Stomatognathic Dysfunction Research Articles

Surface Electromyography as a Method for Diagnosing Muscle Function in Patients with Congenital Maxillofacial Abnormalities.

Electromyography (EMG) is the most objective and reliable method available for imaging muscle function and efficiency, which is done by identifying their electrical potentials. In global surface electromyography (sEMG), surface electrodes are located on the surface of the skin, and it detects superimposed motor unit action potentials from many muscle fibers. sEMG is widely used in orthodontics and maxillofacial orthopaedics to diagnose and treat temporomandibular disorders (TMD) in patients, assess stomatognathic system dysfunctions in patients with malocclusions, and monitor orthodontic therapies. Information regarding muscle sEMG activity in subjects with congenital maxillofacial abnormalities is limited. For this reason, the aim of this review is to discuss the usefulness of surface electromyography as a method for diagnosing muscle function in patients with congenital malformations of the maxillofacial region. Original papers on this subject, published in English between 1995 until 2020, are located in the MEDLINE/PubMed database.

A Review the Relationship of Bruxism with Temporomandibular Disorders in Children

Introduction: Bad habits often found in children such as bruxism may have a profound effect on the health of teeth, periodontium, masticatory muscles and TMJ temporomandibular joints. Excessive masticatory muscle activity can result in disruption of local blood flow and micro circulation, and the pain due to ischemia, bruxism increases excessive strength resulting in an abnormal burden on the mastication system causing changes in some elements of the stomatognathic system resulting in an imbalance that causes stomatognathic system dysfunction. Objective: To review the relationship between bruxism and temporomandibular disorders. Method: Scientific evidence and clinical cases taken from the literature to support this review and information about the relationship of bruxism with temporomandibular disorders (TMD) in children is collected. Results/Discussion: There were several relationships of bruxism with temporomandibular disorders such as joint sounds, myalgia and temporomandibular pain. Conclusion: Brusixm in children is usually influenced by psychological factors such as stress or excessive anxiety. Parafunctional habits such as bruxismn will produce excessive strength so that abnormal loads in the mastication system cause changes in some elements of the stomatognathic system, causing an imbalance that causes stomatognathic system dysfunction such as TMJ pain, joints and myalgia.

INCREASING THE UPPER AIRWAY SPACE USING ORAL APPLIANCES IN PATIENTS WITH MILD SLEEP APNOEA CAUSED BY STOMATOGNATHIC DYSFUNCTIONS

Abnormal breathing can be caused by developmental malformations or anatomical variations in the upper airways. Stomatognathic diseases may significantly impair the patency of the upper respiratory tract. Treatment of advanced stomatognathic dysfunctions is difficult due to their multifactorial aetiology, and often involves many phases. Sleep apnoea is one of the most bothersome complications. The mainstay therapeutic strategy relies on modifying the position of the mandible against the maxilla, achieved by using different types of oral appliances. The study was carried out in 2006-2010 on 92 patients (mean age 42.5 years) with diagnosed advanced dysfunction of the stomatognathic system. The treatment relied on the use of an orthodontic appliance (54 patients) or combined multi-phase therapy with splints used in the first phase (22 patients). Two different appliances were used (one of them was modified by the authors). Parameters assessed in the study included time to resolution of pain, reduction in the incidence of sleep apnoea, and improvement in nasal breathing. Change in the protrusion of the mandible not only relieved problems with the stomatognathic system, but also improved breathing in patients. The use of modified oral appliances reduced treatment duration and improved patients' comfort. Therefore, it may be useful in the treatment of patients with mild sleep apnoea.

Electromyographic evaluation of superficial masseter and anterior temporal muscles after using cyclobenzaprine during extraction of impacted third molars

Objective: The influence of cyclobenzaprine hydrochloride (Miosan®,10mg/orally/single dose), taken prior to the extraction of impacted mandibular third molars on the electrical activity of superficial masseter and anterior temporal muscles was evaluated through electromyographic recordings aiming at contributing to the discussion of the diagnosis of stomatognathic dysfunctions in relation to long lasting operative procedures. Material and Methods: Twenty patients referred for the extraction of impacted and embedded mandibular third molars at the Discipline of Oral and maxillofacial Surgery and Traumatology (Institute of Science and Technology of São José dos Campos/Unesp), without systemic disease and allergic reactions to the drugs used, both sexes were selected. An electromyographer model EMG-800C (EMG System do Brasil Ltd.), with four input channels, previously calibrated with active electrodes and 20-fold amplification gain was used together with a channel linked to the system to record the mouth opening (mandibular goniometer). The following conditions were assessed: rest, maximum voluntary isometric contraction, and maximum mouth opening, at the following periods: pre-surgical, surgical, and post-surgical (7, 15, and 30 days). Results: The electrical activity of the studied muscles was reduced at the beginning of the surgical procedure, but it did not significantly alter by the administration of the drug at all evaluated periods. The masseter muscle, after the drug administration, reestablished its activity just after the post-operative period, unlikely the control group, which reestablished the activity after 7 days. A significant mouth opening was seen for the comparison between control and experimental groups (p < 0.001). Conclusion: Thus, based on these results, we suggest that the single-dose myorelaxant taken prior to the surgical procedure interfere on the motor activity of the studied muscles. This approach can be useful as adjuvant therapy in patients exhibiting stomatognathic system dysfunctions causing damage to the masticatory system due to the presence of embedded mandibular third molar. Keywords: Myorelaxants; Third Molars; Electromyography; Cyclobenzaprine; Surgery.

