Occlusal contacting condition and masticatory function of 2 types of pattern that differ in the closing path of the mandibular incisal point during chewing

Purpose

To clarify the difference in the state of occlusal contact and masticatory function between two patterns of masticatory movement path that differed in the closing path.

Methods

Fifteen healthy subjects with Pattern I (a linear or concave opening path and a convex closing path) and Pattern II (similar opening path to that in Pattern I and a concave closing path) were selected. The state of occlusal contact on the working and balancing sides and the masticatory function (integral value of the masseter muscular activity, gape, masticatory width, cycle time, indicators representing the stability of the path and rhythm, and glucose extraction) were compared between the two patterns.

Results

The occlusal contact on the working side was about the same. For the balancing side, occlusal contact at the molar region was observed for Pattern II in most cases, whereas no occlusal contact was observed for Pattern I. The integral value of the masseter muscular activity and the glucose extraction were greater for Pattern I. The gape was not different between the two patterns. Pattern I had a wide masticatory width and a short cycle time. The values of the indicators representing the stability of the path and rhythm were smaller for Pattern I.

Conclusion

It was suggested that Pattern I with a convex closing path had a functional difference and a superior masticatory function from Pattern II with a concave closing path, and the difference in the occlusal contact on the balancing side was related.