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Query: UMLS:C0030193 (pain)
 261,466 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Over the last 75 years, a variety of etiologic factors has been suggested as the cause of pain and dysfunction in the temporomandibular system. The earliest and still-popular etiologic theory proposed that temporomandibular disorders are induced by abnormal structure, usually described as a malocclusion of the teeth or jaws. The fact that this theory was based on mechanical concepts, ignored biologic diversity, and had limited factual experimental evidence to support it as well as extensive evidence in opposition did not seem to matter to its proponents. In the late 1960's and early 1970's, the structural occlusal model for TM Disorders was challenged and has yielded ground to a more multifactorial model of TMD causation. Other etiologic factors for TM disorders--such as anatomical susceptibility of TM tissues to trauma, polyarthritic diseases, joint laxity, repetitive parafunctional behaviors, and stress-related muscle dysfunction--need to be recognized and quantified. Unfortunately, many practicing dentists demonstrate a very poor understanding of and often fail to recognize these etiologic factors as agents that produce TM disorders. This failure is largely due to the fact that the dental profession has spent the last 90 years dealing with a variety of misconceptions about the etiology of temporomandibular disorders. In the 1990's, one of the more formidable challenges we face is acquiring the ability to segregate and define validly the specific TM Disorder of concern and then correctly identify and measure the specific etiologic factors that produce it. Until these problems are solved, it is unlikely that we will be able to prevent disease of the TM apparatus.
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PMID:Etiologic theory and the prevention of temporomandibular disorders. 181 85

71 patients (16 males and 55 females) with temporomandibular (TM) disorders were examined for clinical symptoms of mandibular dysfunction. The frequency of TM disorders in the present study was higher in females (55 females, 77.5%) than in males (16 males, 22.5%); the ratio of females to males was about 3.4:1. The most frequent chief complaint was pain; limitation of opening movement was the next most common. Many patients had several of the major symptoms simultaneously. TM joint sounds were noted in 47 patients, including reciprocal clicking in 35 patients and crepitation in 12 patients. Tenderness with palpation of the TM joint and muscles were found in 46 patients; most of them complaining at two positions or more. Occlusal interferences were noted in various occlusal positions, and occlusal wear was found in 30 patients (42.3%). In recording the frequency of parafunction and bad habits, grinding of the teeth was found in 6 patients (8.5%), clenching of the teeth in 10 (14.1%), and unilateral mastication in 24 (33.8%).
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PMID:Clinical findings in temporomandibular disorders. 213 Nov 77

Muscle palpation is an important procedure in screening for TM disorders and assessing results of treatment outcome studies, but interpretation of response may be subjective and vulnerable to examiner bias. Masticatory muscle palpation scoring was evaluated with respect to interrater agreement on 31 myofascial pain-dysfunction patients participating in a medication study. Two clinicians independently palpated the temporomandibular joints, muscles of mastication, and related head and neck musculature on three different occasions over the 6-week period of the study. Standardization of palpation technique and initial protocol for interpretation of subject response were discussed prior to the first examination. Further clarification and reinforcement of examination methodology and scoring were carried out prior to the second examination, 1 week later. Another 5 weeks passed, with no further standardization, before the third and last examination. A behaviorally anchored scoring system (0 to 3) was used to rate response to palpation. Results indicate that two investigators can achieve a fair degree of reliability when carefully standardized, further interrater standardization can result in higher reliability, and reliability can be maintained over at least a 5-week period of time.
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PMID:Interrater reliability in masticatory muscle palpation. 263 93

Most population-based studies of TM disorders report a discrepancy between the frequency of symptoms and the frequency of signs of functional disturbances of the temporomandibular joint. In addition, studies have reported varying relationships between subjectively perceived symptoms and signs found on clinical examination. This study examines this relationship in 148 Canadian adults who were part of a larger sample of 677 subjects who completed a telephone administered symptom questionnaire. Symptoms were reported by 63.5% and signs were found in 88.1%. While a degree of discordance was observed, there was a close and statistically significant association between symptoms and signs. This was the case whether summary variables or individual symptoms and signs were used as the dependent variable and whether proportions with or absolute numbers of symptoms and signs were examined. The validity of the symptom questionnaire was examined in order to assess its ability to identify "cases" of TMD. Validity tests showed a sensitivity of 81.4% and a specificity of 48.3%. When "false" positives and "true" positives were compared, the former were found to be significantly less likely to report pain.
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PMID:Association of symptoms and signs of TM disorders in an adult population. 273 96

The purpose of this study was to evaluate tonic masticatory muscle activity and the postural rest position of the mandible, pre- and post-treatment, in patients with TM disorders. Forty-one patients diagnosed as suffering from myofascial pain-dysfunction (MPD) were evaluated, with electromyography (EMG) used to measure the muscle activity of the masseteric and anterior temporal areas at rest. Postural rest position was assessed by measurement of interocclusal distance. Twenty-three asymptomatic subjects were also tested as controls. Treatment for the pain group emphasized cognitive awareness of dysfunctional orofacial behavior and biofeedback training of the masseteric area to teach masticatory muscle relaxation. The pre-treatment EMG values of both the masseteric and anterior temporal areas were significantly higher for the pain group than for the control group. Post-hoc division of the pain group into successful and unsuccessful subgroups was made on the basis of the degree of symptom improvement. EMG activity decreased significantly in the masseters of both subgroups, but only the unsuccessful subgroup showed a significant decrease in anterior temporal activity following therapy. Interocclusal distance was significantly increased in both subgroups. These results suggest that tonic masticatory muscle activity may be elevated in MPD patients. They also suggest that a decrease in EMG activity in the masseter and anterior temporalis muscles and an opening of the postural rest position of the mandible may accompany completion of psychophysiological therapy, but these changes do not correspond directly with the outcome of that therapy.
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PMID:The effects of treatment on masticatory muscle activity and mandibular posture in myofascial pain-dysfunction patients. 316 8

