles may not promote clinically significant shifts in the condyle-fossa relationships of muscular TMD patients.

Histomorphometric Changes of the Masseter Muscle of Rats After a Single Injection of Botulinum Toxin Type A.

BACKGROUND: It has been reported that botulinum toxin type A (BoNT-A) produces structural changes in masticatory muscles. However, not all histomorphometric parameters affected by BoNT-A parameters have been assessed. This study investigated the histomorphometric changes in the masseter muscle of rats after a single injection of BoNT-A. METHODS: Forty-four adult animals were randomly divided into control group (n = 22) and BoNT-A group (n = 22). Controls received a single dose of 0.14 mL/kg of saline in masseter muscles, and the BoNT-A group received a 7 U/Kg of BoNT-A. The groups received the same volume of injected substances. Animals were sacrificed on 7th (n = 5), 14th (n = 5), 21st (n = 5), 28th (n = 4) and 90th (n = 3) days post-treatment. Histological masseter tissue slides were obtained from hematoxylin-eosin treatment and analyzed in optical microscopy regarding muscle cross-sectional area, amount of connective tissue and quantity and diameter of myocytes. For statistical analysis, generalized linear models were used to compare the data (ANOVA). In all test, the significance level of 5% was set. RESULTS: BoNT-A values of cross-sectional area of the masseter muscle were significantly lower than controls (p < 0.01) throughout the study. Regarding myocytes quantity, BoNT-A subgroups presented higher values than controls (p < 0.0001) since the 14th day until the end of the study; however, the diameter of myocytes was smaller in all BoNT-A subgroups (p < 0.0001) in all assessment points. The amount of connective tissue was higher in BoNT-A subgroups (p < 0.0001) throughout the study. CONCLUSION: A single injection of BoNT-A altered the structure of masseter muscle of rats, regarding its histomorphometric parameters. NO LEVEL ASSIGNED: 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 .

Prospective study of the aesthetic effect of botulinum toxin a when injected into the muscles of facial expression

Botulinum neurotoxin A (BoNT-A) causes an anticholinergic effect on neuronal fibers, which control muscle contraction and autonomic disorders. Thus, it has been widely used in facial aesthetics, decreasing the action of motor muscles and consequent wrinkles. This preliminary study evaluated the effect of BoNT-A in 77 patients, the treatment satisfaction index was defined in percentage (from 0% to 100%). The evaluation was carried out on 15th, 30th, 60th, 90th, and 180th days after BoNT. The data were analyzed using the Friedman, Student t, Mann-Whitney test with t (alpha=0.05). The results showed that at 15th and 30th days the scores were similar in all muscles with high level of satisfaction and until 90th days the scores decreased significantly for Corrugator supercilii 79.38%, Occipitofrontalis 71.46%, Orbicularis oculi 70.43%; but the satisfaction was good. At 180 days, there was a drop in effectiveness in all treated muscles since the scores decreased significantly, showing low satisfaction by the participants. This study demonstrated that the BoNT-A had attested satisfaction effect by participants for up to 90th days, but at 180th days the satisfaction was low. In the comparative analyzes between women under 40 and over 40 years of age, there was no significant differences.

Is low dose of botulinum toxin effective in controlling chronic pain in sleep bruxism, awake bruxism, and temporomandibular disorder?

OBJECTIVE: To evaluate the effects of low doses of botulinum toxin type A (BoNT-A) to control pain in patients with sleep bruxism (SB), awake bruxism (AB), and temporomandibular disorder (TMD) during 180 days. METHODS: Overall sample of thirty-five patients with chronic pain related to TMD, SB, and AB received a single dose of 20 U of BoNT-A in masseter and temporalis muscles. The pain was assessed with a visual analog scale (VAS) before and after 15, 30, 60, 90, and 180 days of the application. RESULTS: The three clinical conditions experienced decrease in pain after 15 days of treatment (p < 0.0001); the maximum pain relief persisted for up to 90 days after BoNT-A application in patients with SB and AB and 15 days for patients with TMD. CONCLUSION: A low dose of BoNT-A may be effective for controlling chronic pain related to SB and AB, but TMD pain reduction was short-lived.

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

BACKGROUND: 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.

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.

