Educational effects using a robot patient simulation system for development of clinical attitude.

INTRODUCTION: The aim of this study was to assess the effectiveness of improving the attitude of dental students towards the use of a full-body patient simulation system (SIMROID) compared to the traditional mannequin (CLINSIM) for dental clinical education. MATERIALS AND METHODS: The participants were 10 male undergraduate dental students who had finished clinical training in the university hospital 1 year before this study started. They performed a crown preparation on an upper pre-molar tooth using SIMROID and CLINSIM as the practical clinical trials. The elapsed time for preparation was recorded. The taper of the abutment teeth was measured using a 3-dimensional shape-measuring device after this trial. In addition, a self-reported questionnaire was collected that included physical pain, treatment safety and maintaining a clean area for each simulator. Qualitative data analysis of a free format report about SIMROID was performed using text mining analysis. This trial was performed twice at 1-month intervals. RESULTS: The students considered physical pain, treatment safety and a clean area for SIMROID significantly better than that for CLINSIM (P < .01). The elapsed time of preparation in the second practical clinical trial was significantly lower than in the first for SIMROID and CLINSIM (P < .01). However, there were no significant differences between the abutment tapers for both systems. For the text mining analysis, most of the students wrote that SIMROID was similar to real patients. CONCLUSION: The use of SIMROID was proven to be effective in improving the attitude of students towards patients, thereby giving importance to considerations for actual patients during dental treatment.

Systematic review and recommendations for nonodontogenic toothache.

Nonodontogenic toothache is a painful condition that occurs in the absence of a clinically evident cause in the teeth or periodontal tissues. The purpose of this review is to improve the accuracy of diagnosis and the quality of dental treatment regarding nonodontogenic toothache. Electronic databases were searched to gather scientific evidence regarding related primary disorders and the management of nonodontogenic toothache. We evaluated the level of available evidence in scientific literature. There are a number of possible causes of nonodontogenic toothache and they should be treated. Nonodontogenic toothache can be categorised into eight groups according to primary disorders as follows: 1) myofascial pain referred to tooth/teeth, 2) neuropathic toothache, 3) idiopathic toothache, 4) neurovascular toothache, 5) sinus pain referred to tooth/teeth, 6) cardiac pain referred to tooth/teeth, 7) psychogenic toothache or toothache of psychosocial origin and 8) toothache caused by various other disorders. We concluded that unnecessary dental treatment should be avoided.

Identification of risk factors for fracture of veneering materials and screw loosening of implant-supported fixed partial dentures in partially edentulous cases.

This retrospective study identified the risk factors for fracture of veneering materials and screw loosening of implant-supported fixed partial dentures in partially edentulous cases. The study group included a total of 182 patients who were installed 219 suprastructures at the Fixed Prosthodontic Clinic of Okayama University Dental Hospital between February 1990 and March 2005 and were subdivided in two subgroups: 120 patients (149 facing suprastructures) were included in the subgroup to investigate the risk factors of fracture of veneering materials, and 81 patients (92 suprastructures) were included in the subgroup to identify the risk factors of abutment screw loosening. Each patient was followed up from the day of suprastructure installation until March, 2005. A Cox proportional hazards regression model was used to identify the risk factors related to technical complications, and eight factors were regarded as candidate risk factors. Screw retention was the significant risk factor for fracture of veneering materials, whereas connection of suprastructures with natural tooth was the significant risk factor for screw loosening. It was suggested that screw retention was a significant risk factor for the fracture of veneering materials, and connection of suprastructures with natural tooth was a significant risk factor for screw loosening. Future studies, involving dynamic factors (e.g. bruxism) as predictors as well, are more helpful to discuss the risk factor of fracture of veneering materials and screw loosening.

Occlusal dysesthesia: a qualitative systematic review of the epidemiology, aetiology and management.

