Temporomandibular disorders and bruxism. Part I

Correct functioning of the entire stomatognathic system is achieved by a compatible relationship of all its parts. Four determinants, by their mutual harmonious activity, dictate the function of the entire system: the teeth, periodontium with supporting structure, muscles, temporomandibular joint (TMJ) and CNS. In such a complex system a disorder of any integrative part causes disturbances also in other parts of the system. Changed functions can arise through organic disorder, and also iatrogenically by inadequate conservative, prosthetic, surgical or orthodontic therapy. For this reason it is often difficult to recognise the primary cause. The first responses of the system to the disorder are adaptive mechanisms which occur within one or more integrative parts, and depending on their intensity and duration symptoms grow more prominent. Tissue response can be ortho- or parafunctional. Attempts are made to exclude psychoemotional influences and the obstacle eliminated by either abrasion, clenching or grinding of the teeth. If the obstacle is not eliminated by abrasion, the cause of such functional disorder becomes the trigger for parafunctional activity. From a review of the relevant literature it can be concluded that parafunctional activity is caused by changed occlusion, with determined psychological habits of the patient and specific tissue response of the stomatognathic system. Therefore, therapy of these disorders is made more difficult and includes a multidisciplinary approach.     

Scientific Methodology in Temporomandibular Disorders. Part I: Epidemiology

Epidemiological methodology is examined relative to the following: a) use of proper controls; b) the large magnitude of variation in published epidemiological studies on occurrence of temporomandibular disorders (TMD); c) its suitability for the study of TMD as stress disorders; d) the fact that TMD are a group of diseases each with different etiologies and symptomologies (epidemiological studies directed at the whole group may be misleading and inappropriate); and e) subjectivity of the criteria used in epidemiologic studies of TMD. This article involves the logic of the methodology and does not deal with statistical analysis.     

Temporomandibular disorders,headaches, and cervical pain among females in a Sami population

Objective. The aim of this study was to examine the prevalence and co-morbidity of long-standing, intense, and frequent symptoms of pain and dysfunction in the jaw-face, head, and cervical region among adult females drawn from the Sami population in northern Sweden. Methods. A total of 487 females, taken from the register of the Swedish Sami Parliament or registered as reindeer owners or reindeer herders in the Swedish Board of Agriculture and living in the Arctic region of northern Sweden, participated in a questionnaire study. Results. The prevalence of pain and/or dysfunction in the jaw-face region was 32%, of headaches 61%, and of pain in the cervical region 56%. When the criterion of frequent symptoms (once a week or more often) was used, prevalence dropped to 17%, 19%, and 30%, respectively, and when that of intense symptoms, defined as 5 or more on an 11-point numerical rating scale, was added, prevalence dropped further to 8%, 11%, and 20%, respectively. The majority reported long-standing symptoms (67–98% depending on symptom). A high statistically significant relationship was found between frequent symptoms of pain and/or dysfunction in the jaw-face, frequent headaches, and frequent cervical pain (p<0.0001). Conclusions. Symptoms in the jaw-face, headaches, and cervical pain were frequently reported among a sample of Sami females living in the Swedish Arctic region. The prevalence of symptoms was strongly dependent on criteria of frequency and intensity.     

Temporomandibular disorders, headaches, and cervical pain among females in a Sami population

OBJECTIVE: The aim of this study was to examine the prevalence and co-morbidity of long-standing, intense, and frequent symptoms of pain and dysfunction in the jaw-face, head, and cervical region among adult females drawn from the Sami population in northern Sweden. METHODS: A total of 487 females, taken from the register of the Swedish Sami Parliament or registered as reindeer owners or reindeer herders in the Swedish Board of Agriculture and living in the Arctic region of northern Sweden, participated in a questionnaire study. RESULTS: The prevalence of pain and/or dysfunction in the jaw-face region was 32%, of headaches 61%, and of pain in the cervical region 56%. When the criterion of frequent symptoms (once a week or more often) was used, prevalence dropped to 17%, 19%, and 30%, respectively, and when that of intense symptoms, defined as 5 or more on an 11-point numerical rating scale, was added, prevalence dropped further to 8%, 11%, and 20%, respectively. The majority reported long-standing symptoms (67-98% depending on symptom). A high statistically significant relationship was found between frequent symptoms of pain and/or dysfunction in the jaw-face, frequent headaches, and frequent cervical pain (p<0.0001). CONCLUSIONS: Symptoms in the jaw-face, headaches, and cervical pain were frequently reported among a sample of Sami females living in the Swedish Arctic region. The prevalence of symptoms was strongly dependent on criteria of frequency and intensity.     

