The role of occlusal adjustment in the management of temporomandibular disorders

Temporomandibular Disk Dislocation Impacts the Stomatognathic System: Comparative Study Based on Biexponential Quantitative T2 Maps

In this study, we aimed to assess the potential impact of temporomandibular disk displacement on anatomical structures of the stomatognathic system using biexponential T2 magnetic resonance imaging (MRI) maps. Fifty separate MRI scans of the temporomandibular joints (TMJ) of 25 patients were acquired with eight echo times. Biexponential T2 maps were created by weighted reconstruction based on Powell's conjugate direction method and divided into two groups: the TMJ without (32 images) and with (18 images) disk displacement. The disk, retrodiscal tissue, condylar bone marrow, masseter muscle, lateral and medial pterygoid muscles and dental pulp of the first and second molars were manually segmented twice. The intrarater reliability was assessed. The averages and standard deviations of the T2 times and fractions of each segmented region for each group were calculated and analysed with multiple Student's t-tests. Significant differences between groups were observed in the retrodiscal tissue, medial pterygoid muscle and bone marrow. The pulp short T2 component showed a trend toward statistical significance. The segmentation reliability was excellent (93.6%). The relationship between disk displacement and quantitative MRI features of stomatognathic structures can be useful in the combined treatment of articular disk displacement, pterygoid muscle tension and occlusive reconstruction.

Occlusal characteristics in facial pain cases and controls - 12-year follow-up of the Northern Finland Birth Cohort (NFBC) 1966

Objective: The purpose of this study was to investigate the occlusal characteristics in Finnish adults at 12-year follow-up based on the Northern Finland Birth Cohort 1966 (NFBC1966) subjects.Methods: The occlusal analyses were performed at ages 34 and 46 years of facial pain cases (n = 52) and controls (n = 49) by two different methods.Results: At 12-year follow-up, a significant decrease in upper anterior segment peer assessment rating (PAR) score was found in the controls, indicating improvement in teeth alignment. In facial pain cases, left lateral occlusal relationship and midline asymmetry were significantly decreased. Occlusal asymmetry and overjet were significantly increased. In controls, the left canine showed a more normal occlusal relationship, cuspid asymmetry was changed, and midline asymmetry was significantly decreased.Conclusion: During a 2-year period, occlusal asymmetry and overjet increased significantly in facial pain cases, while occlusal relationship showed more normal characteristics in controls.

Condylar long axis and articular eminence in MRI in patients with temporomandibular disorders

OBJECTIVE

To compare morphologic findings in MRI and skeletal divergence of a group of patients with temporomandibular joint disorders (TMD) subdivided into condylar symmetric and asymmetric.

METHODS

Fifty-nine adults (26.7 years old) with TMD were retrospectively recruited. Condylar height symmetry was evaluated by orthopantomography (Habets's method) and used to divide patients into Symmetric and Asymmetric groups; skeletal divergence was assessed on lateral cephalograms. MRI was used to evaluate the condylar long axis' angle, the glenoid fossa morphology, and the degree of disc displacement.

RESULTS

Asymmetric subjects showed a hyperdivergent skeletal pattern (p = 0.036), asymmetric condylar long axis (p = 0.018), and deeper (p = 0.025) and asymmetric (p = 0.001) glenoid fossa compared to symmetric subjects.

CONCLUSION

Patients with TMD and condylar asymmetry diagnosed with orthopantomography are more likely to show hyperdivergent skull in cephalometry, condylar asymmetry of both height and major axis, and a steeper glenoid fossa in MRI.

Occlusal Characteristics in Subjects with Facial Pain Compared to a Pain-Free Control Group

Facial pain has been considered a common symptom of temporomandibular disorders (TMD) with a multifactorial etiology. There is controversy regarding the role of occlusion in the background of facial pain and TMD. The aim of the study was to compare the occlusal relationships with two definite measurements in subjects with and without facial pain, in a population-based sample of young adults. The study is part of the Northern Finland 1966 Birth Cohort Project. A subsample of the cohort was formed based on a questionnaire and consisted of 104 subjects, including 52 subjects with facial pain and 52 non-pain controls. Analyses of the dental occlusion of the subjects were performed in gypsum casts by following two methods: 1. the Peer assessment rating (PAR), according to Richmond, et al. (Method 1), and 2. the bilateral canine relationship and the dental midline measurement by the method presented by Pirttiniemi, et al. (Method 2). Method 2 showed higher sensitivity in detecting sagittal occlusal discrepancies than Method 1. Assessment of the intermaxillary relationships in terms of the canine relation showed the lower canine to be more mesially located in the facial pain group, compared to the controls, measured by Method 2. It can be concluded that differences in occlusal sagittal relationships, especially mesial canine relation, seem to correlate with facial pain symptoms at population level.

