Frequency spectrum of condylar movement in clinically normal subjects, using an amorphous sensor.

The purpose of this study was to determine the properties of the frequency spectrum produced by condylar movements in normal subjects, by the use of an amorphous sensor. The gender-matched sample consisted of white people (17 males and 17 females, aged 25.8 +/- 2.5 and 25.5 +/- 2.8 years, respectively) who had no subjective or objective symptoms related to temporomandibular joint sounds. Bilateral condylar and jaw movements were recorded simultaneously. The results showed that the mean +/- standard deviation (s.d.) for the mean frequency of condylar movement during the opening and closing phases was 45.0 +/- 5.2 and 47.0 +/- 3.5 Hz, respectively. The mean +/- s.d. for the peak frequency of condylar movement during the opening and closing phases was 46.6 +/- 8.0 and 49.7 +/- 4.5 Hz, respectively. Significant correlations existed between the left and right sides in the mean frequency as well as the peak frequency during the opening phase. However, there were no significant correlations between the left and right sides in the mean frequency or the peak frequency during the closing phase. These results suggest that the frequency spectrum of normal condylar movement can be obtained when using the amorphous sensor.