Risk management in clinical practice. Part 8. Temporomandibular disorders

Temporomandibular disorders can arise apparently idiopathically, as a result of macro-trauma or micro-trauma such as parafunction, as a result of a separate disease process or as a consequence of dental treatment. The objectives of this chapter are to make the practitioner aware of his/her responsibilities in any of these situations. Precise record keeping and careful risk management are essential. Guidelines are given to protect not only the practitioner but also the patient.     

Thyroid disorders. Part I: hyperthyroidism

The significant thyroid disorders that may be found in dental patients are presented in a series of 3 articles. This article (part I) deals with hyperthyroidism, part II with hypothyroidism and thyroiditis, and part III with neoplastic lesions of the thyroid. The signs and symptoms, laboratory tests used to diagnoses hyperthyroidism, and the medical management of patients with hyperthyroidism are presented in this paper. The dental management of patients with hyperthyroidism is discussed in detail. The dentist, by detecting the early signs and symptoms of hyperthyroidism, can refer the patient for medical diagnosis and treatment and avoid potential complications of treating patients with uncontrolled disease. These complications include the rare thyrotoxic crisis (thyroid storm) that may be precipitated by dental treatment, acute infection, or trauma in the patient with uncontrolled hyperthyroidism. Also, the use of epinephrine or other pressor ammines can cause a hypertensive crisis in the patient with uncontrolled hyperthyroidism. Patients will benefit from the early detection and referral by reducing the risks of the medical complications such as hypertension, cardiac arrhythmias, and congestive heart failure.     

Temporomandibular disorders and psychological status in adult patients with a deep bite

Temporomandibular disorders (TMDs) and psychological status were examined in adult patients with a deep bite and compared with an adult age- and gender-matched control group with neutral occlusion. The deep bite group consisted of 20 females (mean age 30.3 years) and 10 males (mean age 33.1 years). The control group comprised 20 females (mean age 29.4 years) and 10 males (mean age 34.2 years). TMD examination, according to the Research Diagnostic Criteria for TMD (RDC/TMD), cephalometric lateral radiographs, registration of occlusion, and bite force were performed. To test the mean differences between craniofacial morphology, bite force, the occurrence of RDC/TMD diagnostic groups, and headache between the two groups, unpaired t-test, Fisher's exact test, Mann-Whitney U test, and multiple logistic regression analyses were performed. Deep bite patients more frequently reported nocturnal and diurnal clenching (P < 0.01), an uncomfortable bite (P < 0.001), jaw stiffness (P < 0.05), and 'ringing' in the ears (P < 0.001) than the controls. Headache (P < 0.001), muscle disorders (P < 0.001), disc displacement (P < 0.05), and other joint disorders (P < 0.05) occurred significantly more often in the deep bite group compared with the controls. Somatization scores were significantly higher in the deep bite group compared with the controls (P < 0.001). Headache, muscle disorders, disc displacement, and other joint disorders were significantly associated with a number of craniofacial dimensions and psychological factors [R between 0.32 and 0.72; P < 0.05 and odds ratio (OR) from 0.45 to 7.46; P < 0.05]. These findings suggest that a deep bite, in particular with retroclined upper incisors, can represent a risk factor for TMD.     

