Masseter muscle hyperactivity and myofascial pain dysfunction syndrome: a relationship under stress

Myofascial pain dysfunction syndrome (MPD) of the temporomandibular joint (TMJ) is a psychophysiological disorder that develops because of hyperactive muscles of mastication. Ten women meeting criteria for MPD and 12 symptom-free women participated in the study. The rationale for this study was to observe cardiovascular and masseter muscle changes during four contiguous experimental periods: baseline/adaptation, reaction time, recovery, and relaxation. MPD patients showed less masseter muscle activity and higher heart rates at baseline than controls. Controls had significantly higher masseter EMG activity during reaction time. Both groups showed significant elevation in masseter muscle activity and heart rate over the 14-min reaction period. MPD patients' recovery from stress was equivalent to controls' for both heart rate and masseter muscle activity. MPD patients exhibited significantly slower reaction times than controls. The results suggest that masseter muscle hyperactivity may not account for the development and maintenance of MPD.     

Treatment of recurrent dislocation of the temporomandibular joint with type A botulinum toxin

A case is reported of a 56-year-old woman who suffered from recurrent dislocations of the temporomandibular joint (TMJ) secondary to an exacerbated tetraspastic syndrome of multiple sclerosis. Following chemical denervation of the masseter and pterygoid muscles with injections of type A botulinum toxin, no further dislocations occurred for periods of up to four months. The treatment has been repeated five times. Some of the indications and possible adverse reactions to this therapy are discussed and comparisons made with other, conventional methods for managing recurrent dislocation of the TMJ.     

Unilateral medial dislocation of the temporomandibular joint

We present our experience of the rare condition of unilateral medial dislocation of the temporomandibular joint (TMJ) in 11 patients with head trauma who had received a direct lateral blow on the chin. The diagnosis was made by direct coronal CT of the TMJ performed from 6 h to 7 days following the injury. In 6 patients, subcondylar fracture of the ipsilateral mandibular ramus was also demonstrated. A second CT performed 11-16 months following the first one demonstrated pseudoarthrosis of the fractured ramus in these 6 patients. The second CT was identical to the first in the remaining 5 patients with pure dislocation of the condyle. All patients suffered from severe disability of the TMJ. The maximal vertical distance between the upper and lower incisors in patients with uncomplicated dislocation ranged between 8 and 12 mm. In cases with complicated medial condylar dislocation with fracture and pseudoarthrosis of the mandibular ramus, this distance ranged between 16 and 25 mm, probably because of additional movement in the area of the pseudoarthrosis. The maximal vertical distance between the incisors was compared with a control group of 20 normal adults who had values from 40 to 52 mm. Medial unilateral dislocation of the TMJ can appear in two forms: uncomplicated or complicated, with pseudoarthrosis of the ipsilateral mandibular ramus.     

Stress-induced alterations of somatodendritic 5-HT1A autoreceptor sensitivity in the rat dorsal raphe nucleus--in vitro electrophysiological evidence

The role of trauma in the etiology of temporomandibular disorders (TMD) is controversial. The objectives of this study were to compare presenting signs, symptoms, and diagnoses in patients who had motor vehicle accident trauma-related TMD to patients who had nontrauma-related TMD. Files of 50 trauma and 50 matched nontrauma TMD patients were reviewed. Information concerning presenting pain, temporomandibular joint (TMJ) and related symptoms, examination findings, and diagnoses was recorded. Posttraumatic TMD patients reported higher facial (P = .006) and headache (P = .0001) pain ratings, neck symptom frequency (P < .01), ear-related symptoms (P = .02), sleep disturbance (P < .001), and occupational and avocational disability frequencies (P < .0001). They had greater masticatory muscle (P < .001), neck muscle (P < .001), and TMJ tenderness (P = .01) scores and myofascial pain (P = .006) and arthralgia/capsulitis (P = .008) diagnoses. The nontrauma group had more subjective (P = .02) and objective (P = .05) TMJ crepitus and higher self-reports of parafunctional jaw habits (P = .05). Trauma may be an important etiologic factor for some TMD patients.     

