Does altering the occlusal vertical dimension produce temporomandibular disorders? A literature review.

The purpose of this review was to present a comprehensive review of the scientific evidence available in the literature regarding the effect of altering the occlusal vertical dimens-ion (OVD) on producing temporomandibular disorders. The authors conducted a PubMed search with the following search terms 'temporoman-dibular disorders', 'occlusal vertical dimension', 'stomatognatic system', 'masticatory muscles' and 'skeletal muscle'. Bibliographies of all retrieved articles were consulted for additional publications. Hand-searched publications from 1938 were included. The literature review revealed a lack of well-designed studies. Traditional beliefs have been based on case reports and anecdotal opinions rather than on well-controlled clinical trials. The available evidence is weak and seems to indicate that the stomatognathic system has the ability to adapt rapidly to moderate changes in occlusal vertical dimension (OVD). Nevertheless, it should be taken into consideration that in some patients mild transient symptoms may occur, but they are most often self-limiting and without major consequence. In conclusion, there is no indication that permanent alteration in the OVD will produce long-lasting TMD symptoms. However, additional studies are needed.

Smoking and Posttraumatic Stress Disorder Symptomatology in Orofacial Pain.

To explore the impact of interactions between smoking and symptoms of posttraumatic stress disorder (PTSD) on pain intensity, psychological distress, and pain-related functioning in patients with orofacial pain, a retrospective review was conducted of data obtained during evaluations of 610 new patients with a temporomandibular disorder who also reported a history of a traumatic event. Pain-related outcomes included measures of pain intensity, psychological distress, and pain-related functioning. Main effects of smoking status and PTSD symptom severity on pain-related outcomes were evaluated with linear regression analyses. Further analyses tested interactions between smoking status and PTSD symptom severity on pain-related outcomes. PTSD symptom severity and smoking predicted worse pain-related outcomes. Interaction analyses between PTSD symptom severity and smoking status revealed that smoking attenuated the impact of PTSD symptom severity on affective distress, although this effect was not found at high levels of PTSD symptom severity. No other significant interactions were found, but the present results identifying smoking as an ineffective coping mechanism and the likely role of inaccurate outcome expectancies support the importance of smoking cessation efforts in patients with orofacial pain. Smoking is a maladaptive mechanism for coping with pain that carries significant health- and pain-related risks while failing to fulfill smokers' expectations of affect regulation, particularly among persons with orofacial pain who also have high levels of PTSD symptom severity. Addressing smoking cessation is a critical component of comprehensive treatment. Further research is needed to develop more effective ways to help patients with pain and/or PTSD to replace smoking with more effective coping strategies.

Ambulatory electromyogram activity in the upper trapezius region: patients with muscle pain vs. pain-free control subjects.

STUDY DESIGN: This study compared the ambulatory electromyogram activity of persons reporting pain in the shoulder and cervical regions with an equal group of persons not reporting such pain. Ambulatory electromyogram data were obtained over 3-day periods. In addition, all participants completed several standard psychological questionnaires. OBJECTIVES: The results were analyzed with inferential statistics to determine whether subjects reporting significant pain in the shoulder and cervical regions had greater ambulatory electromyogram activity than an equal number of subjects not reporting pain. SUMMARY OF BACKGROUND DATA: Considerable controversy exists regarding the role of muscle activity in the etiology and maintenance of muscle pain disorders. Given the availability of ambulatory recording devices that can provide a detailed record of muscle activity over an extended period of time, the present research was conducted to determine whether persons reporting shoulder and cervical pain could be differentiated from a group of normal subjects. METHODS: All subjects (N = 20) completed a battery of tests with standardized psychometric instruments and then were fitted with ambulatory electromyogram monitors to record electromyographic activity of the upper trapezius region of the dominant side; the time, duration, and amplitude of electromyogram activity greater than 2 microV was recorded. The monitors were worn during normal working hours (mean, 6.2 hours per day) over 3 consecutive days. In addition to wearing the monitors, all subjects completed hourly self-ratings of perceived muscle tension during the recording periods. RESULTS: As expected, subjects with muscle pain reported significantly more pain (mean, 4.9) than did the normal control subjects (mean, 0.9), t(15) = 3.29, P < 0.01. However, patients with muscle pain did not have greater average electromyogram activity (mean, 6.4 microV) over the 3-day period as compared to the normal controls (mean, 7.1 microV), t(18) = -0.25, P < 0.80. Self-monitoring of perceived muscle tension also did not reveal differences between pain subjects and the normal control subjects (P < 0.75). CONCLUSIONS: Ambulatory measurements of electromyogram activity did not differentiate persons reporting upper trapezius or cervical pain from those that did not report such pain. Persons reporting pain are also not distinguishable from normal control subjects on a variety of self-report measures. These results raise questions regarding the role of ambulatory electromyogram recordings in the evaluation and treatment of muscle pain disorders.