Temporomandibular disorders. Part III: Occlusal and articular factors associated with muscle tenderness

Two complete classes of freshman dental and dental hygiene students, 120 men and 102 women (mean age 23.9 years), were assessed for the presence of masticatory pain or dysfunction by questionnaire, clinical examination, and evaluation of dental casts. The purpose of these examinations was to determine potential relationships between clinical muscle tenderness, occlusal relationships, and signs of TMJ dysfunction. Awareness of muscle tenderness increased with the number of muscle sites involved (p less than or equal to .025) but 80% of clinically tender subjects were unaware of any tenderness (p less than or equal to .01). In comparison, subjects with generalized clinical muscle tenderness more often reported TMJ clicking that was not verified at the time of clinical examination (p less than or equal to .001). Occlusal factors, except in highly selective categories, were not associated with muscle tenderness. All subjects with moderate or severe TMJ tenderness had clinically tender muscle sites, whereas subjects with generalized muscle tenderness (greater than or equal to 4 sites) had more severe TMJ tenderness (p less than or equal to .01). Subjects with localized (p less than .05) or generalized muscle tenderness (p less than .05) had more TMJ clicking than those without muscle tenderness. TMJ clicking was reported more commonly than muscle pain among subjects who were clinically determined to have both muscle tenderness and TMJ clicking (p less than or equal to .001). TMJ dysfunction was verified more often in subjects with more localized muscle tenderness (p less than or equal to .025). Although occlusal factors were not good predictors of muscle tenderness, intracapsular signs of TMJ disorders and muscle tenderness were often associated.     

Attitudes to water fluoridation in South Africa 1998. Part I. Analysis by age, sex, population and province.

The successful implementation of water fluoridation (WF) depends upon support from the public. A survey was conducted in 1998 by the Human Sciences Research Council to assess attitudes of the South African population towards WF. A representative sample of 2,220 persons over the age of 18 years was interviewed. Questions relating to current knowledge, sources of information, the purpose of water fluoridation and its desirability as a public health measure were put to respondents. Only 25% of the population had heard or read of WF. The major sources of information were the electronic and printed media (40% and 27% respectively), while 2.5% heard about it from dentists. Just over a third of the sample (35.5%) identified the purpose of WF as protecting teeth from decay; 28% said it was to purify water and 28.5% were uncertain of, or did not know its purpose. Nearly two-thirds (61.9%) indicated that fluoride should be added to drinking water if it can reduce tooth decay, while 9% were not in favour and 29% were uncertain. The results suggest that most people do not know what WF is or does, though most were in agreement that it should be implemented to reduce tooth decay.     

Temporomandibular disorders: a review of current understanding.

OBJECTIVE: The purpose of this article is to conduct a narrative review of current evidence regarding the understanding, evaluation, management, and treatment of temporomandibular disorders to provide a broad perspective and updated introduction to an important and controversial subject with rapidly changing developments and limited well-designed research. DATA SOURCES: Studies were identified through a search of MEDLINE for 3 topics (temporomandibular disorder, temporomandibular joint, and chronic pain) over a 10-year period (January 1988 to August 1998) and of bibliographies of identified studies and review articles. STUDY SELECTION: More than 5000 articles were produced. In-depth review of all of this literature was beyond the scope of the present article, which is intended to provide an overview. The amount and diversity of the literature and the limitations of covering such a broad topic being recognized, the papers selected were those that reviewed limited topics or studied focused areas. This report is not a systematic (qualitative) or meta-analysis (quantitative) review. An acknowledged limitation of this narrative review method lies in the potential for bias in selection. The referenced works do not include all papers reviewed; only pertinent literature and reviews with comprehensive references were selectively included. CONCLUSIONS: Advances in basic and clinical science have resulted in important changes in the understanding and management of temporomandibular disorders. Many treatments are not supported by research, and the role of dentistry is changing to a more diagnostic and management-based model from the hands-on treatment procedures of the past. The present science-based understand-ing of a biopsychosocial disorder is important in properly and responsibly dealing with patients with temporomandibular disorders.     

