Relationship between duration of unilateral masticatory cycles and the type of lateral dental guidance: a preliminary...

This study assessed the duration of different phases of the chewing cycle and the height of the masticatory cycle in relation to the type of lateral guidance.

Fifty-three subjects with the same type of lateral guidance on both sides were categorized into 3 groups: anterior protected articulation, canine protection, and group function. Overbite was measured clinically. Border jaw movements were recorded using a Sirognathograph, and the lateral guidance angle in the frontal plane was measured. Jaw movements during unilateral chewing of peanuts were recorded on the frontal plane using the Sirognathograph connected to an electrocardiograph used for transcription. A single masticatory cycle was divided into opening, closing, and occlusal-level phases. Masticatory parameters were analyzed by one-way analysis of variance, correlations, the paired Student t test, and multiple linear regression.

Women showed significantly longer total cycle duration than men. Subjects with canine protection showed the highest lateral guidance angle and the highest chewing cycle duration. Subjects with anterior protected articulation exhibited significantly longer occlusal-level phases. Fifty-nine percent of the variation in duration of the occlusal-level phase can be explained by the type of lateral dental guidance, gender, and lateral guidance angle. Only overbite was a predictor of height of mastication.

The type of lateral guidance, gender, and frontal guidance angle are correlated with the duration of the occlusal-level phase during unilateral chewing of peanuts. The height of mastication cannot be explained by the type of lateral guidance.