Induction of metallothionein synthesis by bismuth in cultured vascular endothelial cells

The accuracy and reliability of the TMJ Scale were originally determined in cross-validation studies on large, research-based patient samples. It had been assumed that the demographic characteristics and test responses of these research-based samples would be representative of the clinical population in which the TMJ Scale would ultimately find use. The present study on more than 10,000 patients that were evaluated for temporomandibular disorders in clinical practice demonstrates that the test scores, demographic variables, and the patterns of symptom severity that characterize the original TMJ Scale research sample accurately represent the general temporomandibular disorder patient population in which the TMJ Scale is now being used. The results suggest a high degree of confidence in the clinical efficacy of this assessment tool. The overall symptom severity of temporomandibular disorders was found to be normally distributed in the patient population. Women with temporomandibular disorders report a higher level of severity of all physical and psychological symptoms than men. This may explain the high female-to-male ratio in patients seeking treatment. However, a higher percentage of male temporomandibular disorder patients has clinically significant psychological and stress-related problems than do women. The severity and prevalence of symptoms associated with joint dysfunction and range of motion limitation are lower in older age groups, and the overall symptom severity of temporomandibular disorders is not higher in older age groups. However, the severity and prevalence of symptoms associated with joint dysfunction are greater in groups in which temporomandibular disorders have existed for longer durations, although pain levels do not follow this trend. There is also an association between time duration of the temporomandibular disorder and the severity of psychological problems and chronicity. Patients with chronic problems are symptomatically more impaired than those with acute problems.     

Pathology of temporomandibular joint internal derangement and osteoarthrosis

Temporomandibular joint (TMJ) osteoarthrosis and disk displacement seem to be strongly related, but they may also represent mutually independent temporomandibular disorders. This paper presents relevant aspects of normal physiology and degeneration of synovial joints, aspects of normal temporomandibular articular disk physiology and of displacement of the disk, the relationship between TMJ osteoarthrosis and disk displacement, and a general classification of temporomandibular disorders.     

Etiological factors and temporomandibular treatment outcomes: the effects of trauma and psychological dysfunction

This paper examines the effect of trauma and psychological dysfunction as etiological factors in temporomandibular disorder (TMD). It employs a thoroughly validated measurement system, the TMJ Scale, to determine the effects of traumatic temporomandibular joint injury as well as pre-treatment stress and psychological dysfunction levels upon presenting symptom levels. It also addresses these parameters for the eventual treatment outcome. During the course of the study, 754 patients were evaluated at the author's practice, which is limited to the diagnosis and Phase I treatment of temporomandibular dysfunction. Of those individuals, 693 (91.9%) were found to have clinically treatable temporomandibular disorders. At the time of this study, 201 consecutive patients (29%) have completed treatment and were deemed to have reached Maximum Medical Improvement (MMI). The validated measurement system of the TMJ Scale was readministered to this post treatment population. Data analysis revealed that trauma patients did not differ from non-trauma patients in initial symptom levels, nor in levels of symptom improvement (with the exception of a higher palpation pain level reported by the trauma patients). Stress and psychological dysfunction were predictive of higher initial symptom perception levels, but were not significantly related to treatment outcomes. These findings have important implications for practitioners in the field of temporomandibular studies. If it can be confirmed that psychological variables have no impact on treatment outcome, it would be difficult to justify the now frequently employed "dual axis" classifications and major emphasis placed on psychological treatment for temporomandibular patients.     

Chronic mandibular dislocation: the role of non-surgical and surgical treatment

Although the management of acute dislocations of the temporomandibular joint (TMJ) has not changed significantly in recent years, chronic dislocations continue to be treated by a variety of methods. Long-standing cases are the most difficult and frustrating to manage. This paper reports on four cases demonstrating the signs and symptoms associated with some forms of chronic. TMJ dislocations, and the difficulties encountered in the management of some of these conditions. An algorithm based on a critical review of the literature is proposed for the management of both acute and chronic TMJ conditions, and recommendations are made on how to eliminate or reduce their recurrence.     

