Baseline masticatory muscles' performance may predict pain relief in temporomandibular disorders.

OBJECTIVES: To compare masticatory muscles' recruitment in patients with temporomandibular disorders and asymptomatic control subjects. To evaluate if the masticatory muscles' recruitment pattern may predict symptoms' improvement after temporomandibular disorders treatment. MATERIALS AND METHODS: Standardized surface electromyography of anterior temporalis and superficial masseters muscles were recorded and compared at baseline in 26 patients with arthrogenous temporomandibular disorders (study group) and 26 asymptomatic subjects (control group). The study group was treated pharmacologically and by means of five arthrocentesis sessions. Pre-, during-, and post-treatment pain and mandibular function were assessed and compared among timepoints. Clinical improvement in terms of pain and mandibular function was correlated with pre-treatment standardized surface electromyography values. RESULTS: Temporomandibular disorders patients showed improved maximum mouth opening and pain during and after treatment with arthrocentesis compared to baseline (T-test p < 0.01). Standardized surface electromyography values were significantly different in temporomandibular disorders subjects compared to controls (T-test p < 0.05). Improvement in pain at rest after treatment was inversely correlated with pre-treatment masseters standardized surface electromyography symmetry (R-coefficient 0.3936; p < 0.05). CONCLUSIONS: Temporomandibular disorders patients showed a different muscular recruitment pattern compared to controls. The lesser the pre-treatment masseters symmetry, the greater the improvement of pain at rest after treatment.

COVID-19 impact on post-traumatic stress symptoms in burning mouth syndrome: A multicentric study.

OBJECTIVES: This study investigates the psychological impact of COVID-19 on burning mouth syndrome (BMS) patients. It focuses on comparing post-traumatic stress symptoms (PTSS), post-traumatic growth (PTG), and resilience between BMS patients and Controls. METHODS: A total of 100 BMS patients and 100 Controls from five Italian centers participated in this observational cross-sectional study. They completed several assessments, including the General Health Questionnaire, Depression Anxiety and Stress Scale, Insomnia Severity Index, National Stressful Events Survey Short Scale, Impact of Event Scale-Revised, Post Traumatic Growth Inventory Short Form, and Connor-Davidson Resilience Scale. RESULTS: BMS patients had significantly higher stress, anxiety, and depression (DASS-21 score) and post-traumatic stress symptoms (IES-R-6 score), particularly in terms of intrusive thoughts. They showed lower post-traumatic growth (PTGI-SF score) compared to Controls. The resilience scale (CDRS-10) was a key predictor of PTG in both groups, explaining a significant variance in PTGI-SF scores. CONCLUSIONS: BMS patients experienced heightened post-traumatic stress, stress, anxiety, and depression during the COVID-19 pandemic, with reduced post-traumatic growth. This highlights the need to prioritize their psychological well-being, focusing on stress management and fostering post-traumatic growth in challenging times.

Assessment of sleep disturbance in oral lichen planus and validation of PSQI: A case-control multicenter study from the SIPMO (Italian Society of Oral Pathology and Medicine).