Efficacy and Safety of Botulinum Toxin Type A on Persistent Myofascial Pain: A Randomized Clinical Trial.

This study assessed the safety and efficacy of three different doses of BoNT-A for persistent myofascial pain (MFP). One hundred female subjects were randomly assigned into five groups (n = 20): oral appliance (OA), saline solution (SS) and three BoNT-A groups with different doses. Pain intensity and pressure pain threshold were evaluated up to 24 weeks after treatment. Adverse effects related to muscle contraction, masticatory performance, muscle thickness and mandibular bone volume were also assessed. Changes over time were compared within and between groups. The "nparLD" package and Wilcoxon signed-rank test were used to analyze the data. BoNT-A reduced pain intensity (p < 0.0001) and increased pressure pain threshold (p < 0.0001) for up to 24 weeks compared to the placebo. No differences were found between BoNT-A and OA at the last follow-up. A transient decline in masticatory performance (p < 0.05) and muscle contraction (p < 0.0001), and a decrease in muscle thickness (p < 0.05) and coronoid and condylar process bone volume (p < 0.05) were found as dose-related adverse effects of BoNT-A. Regardless of the dose, BoNT-A was as effective as OA on MFP. Notwithstanding, due to BoNT-A dose-related adverse effects, we suggest the use of low doses of BoNT-A in MFP patients that do not benefit from conservative treatments.

Evaluation of pain intensity of the masticatory muscles after occlusal appliance and combined therapy: a 6-months follow-up pilot study

Masticatory muscle pain (MMP) is a common type of orofacial pain.Occlusal appliance (OA) is contemplated as a first-line conservative approach for chronic MMP, however, integrated biopsychosocial approaches such as counseling and self-care therapies (CSG) are also considered essential. Aim: This pilot study aimed to compare the use of a combined therapy (GSG + OA) and solely OA treatment on pain intensity related to chronic MMP over a 6-month follow-up. Methods:For this, 20 patients diagnosed with chronic MMP using the Diagnostic criteria for temporomandibular disorders (DC/TMD) were divided into 2 groups (n=10) and treated with OA or combined therapy (CoT; OA + CSG). Electromyographic muscle activity (EMG), visual analogue scale (VAS) and pressure pain threshold (PPT) were recorded at baseline, 1, 3 and 6 months after treatment. Data was collected and statistical analysis were applied at a significance level of 5%. Results:Results showed no significant differences at baseline among groups for any assessment. VAS showed that both treatments decreased subjective pain in volunteers over time, but no significant differences among both groups were observed at any evaluation time. For electromyography, CoT and OA presented no significant differences throughout the experiment neither on relaxed muscle position or maximum volunteer contraction. Finally, a significantly higher PPT for CoT was found for all muscles at the last assessment point (p<0.05). Conclusion: These findings suggest that both treatments are effective for the reduction of pain perception (VAS) in patients with chronic MMP. However, the addition of CSG to an OA therapy may be more beneficial for the improvement of tenderness on the same patients, at least in a long-term basis (> 3 months). Notwithstanding, a larger study should be performed to substantiate these findings

Distribution of depression, somatization and pain-related impairment in patients with chronic temporomandibular disorders.

OBJECTIVE: the aim of this study was to describe the frequency of psychosocial diagnoses in a large sample of patients attending a tertiary clinic for treatment of temporomandibular disorders (TMD). MATERIAL AND METHODS: six hundred and ninety-one patients who sought treatment for pain-related TMD were selected. Chronic pain-related disability (Graded Chronic Pain Scale, GCPS), depression [Symptoms Checklist-90 (SCL-90) scale for depression, DEP] and somatization levels (SCL-90 scale for non-specific physical symptoms, SOM) were evaluated through the Research Diagnostic Criteria for TMD (RDC/TMD) Axis II psychosocial assessment; TMD diagnoses were based on the Axis I criteria. RESULTS: the majority of patients presented a low disability or no disability at all, with only a small portion of individuals showing a severely limiting, high disability pain-related impairment (4.3%). On the other hand, abnormal scores of depression and somatization were high, with almost half of the individuals having moderate-to-severe levels of depression and three-fourths presenting moderate-to-severe levels of somatization. The prevalence of high pain-related disability (GCPS grades III or IV), severe/moderate depression and somatization was 14.3%, 44% and 74.1% respectively. Gender differences in scores of SCL-DEP (p=0.031) and SCL-SOM (p=0.001) scales were signficant, with females presenting the highest percentage of abnormal values. CONCLUSION: patients with TMD frequently present an emotional profile with low disability, high intensity pain-related impairment, and high to moderate levels of somatization and depression. Therefore, given the importance of psychosocial issues at the prognostic level, it is recommended that clinical trials on TMD treatment include an evaluation of patients' psychosocial profiles.

