Occlusal adjustment using the bite plate-induced occlusal position as a reference position for temporomandibular disorders: a pilot study

Abstract

Background: 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.

Methods: 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.

Results: 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).

Conclusion: 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.

Figure 1

An articulator used in the study. After the casts were attached to the articulator, the BPOP wax record was removed from the casts and the upper cast was vertically lowered until the teeth came into contact.

Figure 2

Mandibular position analyzer. The apparatus added to an articulator for the three-dimensional analysis of the mandibular position consists of right and left recording arms with pins into the condylar post holes. The recording frame is attached to the upper cast. The mandibular positions are recorded on the frame by the needles on both sides.

Figure 3

Dysfunction Index at first examination. Distribution of dysfunction indices before occlusal adjustment. Di O: no TMD; Di I: mild TMD; Di II: moderate TMD; and Di III: severe TMD.

Figure 4

Dysfunction Index at 1-year evaluation. Dstribution of dysfunction indices after occlusal adjustment. Di O: no TMD; Di I: mild TMD; Di II: moderate TMD; and Di III: severe TMD.

Figure 5

Headache frequency before and after treatment. Changes in headache frequency before and after occlusal adjustment. O: almost never; I: 1 to 2 times a month; II: 1 to2 times a week; and III: every day.

Figure 6

Mean HOP-BPOP difference before and after treatment. Changes in the mean difference between the habitual occlusal position (HOP) and the bite plate-induced occlusal position (BPOP) before and after occlusal. adjustment. x: mediolateral; y: anteroposterior; and z:superoinferior.