BACKGROUND: The wellbeing of oral lichen planus patients (OLPs) may be strongly influenced by a poor quality of sleep (QoS) and psychological impairment. The aims were to analyze the prevalence of sleep disturbance, anxiety, and depression in OLPs and to validate the Pittsburgh Sleep Quality Index (PSQI) in OLPs. METHODS: Three hundred keratotic OLPs (K-OLPs), 300 with predominant non-keratotic OLP (nK-OLPs), and 300 controls were recruited in 15 Italian universities. The PSQI, Epworth Sleepiness Scale (ESS), Hamilton Rating Scales for Depression and Anxiety (HAM-D and HAM-A), Numeric Rating Scale (NRS), and Total Pain Rating Index (T-PRI) were administered. RESULTS: Oral lichen planus patients had statistically higher scores than the controls in the majority of the PSQI sub-items (p-values < 0.001**). Moreover, OLPs had higher scores in the HAM-D, HAM-A, NRS, and T-PRI (p-values < 0.001**). No differences in the PSQI sub-items' scores were found between the K-OLPs and nK-OLPs, although nK-OLPs suffered from higher levels of anxiety, depression, and pain (p-values: HAM-A, 0.007**, HAM-D, 0.009**, NRS, <0.001**, T-PRI, <0.001**). The female gender, anxiety, depression (p-value: 0.007**, 0.001**, 0.020*) and the intensity of pain, anxiety, and depression (p-value: 0.006**, <0.001**, 0.014*) were independent predictors of poor sleep (PSQI > 5) in K-OLPs and nK-OLPs, respectively. The PSQI's validation demonstrated good internal consistency and reliability of both the total and subscale of the PSQI. CONCLUSIONS: The OLPs reported an overall impaired QoS, which seemed to be an independent parameter according to the regression analysis. Hence, clinicians should assess QoS in OLPs and treat sleep disturbances in order to improve OLPs management.

Temporal relationship between sleep-time masseter muscle activity and apnea-hypopnea events: A pilot study.

BACKGROUND: Obstructive sleep apnea (OSA) is the most common sleep disorder due mainly to peripheral causes, characterized by repeated episodes of obstruction of the upper airways, associated with arousals and snoring. Sleep bruxism (SB) is a masticatory muscle activity during sleep that is characterized as rhythmic (phasic) or nonrhythmic (tonic) and is not a movement disorder or a sleep disorder in otherwise healthy individuals. Given the potentially severe consequences and complications of apnea, the concurrent high prevalence of SB in daily dental practice, getting deeper into the correlation between these phenomena is worthy of interest.. STUDY OBJECTIVES: The aim of this study was to investigate the correlation between SB-related masseter muscle activity (MMA) and apnea-hypopnea events as well as to assess their temporal sequence. METHODS: Thirty (N = 30) patients with sleep respiratory disorders and clinical suspicion of sleep bruxism (SB) were recruited. Ambulatory polygraphic recording was performed to detect apnea-hypopnea events (AHEs) and sleep bruxism episodes (SBEs). Pearson test was used to assess the correlation between apnea-hypopnea index (AHI) and SB index (SBI). A 5-s time window with respect to the respiratory events was considered to describe the temporal distribution of SBEs. Furthermore, SBI was compared between groups of patients with different AHI severity (i.e., mild, moderate and severe) using ANOVA. RESULTS: On average, AHI was 27.1 ± 21.8 and SBI 9.1 ± 7.5. No correlation was shown between AHI and SBI. Most of SBEs (66.8%) occurred without a temporal relationship with respiratory events. Considering OSA, 65.7% of SBEs occurred within 5 s after AHEs, while in the case of central apnea (CA) 83.8% of SBEs occurred before the respiratory event. The participants with severe apnea (N = 9) show a tendency to have higher bruxism indexes when compared to patients with mild (N = 11) and moderate apnea (N = 10). CONCLUSIONS: Findings suggest that: 1. At the study population level, there is no correlation between AHI and SBI, as well as any temporal relationship between SBEs and respiratory events. 2. Specific patterns of temporal relationship might be identified with future studies focusing on the different types of apnea-hypopnea events and bruxism activities.

Human amniotic membrane: an improvement in the treatment of Medication-related osteonecrosis of the jaw (MRONJ)? A case-control study.