Occlusal dysesthesia refers to a persistent complaint of uncomfortable bite sensation with no obvious occlusal discrepancy. This systematic review aimed to draw a picture of such patients, to present an agreement of previously reported diagnostic criteria and to analyse the evidence level of the recommended management approaches. An electronic search for all relevant reports on occlusal dysesthesia was thoroughly performed based on previous nomenclatures (e.g. phantom bite, occlusal hyperawareness) in PubMed and The Cochrane Library in July, 2011. A total of 84 reports were matched, among which only 11 studies were included after a two-step (abstract and detailed full-text revision) screening process. Additionally, a thorough manual review of reference lists of the included reports enabled the inclusion of two additional studies. Data analysis revealed that 37 occlusal dysesthesia patients presented a mean age of 51.7 ± 10.6 years and were predominantly women (male/female: 1/5.1) with symptom duration of more than 6 years (average: 6.3 ± 7.5 years) and with concomitant psychological disturbances (e.g. mood disorders, somatoform disorders, personality disorders). Only four authors presented diagnostic criteria for occlusal dysesthesia, which served as the basis for an agreement in the diagnostic criteria. Treatment approaches included psychotherapy, cognitive/behaviour therapy, splint therapy and prescription of anti-depressants or anti-anxiety drugs. Classification of evidence level of management approaches, however, revealed that most of them were expert opinions with single- or multiple-case report(s). Future studies are necessary for a deeper understanding of the mechanisms behind the occlusal dysesthesia symptoms, and consequently, for improvements in evidence-based management approaches.

Response shift in oral health-related quality of life measurement in patients with partial edentulism.

The purposes of this study were to determine whether a response shift was observable after partial denture treatment and to identify the predictors that influenced the response shift magnitude and direction. A total of 173 consecutive patients with no more than eight missing teeth who received implant-supported, fixed or removable partial dentures at Okayama University Dental Hospital were asked to complete a full-version Oral Health-Related Quality of Life (OHRQoL) questionnaire before (pre-test) and after treatment (post-test). Additionally, a short form (then-test) consisting of seven questions selected from the full version had its reliability verified and was utilised to retrospectively assess the pre-treatment OHRQoL status. The difference between the summary scores of the then-test and the pre-test determined the response shift magnitude and direction. The then-test mean score (22·9 ± 6·6) was significantly lower (worse OHRQoL) than that of the pre-test (26·4 ± 5·2). The response shift effect size was of moderate magnitude and negative direction (d = -0·78). A multiple regression analysis showed that age (younger patients) (P < 0·01), number of replaced teeth (fewer) (P < 0·01) and pre-test scores (lower) (P < 0·01) were the significant predictors for response shift. In conclusion, a response shift phenomenon with negative and moderate effect size was observed after partial denture treatment. The significant predictor variables were young age, fewer numbers of replaced teeth and lower pre-test scores.

Intradermal injection of Botulinum toxin type A alleviates infraorbital nerve constriction-induced thermal hyperalgesia in an operant assay.

Recent studies have shown that infraorbital nerve constriction (IoNC)-induced mechanical allodynia has been attenuated by administration of highly purified 150-kDa Botulinum neurotoxin type A (BoNT/A). Here, we extend these studies to determine whether BoNT/A could attenuate IoNC-induced symptoms of thermal hyperalgesia. Instead of testing head withdrawal thresholds, a thermal operant assay was used to evaluate cortical processing of sensory input following IoNC. In this assay, a fasted rat's desire to obtain a food reward (sweetened condensed milk) is coupled to its ability to tolerate facial contact with a warm (45 °C) thermode. Bilateral IoNC decreased the ratio of thermode contact duration/event, which is an indicative of thermal hyperalgesia. BoNT/A injection intradermally in the area of infraorbital nerve (IoN) innervation 7 days after IoNC resulted in decreased number of facial contacts and increased the ratio of contact duration/event (measured at 14 days after IoNC). The BoNT/A (2-200 pg) effects were dose dependent and statistically significant at 100 and 200 pg (P < 0·05). Complete reversal of thermal hyperalgesia symptoms was obtained with a 200-pg dose, without affecting sham rat behaviour. Off-site (neck) injection of BoNT/A did not relieve thermal hyperalgesia, while co-injection of BoNT/A with a neutralising antibody in the area of IoN innervation prevented relief of thermal hyperalgesia. Neither IoNC nor BoNT/A injection affected operant assay parameters with a 24 °C thermode, indicating selectivity of thermal hyperalgesia measurements. These results strongly suggest that intradermal injection of BoNT/A in the area of IoN innervation alleviates IoNC-induced thermal hyperalgesia in an operant assay.