Smile because of Dr Robert Murray Ricketts.

Smile because of Dr Robert Murray Ricketts.

Implant‐Supported Fixed Dental Prostheses with CAD/CAM‐Fabricated Porcelain Crown and Zirconia‐Based Framework

Recently, fixed dental prostheses (FDPs) with a hybrid structure of CAD/CAM porcelain crowns adhered to a CAD/CAM zirconia framework (PAZ) have been developed. The aim of this report was to describe the clinical application of a newly developed implant-supported FDP fabrication system, which uses PAZ, and to evaluate the outcome after a maximum application period of 36 months. Implants were placed in three patients with edentulous areas in either the maxilla or mandible. After the implant fixtures had successfully integrated with bone, gold-platinum alloy or zirconia custom abutments were first fabricated. Zirconia framework wax-up was performed on the custom abutments, and the CAD/CAM zirconia framework was prepared using the CAD/CAM system. Next, wax-up was performed on working models for porcelain crown fabrication, and CAD/CAM porcelain crowns were fabricated. The CAD/CAM zirconia frameworks and CAD/CAM porcelain crowns were bonded using adhesive resin cement, and the PAZ was cemented. Cementation of the implant superstructure improved the esthetics and masticatory efficiency in all patients. No undesirable outcomes, such as superstructure chipping, stomatognathic dysfunction, or periimplant bone resorption, were observed in any of the patients. PAZ may be a potential solution for ceramic-related clinical problems such as chipping and fracture and associated complicated repair procedures in implant-supported FDPs.

Effects of social factors on the index of stomatognathic system dysfunction

Effects of social factors on the index of stomatognathic system dysfunction

Headache as a symptom accompanying stomatognathic system dysfunctions

Headache as a symptom accompanying stomatognathic system dysfunctions

Orthognathic Surgery and Partial Glossectomy in a Patient With Merosin-Deficient Congenital Muscular Dystrophy

Muscular dystrophy (MD) describes a group of hereditary muscular diseases. The molecular mechanisms that cause the different forms of MD vary, as do the incidence and impact on a patient’s quality of life. The most common form, Duchenne MD, follows an Xlinked inheritance pattern and occurs with an incidence of approximately 1 in 3,500 live-born male infants. However, rarer forms such as congenital MD (CMD) also exist. CMD has an autosomal recessive inheritance pattern that, according to 1 Italian sample, has an incidence of only 0.7 per 100,000 live births. 1 CMD is characterized by severe muscle hypotonia (first noticeable at birth or within the first months of life), generalized muscle weakness, and muscle contractures of varying severity that result in delayed or missed developmental motor milestones. Each type of CMD is subclassified based on the specific molecular defect or deficiency. One of the more common types of CMD is merosindeficient CMD (MDCMD), which accounts for up to 30% of CMD cases in European countries. CMD results from a deficiency of laminin 2 chains (merosin) because of mutations in the LAMA2 gene located on chromosome 6q22. MDCMD is a severe form of MD that is manifested by an inability to ambulate independently secondary to muscle weakness/contractures and a respiratory insufficiency that may require tracheostomy. 2 Although MDCMD is rare, it and other forms of MD are important to the oral and maxillofacial surgeon because of the impact of the disease on oral and facial anatomy and function. Of particular concern to the oral and maxillofacial surgeon is the phenotype often associated with MDs, which includes bimaxillary discrepancies often presenting with apertognathia. 3 The significance of the malocclusion can be heightened by the compromised masticatory forces resulting from MD. 4,5 Patients with MD may also exhibit limited maximal incisal opening (MIO) because of contracture of the muscles of mastication. In addition, the presence of macroglossia can add to the overall stomatognathic dysfunction and increase the potential for relapse in the postoperative period. 6 Through the surgical treatment of these conditions, the oral and maxillofacial surgeon can address the functional and facial cosmetic concerns the patient may have.