Toothache of cardiac origin.

Pain referred to the orofacial structures can sometimes be a diagnostic challenge for the clinician. In some instances, a patient may complain of tooth pain that is completely unrelated to any dental source. This poses a diagnostic and therapeutic problem for the dentist. Cardiac pain most commonly radiates to the left arm, shoulder, neck, and face. In rare instances, angina pectoris may present as dental pain. When this occurs, an improper diagnosis frequently leads to unnecessary dental treatment or, more significantly, a delay of proper treatment. This delay may result in the patient experiencing an acute myocardial infarction. It is the dentist's responsibility to establish a proper diagnosis so that the treatment will be directed toward the source of pain and not to the site of pain. This article reviews the literature concerning referred pain of cardiac origin and presents a case report of toothache of cardiac origin.

The relationship between forward head posture and temporomandibular disorders.

This study investigated the relationship between forward head posture and temporomandibular disorder symptoms. Thirty-three temporomandibular disorder patients with predominant complaints of masticatory muscle pain were compared with an age- and gender-matched control group. Head position was measured from photographs taken with a plumb line drawn from the ceiling to the lateral malleolus of the ankle and with a horizontal plane that was perpendicular to the plumb line and that passed through the spinous process of the seventh cervical vertebra. The distances from the plumb line to the ear, to the seventh vertebra, and to the shoulder were measured. Two angles were also measured: (1) ear-seventh cervical vertebra-horizontal plane and (2) eye-ear-seventh cervical vertebra. The only measurement that revealed a statistically significant difference was angle ear-seventh cervical vertebra-horizontal plane. This angle was smaller in the patients with temporomandibular disorders than in the control subjects. In other words, when evaluating the ear position with respect to the seventh cervical vertebra, the head was positioned more forward in the group with temporomandibular disorders than in the control group (P < .05).

Emotional and physiologic responses to laboratory challenges: patients with temporomandibular disorders versus matched control subjects.

This study explored psychologic and physiologic factors differentiating patients with temporomandibular disorders (n = 23) from sex-, age-, and weight-matched asymptomatic control subjects. Each subject completed several standard psychologic questionnaires and then underwent two laboratory stressors (mental arithmetic and pressure-pain stimulation). Results indicated that patients with temporomandibular disorders had greater resting respiration rates and reported greater anxiety, sadness, and guilt relative to control subjects. In response to the math stressor, patients with temporomandibular disorders reacted with greater anger than did control subjects. There were no differences between patients with temporomandibular disorders and control subjects on pain measures or any other measured variable for the pressure-pain stimulation trial. In addition, there were no differences in electromyography levels between patients with temporomandibular disorders and control subjects. The results are discussed in terms of their implications for the etiology and treatment of this common and debilitating set of disorders.

Occlusion, Orthodontic treatment, and temporomandibular disorders: a review.

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.

Influence of biased clinician statements on patient report of referred pain.

AIMS: The purpose of this study was to examine the influence of clinician bias on patients' reports of referred pain. Diagnosis of temporomandibular disorders is dependent on subjective reports of pain and referred pain upon manual muscle palpation. The influence of biased clinician statements in such subjective reports has not been previously investigated. METHODS: Forty subjects with pain and who met specific inclusion criteria were randomly assigned to 1 of 2 experimental groups. One group was subjected to a standardized biasing statement, while the other group was not. Tender points in the masseter muscle were then stimulated with a pressure algometer to the pressure-pain threshold. Subjects then recorded the presence or absence, location, intensity, and unpleasantness of any referred pain. State-trait anxiety and social desirability were also assessed to explore the possibility that anxiety levels or subjects' desires to please the experimenter influenced results. RESULTS: The biased group reported increased presence (P < 0.01), intensity (P < 0.001), and unpleasantness (P < 0.003) of referred pain as compared to the non-biased group. There were no differences between groups on state-trait anxiety or social desirability (P > 0.05). CONCLUSION: These data suggest that patient reports of pain referral may be subject to clinician bias, and recommendations to control this bias are offered.