The aim of this article is to report the results obtained by the use of HAM in surgical wound healing and the reduction of relapse in patients affected by Medication-related osteonecrosis of the jaw (MRONJ).The study involved patients with the diagnosis of MRONJ, surgically treated between October 2016 and April 2019, in a case-control setting. Enrolled patients were randomly divided into 2 groups. One group will be treated with resective surgery and with the insertion of HAM patch (Group A), while the second group had been treated exclusively with resective surgery (Group B).The patients underwent MRONJ surgical treatment with the placement of amniotic membrane patches at the wound site. Data regarding the long-term complications/functions were evaluated at 3, 6, 12, and 24 months after surgery. Pain measurements were performed before the intervention (T0), 7(T1) and 30(T2) days after surgery. 49 patients were included in the study. 2 patients of GROUP A after 30 days since they were surgically treated showed persistent bone exposure. 5 patients of group B demonstrated a lack of healing of the surgical wound with the persistence of bone exposed to 30 days after surgery. Statistical analysis ruled out any difference in OUTCOME (relapse) between GROUP A and B (p = 0.23). However, the Fisher test highlighted a significant difference between the use of HAM and only surgical treatment in pain at rest (p = 0.032). The use of amniotic membrane implement the patient's quality of life and reduce pain perception. has a learning curve that is fast enough to justify its routine use.

Computer-assisted surgery with custom prostheses and human amniotic membrane in a patient with bilateral class IV TMJ reankylosis: a case report.

A gold-standard technique has yet to be found for the treatment of temporomandibular joint ankylosis (TMJa), particularly in patients with recurring ankylosis. A 58-year-old male patient, with a history of multiple TMJ surgeries and severe limitation of mouth opening (maximum interincisal distance [MID] was 10 mm). Computerised tomography (CT) imaging highlighted a bilateral type IV ankylosis. The surgical guides were manufactured using a 3D printing method after obtaining a proper design of the osteotomy lines. The positioning of the fossa and condyle components of the custom TMJ prosthesis was digitally performed. Osteotomies were carried out using surgical guides and TMJ prostheses were placed as per the virtual planning. A human amniotic mambrana is inserted between the two prosthetic components to avoid ranchylosis. The post-operative CT showed the correct positioning of the condylar prosthesis. MID after 10 days was 37 mm. Total joint reconstruction surgery using 3D virtual surgical planning may be an effective surgical option for achieving a precise surgical outcome and making use of a single-stage approach in cases of TMJa and the use of the amniotic membrane, thanks to its healing properties and reduction of pain perception, seems to improve the quality of the immediate post-operative period.

Where do you live? North versus Central-South differences in relation to Italian patients with oral lichen planus: a cross-sectional study from the SIPMO (Italian Society of Oral Pathology and Medicine).

BACKGROUND: Oral lichen planus (OLP) is an immune-mediated inflammatory chronic disease of the oral mucosa, with different patterns of clinical manifestations which range from keratotic manifestations (K-OLP) to predominantly non-keratotic lesions (nK-OLP). The aim of the study was to analyze the differences in the clinical, psychological profile and symptoms between Italian patients of the North and Central-South with K-OLP and nK-OLP. METHODS: 270 K-OLP and 270 nK-OLP patients were recruited in 15 Italian universities. The Numeric Rating Scale (NRS), Total Pain Rating Index (T-PRI), Hamilton Rating Scales for Depression and for Anxiety (HAM-D and HAM-A), Pittsburgh Sleep Quality Index (PSQI), and Epworth Sleepiness Scale (ESS) were administered. RESULTS: The Central-South K-OLP (CS-K-OLP) patients reported a higher frequency of pain/burning compared with the K-OLP patients of the North (N-K-OLP) with higher scores in the NRS and T-PRI (p value < 0.001**). The CS-K-OLP and the CS-nK-OLP patients showed higher scores in the HAM-D, HAM-A, PSQI and ESS compared with the Northern patients (p value < 0.001**). Multivariate logistic regression revealed that the NRS and T-PRI showed the greatest increase in the R2 value for the CS-K-OLP (DR2 = 9.6%; p value < 0.001**; DR2 = 9.7% p value < 0.001**; respectively) and that the oral symptoms (globus, itching and intraoral foreign body sensation) and PSQI showed the greatest increase in the R2 value for the CS-nK-OLP (DR2 = 5.6%; p value < 0.001**; DR2 = 4.5% p value < 0.001** respectively). CONCLUSIONS: Pain and mood disorders are predominant in patients with OLP in the Central-South of Italy. Clinicians should consider that the geographical living area may explain the differences in oral symptoms and psychological profile in OLP.