Atualidades sobre o tratamento das disfunções temporomandibulares / Updates on the management of temporomandibular disorders

O crescimento das situações estressantes, associado a outros fatores agravantes, tem tornado as Disfunções Temporomandibulares (DTM) foco de diversas pesquisas e intervenções clínicas. As incorreções oclusais, musculares e comportamentais podem alterar o sistema estomatognático, prejudicando a saúde periodontal, dental e dos demais tecidos bucais, e comprometendo os trabalhos clínicos já realizados. A compreensão dessa patologia deve ser de conhecimento do cirurgião-dentista, especialmente daquele que vai realizar reabilitações bucais implantossuportadas. O controle da DTM pode ser primordial para o sucesso do tratamento planejado. Condições diagnósticas e comportamentais do paciente podem orientar as propostas terapêuticas do profi ssional, e essa tem sido cada vez mais uma realidade para o controle das situações sintomáticas relacionadas às DTM. Fatores inerentes ao diagnóstico são relevantes na condução terapêutica, e somente através de procedimentos sistemáticos e bem estruturados é possível obter dados que assegurem organizar a intervenção necessária ao manejo das DTM. Neste artigo descrevemos alguns procedimentos adotados em nossa conduta clínica para o diagnóstico das DTM, ao mesmo tempo em que abordamos algumas modalidades de intervenção terapêutica, com uma visão voltada à terapia baseada em evidências.

The stressful situations associated with other aggravating factors has made Temporomandibular Disorders (TMD) the focus of several researches and clinical interventions. Occlusal, muscular and behavioral disturbance may alter the stomatognathic system, compromising periodontal, dental and other oral tissues health, as well as some clinical work already done. The understanding of this pathology should be relevant to the dentist, especially when it will be performed supported implant rehabilitations. Control of TMD may be critical to the success of planned treatment. Diagnostic conditions and behavioral understanding of the patient may guide the therapeutic proposals, and it has been an increasingly reality for the control of TMD symptomatic situations. Factors inherent to the diagnosis are relevant in the therapeutic conduction, and it is only through systematic and well structured procedures the data can be obtained to organize the necessary intervention for TMD management. In this article, we describe some of the procedures adopted in our clinical management for the diagnosis of TMD, while addressing some modalities of therapeutic intervention, with a vision focused on evidence-based therapy.

The Role of Prosthesis Spacer for Ocular Prostheses.

Eye defects can lead to emotional, psychological, and social changes, impacting negatively the quality of life of the patient. When these structures cannot be satisfactorily repaired by reconstructive surgery, the prosthetic rehabilitation is the better treatment option to restore lost ocular anatomy and promote the social integration of the individual. The aim of this clinical report is to report and discuss a case of ocular prosthesis confection eviscerated patient with opening limitation eyelid and shortening of the distance between palpebral commissure, to obtain a more natural and comfortable to the patient ocular rehabilitation.

Limitações estéticas na reabilitação de pacientes com prótese bucomaxilo ­ relato de caso / Aesthetic limitations of rehabilitation of patients with maxillofacial prosthesis ­ case report

Pacientes com deformidades palatinas podem apresentar alterações nas funções orais, além da dificuldade do convívio social imposta pelo dano na fonação e na estética. Este caso clínico tem o objetivo de descrever a reabilitação de um paciente parcialmente edêntulo com comunicação buconasal por meio de prótese parcial removível, relatando as dificuldades e limitações do caso. As etapas clínicas e laboratoriais de confecção da prótese parcial removível para obliteração com comunicação buconasal foram semelhantes à de uma prótese parcial removível convencional, diferindo na moldagem para evitar o extravasamento excessivo de material para o interior do defeito, cuidado na manipulação dos tecidos pela reduzida elasticidade provocada pelo processo cicatricial e na polimerização da prótese, uma vez que o bulbo necessitava ser oco para torná-la mais leve. Após as consultas de proservação e a integração harmoniosa da prótese com a cavidade oral, constatou-se a satisfação do paciente com o restabelecimento de suas funções e da estética (AU).