Psychosomatic aspects of the patients with stomatognathic dysfunction

Psychosomatic aspects of the patients with stomatognathic dysfunction

Research on anxiety in patients with Stomatognathic dysfunction

Research on anxiety in patients with Stomatognathic dysfunction

Psychosomatic aspects of patients with stomatognathic dysfunction

Psychosomatic aspects of patients with stomatognathic dysfunction

Quantitative analysis of masticatory activity during unilateral mastication using muscle fMRI

Quantitative analysis of the activities of all masticatory muscles is required to elucidate the mechanism of stomatognathic dysfunction. Electromyography can be used to record the activity of masticatory muscles, but quantification of the overall activity of every masticatory muscle has not been accomplished because of methodological limitations. In this study, we used muscle functional magnetic resonance imaging for simultaneous quantification of the overall activities of the masseter, medial pterygoid and lateral pterygoid muscles during unilateral gum chewing. Seven healthy male volunteers participated in the study. We evaluated changes in the mean proton transverse relaxation time in the bilateral masseter, medial pterygoid and lateral pterygoid muscles before and after unilateral gum chewing, and to quantify the overall activity of these muscles simultaneously during unilateral gum chewing. After 5 min of chewing, the activity of the ipsilateral masseter was highest among the six muscles, followed by the ipsilateral medial pterygoid, contralateral lateral pterygoid and contralateral masseter muscles. These results affirm the importance of the ipsilateral masseter muscle and quantitatively demonstrate the important contribution of the ipsilateral medial pterygoid and contralateral lateral pterygoid muscles during unilateral mastication.

Evaluation of the Stomatognathic System In Patients with Rheumatoid Arthritis According to the Research Diagnostic Criteria for Temporomandibular Disorders

The aim of this study was to investigate the clinical features of stomatognathic dysfunction in patients with rheumatoid arthritis (RA). The study sample consisted of 40 patients with RA (34 female, 6 male), mean age 44 years, recruited at the Rheumatology Division of the Department of Internal Medicine, University of Pisa, Italy. The inclusion criteria were diagnosis of RA according to the criteria of the American Rheumatism Association (ARA). In the study, 82.5% (n=33) of patients affected by RA satisfied at least the criteria of one diagnosis of temporomandibular disorders (TMD), according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). The results are in agreement with the literature and the prevalence of such involvement ranges between 53% and 94% of patients. Several studies reported an involvement of the stomatognathic system in RA. In fact, RA can affect the temporomandibular joint as much as any other synovial joint. A more thorough analysis is required for a multidisciplinary approach to gnathological patients, including assessment by a rheumatologist. This issue and its epidemiologic relevance need further scientific research. Dentistry has a fundamental role in this process since patients who present with a systemic disease such as RA can be recognized and intercepted and referred to medical specialists, i.e., rheumatologists, to provide a diagnosis and therapy.

Electromyographic standardized indices in healthy Brazilian young adults and data reproducibility

The determination of normal parameters is an important procedure in the evaluation of the stomatognathic system. We used the surface electromyography standardization protocol described by Ferrario et al. (J Oral Rehabil. 2000;27:33-40, 2006;33:341) to determine reference values of the electromyographic standardized indices for the assessment of muscular symmetry (left and right side, percentage overlapping coefficient, POC), potential lateral displacing components (unbalanced contractile activities of contralateral masseter and temporalis muscles, TC), relative activity (most prevalent pair of masticatory muscles, ATTIV) and total activity (integrated areas of the electromyographic potentials over time, IMPACT) in healthy Brazilian young adults, and the relevant data reproducibility. Electromyography of the right and left masseter and temporalis muscles was performed during maximum teeth clenching in 20 healthy subjects (10 women and 10 men, mean age 23 years, s.d. 3), free from periodontal problems, temporomandibular disorders, oro-facial myofunctional disorder, and with full permanent dentition (28 teeth at least). Data reproducibility was computed for 75% of the sample. The values obtained were POC Temporal (88.11 +/- 1.45%), POC masseter (87.11 +/- 1.60%), TC (8.79 +/- 1.20%), ATTIV (-0.33 +/- 9.65%) and IMPACT (110.40 +/- 23.69 microV/microV.s %). There were no statistical differences between test and retest values (P > 0.05). The Technical Errors of Measurement (TEM) for 50% of subjects assessed during the same session were 1.5, 1.39, 1.06, 3.83 and 10.04. For 25% of the subjects assessed after a 6-month interval, the TEM were 0.80, 1.03, 0.73, 12.70 and 19.10. For all indices, there was good reproducibility. These electromyographic indices could be used in the assessment of patients with stomatognathic dysfunction.