Few epidemiologic studies of TM disorders have used random samples drawn from the general population. The aim of this study was to estimate the prevalence and distribution of symptoms commonly associated with such disorders among a sample of adults in Toronto, Canada. A random digit dialing technique was used to identify 1002 individuals aged 18 and over. A symptom questionnaire was completed by 67.7%. Overall, 48.8% responded positively to one or more of the nine questions concerning symptoms. Joint sounds, tiredness or stiffness of jaw muscles, and an uncomfortable bite were the symptoms most frequently reported. Functional pain or pain while at rest was reported by 12.9%. Sex and age differences were small although statistically significant, with women and the younger age groups more likely than men or the older age groups to report one or more symptoms. Significant associations were observed between the reporting of symptoms and potential risk factors such as parafunctional behaviours and reports of frequent stress. The proportion in need of treatment varied from 3.5% to 9.7% according to the case definition used.
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PMID:Prevalence of symptoms associated with temporomandibular disorders in a Canadian population. 326 54

This paper reviews the effectiveness of occlusal splints on specific symptoms that are often associated with TM disorders. The research has shown the clicking TMJ is sometimes helped but not cured by the traditional stabilization interocclusal appliance and that TMJ clicking is the least responsive to treatment. Questions have been raised about the need to specifically treat the clicking joint; more research on this issue is necessary. Painful TMJs have been shown to respond to occlusal appliance therapy, but questions still exist about the effectiveness of interocclusal appliances for this symptom. There is little scientific proof available about the ability of splints to effectively slow down or reverse degenerative TMJ changes that are evident on radiographs. Masticatory muscle pain is by far the symptom that has the best experimental evidence to support occlusal splints as a highly effective method of treatment. These changes are probably mediated via an alteration in the patient's muscle activity patterns. Those patients with more severe symptoms are less likely to be helped with splints as a sole treatment modality. The effect of occlusal appliances in muscle trismus has been discussed but not effectively evaluated in the literature. Occlusal splints have been shown to have a distinct influence on improving mandibular muscle coordination. Inter-occlusal splints are a commonly used method of controlling attrition and adverse tooth loading, and few questions have been raised in the literature about this therapeutic application.
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PMID:A critical evaluation of orthopedic interocclusal appliance therapy: effectiveness for specific symptoms. 637 Oct 97

A review of the current literature regarding the interaction of morphologic and functional occlusal factors relative to TMD indicates that there is a relatively low association of occlusal factors in characterizing TMD. Skeletal anterior open bite, overjets greater than 6 to 7 mm, retruded cuspal position/intercuspal position slides greater than 4 mm, unilateral lingual crossbite, and five or more missing posterior teeth are the five occlusal features that have been associated with specific diagnostic groups of TMD conditions. The first three factors often are associated with TMJ arthropathies and may be the result of osseous or ligamentous changes within the temporomandibular articulation. With regard to the relationship of orthodontic treatment to TMD, the current literature indicates that orthodontic treatment performed during adolescence generally does not increase or decrease the odds of developing TMD later in life. There is no elevated risk of TMD associated with any particular type of orthodontic mechanics or with extraction protocols. Although a stable occlusion is a reasonable orthodontic treatment goal, not achieving a specific gnathologically ideal occlusion does not result in TMD signs and symptoms. Thus, according to the existing literature, the relationship of TMD to occlusion and orthodontic treatment is minor. Signs and symptoms of TMD occur in healthy individuals and increase with age, particularly during adolescence; thus, TM disorders that originate during various types of dental treatment may not be related to the treatment but may be a naturally occurring phenomenon.
J Orofac Pain 1995
PMID:Occlusion, Orthodontic treatment, and temporomandibular disorders: a review. 758 Dec 9

This article discusses the subject of causation (etiology) as it has been applied to the field of temporomandibular disorders (TMD). These disorders have been the focus of considerable disagreement about what constitutes proper diagnosis and treatment, and it is clear that the main basis for these controversies has been conflicting views about the etiology of the various disorders. Many earlier theories emphasized dental morphological factors of malocclusion, occlusal dysharmony, and bad mandibular alignment as being primarily responsible for the development of TMD symptoms. Certain versions of these dental/skeletal concepts have long been a part of the belief system of the orthodontic specialty, leading to some special orthodontic protocols for managing TM disorders. Today, it is generally agreed that the etiology of TM disorders includes a multifactorial combination of physical and psychosocial factors, with some of them being either poorly understood or difficult to assess. In most cases, there are no special occlusal or orthodontic factors to be considered, and therefore occlusion-changing procedures are not generally required for successful treatment. This means that contemporary orthodontists must face the same challenge as all their other dental colleagues: to learn about modern concepts of diagnosis and treatment for all types of orofacial pain patients, and then to use currently recommended protocols for pain management and musculoskeletal therapy for those patients who have temporomandibular disorders.
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PMID:Etiology of temporomandibular disorders. 893 52

The orthodontic population has a high probability of internal joint and muscles of mastication disorders. In the past orthodontics has been performed with modest consideration of the jaw joints. Reasons why braces are not effective in the treatment of TM disorders are explained. Presently increased emphasis is given to the function and health of the TM joints. The aware orthodontist has an opportunity to address TM disorders and improve the quality of life for his or her patients by doing a few things differently before or concurrent with conventional orthodontics. Application of orthotic and functional jaw orthopedic appliance therapy principles as presented does address the root cause and will help the majority of individuals with internal derangement and associated craniofacial pain in the orthodontic practice. Consulting services are available from author to help with individual case treatment planning or get treatment back on track.
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PMID:TMJ in your practice. 1724 Sep 38


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