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PubMed2005

Clinical and radiographic findings of the temporomandibular joint in patients with various rheumatic diseases. A case-control study.

OBJECTIVES: To investigate subjective, clinical and radiographic findings relating to the temporomandibular joint (TMJ) in patients with rheumatoid arthritis (RA), mixed connective tissue disease (MCTD), ankylosing spondylitis (AS), and spondyloarthropathy (SPA), and to compare the findings with those in age- and sex-matched control subjects. STUDY DESIGN: Eighty patients (24 with RA, 16 with MCTD, 19 with AS, 21 with SPA) and 80 matched controls participated in the study. Replies to a questionnaire covering oral and TMJ symptoms were analysed in conjunction with medical histories, results of clinical examination of the stomatognathic system, and panoramic and lateral panoramic radiographs. RESULTS: Patients with rheumatic disease reported severe TMJ symptoms significantly oftener than control subjects (P < .001). Patients with AS reported symptoms most frequently (7/19, 37%). Mean maximal opening of the mouth (SD) was significantly less in patients with rheumatic disease (46.3 mm (8.6 mm)) than in control subjects (55.0 mm (7.4 mm)) (P < .001). Marked erosions were observed in 4 RA patients (17%), 3 MCTD patients (19%), 8 SPA patients (38%), 7 AS patients (37%), and 1 control subject (1%) (P < .001). The existence of erosion was associated with evidence of restricted movement of condyle in panoramic radiographs (P < .001). There was correlation between radiographic findings relating to the TMJ and subjective and clinical stomatognathic-system symptoms in patients with rheumatic disease. Subjective TMJ symptoms were associated with evidence of restricted movement of condyle in panoramic radiographs (P < .001). Impairment of laterotrusion movement was significantly associated with erosion (P < .001). CONCLUSIONS: The TMJ is commonly affected in patients with RA, and in patients with other forms of rheumatic disease. There are associations between radiographic findings and subjective symptoms, and between radiographic findings and restricted TMJ movement. In screening for suspected TMJ destruction, it would be appropriate to look for restricted maximal mouth opening, masticatory muscle tenderness and restricted laterotrusion.

Adult↗
PubMed1995

Comparison of the electromyographic activity of individuals with canine guidance and group function occlusion.

The purpose of this study was to investigate occlusal schemes (canine guidance and group function) in relation to masticatory muscle activity. It was performed on 30 subjects, 15 with canine guidance and 15 with group function. Bilateral electromyographic recordings of masseter and anterior temporal muscles were obtained by surface electrodes during gum chewing and sliding laterally from centric relation while the teeth were in contact. The obtained data for both groups were compared statistically. Electromyograms were also evaluated visually. There was no significant difference in results between the occlusal schemes. However, canine guidance showed a narrower chewing model than group function and reduced anterior temporal muscle activity during sliding. This suggests that in the presence of healthy and good supportive canine teeth, canine guidance occlusion will be preferable.

Adolescent↗
PubMed1996

[An electromyographic study on functional adaptations--associated with herbst appliance].

The purpose of this study was to examine functional muscular adaptation to changes in sagittal jaw relation by electromyography. The structural changes were induced by the Herbst appliance. The subjects consisted of four patients with Angle Class II Division 1 malocclusion. The structural changes were evaluated by lateral cephalograms. Functional muscular adaptation was evaluated by electromyogram (EMG) of masticatory muscles, including the inferior head of the lateral pterygoid (ILpt) muscle. The EMG of the ILpt muscle was recorded by using an intraoral surface electrode. The same pattern of cephalometric changes was observed in all patients. The ILpt muscle activity increased immediately after wearing the appliance just like when the construction bite position was taken. However, it reduced remarkably after 4 to 6 months in all patients. On the other hand, the superimposed cephalometric tracings indicated that the locations of the condyles related to the glenoid fossae were still more anteroinferior than their original positions 4 to 6 months after wearing the appliances in three patients. These findings seem to indicate multifactorial effects on the adaptation of the muscle function. It was concluded that functional adaptation to the newly-created morphological changes were not dependent only on the intensity and the duration of the functional stimulation.