Orofacial pain as the sole manifestation of syringobulbia-syringomyelia associated with Arnold-Chiari malformation.

This is a case report of a male patient who presented with orofacial pain for a year as the only manifestation of syringobulbia-syringomyelia associated with Arnold-Chiari malformation. This article places emphasis on the clinical presentation and possible differential diagnoses. The pain was continuous and affected the left side of the face. It was exacerbated by coughing and physical effort, possibly as a consequence of an increase in intracranial pressure. Paroxysmal pain crises developed over this background of continuous pain, compatible with neurogenic trigeminal pain of the left second branch, together with pain episodes similar to cluster headache on the same side. The symptoms were resolved following neurosurgical management with amplification of the foramen magnum.

Physical and sexual abuse among orofacial pain patients: linkages with pain and psychologic distress.

This study examines the incidence of and the potential correlates of sexual and physical abuse among facial pain patients. An anonymous survey composed of standardized self-report measures of abuse, pain, and psychologic status was distributed to 120 adult facial pain patients following their initial evaluations. Forty-five questionnaires were returned by mail. In addition, 206 charts were randomly selected from a population of 520 new patients seen at the Orofacial Pain Center during the same time period that data from the anonymous survey were collected. Results of the anonymous survey indicated that 68.9% of the patients reported a history of abuse. Conversely, a chart review revealed that only 8.5% of the patients indicated a history of abuse on the clinic questionnaire. History of abuse was significantly related to greater pain severity, depression, psychologic distress, and various personality characteristics. Overall, this study indicates that the assessment of the history of abuse may be an important factor in the evaluation and treatment of facial pain.

Comparison of psychologic and physiologic functioning between patients with masticatory muscle pain and matched controls.

This study explored the physiologic and psychologic distinctions between masticatory muscle pain patients and age and sex-matched normal controls. Subjects completed several standardized psychologic tests. They then underwent a laboratory stress profile evaluation to obtain physiologic measures (EMG, heart rate, systolic and diastolic blood pressure) under conditions of rest, mental stress, and relaxation. The pain patients reported greater anxiety, especially cognitive symptoms, and feelings of muscle tension than did the controls. Under stress, pain patients had higher heart rates and systolic blood pressure than the controls. Electromyogram activity in the masseter regions was not significantly different between the pain and control group. The results are discussed in terms of the likely mechanisms that might account for the observed differences between masticatory pain patients and normal subjects.

Current terminology and diagnostic classification schemes.

This article reviews the current terminology and classification schemes available for temporomandibular disorders. The origin of each term is presented, and the classification schemes that have been offered for temporomandibular disorders are briefly reviewed. Several important classifications are presented in more detail, with mention of advantages and disadvantages. Final recommendations are provided for future direction in the area of classification schemes.

The effects of hard and soft occlusal splints on nocturnal bruxism.

Occlusal splints are commonly used for the treatment of nocturnal bruxism. This study investigated the effects of hard and soft occlusal splints on nighttime muscle activity. The nocturnal muscle activity of ten participants was recorded while wearing a hard and then a soft occlusal splint. The hard occlusal splint significantly reduced muscle activity in eight of the ten participants. The soft occlusal splint significantly reduced muscle activity in only one participant while causing a statistically significant increase in muscle activity in five of the ten participants.

Long-term results of treatment for temporomandibular disorders: an evaluation by patients.

In this study, 110 patients with temporomandibular disorders who had been treated 2 to 81/2 years earlier were asked to evaluate the treatment they received. Of the patients, 85.5% reported that they were not experiencing pain or that they were experiencing much less pain; 79.1% reported that the treatment they had received had helped them completely or considerably. Analysis of the data did not disclose a subgroup or factor that could be correlated with the reduction of pain or the patient's perception of the success of treatment.

Evaluation of occlusal splint therapy and relaxation procedures in patients with temporomandibular disorders.