Smartphone-based evaluation of awake bruxism behaviours in a sample of healthy young adults: findings from two University centres.

A smartphone-based ecological momentary assessment (EMA) strategy was used to assess the frequency of awake bruxism behaviours, based on the report of five oral conditions (ie relaxed jaw muscles, teeth contact, mandible bracing, teeth clenching and teeth grinding). One hundred and fifty-three (N = 153) healthy young adults (mean ± SD age = 22.9 ± 3.2 years), recruited in two different Italian Universities, used a dedicated smartphone application that sent 20 alerts/day at random times for seven days. Upon alert receipt, the subjects had to report in real-time one of the above five possible oral conditions. Individual data were used to calculate an average frequency of the study population for each day. For each condition, a coefficient of variation (CV) of frequency data was calculated as the ratio between SD and mean values over the seven recording days. Average frequency of the different behaviours over the seven days was as follows: relaxed jaw muscle, 76.4%; teeth contact, 13.6%; mandible bracing, 7.0%; teeth clenching, 2.5%; and teeth grinding, 0.5%. No significant differences were found in frequency data between the two University samples. The relaxed jaw muscles condition was more frequent in males (80.7 ± 17.7) than in females (73.4 ± 22.2). The frequency of relaxed jaw muscles condition over the period of observation had a very low coefficient of variation (0.27), while for the different awake bruxism behaviours, CV was in a range between 1.5 (teeth contact) and 4.3 (teeth grinding). Teeth contact was the most prevalent behaviour (57.5-69.7). Findings from this investigation suggest that the average frequency of AB behaviours over one week, investigated using EMA-approach, is around 23.6%.

Smartphone-based application for EMA assessment of awake bruxism: compliance evaluation in a sample of healthy young adults.

OBJECTIVE: A smartphone-based ecological momentary assessment (EMA) strategy to collect real time data on awake bruxism (AB) has been recently introduced. The aim of this study was to assess the compliance with its use over 1 week in a sample of healthy young adults. METHOD: Sixty (N = 60) healthy young adults (mean age 24.2 ± 4.1 years) used a dedicated smartphone application that sent 20 alerts at random times throughout the day. Upon alert receipt, the subjects had to report in real time their condition among five possible options: relaxed jaw muscles, teeth contact, teeth clenching, teeth grinding, and mandible bracing. Compliance rate with the app was assessed at the individual and group level in terms of percentage of answered alerts as well as number of days that were needed to reach the targeted observation period of 7 days with a compliance of at least 60%. RESULTS: The mean compliance recorded with the smartphone application was 67.8% of the total alerts. On average, 9.8 ± 3.2 days (range 7-19) have been necessary to achieve the targeted goal of 7 days with a minimum of 60% alerts/day. No gender differences were detected in any compliance data. Response rate was not different during weekdays or weekends. CONCLUSIONS: This investigation is the first attempt to assess individual compliance with EMA for reporting awake bruxism. Results suggest that a smartphone-based strategy can have interesting potential. The compliance rate reported in this study will serve as a comparison standpoint for future investigations. CLINICAL SIGNIFICANCE: Based on the recent multidisciplinary focus on the study of awake bruxism, EMA has emerged as a potential approach for use in the clinical and research settings. This investigation suggests that compliance with such strategy is good, thus making it worthy of adoption for the assessment of AB and its clinical implications.

Temporomandibular Joint Disorders in Patients With Different Facial Morphology. A Systematic Review of the Literature.