Adaptation, Physiological↗
PubMedDate not supplied

Oral rehabilitation with osseointegrated implants in a patient with oromandibular dystonia with blepharospasm (Brueghel's syndrome): a patient history.

Oromandibular dystonia with blepharospasm (also known as Brueghel's syndrome, Meige's syndrome, or idiopathic orofacial dystonia) is characterized by intense and involuntary spasms of the orofacial muscles, with a frequent loss of teeth and occlusal alterations that worsen the dystonic manifestations and cause mucosal lesions that can lead to complete edentulism. The history of a patient with oromandibular dystonia who was rehabilitated with mandibular overdentures supported by endosteal implants is presented. Oral rehabilitation with implant-supported overdentures improved the situation, despite serious problems with instability. Mandibular overdentures supported by endosteal implants were satisfactorily used to re-establish occlusion, ensuring prosthetic stability and improving the dynamics of the masticatory muscles.

Aged↗
PubMed1991

[Mastication and the electromyographic silent period in denture wearers].

The purpose of this study is to compare the masticatory efficiency and the physiological activity of masticatory muscles among patients with removable partial dentures (R.P.D.) and patients with natural dentition. The masticatory efficiency is assessed from the duration of chewing sequences for various foods, from the first masticatory cycle to the swallowing. The physiological activity is tested by the duration of the inhibition reflex called the "silent period" (S.P.) obtained upon each muscle examined: 29 subjects are examined, 24 of them had a R.P.D.; they were divided into four groups according to the extent of their edentation; 5 control subjects have full natural dentition. The study is performed using global electromyography of the two masseter muscles and the two anterior temporal muscles. The mastication of the control subjects appears to have a regular alternance of working potential and periods of rest. The duration of the chewing sequences is determined by the nature of the food, brief for soft food, long for hard food. The mastication of patients with R.P.D. appears more irregular with a lengthening of active phases. The duration of chewing sequences is significantly longer for the control subjects. The duration of the S.P. is 19-21 milliseconds for the masseter muscles of the patients with dentures and the control patients, and 20-22 milliseconds for the temporal muscles for the same individuals. The differences of the S.P. durations between control subjects and patients with R.P.D. is never significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2005

[Changes of functional-diagnostic indices during occlusive contacts reestablishment in the process of orthodontic treatment of patients with incisal disocclusion].

During orthodontic treatment of 42 patients with incisal disocclusions of different severity stages it was determined that during the period of occlusal contacts reestablishment a considerable increase of regional blood flow, a decrease of jaw bone density and an increase of masticatory muscles functional activity occurred. These changes were more pronounced in cases of deep incisal disocclusion than in cases with other types of incisal disocclusion.

Bone Density↗
PubMed1993

A comparison of electromyographic activity between anterior repositioning splint therapy and a centric relation splint.

The purpose of this study was to compare the electromyographic activity of masticatory muscles (temporal and masseter) with the use of an anterior repositioning splint and a centric relation superior repositioning splint. Twenty-six consecutive patients, who referred with the chief complaint of temporomandibular pain and/or headache were selected from one of the author's practices. All these subjects were diagnosed as having internal derangement of the temporomandibular joint. Ten normal subjects were used as controls. Surface electromyographic recordings were taken of each subject prior to the beginning of clinical therapy for the patients. The results show significantly less masseter and temporal muscle activity with anterior repositioning splint therapy compared to the centric relation superior repositioning splint therapy.

Adolescent↗
PubMed2002

Time dependent changes of variables associated with malocclusion in patients with Duchenne muscular dystrophy.

Time dependent changes of parameters associated with malocclusion in patients with Duchenne muscular dystrophy (DMD) were examined in four dental developmental stages in 34 patients. We adopted activities of daily living (ADL) score, dental arch, craniofacial morphology, and electromyograms of the masseter and temporalis muscle as parameters. A comparison was made with the results in DMD subjects to data from healthy subjects with normal occlusion reported in the literature. In DMD subjects, manifestations of open-bite were related to ADL score, sagittal shortening and transverse expansion of the dental arch and vertical overgrowth of the lower jaw. Posterior cross-bite malocclusion was associated with differences in the time dependent changes between the jaws in transverse expansion. The malocclusion in DMD subjects was also related to the time dependent disproportional changes in masticatory muscle function by EMG. Occlusal deviation in DMD subjects became apparent at the late mixed dentition and malocclusion became definitely manifest from early permanent dentition.