Guidelines and recommendations for assessment of somatosensory function in oro-facial pain conditions--a taskforce report.

The goals of an international taskforce on somatosensory testing established by the Special Interest Group of Oro-facial Pain (SIG-OFP) under the International Association for the Study of Pain (IASP) were to (i) review the literature concerning assessment of somatosensory function in the oro-facial region in terms of techniques and test performance, (ii) provide guidelines for comprehensive and screening examination procedures, and (iii) give recommendations for future development of somatosensory testing specifically in the oro-facial region. Numerous qualitative and quantitative psychophysical techniques have been proposed and used in the description of oro-facial somatosensory function. The selection of technique includes time considerations because the most reliable and accurate methods require multiple repetitions of stimuli. Multiple-stimulus modalities (mechanical, thermal, electrical, chemical) have been applied to study oro-facial somatosensory function. A battery of different test stimuli is needed to obtain comprehensive information about the functional integrity of the various types of afferent nerve fibres. Based on the available literature, the German Neuropathic Pain Network test battery appears suitable for the study of somatosensory function within the oro-facial area as it is based on a wide variety of both qualitative and quantitative assessments of all cutaneous somatosensory modalities. Furthermore, these protocols have been thoroughly described and tested on multiple sites including the facial skin and intra-oral mucosa. Standardisation of both comprehensive and screening examination techniques is likely to improve the diagnostic accuracy and facilitate the understanding of neural mechanisms and somatosensory changes in different oro-facial pain conditions and may help to guide management.

Two types of neurotransmitter release patterns in isolectin B4-positive and negative trigeminal ganglion neurons.

Mammalian nociceptors have been classified into subclasses based on differential neurotrophin sensitivity and binding of the plant isolectin B4 (IB4). Most of the nerve growth factor-responsive IB4-negative (IB4 (-)) nociceptors contain neuropeptides such as substance P and calcitonin gene-related peptide, whereas the glial-derived neurotrophic factor-responsive IB4-positive (IB4 (+)) neurons predominantly lack such neuropeptides. We hypothesized that the differences in neuropeptide content between IB4 (+) and (-) neurons might be reflected in differences in stimulated exocytosis and/or endocytosis. To address this, we monitored the secretory activity of acutely dissociated neurons from adult rat trigeminal ganglia (TRG) using cell membrane capacitance (Cm) measurements and the fluorescent membrane-uptake marker N-(3-triethylammoniumpropyl)-4-(6-(4-(diethylamino)phenyl)hexatrienyl)pyridinium dibromide (FM4-64). Cm measurements were performed under whole-cell voltage clamp and neurons were depolarized from -75 mV to +10 mV to elicit exocytosis. Both types of TRG neurons showed similarly-sized, calcium-dependent increases in Cm, demonstrating that both IB4 (+) and (-) TRG neurons are capable of stimulated exocytosis. However, the peak Cm of IB4 (+) neurons decayed faster toward baseline than that of IB4 (-) neurons. Also, IB4 (+) neurons had stable Cm responses to repeated stimuli whereas IB4 (-) neurons loss their secretory response during repeated stimulation. These data suggested that the IB4 (+) neurons possess a faster rate of endocytosis and vesicle replenishment than IB4 (-) neurons. To test this, we measured vesicle trafficking with the fluorescent membrane dye FM4-64. FM4-64 staining showed that IB4 (-) neurons exhibit a larger pool of endocytosed vesicles than IB4 (+) neurons because the peak fluorescence increases in IB4 (-) neurons were larger but slower than in IB4 (+) neurons. However, the recycled vesicles were released faster in IB4 (+) compared with IB4 (-) neurons. Taken together these data suggest that the IB4 (+) TRG neurons have faster exocytosis and endocytosis than the IB4 (-) neurons.

Relationship between capsaicin-evoked substance P release and neurokinin 1 receptor internalization in the rat spinal cord.