PURPOSE: The present article aimed to review systematically the literature on the relation between facial skeletal structures and temporomandibular joint (TMJ) disorders. MATERIALS AND METHODS: A systematic search in the dental and medical literature was performed to identify all studies of humans assessing the relation between TMJ disorders and facial morphology. Articles were included based on study design, irrespective of TMJ disorder (eg, disc displacement, osteoarthrosis, or unspecified), skeletal features, diagnostic strategies (e.g., imaging techniques or clinical assessment), and population (eg, demographic features of participants) under investigation. The selected articles were assessed according to a format based on patients, problem, and population, intervention, comparison, and outcome and quality was evaluated based on the Newcastle-Ottawa Scale. RESULTS: Thirty-four articles were included in the review, 27 of which concerned adult samples and 7 concerned adolescent samples. Quality was generally moderate. The articles dealt with the relation between facial morphology and the following TMJ disorders, assessed clinically or by magnetic resonance (MR): disc displacement (n = 20), osteoarthritis or osteoarthrosis (n = 8), and temporomandibular disorder signs and symptoms (n = 6). The different approaches featuring the various investigations and the presence of some potential methodologic biases complicated a summary of the findings. Most studies reported that some features related to the vertical dimension of the face might help distinguish patients with potential TMJ disc displacement or MR-detected signs of osteoarthrosis from those without TMJ disorders. CONCLUSIONS: The quality of the available literature is not adequate to provide an evidence base on the topic. Despite the heterogeneity of design and findings of the reviewed articles, it seems reasonable to suggest that skeletal Class II profiles and hyperdivergent growth patterns are likely associated with an increased frequency of TMJ disc displacement and degenerative disorders.

Theories on possible temporal relationships between sleep bruxism and obstructive sleep apnea events. An expert opinion.

BACKGROUND: Sleep bruxism (SB) is a term covering different motor phenomena with various risk and etiological factors and potentially different clinical relevance, especially as far as its possible protective role against obstructive sleep apnea (OSA) is concerned. The present expert opinion discusses the possible temporal relationships between the two phenomena. METHODS: Four hypothetical scenarios for a temporal relationship may be identified: (1) the two phenomena are unrelated; (2) the onset of the OSA event precedes the onset of the SB event within a limited time span, with SB having a potential OSA-protective role; (3) the onset of the SB event precedes the onset of the OSA event within a limited time span, with SB having an OSA-inducing effect; and (4) the onset of the OSA and SB event occurs at the same moment. RESULTS: Literature findings on the SB-OSA temporal relationship are inconclusive. The most plausible hypothesis is that the above scenarios are all actually possible and that the relative predominance of one specific sequence of events varies at the individual level. SB activity may be protective against OSA by protruding the mandible and restoring airway patency in those subjects who benefit from mandibular advancement strategies or may even be related to OSA induction, as a consequence of airways' mucosae swelling resulting from a SB-induced trigeminal cardiac reflex. CONCLUSIONS: Clinicians should keep in mind that the SB-OSA relationship is complex and that interindividual differences may explain the possible different SB-OSA relationships, with particular regard to the anatomical site of obstruction.

Prevalence of tinnitus in patients with different temporomandibular disorders symptoms.

OBJECTIVE: To compare the prevalence of tinnitus in temporomandibular disorder (TMD) patients affected by either jaw muscle pain, temporomandibular joint (TMJ) internal derangements, or TMJ arthrosis. METHODS: The presence of self-reported tinnitus was assessed in 250 consecutive TMD patients and correlation analysis was performed with clinical TMD signs and symptoms. RESULTS: Tinnitus prevalence in the TMD population was 30.4%. Any significant patterns of correlation were shown for the overall study group, despite a higher tinnitus prevalence in patients with (32.8%) than without masseter pain (24.8%; p = 0.176) as well as in those with (33.7%) than without TMJ arthrosis (26.1%; p = 0.082). Age-stratified analysis showed correlations with masseter pain in older patients (48.3% vs 16; p < 0.05), and with arthrosis in younger patients (57.1% vs 22.2%; p < 0.05). CONCLUSIONS: Any correlation patterns were shown between tinnitus and TMD. Age-stratified analysis suggested possible hypotheses for a symptom-specific clinical correlation that should be assessed with future research.

A conservative surgical approach to temporomandibular joint ankylosis.