Occlusal Risk Factors for Temporomandibular Disorders

OBJECTIVE

To determine the role of occlusal variables (overbite; overjet; number of anterior and posterior teeth; bilateral canine guidance on lateral and protrusive movements; anterior centric slide; Angle Classes I, II, and III malocclusion) as risk indicators for the development of temporomandibular disorders (TMDs).

MATERIALS AND METHODS

Seventy-two TMD patients with myofascial pain, with or without limited opening and arthralgia, as well as 30 age- and gender-matched pain-free concurrent controls were included. The association (critical odds ratio [OR] = 2.0) between the significant occlusal variables and TMD was calculated. Confounders were controlled in the inclusion-exclusion criteria as well as in the analysis stage (unconditional logistic regression) by variation in the OR (15%).

RESULTS

Angle Class II malocclusion (crude OR = 8.0, confidence interval [CI] = 2.2 to 29.3) and the absence of bilateral canine guidance on lateral excursion (crude OR = 3.9, CI = 1.6 to 9.7) were statistically more common in patients than in controls. Spontaneous pain as well as pain on palpation (Class II or higher) were also statistically worse in TMD patients. Significant confounders (ie, employment, age, cigarette and alcohol consumption) acted as effect modifiers not changing the critical OR (adjusted OR Angle Class II and bilateral canine guidance = 8.3 to 12.4 and 2.2 to 4.1, respectively).

CONCLUSIONS

Absence of bilateral canine guidance on lateral excursion and particularly Angle Class II malocclusion were considered important risk indicators for the development of TMD in this investigation, even when some sociodemographic factors were considered as effect modifiers.

A 5-year follow-up of temporomandibular disorder treatment emphasizing condylar asymmetry

The purpose of this study was to investigate the long-term effect of temporomandibular disorder (TMD) treatment giving priority to oral stability, i.e. creating stability for the mandible in the individual retruded position of the mandible (RPM), focusing condylar asymmetry. Twenty-nine (29) patients treated for TMD participated in the study. A standardized TMD examination was executed originally and an identical examination was performed at the follow-up in a private TMD practice. In general, the patients showed a significant increase of their maximum active mouth opening capacity (p < 0.01) and a significant decrease of dynamic and static pain at the performed tests (p < 0.001). Patients initially suffering facial pain showed a significant reduction of their pain with treatment (p < 0.01). The patients with condylar asymmetry >10%, and who underwent treatment aiming at permanent oral stability, showed the greatest improvement.

Quantification of the relative risk of multiple occlusal variables for muscle disorders of the stomatognathic system

STATEMENT OF PROBLEM

There is no consensus on the association between occlusion and temporomandibular disorders (TMD).

PURPOSE

The purpose of this study was to quantify the relative risk of multiple occlusal variables for muscle disorders of the stomatognathic system.

MATERIAL AND METHODS

Eight occlusal features: retruded contact position (RCP) to maximum intercuspation (MI) slide length, vertical overlap, horizontal overlap, unilateral posterior reverse articulation, anterior open occlusal relationship, incisor dental midline discrepancy, mediotrusive interferences, and laterotrusive interferences, were clinically assessed by the same trained operator. The sample consisted of 81 women with a Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) axis I diagnosis of muscle disorder, for example myofascial pain, with or without limited opening, and 48 healthy women (control group). A stepwise multiple logistic regression was used to identify the significant associations between occlusal features and disease.

