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Toxins Mar 2020The purpose of this study is to evaluate the effects of botulinum toxin type A (BoNT-A) for managing sleep bruxism (SB) in a randomized, placebo-controlled trial. Thirty... (Randomized Controlled Trial)
Randomized Controlled Trial
The purpose of this study is to evaluate the effects of botulinum toxin type A (BoNT-A) for managing sleep bruxism (SB) in a randomized, placebo-controlled trial. Thirty SB subjects were randomly assigned into two groups evenly. The placebo group received saline injections into each masseter muscle, and the treatment group received BoNT-A injections into each masseter muscle. Audio-video-polysomnographic recordings in the sleep laboratory were made before, at four weeks after, and at 12 weeks after injection. Sleep and SB parameters were scored according to the diagnostic and coding manual of American Academy of Sleep Medicine. The change of sleep and SB parameters were investigated using repeated measures analysis of variance (RM-ANOVA). Twenty-three subjects completed the study (placebo group 10, treatment group 13). None of the SB episode variables showed a significant time and group interaction ( > 0.05) except for electromyography (EMG) variables. The peak amplitude of EMG bursts during SB showed a significant time and group interaction ( = 0.001). The injection decreased the peak amplitude of EMG bursts during SB only in the treatment group for 12 weeks ( < 0.0001). A single BoNT-A injection cannot reduce the genesis of SB. However, it can be an effective management option for SB by reducing the intensity of the masseter muscle.
Topics: Adult; Botulinum Toxins, Type A; Double-Blind Method; Electromyography; Female; Humans; Injections, Intramuscular; Male; Masseter Muscle; Middle Aged; Sleep Bruxism; Treatment Outcome; Young Adult
PubMed: 32182879
DOI: 10.3390/toxins12030168 -
The Cochrane Database of Systematic... Sep 2013Benign masseter muscle hypertrophy is an uncommon clinical phenomenon of uncertain aetiology which is characterised by a soft swelling near the angle of the mandible.... (Review)
Review
BACKGROUND
Benign masseter muscle hypertrophy is an uncommon clinical phenomenon of uncertain aetiology which is characterised by a soft swelling near the angle of the mandible. The swelling may on occasion be associated with facial pain and can be prominent enough to be considered cosmetically disfiguring. Varying degrees of success have been reported for some of the treatment options for masseter hypertrophy, which range from simple pharmacotherapy to more invasive surgical reduction. Injection of botulinum toxin type A into the masseter muscle is generally considered a less invasive modality and has been advocated for cosmetic sculpting of the lower face. Botulinum toxin type A is a powerful neurotoxin which is produced by the anaerobic organism Clostridium botulinum and when injected into a muscle causes interference with the neurotransmitter mechanism producing selective paralysis and subsequent atrophy of the muscle.This review is an update of a previously published Cochrane review.
OBJECTIVES
To assess the efficacy and safety of botulinum toxin type A compared to placebo or no treatment, for the management of benign bilateral masseter hypertrophy.
SEARCH METHODS
We searched the following databases from inception to April 2013: the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE (via PubMed); EMBASE (via embase.com); Web of Science; CINAHL; Academic Search Premier (via EBSCOhost); ScienceDirect; LILACS (via BIREME); PubMed Central and Google Scholar (from 1700 to 19 April 2013). We searched two bibliographic databases of regional journals (IndMED and Iranmedex) which were expected to contain relevant trials. We also searched reference lists of relevant articles and contacted investigators to identify additional published and unpublished studies.
SELECTION CRITERIA
Randomised controlled trials (RCTs) and controlled clinical trials (CCTs) comparing intra-masseteric injections of botulinum toxin versus placebo administered for cosmetic facial sculpting in individuals of any age with bilateral benign masseter hypertrophy, which had been self-evaluated and confirmed by clinical and radiological examination were considered for inclusion. We excluded participants with unilateral or compensatory contralateral masseter hypertrophy resulting from head and neck radiotherapy.
DATA COLLECTION AND ANALYSIS
Two review authors independently screened the search results. For future updates, two authors will independently extract data and assess trial quality using the Cochrane risk of bias tool. Risk ratios (RR) and corresponding 95% confidence intervals (CI) will be calculated for all dichotomous outcomes and the mean difference (MD) and 95% CI will be calculated for continuous outcomes.
MAIN RESULTS
We retrieved 683 unique references to studies. After screening these references 660 were excluded for being non-applicable. We assessed 23 full text articles for eligibility and all of these studies were excluded from the review.