The current article describes a case of a patient with temporomandibular joint (TMJ) ankylosis undergoing surgery performed with a tailored technique for condylar reshaping. A patient with posttraumatic bilateral TMJ ankylosis underwent interpositional arthroplasty with temporalis fascia, and focus was put on the need to maintain the vertical height of the mandible. The postoperative course was uneventful, and positive outcomes were kept during a 1-year follow-up span. The adoption of surgical strategies aiming at restoring a condylar shape as similar as possible to the natural one may be important in the light of the search for surgeries providing and/or recreating normal function of the TMJ.

Jaw clenching effects in relation to two extreme occlusal features: patterns of diagnoses in a TMD patient population.

OBJECTIVE: The aim of this investigation was to compare the pattern of temporomandibular disorder (TMD) diagnoses in clenching patients with different occlusal features, the null hypothesis being that no between-group differences exist. MATERIALS AND METHODS: Two groups of subjects receiving a jaw clenching diagnosis and having large overjet or anterior open bite (Group A; N=45, 75.5% females, mean age: 38.1 +/- 15.9 years) or normal occlusion (Group B; N=69, 71% females, mean age: 34.6 +/- 13.8 years) were recruited among a TMD patient population and were given Research Diagnostic Criteria for TMD (RDC/TMD) axis I diagnoses, namely, group I muscle disorders, group II disc displacements, and group III arthralgia/osteoarthritis/osteoarthrosis. MAJOR FINDINGS: The distribution of RDC/TMD single and combined group diagnoses was significantly different between the two groups (P<0.05), with Group A subjects showing a higher prevalence of multiple diagnoses (60% versus 43.3%), as well as a higher prevalence of combined RDC/TMD axis I group II and III diagnoses (37.8% versus 20.2%). All TMD signs and symptoms were more frequent in the patients with large overjet or anterior open bite with respect to the patients with normal occlusion. CONCLUSION: In a TMD patient population, jaw clenching may have different consequences in subjects with large overjet or anterior open bite with respect to subjects featuring normal occlusion.

Are occlusal features associated with different temporomandibular disorder diagnoses in bruxers?

AIMS: The present study was designed to test the hypothesis that dental occlusion may have a role in mediating the effects of bruxism in temporomandibular disorders (TMD) patients. It aimed to answer the clinical research question: in a population of TMD patients with clinically diagnosed clenching-type bruxism, are the different TMD diagnoses associated with different occlusal features? MATERIALS AND METHODS: A total of 294 TMD patients (73% females, mean age 38·3±9·2 years) who were positive for a clinical diagnosis of clenching-type bruxism underwent an assessment in accordance with the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) axis I, as well as a recording of nine occlusal features. Statistical analyses were performed to test the null hypotheses that: (1) no differences existed between the patients with or without the various occlusal features as for the prevalence of the various single and combined RDC/TMD group diagnoses (single variable analysis), and (2) having any specific occlusal feature makes no difference in distinguishing within the RDC/TMD diagnoses (multiple variable analysis). RESULTS: The distribution of the different combination of RDC/TMD axis I diagnoses was significantly different in patients with laterotrusive interferences with respect to those without such interferences (chi-square = 15·209; P = 0·033) as well as in patients with a slide from retruded contact position (RCP) to maximum intercuspation (MI) >2 mm with respect to those without such slide (chi-square = 4·029; P = 0·012) and in those with or without molar class asymmetry (chi-square = 17·438; P = 0·015). Multinomial regression analysis showed that the model including the various occlusal features account for 20·4% of the variance for RDC/TMD diagnoses (Nagelkerke R(2) = 0·204) and allowed the rejection of the null hypothesis that having such specific occlusal features makes no difference in distinguishing within the RDC/TMD diagnoses. CONCLUSIONS: Within the limitations of this study, it can be suggested that in a population of patients with TMD and clinically-diagnosed clenching-type bruxism, the patterns of TMD diagnoses may be influenced, at least in part, by the presence of some features of dental occlusion, namely, slide RCP-MI, laterotrusive interferences, and molar asymmetry.