Comparison of morphine and morphine with ketamine for postoperative analgesia

In addition to the patient's history and a thorough clinical investigation, magnetic resonance imaging (MRI) of the temporomandibular joint (TMJ) has been introduced to complete the findings for the diagnosis of internal derangement of the TMJ. However, 'dynamic information' is desirable to help us to understand the mechanism of internal derangement. This information is given for example by electronic axiography recording systems. The lack of any ability to assess joint function dynamically in MRI is a point of criticism. Using a computer-driven pseudodynamic MRI system (CINE mode) 'dynamic information' should be now available. In this investigation 21 patients with TMJ disorders were examined using both conventional static MRI and CINE mode. For the diagnosis of an anterior displaced disc with or without reduction in 18 cases (86%) it was only necessary to consider two static MRIs: a closed mouth position and a maximal open mouth position. Comparison showed there was no advantage in using CINE mode. Contrast and resolution of the static MRIs were shown to be better and so additional findings such as joint effusion and disc deformation could be diagnosed on static MRIs with greater certainty. Only in three (14%) cases was the dynamic information from CINE mode useful for the diagnosis of the displacement of the disc.     

A balloon pumping technique for treatment of internal derangement of the temporomandibular joint

PURPOSE: This article reports on the use of a silicone or latex balloon to ablate adhesions associated with internal derangement of the temporomandibular joint (TMJ). MATERIALS AND METHODS: Wedge pressure catheters or Swan-Ganz catheters were used. The balloon was inflated with air and also moved forward and backward. RESULTS: TMJ arthroscopic balloon pumping therapy was performed on 11 joints in 11 cases of persistent closed locking. Ablation could be completed with only a balloon in seven joints. Maximal interincisal distances were increased in all cases. The increases ranged from a minimum of 3 mm to a maximum of 23 mm. TMJ pain was not recognized in any case in which 5 months or more had passed since surgery. TMJ noise (clicking) after surgery were recognized in six cases and was dependent on time after surgery. CONCLUSIONS: We are convinced that TMJ balloon pumping therapy is a useful and easy noninvasive method of ablation.     

Symptoms of the stomatognathic system in temporomandibular and cervical spine disorders

This study was performed to assess the prevalence of signs and symptoms of temporomandibular disorders (TMD) in patients with cervical spine disorders (CSD) and to compare patients with CSD and subgroups of patients with TMD with regard to the results of orthopaedic tests of the stomatognathic system. A group of 103 consecutive patients with signs and symptoms of CSD and a group of 111 consecutive patients with TMD were examined. All subgroups of TMD patients showed a significantly smaller range of motion than the CSD patients. Patients with TMD had limited mouth opening (< 40 mm) on active and passive mouth opening more often than CSD patients. TMD patients with myogenous problems reported oral habits more often than CSD patients, although no objective differences between CSD and TMD patients were found. Subgroups of TMD patients reported joint sounds, and pain on palpation and joint play tests of the temporomandibular joint (TMJ) more frequently than CSD patients. Joint sounds on active movements, pain on palpation of the TMJ, and pain on joint play tests correctly classified 82% of the patients with TMD and 72% of the patients with CSD. In spite of the biomechanical and anatomical relationship between the neck and the stomatognathic system, the results of the study show that CSD patients have signs and symptoms of TMD comparable with those of the adult Dutch population. It was concluded that the function of the masticatory system should be evaluated in patients with neck complaints in order to rule out a possible involvement of the masticatory system.     

Resistance to antiretroviral drugs]

A sample of 30 subjects, 15 with and 15 without subjective temporomandibular joint (TMJ) complaints (noises, sounds), underwent a clinical examination, a sonography and an axiography, to detect TMJ clicking. The clinical examination found 22 noisy joints in a total of 60 TMJs considered. Axiography found 19 noisy joints and sonography 32. While 90% of the examined joints showed agreement between axiography and clinical examination (with a little higher sensitivity demonstrated by clinical examination with respect to axiography), 20% of the joints were positive for clicking in sonography only. Sonography showed a high sensitivity in detection of joint noises which suggests its utility as a screening test for early detection of craniomandibular disorders.     

