Abstract
The speed analysis of mandibular movement is one of the most useful methods which give important information for evaluating the stomatognathic function. The purpose of this study is to clarify the characteristics of the speed at incisor, molars and condyles during jaw opening and closing movement. Mandibular movements were measured with Kyushu University 3-D movement analyzing system in 40 normal subjects then the speed was calculated.
The following results were obtained:
1. The averages of maximum speed were 253.42 mm/s during opening, 311.92 mm/s during closing at incisors; 173.14 mm/s during opening, 197.50 mm/s during closing at molars ; 91.82 mm/s during opening, 157.24 mm/s during closing at condyles. The value of maximum closing speed was significantly larger than that of maximum opening speed for each portion.
2. The averages of the moved distance where the reached maximum speed expressed as a percentage against the maximum moved distance were 32.46% during opening, 63.75% during closing at incisors ; 33.45% during opening, 62.76% during closing at molars ; 47.26% during opening, 58.63% during closing at condyles.