Oral appliances for the treatment of obstructive sleep apnea in patients with low C-PAP compliance: a long-term case series.

OBJECTIVES: To assess the effectiveness of mandibular advancement devices (MADs) for the treatment of obstructive sleep apnea syndrome (OSAS) over a long-term follow-up in patients non-compliant with continuous positive airway pressure (CPAP) and to identify potential predictive factors of response to MADs. METHODS: Fifteen OSAS patients were enrolled. Apnea-hypopnea index (AHI) and daytime sleepiness were assessed at baseline and at the end of follow-up. Potential baseline predictors of treatment effectiveness were assessed. RESULTS: AHI and Epworth Sleepiness Scale (ESS) scores improved significantly with MADs. Sixty per cent of patients were 'responders', of whom 33% were 'full responders'. Sixty-seven per cent of patients showed total compliance. No correlations between the potential predictors and the response to MAD therapy were found. DISCUSSION: Effectiveness of MAD therapy was shown over a long-term follow-up in OSAS patients with low compliance to CPAP. Efforts to identify predictive success factors fell short.

Intramuscular Botulinum Toxin as an Adjunct to Arthrocentesis with Viscosupplementation in Temporomandibular Disorders: A Proof-of-Concept Case-Control Investigation.

BACKGROUND: The reduction in joint load is a potential beneficial factor in managing osteoarthritis of the temporomandibular joint (TMJ). This paper aims to compare the effectiveness of the intramuscular injection of botulinum toxin (BTX-A) as an adjunct to TMJ arthrocentesis plus viscosupplementation with arthrocentesis plus viscosupplementation alone in the management of TMJ osteoarthritis. METHODS: A pilot clinical retrospective study examined TMJ osteoarthritis treatments. Patients were divided into two groups: Group A received BTX-A injections and arthrocentesis with viscosupplementation, while Group B received only arthrocentesis with viscosupplementation. The study assessed outcomes based on mouth opening (MO), pain at rest (PR), pain at mastication (PF), and masticatory efficiency (ME) at various time points (baseline (T0), 1 week (T1), 2 weeks (T2), 3 weeks (T3), and 4 weeks (T4)) up to 2 months after treatment. RESULTS: The study included two groups, each with five patients. Group A received five weekly sessions of arthrocentesis plus viscosupplementation and a single BTX-A injection during the first arthrocentesis appointment. Group B underwent the five-session protocol of arthrocentesis plus viscosupplementation alone. MO, PF, PR, and ME improved quickly in T2 in both groups, but the improvement was of greater importance over the following weeks and lasted longer in Group A. CONCLUSIONS: Arthrocentesis with viscosupplementation associated with BTX-A was found to be more effective than arthrocentesis alone in improving clinical outcomes. This suggests that patients with TMJ osteoarthritis and myofascial pain may benefit from reduced muscle tone and joint load.

Surface electromyography findings in unilateral myofascial pain patients: comparison of painful vs. non painful sides.

OBJECTIVES: To answer the clinical research question: in patients with myofascial pain, are there any differences in the surface electromyography (sEMG) activity of muscles of the painful and nonpainful sides that can be detected by commercially available devices? METHODS: The study sample (N = 39; 64% F, mean age 35.7 ± 15 years) consisted of patients seeking for temporomandibular disorders Temporomandibular Disorders (TMD) treatment and meeting Research Diagnostic Criteria for TMD (RDC/TMD) diagnosis of myofascial pain, with pain referred only in muscles on one side. They underwent sEMG of jaw muscles to record levels of standardized sEMG activity at rest, as well as during maximum clenching on teeth for the four investigated muscles, viz., bilateral masseter and temporalis. The existence of differences between sEMG values of muscles of the painful and nonpainful sides during the standardization test (i.e., clenching on cotton rolls) at rest and during clenching on teeth was assessed. RESULTS: At the study population level, differences between the sEMG values of muscles of the painful and nonpainful sides were not significant in any conditions, viz., either at rest or during clenching tasks. At the individual level, the difference between the sEMG activity of painful and nonpainful sides was very variable. CONCLUSIONS: The above findings were not supportive of the existence of any detectable difference in sEMG activity between jaw muscles of the painful and nonpainful sides in patients with unilateral myofascial pain. Centrally mediated mechanism for pain adaptation may explain these findings, and the role of sEMG as a diagnostic tool for muscle pain needs to be carefully reconceptualized.