Osteoarthritis and synovitis as major pathoses of the temporomandibular joint: comparison of clinical diagnosis with arthroscopic morphology

PURPOSE: The purposes of this investigation were to determine how common osteoarthritis and synovitis are in patients with severe, recalcitrant temporomandibular joint (TMJ) symptoms using clinical diagnostic criteria as well as arthroscopic examination, and to compare the accuracy of the clinical and arthroscopic diagnoses with respect to specificity and sensitivity. PATIENTS AND METHODS: Clinical and arthroscopic diagnoses were established in 126 joints of 84 patients with severe TMJ symptoms recalcitrant to conservative therapy. All joints were classified as having osteoarthritis (OA) or no osteoarthritis (non-OA) and synovitis (syn) or no synovitis (non-syn) using clinical and arthroscopic criteria. Chi-squared analysis was used to determine whether there was a relationship between the clinical and arthroscopic diagnoses. Preoperative clinical diagnoses were compared with arthroscopic morphologic diagnoses to determine the specificity and sensitivity of the clinical diagnostic criteria for synovitis and osteoarthritis. RESULTS: A preoperative clinical diagnosis of OA was established in 59 of 126 joints (47%) compared with an arthroscopic diagnoses of OA in 82 of 126 joints (65%). Chi-squared analysis showed a significant relationship between the clinical and arthroscopic diagnosis of OA. A clinical diagnosis of OA was associated with a high specificity (.977); however, there were 23 of 82 (.293) false-negative findings and a sensitivity of only .707. A preoperative clinical diagnosis of synovitis was established in 114 of 126 joints (90%), compared with an arthroscopic diagnosis of synovitis in 112 of 126 (89%). Chi-squared analysis did not show a significant relationship between the clinical and arthroscopic diagnosis of synovitis. A clinical diagnosis of synovitis was associated with a high sensitivity (.920); however, there were 11 of 14 false-positive findings (.786) associated with a low specificity (.214). CONCLUSIONS: Although there was high specificity for the clinical diagnosis of OA, the sensitivity was very low. (Comparison of clinical and arthroscopic diagnoses showed that osteoarthritis frequently escapes clinical detection. The clinical diagnosis of synovitis showed that low specificity and symptoms may be caused by other pathoses.     

Can endothelial function be assessed in vivo by measuring acetylcholine induced changes in nitrate in the forearm in man?

A 26-yr-old AC-130 gunner developed unilateral temporomandibular joint (TMJ) pain while flying a combat support mission. A diagnosis of decompression sickness (DCS) was made based on his symptoms and risk factors that included prolonged exposure to high altitude (60 to 90 min at 18,000 ft), cold temperature (-11 degrees C), and increased inflight activity. His symptoms resolved with 100% oxygen and he was returned to flying status after 72 h. Altitude related DCS is an unusual occurrence and this is the first reported case of inflight DCS affecting the temporomandibular joint.     

The hypomobile temporomandibular joint

The hypomobile (restricted) temporomandibular joint (TMJ) is usually caused by a restricted joint capsule or by an anteriorly displaced disk. Here, painful unilateral hypomobility (19 mm jaw opening), with normal disk position, caused by voluntary immobilization after a dental procedure, was the presenting symptom. Management included inflammation control, TMJ manipulation (mobilization), and lateral pterygoid muscle relaxation. Inflammation and pain were alleviated by nonsteroidal anti-inflammatory drugs (NSAIDs) and local TMJ ice massage. TMJ mobilization was performed at every visit, to tear joint capsule adhesions and to realign collagen fibers. Exercise consisted mainly of resistive opening (the patient resists an upward force applied to the chin), with the jaw maintained at full opening. This produced lateral pterygoid muscle relaxation at full length, aiding in the restoration of a pain-free 44 mm opening.     

Electronic thermography for the assessment of acute temporomandibular joint pain

Electronic thermography (ET) has the potential to be a nonionizing, noninvasive, low-cost diagnostic alternative for evaluating temporomandibular joint (TMJ) disorders. This study was designed to evaluate the use of ET as a diagnostic aid in the assessment of patients with acute TMJ pain. Computer measurements made using facial thermography were able to distinguish normal patient populations from symptomatic patients with acute TMJ pain. Additional studies are needed before thermographic diagnosis of TMJ disorders will be clinically accepted.     