Activities of Daily Living↗
PubMed1989

Patterns of activity of perioral facial muscles during mastication in man.

The activity of buccinator, orbicularis oris superior and inferior, quadratus and triangularis muscles was recorded by surface and needle electrodes during spontaneous unilateral mastication of small or large boluses. Their activity was compared with that of the masticatory muscles masseter and digastric, and with the vertical movement of the jaw. The facial muscles were active during mastication, displaying both tonic and phasic activity. Although the cyclic activity was broadly linked to lowering of the jaw, there was no strict time correspondence between the activity of the various facial muscles themselves, or between the activity of the facial muscles and the digastric. The timing and amplitude of facial muscle activity were affected by the duration of the masticatory cycle, the side on which chewing took place, the size of the bolus, and whether or not lip to lip contact was made.

Adult↗
PubMed2005

Pressure pain threshold in the detection of masticatory myofascial pain: an algometer-based study.

AIMS: To compare pressure pain threshold (PPT) values for masticatory muscles in patients with signs and symptoms of myofascial pain and in asymptomatic individuals. METHODS: Fifty women with masticatory myofascial pain comprised the symptomatic group (group 1), while 49 TMD symptom-free women were selected as controls (group 2). The PPT was obtained with the aid of an algometer by applying pressure to the masseter and to the anterior, middle, and posterior temporalis. A 90.8% specificity value was used to determine the appropriate PPT cutoff values for all 4 muscles studied. Receiver operator characteristic (ROC) curve areas and the likelihood ratio (LR) were also evaluated. RESULTS: The 3-way ANCOVA test (group, muscle, and side) revealed a significantly lower PPT for all muscles in the symptomatic group (P < .001). The lowest overall PPT was found for the masseter muscle, followed by the anterior, middle, and posterior temporalis (P < .001). The 90.8% specificity was obtained with PPT values of 1.5 kgf/cm2 for the masseter, 2.47 kgf/cm2 for the anterior temporalis, 2.75 kgf/cm2 for the middle temporalis, and 2.77 kgf/cm2 for the posterior temporalis. The anterior temporalis had the highest LR. ROC curve areas of 0.84, 0.92, 0.90, and 0.90 were obtained for the masseter, anterior, middle, and posterior temporalis, respectively. CONCLUSION: The masseter and temporalis muscles require different pressures for distinguishing masticatory myofascial pain patients from asymptomatic individuals. Because the highest sensitivity (77%) and LR were found for the anterior temporalis, this muscle was considered to have the most suitable discriminative capacity.

Adolescent↗
PubMed2004

Changes in bite force and muscle forces in the upper extremities after counter irritation.

Today, physical therapy is recognized as an effective, reversible, and conservative treatment for temporomandibular disorders (TMD). The purpose of this investigation is to explore the feasibility of utilizing counter irritation with ischemic pain at a remote site outside of the head and neck region as a method for restoring muscle force in a course of physical therapy. Twenty healthy asymptomatic female subjects were recruited for this study. The experiments were performed over two days, with the two experimental days randomly assigned to the experiment performed with or without counter irritation. The counter irritation was applied to the subject's left hand using a submaximal effort tourniquet procedure. The maximal bite, finger-pinch, and handgrip forces were measured on the right side, and the results from the days with and without the counter irritation were compared. As a result, a significantly higher mean maximal bite force and a trend toward higher finger-pinch force were observed with the irritation than without the irritation, while there was no significant difference in the handgrip force. These findings indicate that counter irritation outside of the head and neck may be useful for increasing bite force, and may be applicable in the treatment of TMD for the restoration of masticatory muscle force.

Adolescent↗
PubMed1999

Mandibular-position sensation during sedation by administration of nitrous-oxide (N2O) gas.

