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PubMed1995

The role of bioelectronic instruments in the management of TMD.

Temporomandibular disorders (TMD) comprise a group of conditions that can affect the form and function of the temporomandibular joint (TMJ), masticatory muscles and dental apparatus. Proper management of TMD by the dentist requires accurate appraisal of the status of the patient's dentition, TMJ and associated neuromuscular apparatus. Certain predefined standards or parameters of function/dysfunction are accepted by the profession. Electronic instrumentation provides objective measurement of many of these biological phenomena, and thus can be used throughout treatment for critical analyses that monitor and enhance treatment efficacy. A treatment protocol for TMD is presented that uses electronic instrumentation to establish a neuromuscular occlusion.

Clinical Protocols↗

PubMedDate not supplied

[Foix-Chavany-Marie syndrome. Case report].

Foix-Chavany-Marie syndrome is characterized by diplegia involving the face, the pharynx, the tongue and the masticatory muscles, with automatic-voluntary dissociation due to vascular damage of both operculi. The prognosis is usually good for life expectancy. The authors describe a 46-year-old man in whom one operculum was destroyed because of a birth trauma, the other one was injured by an ischemic infarct in the territory of the middle cerebral artery. The clinical correlations to the site of the lesions are discussed. They confirm the diagnostic value of CT scan in evaluating this syndrome.

Birth Injuries↗

PubMed2000

Craniomandibular status and function in patients with habitual snoring and obstructive sleep apnoea after nocturnal treatment with a mandibular advancement splint: a 2-year follow-up.

The aim of the investigation was to evaluate the status and function of the temporomandibular joint (TMJ) and masticatory system in patients with habitual snoring and obstructive apnoea after 2 years nocturnal treatment with a mandibular advancement splint. Thirty-two patients participated in the study, ranging from 43.0 to 79.8 years of age (mean 54.4 years, SD 8.78) at the start of treatment. All patients had been referred from the ENT department for treatment with a mandibular advancement splint. The acrylic splint advanced the mandible 50-70 per cent of maximal protrusion, opened 5 mm vertically, and was used 6-8 hours per night and 5-7 nights per week. Overjet, overbite, and molar relationship were measured on dental casts. The patients were asked to answer a questionnaire concerning symptoms of craniomandibular dysfunction (CMD). They were also clinically examined in a standardized manner, including registration of range of mandibular movements, TMJ sounds, pain on movement, and palpatory tenderness of the TMJ and the masticatory muscles. None of the patients showed more than five symptoms of dysfunction either at the start of or after 2 years of treatment. A decrease in the frequency of headache was found for nine of those 18 patients that reported headache (P = 0.004). A minor, but significant decrease in overjet and overbite was found and the molar relationship was also changed. It was concluded that 2 years' treatment with a mandibular advancement splint had no adverse effects on the craniomandibular status and function, but the observed occlusal changes requires further evaluation.

Adult↗

PubMed2001

Sleep bruxism: an oromotor activity secondary to micro-arousal.

Spontaneous rhythmic masticatory muscle activity (RMMA) during sleep occurs in relation to transient activation in the cerebral and autonomic nervous systems of normal subjects and in patients with sleep bruxism (SB). In this study, we made a quantitative assessment of the sequential changes in cortical electroencephalographic (EEG) and autonomic-cardiac activities associated with micro-arousals preceding RMMA episodes. We matched 10 SB patients with 10 normal subjects. The onset of RMMA episodes was defined in terms of the onset of activation in the suprahyoid muscles. In SB patients, an increase in cortical EEG activity was observed 4 seconds before the onset of suprahyoid activity in 79% of episodes. A significant acceleration in heart rate was initiated one cardiac cycle before RMMA onset. A clear sequence of cortical to autonomic-cardiac activation precedes jaw motor activity in SB patients. This suggests that SB is a powerful oromotor manifestation secondary to micro-arousal.

Adult↗

PubMed1990

[Electromyographic study on motor skill in chewing movement. A new concept on relating electromyographic analysis to chewing movements].

This article was aimed to propose a new concept on evaluating electromyographic activities of masticatory muscles during chewing movements viewed from the standpoint of motor skill. Correlation coefficients between the ratio of lateral distance to ten vertical level set at 0.5 mm to 5.0 mm with 0.5 mm step from the end of closing phase and activities of bilateral masseter, anterior and posterior temporalis in each chewing stroke were evaluated using raisin, peanut, soft and hard testing gum in five subjects. Habitual chewing side always demonstrated less numbers of subjects who showed high correlation coefficients especially in the case of soft testing gum.

Chewing Gum↗

PubMed2006

[Pain on mandibular movements].