The relationship between substance P release and the activation of its receptor in the spinal cord remains unclear. Substance P release is usually measured by radioimmunoassay, whereas the internalization of the neurokinin 1 (NK1) receptor has been used to assess its activation by noxious stimuli. Our objective was to compare substance P release and NK1 receptor internalization produced by capsaicin in rat spinal cord slices. Superfusion of the slices with capsaicin for 3 min produced a gradual increase in substance P release that peaked 3-7 min afterward, and then decreased to baseline levels. The concentration-response curve for capsaicin was biphasic, with concentrations above 10 microM producing significantly less release. The effective concentration for 50% of response (EC(50)) for capsaicin, calculated from its stimulatory phase, was 2.3 microM. However, the potency of capsaicin to elicit NK1 receptor internalization in the same slices was one order of magnitude higher (EC(50)=0.37 microM) in lamina I, probably because NK1 receptors become saturated at relatively low concentrations of substance P. The potency of capsaicin to produce internalization was progressively lower in lamina III (EC(50)=1.9 microM) and lamina IV (EC(50)=14.5 microM), suggesting that neurokinins released in laminae I-II become diluted as they diffuse to the inner dorsal horn. To study the correlation between these two measures, we plotted substance P release against NK1 receptor internalization and fitted a saturation binding function to the points. The correlation was good for laminae I (R(2)=0.82) and III (R(2)=0.78), but it was poor (R(2)=0.35) for lamina IV because NK1 receptor internalization kept on increasing at high concentrations of capsaicin, whereas substance P release decreased. In conclusion, amounts of substance P able to activate NK1 receptors may fall under the threshold of detection of radioimmunoassay. Conversely, radioimmunoassay often detects levels of substance P release well over those required to saturate NK1 receptors in the superficial dorsal horn, but that may be able to activate these receptors in nearby regions of the spinal cord.

Concurrent release of ATP and substance P within guinea pig trigeminal ganglia in vivo.

Neurons within sensory ganglia have been proposed to communicate via non-synaptic release of a diffusible chemical messenger, but the identity of the chemical mediator(s) remains unknown [J. Neurosci. 16 (1996) 4733-4741]. The present study addressed the possibility of co-released ATP and substance P (SP) within sensory ganglia to further advance the hypothesis of non-synaptic communication between sensory neurons. Microdialysis probes inserted into trigeminal ganglia (TRGs) of anesthetized guinea pigs were perfused with artificial cerebrospinal fluid and the collected perfusate analyzed for ATP and SP content using the firefly luciferin-luciferase (L/L) assay and radioimmunoassay, respectively. Significant reversible increases in ATP and SP levels were observed after infusion of 100 mM KCl or 1 mM capsaicin. Ca(2+)-free ACSF produced an eightfold increase in ATP levels, interpreted as a decrease in activity of Ca(2+)-dependent ecto-nucleotidases that degrade ATP. In contrast, KCl-induced release of ATP in the presence of normal Ca(2+) was blocked by Cd(2+), a voltage-gated Ca(2+) channel blocker, illustrating Ca(2+)-dependence of evoked ATP release. Since ganglionic release of ATP could arise from several neuronal and non-neuronal sources we directly tested acutely dissociated TRG neuron somata for ATP release. Neuron-enriched dissociated TRG cells were plated onto glass tubes and tested for ATP release using the L/L assay. Robust ATP release was evoked with 5 microM capsaicin. These data suggest that ATP is released concurrently with SP from the somata of neurons within sensory ganglia.

Inflammation-induced changes in primary afferent-evoked release of substance P within trigeminal ganglia in vivo.

Substance P (SP) is synthesized in a subset of nociceptive sensory neurons and is released from their peripheral and central terminals. Here we demonstrate with the use of in vivo microdialysis and radioimmunoassay techniques that SP is also released within trigeminal ganglia following intraganglionic application of KCl, veratridine or capsaicin, and after electrical stimulation of peripheral afferent fibers. Both the basal and KCl-evoked release of SP are shown to be dependent on extracellular calcium. Using the turpentine-induced model of unilateral orofacial inflammation we also show that both the basal and KCl-evoked release of SP within trigeminal ganglia are greatly increased on the inflamed side 48 h after induction of inflammation. Coupled with previous demonstrations of excitatory effects of SP on sensory neurons, these results suggest that SP fulfils the role of a non-synaptically released diffusible chemical messenger that may modulate the somatic excitability of neurons within sensory ganglia in inflammatory pain states.

Randomized controlled evaluation of non-surgical treatments for temporomandibular joint anterior disk displacement without reduction.