Patients with cleft deformities may present changes in oral functions, as well as social problems due to compromised phonation and aesthetics. This clinical case aims to describe the rehabilitation of a partially edentulous patient with oronasal communication, through partial prosthesis, reporting the difficulties and limitations of the case. Clinical and laboratory stages of the manufacture of the removable partial denture to obliterate the oronasal communication were similar to those of a conventional removable partial denture. It differed in the molding to avoid excessive leakage of material into the defect, careful handling of the tissues, the reduced elasticity caused by the cicatricial process and the polymerization of the prosthesis since the bulb needed to be hollow to make it lighter. After proservation consults and harmonious integration of the prosthesis with the oral cavity, it was verified the patient's satisfaction with the restoration of his functions and the aesthetics (AU).

Relação de distúrbios temporomandibulares e alterações do padrão de sono na síndrome da fibromialgia ­ revisão da literatura / Relationship of temporomandibular disorders and sleep patterns in fibromyalgia syndrome

A fibromialgia é uma síndrome reumática caracterizada por quadros dolorosos intensos. A presença da dor muitas vezes chega a causar incapacidade e indisposição, mesmo para realização de atividades rotineiras, bem como parece afetar o sono em grande parte dos pacientes. Acredita-se que a perpetuação de alterações no padrão de sono crie uma situação cíclica que intensifica os quadros dolorosos e a fadiga. Os distúrbios temporomandibulares (DTM) que são caracterizados por quadros de dor também vêm sendo relacionados com alterações no sono. Essas duas condições, apesar de distintas, parecem coexistir em um grande número de portadores de fibromialgia, levando-se a pesquisas que visam buscar a influência dessa relação como causa e efeito dentro deste grupo de pacientes. Neste contexto, este trabalho teve o objetivo de recolher informações dentro da literatura sobre essas duas condições, sua influência nas alterações do sono, bem como reunir estudos que busquem esclarecer a relação existente entre as duas condições. Para isto foram reunidos trabalhos publicados na base de dados PubMed, LILACSeMEDLINEutilizando-se os termos fibromialgia, DTM e sono, nos idiomas inglês e português. Os trabalhos apontam que há uma prevalência alta entre mulheres e que os portadores de fibromialgia apresentam alterações específicas no padrão de sono, bem como há uma importante correlação desta condição com os distúrbios temporomandibulares (AU).

Fibromyalgia syndrome is characterized by severe painful conditions. The presence of pain can result in some disability and even unwillingness to perform routine activities, and seems to affect sleep in most patients. It is believed that the changes in sleep pattern creates a cyclic condition and can increase fatigue painful conditions. The temporomandibular disorder (TMD) is characterized by pain frameworks have also been related to changes in sleep. These two conditions, while distinct, seem to coexist in a large number of patients with fibromyalgia, leading several researchs concerning the influence of this relationship within this group of patients. Therefore, this work aimed to collect information in the literature on these two conditions, its influence on sleep disorders as well as gathering studies that seek to clarify the relationship between these two conditions. For this were selected studies published in PubMed, LILACS, and MEDLINE using the terms fibromyalgia, TMD and sleep, in English and Portuguese. The studies indicate that there is a high prevalence among women and that patients with fibromyalgia have specific changes in sleep patterns, and there is a significant correlation of this condition with temporomandibular disorders (AU).

Chronicity factors of temporomandibular disorders: a critical review of the literature.