AUTHORS' CONCLUSIONS
We were unable to identify any RCTs or CCTs assessing the efficacy and safety of intra-masseteric injections of botulinum toxin for people with bilateral benign masseter hypertrophy. The absence of high level evidence for the effectiveness of this intervention emphasises the need for well-designed, adequately powered RCTs.
Topics: Botulinum Toxins, Type A; Humans; Hypertrophy; Injections, Intramuscular; Masseter Muscle; Neuromuscular Agents
PubMed: 24018587
DOI: 10.1002/14651858.CD007510.pub3 -
Clinical Oral Investigations Mar 2022To investigate the effects of dental/skeletal malocclusion and orthodontic treatment on four main objective parameters of chewing and jaw function (maximum occlusal bite... (Review)
Review
OBJECTIVE
To investigate the effects of dental/skeletal malocclusion and orthodontic treatment on four main objective parameters of chewing and jaw function (maximum occlusal bite force [MOBF], masticatory muscle electromyography [EMG], jaw kinematics, and chewing efficiency/performance) in healthy children.
MATERIALS AND METHODS
Systematic searches were conducted in MEDLINE (OVID), Embase, and the Web of Science Core Collection. Studies that examined the four parameters in healthy children with malocclusions were included. The quality of studies and overall evidence were assessed using the Joanna Briggs Institute and GRADE tools, respectively.
RESULTS
The searches identified 8192 studies; 57 were finally included. The quality of included studies was high in nine studies, moderate in twenty-three studies, and low in twenty-five studies. During the primary dentition, children with malocclusions showed similar MOBF and lower chewing efficiency compared to control subjects. During mixed/permanent dentition, children with malocclusion showed lower MOBF and EMG activity and chewing efficiency compared to control subjects. The jaw kinematics of children with unilateral posterior crossbite showed a larger jaw opening angle and a higher frequency of reverse chewing cycles compared to crossbite-free children. There was a low to moderate level of evidence on the effects of orthodontic treatment in restoring normal jaw function.
CONCLUSIONS
Based on the limitations of the studies included, it is not entirely possible to either support or deny the influence of dental/skeletal malocclusion traits on MOBF, EMG, jaw kinematics, and masticatory performance in healthy children. Furthermore, well-designed longitudinal studies may be needed to determine whether orthodontic treatments can improve chewing function in general.
CLINICAL RELEVANCE
Comprehensive orthodontic treatment, which includes evaluation and restoration of function, may or may not mitigate the effects of malocclusion and restore normal chewing function.
Topics: Bite Force; Child; Electromyography; Humans; Malocclusion; Masseter Muscle; Mastication; Masticatory Muscles
PubMed: 34985577
DOI: 10.1007/s00784-021-04356-y -
Journal of Prosthodontic Research Oct 2022To investigate the effect of masseter muscle activity during wakefulness and sleep on tooth wear.
PURPOSE
To investigate the effect of masseter muscle activity during wakefulness and sleep on tooth wear.
METHODS
Sixteen participants with no or mild tooth wear (NMTW group) and sixteen participants with moderate-to-severe tooth wear (MSTW group) were enrolled. The severity of tooth wear was evaluated using the occlusal and incisal indices of the tooth wear index. Surface electromyography was performed to record the electrical activity of the left masseter muscle during wakefulness and sleep. Electromyographic activity was detected using an electromyographic threshold of 5% and 20% of maximal voluntary clenching (MVC). The total duration of electromyographic activity and bruxism episodes were calculated.
RESULTS
The mean ages of the NMTW and MSTW groups were 71.75 ± 7.61 years and 71.69 ± 7.49 years, respectively. The mean cumulative duration of electromyographic activity during wakefulness using a threshold of >5% MVC was 6.44 ± 4.52 min/h and 13.62 ± 10.08 min/h for the NMTW and MSTW groups, respectively (p=0.048). The mean total durations of electromyographic activity during wakefulness and sleep using a threshold of >20% MVC were 1.08 ± 1.70 min/h and 1.05 ± 3.02 min/h, respectively, in the NMTW group and 4.78 ± 6.37 min/h and 1.61 ± 1.79 min/h, respectively, in the MSTW group (p=0.048 and p=0.003, respectively).
CONCLUSION
These results suggest that masseter electromyographic activity during wakefulness and sleep may be related to the severity of tooth wear.
