Donald A. Seligman

A Multiple Logistic Regression Analysis of the Risk and Relative Odds of Temporomandibular Disorders as a Function of Common Occlusal Features

A multiple logistic regression analysis was used to compute the odds ratios for 11 common occlusal features for asymptomatic controls (n = 147) us. five temporomandibular disorder groups: Disc Displacement with Reduction (n = 81), Disc Displacement without Reduction (n = 48), Osteoarthrosis with Disc Displacement History (n = 75), Primary Osteoarthrosis (n = 85), and Myalgia Only (n = 124). Features that did not contribute included: retruded contact position (RCP) to intercuspal position (ICP) occlusal slides < 2 mm, slide asymmetry, unilateral RCP contacts, deep overbite, minimal overjet, dental midline discrepancies, ≤ 4 missing teeth, and maxillo-mandibular first molar relationship or cross-arch asymmetry. Groupings of a minimum of two to at most five occlusal variables contributed to the TMD patient groups. Significant increases in risk occurred selectively with anterior open bite (p < 0.01), unilateral maxillary lingual crossbite (p < 0.05 to p < 0.01), overjets > 6-7 mm (p < 0.05 to p < 0.01), ≥5-6 missing posterior teeth (p < 0.05 to p < 0.01), and RCP-ICP slides > 2 mm (p < 0.05 to p < 0.01). While the contribution of occlusion to the disease groups was not zero, most of the variation in each disease population was not explained by occlusal parameters. Thus, occlusion cannot be considered the unique or dominant factor in defining TMD populations. Certain features such as anterior open bite in osteoarthrosis patients were considered to be a consequence of rather than etiological factors for the disorder.

Quantification and validation of predictive values of occlusal variables in temporomandibular disorders using a multifactorial analysis.

STATEMENT OF PROBLEM A consensus is lacking on the association between occlusal variables and temporomandibular disorders (TMDs). PURPOSE This study estimated the maximum potential power of occlusal variables to differentiate patients with TMD from asymptomatic normal adult subjects. MATERIAL AND METHODS The occlusal characteristics in 2 sets of female patients with intracapsular TMD (1993, n = 257, and 1998, n = 124) differentiated into disk displacement and osteoarthrosis subdiagnoses were compared with asymptomatic female controls (n = 51 and 47) with multiple logistic regression analysis. Significant variables and total contribution to the log likelihood were compared with the predictive value of univariate analysis, including sensitivity and specificity. RESULTS Occlusal factors in the females (1993, 1998) explained no more than 4.8% to 27.1% of the log likelihood. In comparison to the logistic regression analysis, univariate analysis was less predictive of patients with TMD, due to notably lower sensitivity. Patients with disk displacement were mainly characterized by unilateral posterior crossbite and longer RCP-ICP slides. Patients with osteoarthrosis were most consistently characterized by longer RCP-ICP slides and larger overjet, and in part to reduced overbite. Significant relative risk for disease (odds ratio > 2:1) was mainly associated with infrequent, more extreme ranges of occlusion measurements. CONCLUSION Occlusal factors may be cofactors in the identification of patients with TMD, but their role should not be overstated. Some occlusal variation may be a consequence of rather than a cause for TMD. Single variables have more limited value and it takes sets of adverse variables to model TMD. Combinations of variables appear to be disease specific. Some extreme ranges of occlusion were the domain of patients with TMD, but most patients were within the normal ranges.

The Prevalence of Dental Attrition and its Association with Factors of Age, Gender, Occlusion, and TMJ Symptomatology

Dental attrition severity in 222 young adults was assessed from dental casts as the sum of the most severe facet in each arch segment. The attrition scores were compared by age, gender, bruxism awareness, prior bite adjustment, orthodontic class, maxillomandibular relationship, and temporomandibular dysfunction symptoms. Awareness of bruxism was not associated with the wear scores and should not be used to define bruxist groups. Attrition scores did not differ significantly between age groups, indicating that notable attrition, when present, often occurs early. Men had higher attrition scores than women (p<0.01), despite fewer signs and symptoms. Dental attrition was not associated with the presence or absence of TMJ clicking, TMJ tenderness, or masticatory muscle tenderness. Class II division 2 males had laterotrusive attrition scores lower than those of Class III (p<0.05). Class III females had lower incisor attrition scores than did other Angle Classes (p<0.05). Discernible dental attrition in a non-patient population was not associated with signs and symptoms of temporomandibular disorders, nor with the occlusal factors studied. These results are compatible with the findings in other studies that point to bruxism as a centrally induced phenomenon common to all people and unrelated to local factors.

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.

Temporomandibular disorders. Part I: Functional status, dentomorphologic features, and sex differences in a nonpatient population

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 and analyze the level of signs and symptoms in a nonpatient population and describe occlusal variation. The prevalence of TMJ signs and symptoms was notable even though two thirds reported only mild or early symptoms, with only 3% reporting severe symptoms. This population was noted for the absence of locking, the low frequency of severe pain or severe TMJ dysfunction, and the low prevalence of restricted ranges of mandibular movement and TMJ crepitation. Women showed significantly more headache, TMJ clicking and tenderness, and muscle tenderness than men. Men were noted for the absence of severe and widespread muscle tenderness and severe TMJ tenderness. TMJ clicking was not always clinically confirmable in subjects with widespread muscle tenderness. This group was considered compatible with previous epidemiologic findings, and also matches the age range of most subjects seeking treatment for TMJ disorders. Therefore, the subjects in the study were considered a representative group of young adults and suitable for study of the possible associations between early signs of TMJ disorders and variables of morphologic malocclusion, which are discussed in Parts II and III of this article.

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.