The common methods for treating anterior disk displacement without reduction (ADDwor) are not based on randomized controlled clinical trials. Our study evaluated non-surgical treatments in 69 MRI-confirmed ADDwor subjects (m/f = 6/63). Subjects were randomly assigned to a control group and one of two treatment groups. Outcomes included maximum mouth opening, visual analogue scale of pain, and daily activity limitation. Calibrated examiners collected data at the initial interview and at 0, 2, 4, and 8 weeks of treatment. At the eight-week point, within-group improvements were present for all variables, for all groups. Between-group differences were not highly evident, with only mean daily activity limitation for the self-care/NSAID group being significantly lower than that of the occlusal appliance/jaw mobilization + self-care/NSAID group at the two- and four-week time-points. These results suggest that ADDwor subjects will improve with only minimal treatment intervention, and no significant difference was evident for the treatments tested and the control condition.

Clinical predictability of temporomandibular joint disc displacement.

Single items from a typical clinical examination have proved disappointing in their predictive value for temporomandibular joint (TMJ) disc displacement. Only one criterion (the 12 o'clock) is used to diagnose normal disc position. According to this criterion, the posterior band of the disc should be located at the top of the condyle, at the 12 o'clock position. The purpose of this study was to determine which signs and symptoms provide a valid prediction of the condition of the joint based on 4 magnetic resonance imaging (MRI) criteria used to define normal disc position. Sagittal MRI and clinical findings of 137 temporomandibular disorder patients and 23 normal asymptomatic volunteers were used. Three calibrated and blinded observers interpreted the images. Disc position with the mouth closed was evaluated based on 4 MRI criteria: 12, 11, 10 o'clock, and the intermediate zone. Disc position with the mouth open was determined based on one criterion. It was considered normal if the intermediate zone of the disc was located between the condyle and the articular eminence. Joints were classified as normal or as having disc displacement with or without reduction. The sensitivity and specificity of multiple clinical parameters for predicting the condition of the joint established by each of these 4 gold-standard MRI criteria were then determined. Regarding disc displacement with reduction, significant differences were observed in the sensitivity and specificity of all of the clinical parameters used to predict the imaging diagnosis established by each of the criteria. Concerning disc displacement without reduction, no significant differences were observed. The intermediate zone criterion was the criterion that most accurately reflected the condition of the joint. The clinical predictability of the disorder diagnosed according to this criterion suggests that clinical findings alone are too often nonspecific as predictors of the imaging stage of disc displacement. However, we found that combining the most sensitive clinical items to predict the disorder and using an overall criterion for positivity to interpret the results led to an impressive increase in the specificity of the combination, enabling false-positive diagnoses to be excluded.

Trigeminal neuralgia due to an acoustic neuroma in the cerebellopontine angle.

This case report first reviews the intracranial tumors associated with symptoms of trigeminal neuralgia (TN). Among patients with TN-like symptoms, 6 to 16% are variously reported to have intracranial tumors. The most common cerebellopontine angle (CPA) tumor to cause TN-like symptoms is a benign tumor called an acoustic neuroma. The reported clinical symptoms of the acoustic neuroma are hearing deficits (60 to 97%), tinnitus (50 to 66%), vestibular disturbances (46 to 59%), numbness or tingling in the face (33%), headache (19 to 29%), dizziness (23%), facial paresis (17%), and trigeminal nerve disturbances (hypesthesia, paresthesia, and neuralgia) (12 to 45%). Magnetic resonance imaging with gadolinium enhancement or computed tomography with contrast media are each reported to have excellent abilities to detect intracranial tumors (92 to 93%). This article then reports a rare case of a young female patient who was mistakenly diagnosed and treated for a temporomandibular disorder but was subsequently found to have an acoustic neuroma located in the CPA.

The long-term effect of occlusal therapy on self-administered treatment outcomes of TMD.