Facial pain often persists long after any identifiable organic pathology has healed. Moreover, in a subgroup of patients with temporomandibular disorder (TMD), no treatment is effective. Knowledge of factors associated with persistent pain in TMD could help identify personalized treatment approaches. Therefore, we conducted a critical review of the literature for the period from January 2000 to December 2013 to identify factors related to TMD development and persistence. The literature findings showed that chronic TMD is marked by psychological distress (somatization and depression, affective distress, fear of pain, fear of movement, and catastrophizing) and characteristics of pain amplification (hyperalgesia and allodynia). Furthermore, these factors seem to interact in TMD development. In addition, our review demonstrates that upregulation of the serotonergic pathway, sleep problems, and gene polymorphisms influence the chronicity of TMD. We conclude that psychological distress and pain amplification contribute to chronic TMD development, and that interactions among these factors complicate pain management. These findings emphasize the importance of multidisciplinary assistance in TMD treatment.

Temporomandibular disorders in fibromyalgia syndrome: a short-communication.

Fibromyalgia syndrome (FMS) is a chronic painful syndrome and the coexistence of a painful condition caused by Temporomandibular Disorders (TMD) and FMS has been frequently raised for several studies, however, more likely hypothesis is that a set of FMS characteristics may lead to the onset of TMD symptoms and they are not merely coexisting conditions. Therefore, our aim is presenting a review of literature about the relation between fibromyalgia and the signs and symptoms of temporomandibular disorders. For this purpose, a bibliographic search was performed of the period of 1990-2013, in the Medline, Pubmed, Lilacs and Scielo databases, using the keywords fibromyalgia, temporomandibular disorders and facial pain. Here we present a set of findings in the literature showing that fibromyalgia can lead to TMD symptoms. These studies demonstrated greater involvement of the stomatognathic system in FMS and myogenic disorders of masticatory system are the most commonly found in those patients. FMS appears to have a series of characteristics that constitute predisposing and triggering factors for TMD.

Partial denture metal framework may harbor potentially pathogenic bacteria.

PURPOSE: The aim of this study was to characterize and compare bacterial diversity on the removable partial denture (RPD) framework over time. MATERIALS AND METHODS: This descriptive pilot study included five women who were rehabilitated with free-end mandibular RPD. The biofilm on T-bar clasps were collected 1 week (t1) and 4 months (t2) after the RPD was inserted (t0). Bacterial 16S rDNA was extracted and PCR amplified. Amplicons were cloned; clones were submitted to cycle sequencing, and sequences were compared with GenBank (98% similarity). RESULTS: A total of 180 sequences with more than 499 bp were obtained. Two phylogenetic trees with 84 (t1) and 96 (t2) clones represented the bacteria biofilm at the RPD. About 93% of the obtained phylotypes fell into 25 known species for t1 and 17 for t2, which were grouped in 5 phyla: Firmicutes (t1=82%; t2=60%), Actinobacteria (t1=5%; t2=10%), Bacteroidetes (t1=2%; t2=6%), Proteobacteria (t1=10%; t2=15%) and Fusobacteria (t1=1%; t2=8%). The libraries also include 3 novel phylotypes for t1 and 11 for t2. Library t2 differs from t1 (P=.004); t1 is a subset of the t2 (P=.052). Periodontal pathogens, such as F. nucleatum, were more prevalent in t2. CONCLUSION: The biofilm composition of the RPD metal clasps changed along time after RPD wearing. The RPD framework may act as a reservoir for potentially pathogenic bacteria and the RPD wearers may benefit from regular follow-up visits and strategies on prosthesis-related oral health instructions.

Chronicity factors of temporomandibular disorders: a critical review of the literature

Facial pain often persists long after any identifiable organic pathology has healed. Moreover, in a subgroup of patients with temporomandibular disorder (TMD), no treatment is effective. Knowledge of factors associated with persistent pain in TMD could help identify personalized treatment approaches. Therefore, we conducted a critical review of the literature for the period from January 2000 to December 2013 to identify factors related to TMD development and persistence. The literature findings showed that chronic TMD is marked by psychological distress (somatization and depression, affective distress, fear of pain, fear of movement, and catastrophizing) and characteristics of pain amplification (hyperalgesia and allodynia). Furthermore, these factors seem to interact in TMD development. In addition, our review demonstrates that upregulation of the serotonergic pathway, sleep problems, and gene polymorphisms influence the chronicity of TMD. We conclude that psychological distress and pain amplification contribute to chronic TMD development, and that interactions among these factors complicate pain management. These findings emphasize the importance of multidisciplinary assistance in TMD treatment.