RESULTS

A slide from the retruded contact position to maximum intercuspation > or =2 mm and mediotrusive interferences were the only 2 occlusal features significantly associated with the presence of myofascial pain according to the RDC/TMD criterion symptoms. The odds ratio for myofascial pain was 2.57 for a slide from RCP to MI > or =2 mm and 2.45 for mediotrusive interferences. The percentage of the total log likelihood for myofascial pain explained by the significant occlusal factors amounted to 10.8% (Nagelkerke's R2=0.108). The multifactorial model, including the 2 significant occlusal factors, showed an acuracy to predict disease of 66.7% (sensitivity 71.6%; specificity 58.3%).

CONCLUSION

Occlusal features showed a low predictive value to detect muscle disorders of the stomatognathic system. Multifactorial complex pathologies, such as TMD, should be studied using multivariate statistical analyses, as univariate models may overestimate some resulting associations.

Temporomandibular disorders, occlusion, and neck pain in subjects with facial pain: a case-control study

The etiology of facial pain is multifactorial. Based on the results of a questionnaire included in the study of the 1966 Northern Finland Birth Cohort, performed in 1997-98, we found an association of facial pain with subjective symptoms of temporomandibular disorders (TMD), neck pain and with occlusal factors reported by 5,696 subjects. The aim of the present study was to examine these associations clinically. In the year 2000, a new inquiry was sent to the following subjects living in Oulu: 1. all subjects who had reported facial pain in the former questionnaire (n=162) (case group); and 2. to a randomly selected group of nonpain controls (n=200), group matched for gender. Those who reported willingness to participate were invited to a clinical examination. Finally, the total number of subjects was 104, including 52 (10 men, 42 women) cases and 52 (10 men, 42 women) controls. Anamnestic data were collected, and clinical stomatognathic and musculoskeletal examinations were performed, both the clinicians and the subjects being unaware of the case-control status. Anamnestically, stress was the most often reported provoking factor for facial pain. Facial pain associated significantly with reported TMD symptoms and allergies. Based on clinical findings, most of the cases were classified in the myogenous subgroup of TMD. The risk for facial pain was six-fold in subjects with clinically assessed TMD, defined as moderate (DiII) or severe (DiIII) by Helkimo's clinical dysfunction index, almost six-fold in subjects with protrusion interferences and approximately three-fold in subjects with clinically assessed tenderness of distinct fibromyalgia (FM) points in the neck. According to the adjusted logistic regression analyses, TMD had the strongest influence on facial pain, followed by protrusion interferences, anamnestically reported allergies and "other headaches". The present study shows that as well as being connected with TMD, facial pain is associated with pain and muscle tenderness in the neck area.

Chiropractic care of a patient with temporomandibular disorder and atlas subluxation

OBJECTIVE

To describe the chiropractic care of a patient with cervical subluxation and complaints associated with temporomandibular disorder.

CLINICAL FEATURES

A 41-year-old woman had bilateral ear pain, tinnitus, vertigo, altered or decreased hearing acuity, and headaches. She had a history of ear infections, which had been treated with prescription antibiotics. Her complaints were attributed to a diagnosis of temporomandibular joint syndrome and had been treated unsuccessfully by a medical doctor and dentist.

INTERVENTION AND OUTCOME

High-velocity, low-amplitude adjustments (ie, Gonstead technique) were applied to findings of atlas subluxation. The patient's symptoms improved and eventually resolved after 9 visits.

CONCLUSION

The chiropractic care of a patient with temporomandibular disorder, headaches, and subluxation is described. Clinical issues relevant to the care of patients with this disorder are also discussed.

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.

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 treatment outcomes within five diagnostic categories

This study of temporomandibular disorder (TMD) treatment outcomes examines 274 consecutive patients in five diagnostic categories and a 25 patient comparison group to determine relative levels of symptom improvement. Employing a psychometric outcome measure, the TMJ Scale, it was found that patients receiving active TMD treatments manifest statistically significant symptom improvements. Untreated patients reported minor and statistically insignificant symptom variations. Patients with intracapsular TM joint dysfunctions exhibited higher levels of improvement in pain and other TMD symptoms than patients presenting with primarily muscle symptoms. This research supports the hypothesis that TMDs are not self-limiting and require active treatment interventions. It is suggested that some studies cited to show that TMDs are self-limiting have major methodological limitations, relying upon unvalidated and subjective assessments of symptom levels. This research also outlines a procedure for TMD practitioners to measure treatment efficacy and the relative effectiveness of differing treatment modalities in a valid, consistent and unbiased manner.