Because of a lack of substantial scientific data, the efficacy of occlusal therapy for the management of temporomandibular disorders (TMD) is still controversial. Of a total of 1405 consecutive TMD patients examined over the last 10 years, 369 (26.3%) were determined to have completed treatment at least 1 year before the present survey. A sample questionnaire was mailed to each patient in this sample population. The questionnaire failed to reach 46 patients; of the 323 patients who received the questionnaire, 260 (80.5%) responded. The mean duration of time between their last visit and this survey was 3.7 years. The questionnaire elicited information on treatment outcomes, present treatment needs, and current signs and symptoms. Participants were divided into two treatment groups: (a) those who underwent some occlusal therapies (Phase II) following successful reversible therapies (Phase I) (20 men and 114 women); and (b) those who underwent reversible therapy only (33 men and 93 women). Participants were further differentially diagnosed into five diagnostic subgroups of TMD, based on the clinical examination at the initial visit, tomography, and, for some patients, magnetic resonance imaging. The subgroups included myalgia, arthralgia, anterior disc displacement with an without reduction, and osteoarthritis/osteoarthrosis. Only 12.3% of the total population surveyed reported lack of improvement to an acceptable level and further need for treatment. The remaining patients reported satisfactory results in the reduction of TMD symptomatology and no further need for treatment, because their symptoms had either disappeared or improved to an acceptable level. Regardless of treatment groups and diagnostic subgroups, the current subjective signs and symptoms were negligible in most patients, and mean mouth openings were in the normal range. No particular diagnostic subgroups seemed to have significantly better outcome following Phase II occlusal therapy. These results suggest that the majority of TMD signs and symptoms improve to an acceptable level with only reversible therapy, and the long-term value of additional occlusal therapy following reversible therapy is minimal. Therefore, permanent occlusion-changing therapies apparently are not generally needed to maintain TMD symptom reduction over time.

Four-year longitudinal course of TMD symptoms in an adult population and the estimation of risk factors in relation to symptoms.

AIMS: To investigate the natural course of symptoms of temporomandibular disorders (TMD) in a non-patient population and to estimate the strength of the relationship between several hypothesized risk factors and precipitation and perpetuation of the symptoms. METHODS: A total of 672 randomly selected citizens of Okayama City was requested to answer the same self-administered questionnaire that they had answered 4 years earlier. The mailed questionnaire failed to reach 58 subjects at the second survey, and 367 of the remaining subjects (59.8%) responded. The fluctuation of TMD symptoms was assessed by comparison of 6 pairs of answers for questions regarding temporomandibular joint (TMJ) pain, limitation of mouth opening, TMJ noise, headache, neck pain, and shoulder stiffness. Six factors (age under 40, female, clenching habit, history of extrinsic trauma, sleep disturbance, and family history of TMD) were tested for their relative risk in precipitating and perpetuating each TMD symptom by the use of its confidence interval to define significance. RESULTS: The incidence of TMD symptoms ranged from 6.1% (TMJ pain) to 12.9% (TMJ noise). More than half of the subjects who had reported TMJ and neck pain at the initial survey no longer reported these symptoms at the second survey, whereas TMJ noise and shoulder stiffness remained in more than 70% of the subjects. Individuals under 40 years old had a 3.3:1 increased risk of precipitating TMJ noise (P < 0.01), individuals with a history of extrinsic trauma had a 2.85:1 increased risk of precipitating limited mouth opening (P < 0.01), and females had a 2.81:1 increased risk of perpetuating TMJ pain (P < 0.01). CONCLUSION: The possible etiologic significance of these factors in TMD should be validated by future research.

Long-term follow-up study on drop-out TMD patients with self-administered questionnaires.

Although patient attrition might be a serious threat to the validity of treatment-outcome studies on temporomandibular disorders (TMD), studies on TMD patient attrition are scarce. Of the 1405 consecutive TMD patients examined in a recent 10-year period, 367 (26.1%) drop-out patients or patients identified with a control group were sampled. A mailed questionnaire failed to reach 41 patients, and 203 (62.3%) were returned. The questionnaire elicited information on reasons for dropping out, changes in symptoms, treatment received in other clinics after dropping out, present treatment needs, and current signs and symptoms. Dropouts were divided into two groups: (1) those who failed to show up for their first scheduled appointment after the clinical examination; (2) those who failed to complete treatment. A group of patients who were judged by the examiner not to need treatment were included as a control group. The main reasons for dropping out were environmental obstacles, perceived improvement of the disease, and dissatisfaction with services. Only 21.7% considered themselves to be in need of treatment, and only 10.3% had visited other clinics after dropping out. Only 8.9% complained of the continued aggravation of symptoms, whereas 57.6% reported improvement. In addition, pain, dysfunction, and daily activity limitation tended to improve with time, although temporomandibular joint noise tended to persist. These results suggest that TMD signs and symptoms tend to decrease in patients after dropping out, and that the natural fluctuation of TMD signs and symptoms should be taken into consideration when treating TMD.