Pain or fatigue in the masticatory muscles or pain in the temporomandibular joints are well-known complaints. Diagnosing these complaints, that have a relation with mandibular movements, can be challenging since they can arise from the teeth and surrounding tissues, the temporomandibular joints or other musculoskeletal structures. Also referred pains are a common finding in this area. Pain history and clinical examination are crucial for a comprehensive diagnosis. Besides the disorders underlying the pain (so called axis I), the impact of the pain on the patient's physical and psychosocial functioning can play an important role in the diagnosis (axis II).

Craniomandibular Disorders↗

PubMed1997

[Neurogenic temporomandibular joint dislocation. Definition and therapy with botulinum toxin].

Dislocation of the temporomandibular joint results from trauma, articulation disorders and changes in the equilibrium of the masticatory muscles. Previous classifications were mostly oriented on the interrelationships between the anatomical positions of the dislocated articular surfaces, like luxation, subluxation and discuss luxation. Etiologically, a distinction is made between traumatic and non-traumatic dislocation. Dislocation of the temporomandibular joint is described as a complication of a number of neurological diseases. We report on a patient who suffered recurrent dislocations of the temporomandibular joint as a complication of multiple sclerosis and whose luxations were successfully treated with botulinum toxin, thus warranting the introduction of the term "neurogenic dislocation of the temporomandibular joint".

Botulinum Toxins↗

PubMed1975

[Masticatory sysarcosis. Significance in maxillofacial surgery and pathology].

The masticatory muscles and the vertical ramus move in a closed aponeurotic lodge; sliding spaces containing cellulo-adipose formations, veritable sysarcoses, are situated between the muscles of mastication as well as between these muscles and their osteo-aponeurotic covering. Sysarcoses are embryological, anatomical and functional units. Bichat's ball must be considered as being the antero-inferior pole of these cellulo-adipose containing spaces. Apart from the mechanical role of these spaces, their value in pathology and in traumatological surgery must again be pointed out, because firstly they are the pathways of approach and fixation of fractures of the zygomamalar region. They are also of great value in reparatory surgery as knowledge of the vascularization of the fat in these spaces enables the making of flaps of fat in the surrounding area.

Adipose Tissue↗

PubMed2003

Computer-assisted simulations in orthodontic diagnosis and the application of a new cone beam X-ray computed tomography.

Computational simulations which include three-dimensional (3-D) image processing and biomechanical calculations should provide useful information to our research and orthodontic clinic as a clinical tool defined as 'thinking'. In this review, 1) biomechanical simulations applied to predict the mandibular growth; 2) mathematical models of virtual bone cells and 3) 3-D images and solid model simulations for surgical planning are introduced. In biomechanical simulation, biting force, electromyographic (EMG) activity and cephalograms of 32 subjects were applied. Computational results of mathematical model were compared with actual bone growth in a rat. Three-dimensional image and solid model of 14 patients were utilized for their treatment planning. From the results, several concepts of our simulations were confirmed: 1) reaction forces generated by masticatory muscles at the condyle control the direction of mandibular growth; 2) some mathematical models have the possibility to describe the process of bone growth; 3) 3-D image processing software and solid models are necessary for diagnosis and planning of orthognathic surgery. We also believe that the orthodontists can more accurately predict the affects of surgical procedures and orthodontic tooth movement using the new cone beam X-ray computed tomography (CT) (CB MercuRay; Hitachi Medico Technology, Tokyo, Japan) and its advanced application software.

Animals↗

PubMed1991

A microcomputer system for collecting and processing physiological information about the masticatory system.

A software system has been written for IBM PC, XT, AT and compatible computers to be used for data collection, analysis and display. The system supports the sampling and processing of data for jaw movement tracks, myoelectrical activities of masticatory muscles, the temporomandibular joint (TMJ) and occlusal sounds and bite force, etc. The package includes the following functions: calculating displacement, velocity, curvature, and curvature center of jaw movement trace, analyzing myoelectrical signals in amplitude integration, root mean square and power spectrum, processing TMJ sounds and occlusal sounds and bite force, analysing jaw movement traces and myoelectrical activities during mastication simultaneously, determining the maxillomandibular relations, etc. The program also provides versatile formatting capability for video, printing and plotting of data, and graph creation. The most of the above programs have flexibility and adaptability to other physiological signal processes.

Bite Force↗

PubMed1977

[Bite plates and occlusal splints].

Occlusal adjustments are often necessary in cases of masticatory muscle spasm, bruxism, traumatic occlusion and TMJ disturbancies. Before such occlusal adjustments are performed, the patient should either wear a bite plate or an occlusal splint which frees the occlusion for a certain time. The splint is fabricated on a semiadjustable articulator such as the Hanau H2-XPR which is also used for the functional analysis on the models prior to any adjustments. Advantages and disadvantages of different types of plates and occlusal splints are discussed. The authors conclude that an occlusal splint covering the entire dental arch, such freeing the occlusion, seems to be the most appropriate appliance available today.