Temporomandibular disorders. Part II: Occlusal factors associated with temporomandibular joint tenderness and dysfunction

Two complete classes of freshman dental and dental hygiene students, 120 men and 102 women (mean age 23.9 years) were assessed for the presence of masticatory pain or dysfunction by questionnaire, clinical examination, and evaluation of dental casts according to strict criteria. The purpose was to identify the degree of association between observable signs of TMJ disorders and selected combinations of occlusal variables. TMJ tenderness was more frequent in class II, division 2 than in class I (p less than .05), but overall was not associated with occlusal factors such as deep overbites, length of a symmetric RCP-ICP slide, and unilateral contact in RCP. Overall, clicking was not associated with Angle class, deep overbite, length of symmetric RCP-ICP slide, or unilateral RCP contact. Among subjects with unilateral RCP contact, those with no clinically obvious RCP-ICP slide (p less than .005) and those with asymmetric slides (p less than .05) had more TMJ clicking than subjects with symmetric slides. Luxation clicking of the condyle over the articular eminence on wide opening was absent in class II, division 2 subjects, but was most frequent in subjects with some teeth in unilateral posterior crossbite, particularly when this was a unilateral condition (p less than .001). Certain occlusomorphologic conditions may require less adaptation in the TMJs. This article indicates that an ICP anterior to the RCP in association with bilateral occlusal stability may be protective.     

颞下颌关节紊乱病相关疼痛与年龄、性别及骨关节病影像学改变的关系

目的探讨颞下颌关节紊乱病（TMD）患者相关疼痛和年龄、性别及骨关节病（OA）影像学改变的关系。方法1206例TMD患者根据年龄、性别、是否疼痛及影像学改变分组；计算颅下颌关节紊乱指数（CMI）并进行统计学分析。结果TMD相关疼痛女性多见，45岁以下各年龄组间CMI差异有统计学意义，女性OA影像学改变发生率高于男性（P〈0．001）。结论TMD相关疼痛和OA影像学改变易发生于女性，临床病例中16～30岁女性患者最多，并存在TMD相关疼痛和OA影像学改变。     

Temporomandibular disorders and science: a response to the critics.

This article was prepared by the above authors and submitted to members of the TMD academic community for their endorsement. A total of 120 people signed an endorsement; their names are available on request.     

Temporomandibular joint osteoarthrosis and internal derangement. Part I: Clinical course and initial treatment

A certain natural sequence exists in the occurrence of the major clinical symptoms of 'craniomandibular dysfunction', usually leading to a final stage in which the disease is burned out. Most clinical symptoms can be explained by an internal derangement. As long as we do not know the real cause of, and the exact relationship between, osteoarthrosis and internal derangement, management should be primarily directed at the symptoms. In this paper, the major stages of the disorder are described and illustrated with three characteristic cases.     

Temporomandibular disorders: the past,present, and future

This article traces the history of the development of the current diagnostic and therapeutic approaches to the management of temporomandibular disorders, with emphasis on the mistakes or misconceptions that occurred during their development and the lessons that can be learned from these errors. It also makes recommendations for future areas of investigation, and methods for facilitating such studies, in order to improve the future treatment of these patients. Based on a lecture entitled “Temporomandibular Disorders: The Past, Present and Future” presented at the 1st International and 19th Annual Meeting of the Japanese Society of the Temporomandibular Joint, Nagoya, Japan, July 19, 2006.     

Unhealthy differences. Part I. Socioeconomic deprivation and health

Socioeconomic deprivation often concurs with deprivation in health. In this paper, the available evidence on socioeconomic health differences in The Netherlands is summarized. Furthermore explanations for the existence of these differences are given. Socioeconomic deprivation often leads to a worse health, but the reverse can also occur sometimes. Policies on the causes of these health differences usually concern fields like income distribution and employment. Health care can offer a compensation for the adverse health effects of socioeconomic deprivation.     

Scientific Methodology in Temporomandibular Disorders. Part II: Ethology

The historical background of ethology and the paradigm of clinical treatment as scientific experiment, rather than practice of the art of dentistry are discussed. Ethology is defined and explained relative to the study of temporomandibular disorders (TMDs) using instrumentation, measurement and retrospective clinical studies of successfully treated cases as meaningful research for improvement of future treatment.