THE MANAGEMENT OF MALUNION SYMPHISIS MANDIBLE FRACTURE

One of the impacts of traffic accident that is often seen by a dentist is mandible fracture. To prevent deformation of mandible because of a slow management, it is better to treat the fracture as soon as possible. The treatment can be done with an open/closed reduction, depending on the case. An immediate management of mandible fracture is very important to prevent malunion, malocclusion and stomatognathic dysfunction.

Clinical Features of the Stomatognathic Involvement in Fibromyalgia Syndrome: A Comparison with Temporomandibular Disorders Patients

Several studies have reported an involvement of the stomatognathic system in the course of fibromyalgia (FM) similar to that which characterizes temporomandibular disorders (TMD). The aim of this study was to investigate and compare the clinical features of stomatognathic dysfunction in patients with FM and TMD. Ninety-three FM patients underwent an assessment according to the RDC/TMD guidelines. Prevalence of the different RDC/TMD diagnoses and some clinical parameters of FM patients were compared with those of 181 patients affected by TMD. Seventy-four (79.6%) FM patients presented at least one RDC/TMD diagnosis and showed lower mean maximum voluntary and passive mouth opening values than TMD patients. Moreover, 34 FM patients presented with trigger and/or tender points. Results of the present study confirm the high rate of involvement of the stomatognathic system in the course of FM and support the need for a careful multidisciplinary approach to patients with TMD, including the rheumatologist.

Influence of Body and Head Posture on Deviation of the Incisal Point Undergoing Dental Treatment

Purpose: The objectives of this study were to determine how changes in body and head position undergoing dental treatment affect mandibular position, and to develop a set of standards for patient posture.Methods: Mandibular position was investigated in 8 subjects with normal occlusion and not suffering any stomatognathic dysfunction. This was done by measuring the location of the tapping point on the incisal point using a Gnathohexagraph (a 3-dimensional jaw movement measurement device with 6 degrees of freedom), with the subject’s head in 4 different positions while sitting, and the body and head in 16 different positions with the subject supine, and then comparing deviation from the reference position in each of these positions. Statistical analysis of data was performed using first, repeated measures of 1-way ANOVA (α=.05), second Bonferroni’s multiple comparison test was undertaken in seated positions. In supine positions, repeated measures of 2-way ANOVA was performed, and followed by Bonferroni’s multiple comparison test was performed.Results: The incisal point deviated significantly in the anteroposterior direction due to changes in head and body position. With the subjects seated, the incisal point tended to move backwards when the subjects were asked to lean backwards from the reference position. The incisal point tended to move forward when the subjects were asked to lean forward. With the subjects in a supine position, the incisal point was inclined backwards. The degree of backwards inclination of the incisal point tended to decline as the head position was varied from 10 degrees backwards to 20 degrees forward, regardless of the degree of backwards inclination of the body.Conclusion: Changes in body and head posture undergoing dental treatment affect incisal point deviation.

顎機能の臨床的検査 ナソヘキサグラフを用いて

From a clinical viewpoint, it is important to clarify the stomatognathic functions. In order to diagnose stomatognathic dysfunctions, it is necessary to record and examine stomatognathic functional phenomena simultaneously such as mandibular movement, muscular activities, TMJ sounds, and occlusal sounds.A Gnatho-hexagraph is capable of recording simultaneously the various phenomena related to stomatognathic functions in the following manners.1. It can record many phenomena simultaneously such as EMG, TMJ sounds, and occlusal contact sounds related to mandibular movement.2. The mandibular movement is recorded in six-degree-of-freedom with an accuracy of ±150 μm.3. The reference points can be indicated by employing a handy optical pointer.4. By applying a lightweight facebow (weight: 12 g), the patients can demonstrate mandibular movements more physiologically without feeling any stress.5. In this system, the operation is easy and does not require much space.The outline, advantages, and disadvantages of the Gnatho-hexagraph are presented herein, and clinical application of the system to stomatognathic functional examination are discussed using some results obtained from patients.

Craniomandibular disorders. Conception of a screening method for patients with chronic head and facial pain

Craniomandibular disorders are suggested to be responsible for many cases of chronic pain of the head and face. The assessment of dysfunctional factors in diseases of chronic head and facial pain normally requires special knowledge and equipment for the diagnosis and therapy of stomatognathic dysfunction. However, the first signs can be evaluated rather well without using complete equipment, which is not always available in general practice. It is therefore important that general practitioners have a simple, time-efficient method of routine screening based on sufficient methods and tests. Thus, we would like to present a questionnaire consisting of ten points that cover the valid elements of complete stomatognathic assessment. Answering these questions reveals signs of dysfunctional components of craniomandibular disorders, which indicate a dysfunction diagnosis and even better, consultation with a specialist.