Topics: Aged; Electromyography; Humans; Masseter Muscle; Middle Aged; Sleep; Sleep Bruxism; Tooth Abrasion; Tooth Attrition; Tooth Wear; Wakefulness
PubMed: 34955483
DOI: 10.2186/jpr.JPR_D_21_00171 -
Clinical and Experimental Dental... Jun 2022Masseter muscle thickness and its relationship with vertical craniofacial morphology have been extensively studied in adults, but data on children are lacking.
BACKGROUND
Masseter muscle thickness and its relationship with vertical craniofacial morphology have been extensively studied in adults, but data on children are lacking.
OBJECTIVE
To examine the association between masseter muscle thickness and vertical cephalometric parameters in a group of Class II malocclusion growing children.
METHODS
The current study design was retrospective and cross-sectional, looking at a sample of 211 growing children with Class II malocclusion between the ages of 6 and 15 derived from two centers. Ultrasonographic masseter muscle thickness measurements and vertical cephalometric variables, including the gonial angle, were evaluated before any orthodontic treatment had been carried out. Multiple linear regression analysis was used to examine the association between masseter muscle thickness and vertical cephalometric measurements, including age and patient origin as independent variables in the analysis.
RESULTS
In the present sample, masseter muscle thickness was found to be independent of sex, but correlated with age, with older children presenting thicker masseter muscles. In the total patient sample, using multiple regression analyses, children with thicker masseter muscles had significantly smaller intermaxillary and gonial angles. No other cephalometric vertical characteristics showed associations with masseter muscle thickness.
CONCLUSION
In growing children with Class II malocclusion, those with thicker masseter muscles are more likely to display smaller intermaxillary and gonial angles respectively.
Topics: Adolescent; Adult; Child; Cross-Sectional Studies; Humans; Malocclusion, Angle Class II; Masseter Muscle; Retrospective Studies; Vertical Dimension
PubMed: 35150084
DOI: 10.1002/cre2.528 -
Revue de Stomatologie, de Chirurgie... Apr 2013The aim of this work is to review the relationship between the function of the masseter muscle and the occurrence of malocclusions. An analysis was made of the masseter... (Review)
Review
The aim of this work is to review the relationship between the function of the masseter muscle and the occurrence of malocclusions. An analysis was made of the masseter muscle samples from subjects who underwent mandibular osteotomies. The size and proportion of type-II fibers (fast) decreases as facial height increases. Patients with mandibular asymmetry have more type-II fibers on the side of their deviation. The insulin-like growth factor and myostatin are expressed differently depending on the sex and fiber diameter. These differences in the distribution of fiber types and gene expression of this growth factor may be involved in long-term postoperative stability and require additional investigations. Muscle strength and bone length are two genetically determined factors in facial growth. Myosin 1H (MYOH1) is associated with prognathia in Caucasians. As future objectives, we propose to characterize genetic variations using "Genome Wide Association Studies" data and their relationships with malocclusions.
Topics: Cephalometry; Genetic Predisposition to Disease; Humans; Jaw Abnormalities; Malocclusion; Masseter Muscle; Muscle Fibers, Skeletal
PubMed: 23838245
DOI: 10.1016/j.revsto.2013.01.015 -
Dento Maxillo Facial Radiology Aug 2017The aim of this study was to systematically review the existing scientific literature and evidence about (a) the validation of masseter muscle ultrasonography for... (Review)
Review
The aim of this study was to systematically review the existing scientific literature and evidence about (a) the validation of masseter muscle ultrasonography for accurate assessment of muscle thickness and (b) the reproducibility of masseter muscle thickness measures. An electronic literature search was conducted using determined keywords on specific databases. Preliminary search revealed 298 articles listed in Medline, Scopus and Web of Science. 60 duplicates were rejected, leaving 238 articles for review. After reading titles and abstracts, 31 articles remained. 23 articles were assessed for eligibility. These articles were categorized as follows: thickness, cross-section, volume and the length of the masseter muscle measured by ultrasonography. It is possible to verify the thickness of the masseter muscle in males and females in relaxation (10-15 and 9-13 mm, respectively) and contraction (14-19 and 12-15 mm, respectively). A similar tendency can also be evidenced in other measurements. Many studies evaluate masseter muscle dimensions to relate it to cephalometric analysis as such to evaluate morphological variations. It can be concluded that ultrasound is a reliable clinical tool for masseter muscle measurements, yet there is a need for standardization of methods and parameters to be recorded.
