An evidence-based assessment of occlusal adjustment as a treatment for temporomandibular disorders
Faculty of Dental Science, Kyushu University, Hukuoka, Fukuoka, Japan Journal of Prosthetic Dentistry
(Impact Factor: 1.75).
08/2001; 86(1):57-66. DOI: 10.1067/mpr.2001.115399
Occlusal adjustment therapy has been advocated as a treatment modality for temporomandibular disorders. In contrast to this position, a panel at the 1996 National Institute of Health technology assessment conference on TMD indicated that no clinical trials demonstrate that occlusal adjustment is superior to noninvasive therapies.
This article summarizes the published experimental studies on occlusal adjustments and temporomandibular disorders.
Eleven research experiments involving 413 subjects with either bruxism (n = 59), temporomandibular disorders (n = 219), headaches and temporomandibular disorders (n = 91), or chronic cervical pain (n = 40) were selected for critical review from the English dental literature.
Three experiments evaluated the relationship between occlusal adjustment and bruxism. Six experiments evaluated occlusal adjustment therapy as a treatment for patients with primary temporomandibular disorders. One experiment looked at occlusal adjustment effect on headache/temporomandibular disorder symptoms; another looked at its effect on chronic neck pain. Most of these experiments used a mock adjustment or a comparison treatment as the control condition in adults who had an existing nonacute general temporomandibular disorder. Overall, the data from these experiments did not demonstrate elevated therapeutic efficacy for occlusal adjustment over the control or the contrasting therapy.
The experimental evidence reviewed was neither convincing nor powerful enough to support the performance of occlusal therapy as a general method for treating a nonacute temporomandibular disorder, bruxism, or headache.
Available from: Kengo Torii
- "Since this conference, many conflicting opinions have been reported (Dawson, 1999; Green et al., 1998), and most clinical researchers and basic researchers have become estranged from investigations of the relationship between occlusion and TMD. Therefore, studies on occlusion and TMD have been rarely performed since that time, and treatment for TMD has shifted to more conservative modalities (Tsukiyama et al., 2001). The outcomes of these conservative treatments for TMD have been symptomatic and temporary, not resulting in a cure, because the treatments have not been applied to patients based on evidence, as the causes of TMD remain unknown. "
Available from: Ichiro Chiwata
- "Forssell et al.  and Tsukiyama et al.  reviewed the published studies on occlusal adjustments and TMD and concluded that no evidence existed to support the use of occlusal adjustments in randomized controlled trials. In previously described studies [1-12], passively guided centric relation was used as the reference position for the procedures of occlusal adjustments. "
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ABSTRACT: Many researchers have not accepted the use of occlusal treatments for temporomandibular disorders (TMDs). However, a recent report described a discrepancy between the habitual occlusal position (HOP) and the bite plate-induced occlusal position (BPOP) and discussed the relation of this discrepancy to TMD. Therefore, the treatment outcome of evidence-based occlusal adjustments using the bite plate-induced occlusal position (BPOP) as a muscular reference position should be evaluated in patients with TMD.
The BPOP was defined as the position at which a patient voluntarily closed his or her mouth while sitting in an upright posture after wearing an anterior flat bite plate for 5 minutes and then removing the plate. Twenty-one patients with TMDs underwent occlusal adjustment using the BPOP. The occlusal adjustments were continued until bilateral occlusal contacts were obtained in the BPOP. The treatment outcomes were evaluated using the subjective dysfunction index (SDI) and the Helkimo Clinical Dysfunction Index (CDI) before and after the occlusal adjustments; the changes in these two indices between the first examination and a one-year follow-up examination were then analyzed. In addition, the difference between the HOP and the BPOP was three-dimensionally measured before and after the treatment.
The percentage of symptom-free patients after treatment was 86% according to the SDI and 76% according to the CDI. The changes in the two indices after treatment were significant (p < 0.001). The changes in the mean HOP-BPOP differences on the x-axis (mediolateral) and the y-axis (anteroposterior) were significant (p < 0.05), whereas the change on the z-axis (superoinferior) was not significant (p > 0.1).
Although the results of the present study should be confirmed in other studies, a randomized clinical trial examining occlusal adjustments using the BPOP as a reference position appears to be warranted.
Available from: Gregor Slavicek
- "However, in recent overviews doubts have been raised about the degree of evidence of the existing studies      . In general the majority of systems seem to affect acute symptoms of CMD, whereas the long-term curative effect appears to be doubtful at the present time      . On the other hand, the protective effect of occlusal splints with regard to abrasions appears to be useful in patients with bruxism . "
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ABSTRACT: The present study examined possible advantages of a kinematical determination of hinge axis points over arbitrary axis points
in the fabrication of occlusal splints for CMD treatment. The single blinded prospective randomised trial was performed in
a general dental practice. A total of 14 consecutive patients presenting for CMD treatment were considered for participation
and declared informed consent, and 12 patients (average age about 40 years) eventually participated. These patients were randomly
assigned to either fabrication method and were not informed about how their individual splint was constructed. Condylography,
required for the kinematical hinge axis determination, was therefore performed in both groups. Patients were recalled after
1, 2, 4, 14 and 28 days, and splints were selectively ground in order to achieve full occlusal contact in 12 points. The required
number of corrective grindings was recorded, as was the clinical course of the patients. Kinematical splint construction yielded
the desired result – mandibular repositioning as reflected by the full number of occlusal contact points – faster and more
completely than the employment of an arbitrary hinge axis, and substantially (about 50%) less corrective grinding was required.
The difference was statistically significant despite the rather small sample size. Clinically, both methods appeared to be
equally effective. The greater initial effort required by kinematical determination of the individual hinge axis seems to
be at least partially outweighed by a lower amount of corrective grinding required achieving the desired splint effect. Which
method has the superior cost-benefit ratio remains to be determined.
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