William K. Solberg

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.

Relationship of mandibular condylar position to dental occlusion factors in an asymptomatic population.

This article investigates the influence of occlusion on condylar position as seen on TMJ tomograms in a group of 44 young adults with no histories of orthodontic or occlusal therapy and no objective signs of masticatory dysfunction; the sample was screened from a population of 253 students. Nonconcentric condylar position at ICP was a feature of Class II malocclusion with significantly more anterior positions in Class II, Division 1 than in Class I. Condylar position was unrelated to the amount of sagittal RCP-ICP slide, although most slides were less than 0.5 mm. The frequency of lateral slides was low, but was mildly related to bilaterally asymmetric condylar positions. Position was unrelated to the degree of overbite, which ranged from 0 to 10 mm. Bilateral condylar position asymmetry was not related to the direction of dental midline discrepancy, which ranged from 0 to 2 mm. No open bites or mandibular overjets were seen in this asymptomatic normal sample.

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 joint pain and dysfunction: A clinical study of emotional and occlusal components

Abstract Mandibular pain and dysfunction are thought to arise through muscle hyperactivity and some form of tooth contact. The presence of elevated anxiety and occlusal disharmonies as etiologic factors has not been conclusively investigated. This study is an effort to examine these factors in a sample population selected under definable conditions. The anxiety level in matched symptom and control groups (29 each) was evaluated with the use of a standard psychometric instrument (MMPI). Occlusal features were analyzed in oral examination and by casts mounted to the terminal hinge axis. For the symptom group, the latter analysis was delayed until after bite-plane therapy to gain muscular relaxation. Results of the MMPI revealed both groups to be relatively free of anxiety, although approximately half of the symptom group showed clinical signs of greater anxiety than that found in the matched controls. This half may be a sub-symptom group where anxiety and symptoms are lined. These findings do not justify regarding all patients who display this disorder as homogeneous in psychologic make-up. The present findings lead to the speculation that the entire symptom population consists of a number of subgroups, which would account for the weak relationship between pain dysfunction and anxiety found in the entire symptom population. Occlusal features evaluated in this study were similar between groups. That is, both symptom and control subjects had deflective or interceptive occlusal contacts on terminal hinge closure and similar mandibular shifts from centric relation to centric occlusion.

Malocclusion associated with temporomandibular joint changes in young adults at autopsy

The purpose of this study was to identify variables of malocclusion that might be associated with previously reported temporomandibular joint morphologic findings. Before removing the left TMJ from each of 96 cadavers (age means equals 26.4 +/- 6.8 years), an intraoral examination was performed. Angle classification, crossbite, overbite, and overjet were evaluated. These parameters were analyzed with respect to their association with the following TMJ features: overall shape of the condyle and temporal bone, gross and histologic evidence of remodeling, and position of the articular disk. When combined with age, Angle Class II and III dentitions were associated with temporal and condylar deviation in form (DIF) (P less than 0.05) and more Class II dentitions were accompanied by histologic evidence of remodeling changes in the TMJs. Crossbite was associated with increasing presence of DIF in all components (P less than 0.01). Anterior crossbite was associated with DIF on the articular eminence (P less than 0.01). Deep overbite was more common in persons with flat condyles, open mandibular fossae, and anterior extension of the temporal articular surfaces (P less than 0.05). Abnormal overjet was more evident in those with DIF in the disk (P less than 0.05); greater overjet was associated with disk displacement (P less than 0.05). Considered together, abnormal overbite and overjet were associated with more extensive DIF on the condyle (P less than 0.05). In conclusion, malocclusion was associated with morphologic changes in the TMJ, particularly when combined with age. This evidence supports the belief that longer exposure to malocclusion may be associated with more extensive TMJ changes.

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.

Is atypical odontalgia a psychological problem

Several authors have asserted that psychological factors are the underlying cause of atypical odontalgia. However, objective evidence is lacking to support this claim. In this study, the Minnesota Multiphasic Personality Inventory was used to assess psychological functioning of an atypical odontalgia population. Means of the standard scores for each Minnesota Multiphasic Personality Inventory scale were within normal ranges. Standard scores for atypical odontalgia profiles compared with standard scores for a chronic headache group (matched for age, sex, and chronicity) were similar and scales for both groups were within normal ranges. These findings fail to support psychological dysfunction as a primary condition associated with patients suffering from atypical odontalgia.

Electronic thermography in the diagnosis of atypical odontalgia: A pilot study☆

Atypical odontalgia (AO) is a dental condition that is usually diagnosed by exclusion after failure of multiple dental treatments. A functional definition of AO includes (1) continuous pain in and about a tooth or teeth, (2) pain present for longer than 4 months, (3) inadequate local cause (no abnormality detected on dental radiographs), and (4) anesthetic blockade gives equivocal relief of toothache. The purpose of this study was to assess the potential role of electronic thermography in the diagnosis of AO. Results from measurements of facial thermal symmetry indicated that normal subjects = 83.5%, AO group = 65.8% (p less than 0.01). Electronic thermography interpreted by thermography experts has promise as a diagnostic test for AO among patients with toothache for which the dentist can find no convincing dental explanation.

The measurement of human oral forces

This paper reviews the types of instruments used and problems encountered in the measurement of human biting forces. A new instrument, developed for this purpose, which employs strain gauges mounted on a cantilever bridge bite element is described. Associated circuitry, which includes a Wheatstone bridge, amplifier, and integrator, is described. The integrator enables the investigator to record accumulative force over time. Biting force values recorded at five different areas of the mouth are presented from 11 male and 8 female Ss.