Twenty-four patients were selected to participate in this study. Twelve patients were randomly selected to receive occlusal splint therapy and the other 12 to receive a simplified relaxation therapy technique. Observable pain scores, maximum comfortable interincisal distance, and maximum interincisal distances were recorded for each group before and after treatment. The occlusal splint group showed a significant decrease in total mean observable pain scores (decrease score of 10.5, t = 3.124; P less than 0.1). The relaxation group showed no significant decrease in total mean observable pain scores (decrease score of 1.8, t = 0.888; P = ns). The occlusal splint group showed a significant increase in the mean maximum comfortable opening (an increase of 12.4 mm, t = 5.085; P less than .01). The relaxation group showed no significant increase in the mean maximum comfortable opening (an increase of 2.3 mm, t = 0.734; P = ns). The occlusal splint group showed a significant increase in the mean maximum opening (an increase of 6.0 mm, t = 2.471; P less than .05). The relaxation group showed no increase in the mean maximum opening (decrease of 0.7 mm, t = 0.343; P = ns). This study suggests that occlusal splint therapy is a more effective treatment for the pain, tenderness, and limited mandibular opening associated with temporomandibular disorders than relaxation therapy. In this study, the relaxation technique used had no significant effect on the patients' pain, tenderness, or limited opening.

Occlusion and functional disorders of the masticatory system.

Understanding the relationship between occlusion and functional disorders of the masticatory system is no easy task. This article explores the static, functional, and dynamic relationships of the occlusal condition to the signs and symptoms of masticatory dysfunction. Some possible relationships are discussed.

Nonsurgical management of disc-interference disorders.

Disc-interference disorders are a group of intracapsular problems that make up one category of temporomandibular disorders. The dental profession's understanding of these disorders has changed greatly in recent years. This article reviews current concepts regarding the diagnosis and management of these disorders as revealed through recent clinical studies.

Nonodontogenic toothache.

Toothache is a common complaint in the dental office. Most toothaches have their origin in the pulpal tissues or periodontal structures. These odontogenic pains are managed well and predictably by dental therapies. Nonodontogenic toothaches are often difficult to identify and can challenge the diagnostic ability of the clinician. The most important step toward proper management of toothache is to consider that the pain may not be of dental origin. Signs and symptoms suggestive of nonodontogenic toothache are as follows: 1. Inadequate local dental cause for the pain. 2. Stimulating, burning, nonpulsatile toothaches. 3. Constant, unremitting, nonvariable toothaches. 4. Persistent, recurrent toothaches over months or years. 5. Spontaneous multiple toothaches. 6. Local anesthetic blocking of the suspected tooth does not eliminate the pain. 7. Failure to respond to reasonable dental therapy of the tooth.

Comparison of three clinical techniques for evaluating joint sounds.

Two-hundred two consecutive adult patients presenting to the University of Kentucky for general dental care screening were examined for temporomandibular joint sounds by three techniques: (1) lateral pole surface palpation, (2) digital palpation in the external auditory canal, (3) auscultation by a stethoscope. Sixty-nine patients reported joint sounds, but only 32 had sounds diagnosed by auscultation resulting in a 54% false-negative reporting rate. Stethoscopic auscultation was used as the standard to which the other two techniques were compared. The false-negative rate for auditory canal digital palpation was 71% and 77% for lateral pole surface palpation. Surface palpation had only a 2% false-positive incidence while auditory canal digital palpation had a 51% false-positive rate. There was poor agreement between the patients' subjective reporting and clinical exam by any technique. Using stethoscopic auscultation as the standard, both auditory canal and surface palpation had a very high false-negative rate, but only the auditory canal palpation had a poor false-positive incidence. Auditory canal palpation often produces TMJ sounds that are not heard with a stethoscope during normal opening and closure.

Temporomandibular disorders in the medical practice.

Patients suffering with various orofacial pain conditions are likely to seek advice and treatment from a family physician. Temporomandibular disorders (TMD) are common in the general population, and the clinician should be aware of the common associated signs and symptoms so that proper therapy can be provided. The family physician can often provide initial therapies that are effective in reducing TMD symptoms. In some instances, it is appropriate for the family physician to refer the patient to a dentist for a more comprehensive evaluation of the masticatory system. This article describes the common patient complaints associated with TM disorders. A few simple therapies are discussed along with suggestions regarding the appropriate time for referral to a dentist for a thorough dental evaluation.