Bruxism↗

PubMed1995

[Highlights in the subject of low frequency-high intensity TENS (review)].

Transcutaneous electrical neural stimulation (l.f.-h.i. TENS), employed in dentistry, allows masticatory muscles relaxation, temporary clearance of muscular and periodontal proprioceptive input and even oro-facial pain relief. The mechanisms involved in this type of stimulation are not entirely clarified. According to the most recent neurophysiological researches, the authors describe several l.f.-h.i. TENS. action modalities. Some of them are well known such as the gate control theory, the endogenous antinociceptive system activation, the metabolic recovery of the muscular tissue and the unloading reflex. Other mechanisms, instead, are less known such as hypnosis and stress analgesia, exteroceptive suppression and counterirritation (DNIC). Some hypothetical mechanisms are also considered such as endogenous inhibition and sympathetic activity reduction.

Acupuncture Analgesia↗

PubMed1996

Influence of antineoplastic therapy on function of the masticatory system, tooth development, and cariogenic status: a case report.

Antineoplastic therapy causes developmental disturbances in the dental enamel and root if children are treated during tooth development. Increased caries activity has also been reported. The effect of anticancer therapy on the function of the masticatory system (i.e. jaws, dentition, masticatory muscles) is not well known. A case report of a 9-year-old girl with right auricular rhabdomyosarcoma is presented. She received irradiation of 50 Gy to the right auricular area and chemotherapy. A year and a half after cessation of cancer therapy, she was disease free and the clinical stomatognathic examination combined with electromyogram (EMG) registration of the masseter and temporal muscles and magnetic resonance imaging (MRI) examination of the temporomandibular joints (TMJ) revealed a strongly restricted mouth opening capacity, painful right TMJ, and flattened head of the right mandibular condyle. Muscle atrophy in the right masseter muscle was clearly visible but EMG activities of the masseter and temporal muscles, however, were higher on the right than on the left. More severe developmental defects, and worse gingival and cariological health were observed on the right side than on the left side. She developed 12 carious lesions and all the lesions were on the right maxilla or mandible or on anterior teeth. The left side was not affected. Intensive prophylactic dental care after cancer treatment is important in order to prevent caries and gingival inflammation. Stomatognathic treatment (i.e. management of occlusal and dysfunctional problems) may improve the mouth opening capacity and relieve pain.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1975

[Trismus, trigeminal motor dyssynergy with brain stem lesions (author's transl)].

Paradox activity of masticatory muscles was observed clinically and electromyographically in 4 patients with brain steem lesions who had trismus. There was no activity in the elevators of the jaw on the side affected during voluntary biting, as if the muscles were paralyzed. There was strong activity of the elevators on the side of the trismus on opening the mouth, inactivity on the unaffected side, or inverse activity appeared on both sides. In view of the trigeminal anesthesia on the side of paradox activation, and the absence of pyramidal signs, a stretch reflex mechanism and abolition of inhibition can not be the only basis for these phenomena; so, a disturbance of bilateral synergism, in the sense of an internuclear lesion, is postulated. In one case of motor and sensory paralysis after the extirpation of a meningioma of the cerebellopontine angle, intensive paradox activity was observed, without trismus.

Adult↗

PubMed1990

[Effects of cusp angle on the adaptation of masticatory function].

The purpose of this study was to elucidate the adaptation in masticatory function by changing the cusp angle of the natural dentition of one person using a metal splint. During each experiment mandibular movements and EMG were recorded during a period of weeks. While chewing raisins as test food, mandibular movements as measured by the lower incisal point displacement were detected three-dimensionally using the Selspot system, and electrical activity of the masticatory muscles was picked up for the anterior temporal and masseter muscles, at the right and left using surface electrodes. The time schedule was composed of three terms: (1) before insertion of the splint, (2) for 20 days after insertion of the splint and then for 30 days after removal (Experiment-1), (3) for 14 days after reinsertion of the splint and then for 7 day after removal (Experiment-2). The measurements were done for the following 7 indices: (1) opening phase, (2) closing phase, (3) cycle time, (4) stopping phase (St), which is the period when the mandible was stationary during occlusal contact, (5) duration of EMG activity, (6) duration of EMG silence, (7) the period of EMG silence (IA), which is the period from the end of EMG activity to the end of the stopping phase. The following results were obtained 1) On changing the cusp angle, there was an increase in cycle time, closing phase, opening phase, duration of EMG activity, and duration of EMG silence, but the stopping phase was less than before insertion of the splint. These 6 indices showed a great variation and became irregular at first. 2) The irregularity of the masticatory function disappeared gradually, and then all indices approached the value before insertion of the splint from day 5 or day 20 at the latest. 3) Scarcely any reaction was detected in IA or in the ratio of cycle time and opening phase throughout the measurement period. 4) The indices of the reinsertion period (Experiment 2) approached the value before insertion more rapidly than the period of the insertion (Experiment-1). And the indices after removal quickly approached pre-insertion values. In short, the indices of the time factor of the masticatory function showed that the effect of changing cusp angle was handled as only disturbances. And once the first adaptation was completed, masticatory function responded more quickly to the same stimulus.(ABSTRACT TRUNCATED AT 400 WORDS)