Our aim was to confirm the influence of N2O gas on mandibular-position sensation. The subjects in this study were eight healthy adults. Each subject was asked to hold the reference stick for five seconds between the central tooth in his or her upper and lower jaws. Then, the reference stick was replaced by the test sticks with different thickness, each of which the subjects were again asked to hold at the same position for five seconds. The subjects were instructed to determine, based on judgement of the interincisal distance, whether the thickness of each test stick was larger or smaller than the reference stick. A series of trials was administered to each subject using all eight sizes of test sticks. We compared the ability of the subjects to discriminate mandibular position both before and after the application of a vibrating stimulus to the masticatory muscles, and before and during the administration of N2O gas. Discrimination ability was significantly decreased after the application of the vibrating stimulus. However, during the administration of N2O gas, no significant difference in discrimination ability was observed between before and after the vibrating stimulus. The results of this study indicated that N2O gas had an inhibitory effect on gamma-motor neuron activity, which is presumed to be mediated to some extent through the higher central nervous system. This is the case because the gamma-motor neurons are generally activated by vibrating stimuli applied to the muscle causing decreased discrimination ability of mandibular position. Thus, we conclude that mandibular-position sensation was influenced by N2O gas during the administration of N2O gas.

Adult↗
PubMed1998

A polysomnographic study on masticatory and tongue muscle activity during obstructive and central sleep apnea.

Masticatory and tongue muscle activity was examined polysomnographically in 14 patients with sleep apnea syndrome and six snorers. The all-night polysomnographic recordings included electromyograms (EMG) of the genioglossal, the masseter and the inferior head of the lateral pterygoid muscles, nasal airflow and thoracoabdominal respiratory effort. The apneas were defined and classified into three types (obstructive, central and mixed). EMG amplitudes of each muscle were measured before, during and after the obstructive and central apneas. In the apnea patients the three muscles showed significantly lower EMG amplitudes during the obstructive apnea than before the apnea, and then significantly higher amplitudes after the apnea. These findings indicate that the hypotonia of the muscles during sleep can result in obstructive apnea. There was no significant difference in the pattern of muscle activity during obstructive apnea between the apnea patients and the snorers. On the other hand, a decrease in the mean EMG amplitude during the central apnea was not observed. It is suggested that central apnea occurs independently of masticatory and tongue muscle activity.

Abdomen↗
PubMed2004

[Severe limitation of mouth opening].

Limitation of mouth opening is a common source of referral to an orofacial pain clinic with a proposed diagnosis of Temporomandibular Joint Dysfunction (TMD). The word "trismus" is defined by the American academy of orofacial pain as: "Myospasm of masticatory muscles specifically causing limited jaw opening; early symptom of tetanus". Therefore, once trismus is suspected, TMD should be ruled out. However, it is not uncommon to find the usage of this term to describe severe limitation of opening by causes other than myospasm, therefore posing the risk of misdiagnosis. The purpose of this article is to describe the differential diagnosis of hard end limitation of opening with emphasis on the clinical tools used to differentiate between muscle source of hard end limitation and other sources of hard end limitation. Several cases of hard end limitation of mouth opening are presented and through them major principles of orofacial diagnosis are discussed.

Diagnosis, Differential↗
PubMed1977

[Functional analysis in orthodontics and pedodontics].

The special examination of occlusion in the gnathological sense is less important for functional analysis in orthodontics and pedodontics. At the beginning of and during therapy, simple clinical examinations and observations provide the necessary diagnostic and prognostic information on the functioning of the individual parts of the masticatory system or their relation to each other. The clinical relevance of these findings was tested by electromyographic examinations, electronic pressure and volume measurements and tele- and cineradiographic tests. In the retention period, i.e. after therapy had been concluded, a gnathological examination was made in some cases in addition to the general functional analysis. The examination mainly centered on anatomic regions: lips, tongue, masticatory muscles, and temporomandibular joint. The following functions were examined: closing of the mouth, breathing, swallowing, speech, mandibular movements and the relation of rest position to habitual occlusion. In addition, general posture and habits like suckling and nibbling were studied.

Adult↗