Epidemiology of bruxism in adults: a systematic review of the literature.

AIMS: To perform a systematic review of the literature dealing with the prevalence of bruxism in adult populations. METHODS: A systematic search of the medical literature was performed to identify all peer-reviewed English-language papers dealing with the prevalence assessment of either awake or sleep bruxism at the general population level by the adoption of questionnaires, clinical assessments, and polysomnographic (PSG) or electromyographic (EMG) recordings. Quality assessment of the reviewed papers was performed according to the Methodological evaluation of Observational REsearch (MORE) checklist, which enables the identification of flaws in the external and internal validity. Cut-off criteria for an acceptable external validity were established to select studies for the discussion of prevalence data. For each included study, the sample features, diagnostic strategy, and prevalence of bruxism in relation to age, sex, and circadian rhythm, if available, were recorded. RESULTS: Thirty-five publications were included in the review. Several methodological problems limited the external validity of findings in most studies, and prevalence data extraction was performed only on seven papers. Of those, only one paper had a flaw less external validity, whilst internal validity was low in all the selected papers due to their self-reported bruxism diagnosis alone, mainly based on only one or two questionnaire items. No epidemiologic data were available from studies adopting other diagnostic strategies (eg, PSG, EMG). Generically identified "bruxism" was assessed in two studies reporting an 8% to 31.4% prevalence, awake bruxism was investigated in two studies describing a 22.1% to 31% prevalence, and prevalence of sleep bruxism was found to be more consistent across the three studies investigating the report of "frequent" bruxism (12.8% ± 3.1%). Bruxism activities were found to be unrelated to sex, and a decrease with age was described in elderly people. CONCLUSION: The present systematic review described variable prevalence data for bruxism activities. Findings must be interpreted with caution due to the poor methodological quality of the reviewed literature and to potential diagnostic bias related with having to rely on an individual's self-report of bruxism.

Occlusal factors are not related to self-reported bruxism.

AIMS: To estimate the contribution of various occlusal features of the natural dentition that may identify self-reported bruxers compared to nonbruxers. METHODS: Two age- and sex-matched groups of self-reported bruxers (n = 67) and self-reported nonbruxers (n = 75) took part in the study. For each patient, the following occlusal features were clinically assessed: retruded contact position (RCP) to intercuspal contact position (ICP) slide length (< 2 mm was considered normal), vertical overlap (< 0 mm was considered an anterior open bite; > 4 mm, a deep bite), horizontal overlap (> 4 mm was considered a large horizontal overlap), incisor dental midline discrepancy (< 2 mm was considered normal), and the presence of a unilateral posterior crossbite, mediotrusive interferences, and laterotrusive interferences. A multiple logistic regression model was used to identify the significant associations between the assessed occlusal features (independent variables) and self-reported bruxism (dependent variable). RESULTS: Accuracy values to predict self-reported bruxism were unacceptable for all occlusal variables. The only variable remaining in the final regression model was laterotrusive interferences (P = .030). The percentage of explained variance for bruxism by the final multiple regression model was 4.6%. This model including only one occlusal factor showed low positive (58.1%) and negative predictive values (59.7%), thus showing a poor accuracy to predict the presence of self-reported bruxism (59.2%). CONCLUSION: This investigation suggested that the contribution of occlusion to the differentiation between bruxers and nonbruxers is negligible. This finding supports theories that advocate a much diminished role for peripheral anatomical-structural factors in the pathogenesis of bruxism.