Adaptation, Physiological↗

PubMed2006

The treatment of painful temporomandibular joint clicking with oral splints: a randomized clinical trial.

BACKGROUND: The authors compared the efficacy of bilateral balanced and canine guidance (occlusal) splints in the treatment of temporomandibular joint (TMJ) pain in subjects who experienced joint clicking with a nonoccluding splint in a double-blind, controlled randomized clinical trial. METHODS: The authors randomly assigned 57 people with signs of disk displacement and TMJ pain into three groups according to the type of splint: bilateral balanced, canine guidance and nonoccluding. The authors followed the groups for six months using analysis of a visual analog scale (VAS), palpation of the TMJ and masticatory muscles, mandibular movements and joint sounds. They used repeated analysis of variance and a chi(2) test to test the hypothesis. RESULTS: The type of guidance used did not influence the pain reduction, yet both occlusal splints were superior to the nonoccluding splint, on the basis of the VAS. Despite similar outcomes in relation to opening, left lateral and protrusive movements, TMJ and muscle pain on palpation, subjects who used the occlusal splints had improved clinical outcomes. The frequency of joint noises decreased over time, with no significant differences among groups. Subjects in the groups using the occlusal splints reported more comfort. CONCLUSION: The type of lateral guidance did not influence the subjects' improvement. All of the subjects had a general improvement on the VAS, though subjects in the occlusal splint groups had better results that did subjects in the nonoccluding splint group.

Adult↗

PubMed1986

[Skull deformities following unilateral mandibular imbalance. V. Discussion of results].

The unilateral dysbalance induced artificially in the mandibles of Beagles yields information regarding the action of the masticatory musculature as a local factor affecting craniofacial growth. Time is an important factor, particularly the age and maturity of the animals at the time of the operation and the length of the post-surgical interval prior to the measurements being taken. The time factor and differences between chewing types provide some explanation for the lack of uniformity and, sometimes, the contradictory nature of the available information regarding the secondary changes to the skull following the elimination of masticatory muscles in experimental animals. The cranial scoliosis observed as a result of mandibular dysbalance suggests strongly that the viscerocranium responds plastically to functional influences. The neurocranium, in contrast, whose shape is governed largely by the brain, is to great extent immune to such postnatal manipulations. The fact that growth of the residual mandibular stump is retarded shows that the condylar cartilage is not a primary growth centre. Postnatal mandibular growth is mainly periosteal and governed by functional stimuli. Any attempt to apply these results obtained with animal models to man must naturally take the differences between the structures of the maxillo-mandibular apparatuses into account.

Age Factors↗

PubMed2001

The utility of panoramic imaging of the temporomandibular joint in patients with temporomandibular disorders.

OBJECTIVE: The objective of this study was to evaluate the utility of panoramic imaging in assessment of patients with temporomandibular disorders (TMDs). STUDY DESIGN: Fifty-five consecutive patients referred for diagnosis and management of facial pain and jaw dysfunction were included. A single examiner completed the history and clinical examination on all patients. All patients received panoramic imaging. On the basis of clinical and radiographic findings, a subset of patients received advanced imaging modalities. The panoramic radiographs were interpreted by 2 examiners; if any disagreement was noted, a third examiner interpreted the radiographs. RESULTS: Seventy-five percent of the patients had complaints of facial pain, and 75% exhibited tenderness in masticatory muscles. Tenderness was present in TM joint regions in 62%. Altered bony anatomy was seen in 43.6% of panoramic radiographs. Panoramic imaging did not lead to changes in clinical diagnosis in any of the patients seen, although the findings on the radiographs did lead to requests for additional imaging studies in 3 cases, one of which was later referred for surgical intervention because of radiographic findings. CONCLUSION: Clinical findings may be of greater relevance leading to the diagnoses associated with TMD and to determination of the need for additional imaging rather than the use of panoramic imaging in all patients with facial pain and TMD.

Adolescent↗