Loading of a unilateral temporomandibular joint prosthesis: a three-dimensional mathematical study

The load on the prosthetic side and the influence of the design on the remaining natural contralateral TMJ must be known before a unilateral temporomandibular joint (TMJ) prosthesis can be developed. The aim of the present study was to determine the maximum loading of the TMJ prosthetic side and the natural contralateral TMJ and to investigate the influence of the location of the center of rotation of the prosthesis on the maximum loading. For this purpose, a mathematical model of the mandible with a unilateral TMJ prosthesis with a fixed center of rotation (CR) was developed. The location of the CR of the TMJ prosthesis was varied from the middle of the natural mandibular condyle to 15 mm inferior to this location. Although the maximum joint reaction forces changed as a result of a unilateral TMJ prosthesis, the trend of the loading curves was similar to that of an intact mandible. A unilateral TMJ prosthesis resulted in a 50% higher loading of the prosthetic side, while the load on the natural contralateral TMJ remained within normal limits. The maximum load on the prosthetic side occurred during molar bites and could reach 100 N in the cranial direction, 30 N in the ventral direction, and 25 N in the medio-lateral direction. The location of the CR did not have a significant influence on the loading of the TMJ prosthesis and the natural contralateral TMJ.     

Long-term administration study of propiverine hydrochloride (BUP-4 tablets) in pollakiuria and urinary incontinence

The purpose of this study was to investigate the relationship between osseous changes in the temporomandibular joint (TMJ) and dental attrition in the Japanese macaque. One hundred and thirty Japanese macaque skulls (54 male and 76 female) from animals which had been bred in the same environment, were randomly sampled from a collection at the Primate Research Institute of Kyoto University. The age at death had been recorded in all cases. TMJ osseous changes were independently evaluated by three examiners, and were defined as an irregular surface or a perforated compact bone layer with a markedly irregular surface on either the temporal or condylar components. Age was a significant factor in predicting TMJ osseous changes (P < 0.001). A strong relation was observed between age and dental attrition (P < 0.001), while dental attrition was not a significant factor in predicting TMJ osseous changes (P = 0.334). The prevalence TMJ osseous changes in male animals was slightly higher than in females (P = 0.057). The results of this study suggest that osseous changes in the macaque TMJ are mainly related to age, not to dental attrition.     

Effects of posterior teeth replacement on temporomandibular joint sounds: a preliminary report

Previous reports have shown the prevalence of jaw clicking to be significantly higher in a population with missing posterior teeth compared with an dentulous population. This study presents a 2- to 5-year assessment of the effects of posterior teeth replacement on the amplitude of jaw clicking in subjects who were asymptomatic in all respects except jaw clicking. Patients requiring removable partial dentures (RPDs) were clinically and anamnestically examined and temporomandibular joint (TMJ) sounds were recorded using a modified stethoscope attached to an adjustable headgear. Amplified signals were displayed on a strip chart recorder. The amplitude of TMJ sounds at preinsertion of RPDs were 27.5 +/- 17.7 dB at opening, and 11.1 +/- 12.7 dB at closing. Similar values after prosthesis insertion were 15.8 +/- 17.0 dB and 7.4 +/- 7.5 dB, respectively. Paired t test analyses showed significant differences in the amplitude of sound for opening and closing before inserting the prosthesis (p = 0.003) and for opening before and after treatment (p = 0.014). Following replacement of posterior teeth, the clicking amplitude decreased in 68% of recordings, remained unchanged in 11%, and increased in 21%.     

Efficacy of arthroscopic lysis and lavage in patients with temporomandibular joint symptoms associated with generalized osteoarthritis or rheumatoid arthritis

PURPOSE: This study evaluated the efficacy of arthroscopic lysis and lavage in patients with temporomandibular joint (TMJ) symptoms and generalized osteoarthritis (GOA) or rheumatoid arthritis (RA). PATIENTS AND METHODS: Twenty-three GOA patients and 23 RA patients were evaluated after 1 year. RESULTS: Seventeen of 23 patients (74%) in the RA group improved after arthroscopic lysis and lavages compared with 10 of 23 (43%) of the GOA patients. Lateral joint tenderness, crepitation, maximal opening, and maximal protrusion showed most improvement in the RA group. CONCLUSIONS: On the basis of this short-term follow-up study, arthroscopic lysis and lavage seem to provide an effective treatment for TMJ pain and dysfunction in RA patients but not in GOA patients.