Abnormal signal-averaged electrocardiogram in patients with Duchenne muscular dystrophy: comparison of time and frequency domain analyses from the signal-averaged electrocardiogram.

The clinical significance of an abnormal signal-averaged electrocardiogram (SA-ECG) in time- and frequency-domain analyses was assessed in patients with Duchenne muscular dystrophy (DMD). Twenty-four DMD patients and 20 age-matched healthy volunteers were studied. The SA-ECG was recorded by time-domain signal processing using the vector-magnitude method and frequency-domain signal processing using the fast-Fourier transform. Abnormal SA-ECGs were based on comparison with controls and eight abnormal SA-ECGs were detected among 24 DMD patients, seven by frequency-domain analysis and four by time-domain analysis. The end-diastolic left ventricular volume was larger in the patients with abnormal SA-ECG than in those with normal SA-ECG (136 +/- 32 ml vs. 77 +/- 43 ml, p < 0.01). Compared with patients with normal SA-ECGs, the DMD patients with abnormal SA-ECGs had a lower left ventricular (LV) ejection fraction (54 +/- 6 vs. 61 +/- 8%, p < 0.05), as an index of LV contractility, and less LV posterior wall velocity (46 +/- 9 mm/min vs. 62 +/- 16 mm/min, p < 0.01), as an index of LV relaxation. The sensitivity and specificity of frequency-domain analysis for predicting malignant ventricular arrhythmias was 60 and 85%, respectively, compared with 30 and 92%, respectively, for time-domain analysis. The combination of time- and frequency-domain analyses can facilitate identification of DMD patients with ventricular tachyarrhythmias associated with depression of cardiac performance.

Self-reported remission, difficulty, and satisfaction with nonsurgical therapy used to treat anterior disc displacement without reduction.

OBJECTIVE: The purpose of this study was to identify the appropriate treatment element for initial anterior disc displacement without reduction subjects. STUDY DESIGN: Sixty-nine consecutive patients with temporomandibular joint disc displacement without reduction confirmed on magnetic resonance images were randomly divided into 3 experimental treatment groups. The treatment of group 1 consisted of short-term nonsteroidal anti-inflammatory drugs and self-care instructions (palliative care group); group 2, nonsteroidal anti-inflammatory drugs, self-care instructions, and occlusal appliance and mobilization therapy (physical medicine group); and group 3, no treatment (control group). Outcomes were assessed by means of a 5-item questionnaire that evaluated (1) symptom improvement, (2) difficulty of treatment, and (3) satisfaction with treatment during the 8-week observation period. RESULTS: Improvement scores in the palliative care group were significantly better than those in the physical medicine group or the no-treatment group. Satisfaction scores showed no significant difference among the 3 groups. Difficulty from treatment for the physical medicine group was significantly greater than that for other 2 groups. CONCLUSION: These data suggest that palliative care would be more appropriate as the initial therapy to treat painful anterior disc displacement without reduction.

The influence of observer calibration in temporomandibular joint magnetic resonance imaging diagnosis.

OBJECTIVE: This study was undertaken to investigate the potential of reducing observer variation through a calibration program. STUDY DESIGN: The study was based on three sets of randomly selected temporomandibular joint magnetic resonance images. Each set consisted of bilateral images from 20 consecutive patients with temporomandibular disorders. As a baseline, three well-experienced noncalibrated investigators interpreted the images individually for disk position and disk configuration. After the initial interpretation, interobserver agreement was calculated as a kappa index and presented to the examiners. On the same occasion, the investigators analyzed agreement between them on the criteria to be used. RESULTS: Overall data in this study showed an increase in the frequency of interobserver agreement with regard to disk position after the calibration trials were instituted. With regard to disk configuration, substantial interindividual variations were observed even after the observers reached consensus as to the criteria to be used. CONCLUSIONS: These data suggest that after calibration trials, it is possible for three examiners to obtain reliable and reproducible results in reporting temporomandibular joint disk position on magnetic resonance images.