Daniel Paesani

Epidemiology of bruxism in adults: a systematic review of the literature

AIMS To investigate the association among temporomandibular disorders (TMD), sleep bruxism, and primary headaches, assessing the risk of occurrence of primary headaches in patients with or without painful TMD and sleep bruxism. METHODS The sample consisted of 301 individuals (253 women and 48 men) with ages varying from 18 to 76 years old (average age of 37.5 years). The Research Diagnostic Criteria for Temporomandibular Disorders were used to classify TMD. Sleep bruxism was diagnosed by clinical criteria proposed by the American Academy of Sleep Medicine, and primary headaches were diagnosed according to the International Classification of Headache Disorders-II. Data were analyzed by chi-square and odds ratio tests with a 95% confidence interval, and the significance level adopted was .05. RESULTS An association was found among painful TMD, migraine, and tension-type headache (P < .01). The magnitude of association was higher for chronic migraine (odds ratio = 95.9; 95% confidence intervals = 12.51-734.64), followed by episodic migraine (7.0; 3.45-14.22) and episodic tension-type headache (3.7; 1.59-8.75). With regard to sleep bruxism, the association was significant only for chronic migraine (3.8; 1.83-7.84). When the sample was stratified by the presence of sleep bruxism and painful TMD, only the presence of sleep bruxism did not increase the risk for any type of headache. The presence of painful TMD without sleep bruxism significantly increased the risk in particular for chronic migraine (30.1; 3.58-252.81), followed by episodic migraine (3.7; 1.46-9.16). The association between painful TMD and sleep bruxism significantly increased the risk for chronic migraine (87.1; 10.79-702.18), followed by episodic migraine (6.7; 2.79-15.98) and episodic tension-type headache (3.8; 1.38-10.69). CONCLUSION The association of sleep bruxism and painful TMD greatly increased the risk for episodic migraine, episodic tension-type headache, and especially for chronic migraine.

Prevalence of temporomandibular joint internal derangement in patients with craniomandibular disorders

To determine the prevalence of temporomandibular joint internal derangement in patients with signs and symptoms of craniomandibular disorders, bilateral imaging was performed in a consecutive series of 115 patients with signs and symptoms of craniomandibular disorders. Ninety patients (78%) had different stages of unilateral or bilateral internal derangement, and 25 patients (22%) had normal temporomandibular joints bilaterally. Out of 230 joints, 60 showed disk displacement with reduction, 8 showed disk displacement without reduction, and 29 showed disk displacement without reduction associated with anthrosis. The study indicates that almost 80% of patients with signs and symptoms of craniomandibular disorders have different forms of internal derangement.

Accuracy of clinical diagnosis for TMJ internal derangement and arthrosis

This study investigated the accuracy of clinical examination in determining the status of the temporomandibular joint with respect to internal derangement and arthrosis. A series of 110 patients was given standard clinical examinations followed by bilateral imaging with arthrography and/or magnetic resonance imaging. There was agreement between the clinical diagnosis and the imaging finding in 95 joints (43%). In the other 125 joints (57%), the clinical diagnosis did not agree with imaging findings. There were false-positive clinical diagnoses in 39 joints and false-negative clinical diagnoses in 31 joints. In the other 55 joints the clinical diagnosis correctly indicated that the joint was abnormal but was incorrect about the stage of abnormality. On the basis of the overall diagnostic accuracy of 43%, it was concluded that a clinical examination is not reliable for determining the status of the joint in patients with signs and symptoms of temporomandibular joint internal derangement.

MR imaging of the TMJ : decreased signal from the retrodiskal tissue

In clinical work we have observed decreased signal intensity from the retrodiskal tissue in some patients with temporomandibular joint disk displacement. The frequency and clinical significance of this observation is unknown. To document the frequency and to assess its clinical significance we analyzed magnetic resonance images of the temporomandibular joints of 69 patients with temporomandibular joint displacement and 28 asymptomatic volunteers. All the subjects had a clinical examination, and their level of pain was recorded. Decreased signal intensity from the retrodiskal tissue was seen in 16 joints in the patients (12%). None of the asymptomatic volunteers exhibited this feature. It was seen in one joint with disk displacement with reduction, in nine joints with disk displacement without reduction, and in six joints with disk displacement without reduction and arthrosis. It was not seen in any joint with superior disk position. We could not appreciate an association between the decreased signal intensity from the retrodiskal tissue and the level of pain because this feature was seen in both painfree and painful joints. It was concluded that decreased signal intensity from the retrodiskal tissue was most frequently associated with later stages of disk displacement and its clinical significance remains unclear because there was no appreciable correlation to patient symptoms of pain.

Temporomandibular joint sounds: Correlation to joint structure in fresh autopsy specimens

In an attempt to better understand the cause of different types of temporomandibular joint (TMJ) sounds, we recorded joint sounds from 27 fresh autopsy specimens, displayed the time frequency distribution of the sound as a three-dimensional graph, and correlated the sound character to morphologic observations at subsequent dissection. Eleven joints elicited sounds, and 16 joints were silent. All joints with sounds had different degrees of intraarticular changes. These ranged from disk displacement with reduction to displacement without reduction and arthrosis of the articular surfaces. Reciprocal clicking occurred both in joints with disk displacement with and without reduction, as well as in joints with arthrotic changes. Crepitation only occurred in joints with arthrosis and perforation. The sample was too small to demonstrate any statistically significant association between the joint sound classified as clicking or crepitation and joint structure types of joint pathosis in this small sample. A high frequency component to the sound appeared to be associated with arthrosis of the articular surfaces. It was concluded that joint sounds indicate joint abnormality but that the absence of joint sound does not exclude intraarticular pathosis.

Temporomandibular joint axiography and MRI findings: A comparative study

Axiography may be useful in the evaluation of condyle motion and the effects of internal derangements on this motion. Fifty-one patients were selected by one investigator (RHT) to provide a representative sample of asymptomatic and symptomatic subjects for the following categories: (1) normal disk position, (2) disk displacement with reduction, (3) disk displacement without reduction and (4) disk displacement without reduction associated with degenerative joint disease. Axiography was performed by a separate investigator (KGP) in a blinded fashion. The diagnosis of the presence of internal derangement was based on the tracings only. All subjects had bilateral magnetic resonance imaging scans to evaluate for the presence or absence of internal derangement. The diagnostic sensitivity was 0.64, which indicated that axiography is marginal at identifying disease when present. The negative predictive value was 0.78, which indicated that axiography is accurate in the detection of normal disk condyle relationship.