Topics: Humans; Masseter Muscle; Reproducibility of Results; Ultrasonography
PubMed: 28467130
DOI: 10.1259/dmfr.20170052 -
Annals of Anatomy = Anatomischer... Jun 2022A report published in the Annals of Anatomy recently stated that the coronoid part of the masseter was a newly described layer. However, there have been numerous... (Review)
Review
A report published in the Annals of Anatomy recently stated that the coronoid part of the masseter was a newly described layer. However, there have been numerous discussions regarding the layered structures in the masseter and temporalis. In this review, we show that the muscle bundle stated as a newly described layer could be similar to the zygomaticomandibularis that was previously reported. Knowledge of various muscle bundles with different fiber directions is essential to understanding the stabilization and closing functions of the jaw. Therefore, the layered structure of the masseter and temporalis should be considered more for clinical and functional applications.
Topics: Electromyography; Humans; Masseter Muscle; Masticatory Muscles; Temporal Muscle
PubMed: 35183707
DOI: 10.1016/j.aanat.2022.151907 -
Clinical Oral Investigations Apr 2022To determine sleep bruxism (SB) behavior during five consecutive nights and to identify correlations between SB episodes per hour (SB index) and sleep-time...
OBJECTIVES
To determine sleep bruxism (SB) behavior during five consecutive nights and to identify correlations between SB episodes per hour (SB index) and sleep-time masseter-muscle activity (sMMA).
MATERIAL AND METHODS
Thirty-one participants were included in the study. Of these, 10 were classified as sleep bruxers (group SB-1) and nine as non-sleep bruxers (group non-SB). The bruxism status of these 19 patients was identified by means of questionnaires, an assessment of clinical symptoms, and electromyographic/electrocardiographic data (Bruxoff® device). The remaining 12 participants were also identified as bruxers, but based exclusively on data from the Bruxoff device (group SB-2). Data analysis included descriptive statistics and Spearman's correlation to assess the relationship between the SB index and sMMA.
RESULTS
Participants in group SB-1 showed an overall mean SB index of 3.1 ± 1.6 and a mean total sMMA per night of 62.9 ± 38.3. Participants in group SB-2 had an overall mean SB index of 2.7 ± 1.5 and a mean total sMMA of 56.0 ± 29.3. In the non-SB group, participants showed an overall mean SB index of 0.8 ± 0.5 and a mean total sMMA of 56.8 ± 30.3. Spearman's correlation yielded values of - 0.27 to 0.71 for the correlation between sMMA and SB index.
CONCLUSIONS
The data revealed variable SB activity and the absence of a reliable correlation between sMMA and the SB index.
CLINICAL RELEVANCE
The high variation in SB activity and lack of correlation between sMMA and the SB index should be considered when diagnosing SB.
TRIAL REGISTRATION
Clinical Trials [NIH], clinical trial no. NCT03039985.
Topics: Electromyography; Humans; Masseter Muscle; Polysomnography; Sleep; Sleep Bruxism
PubMed: 34862565
DOI: 10.1007/s00784-021-04314-8 -
Dento Maxillo Facial Radiology Dec 2022The aim of this study was to determine the normal range of masseter muscle thickness by ultrasonographic measurement in individuals over 15 years of age, and to evaluate...
OBJECTIVE
The aim of this study was to determine the normal range of masseter muscle thickness by ultrasonographic measurement in individuals over 15 years of age, and to evaluate its relationship with age, gender, facial morphology, body mass index and parafunctional habits.
METHODS
The study was conducted on 115 volunteers whose lateral cephalometric radiography was performed within the indication in Gazi University Faculty of Dentistry, Department of Dentomaxillofacial Radiology. The participants in the study were asked questions about their parafunctional habits, age, height and weight. Individuals were grouped as hypodivergent ( = 28), normdivergent ( = 55), or hyperdivergent ( = 32) according to vertical face morphology by making measurements on lateral cephalometric films. Right and left masseter muscle thicknesses of individuals were measured by ultrasonography while at rest and in contraction.
RESULTS
The mean value of masseter muscle thickness was found to be 13.57 ± 2.57 mm. The rest and contracted muscle thicknesses were significantly higher in males than in females for the right and left masseter muscles ( < 0.05). When the masseter muscle was at rest and contracted, its thickness was higher in individuals with hypodivergent facial morphology, than in the other groups. No statistically significant difference was found in terms of masseter muscle thickness between individuals having parafunctional habits and those who did not have parafunctional habits ( > 0.05).
CONCLUSION
Although masseter muscle thickness varied according to vertical facial morphology, this was not the case for parafunctional habits.
Topics: Male; Female; Humans; Masseter Muscle; Face; Cephalometry; Ultrasonography; Habits
PubMed: 35926082
DOI: 10.1259/dmfr.20220166