Mandibular Movement Pattern During Mastication

저작시(咀嚼時) 하악운동(下顎運動)의 양상(樣相)

Numerous studies have been reported on the movement of the jaw during chewing. However, there is still much controversy. The purposes of this study were to observe the jaw movement during mastication and to provide the information in prosthodontic treatment and diagnosis of temporomandibular disorder. The author analyzed the time and characteristics of the masticatory movement during chewing using mandibular kinesiograph in 24 subjects, 17 males 7 females, age of 22-27 without orofacial problems. The obtained results were as follows: The duration of single chewing cycle was $515{\pm}87msec.$. Comparing the three phases of the chewing cycle (opening, closing, centric pause), the closing phase had the longest duration, and the centric pause had the shortest duration. The maximal laterotrusive movement of the mandible druing chewing was $3.5{\pm}1mm$. The maximal mediotrusive movement of the mandible during chewing was $1.0{\pm}0.7mm$. The maximal vertical velocity of the mandible during chewing was $120{\pm}28mm/sec.$ in opening phase, and $109{\pm}21mm/sec.$ in closing phase.

경북대학교 치과대학에 재학중인 남자 17명, 여자 7명 총 24명을 연구대상으로 M.K.G의 sweep mode에 나타나는 저작운동을 분석한 바 다음과 같은 결과를 얻었다. 단일 저작회로의 기간은 $515{\pm}87msec.$ 이며, 이중 폐구 기간이 가장 길었고, 개구 기간, centric pause의 기간 순위였다. (P<0.005). 개구시 저작측으로 측방변위한 양은 $3.5{\pm}1mm$이었고, 비저작측으로 측방변위한 양은 $1.0{\pm}0.7mm$이었다. 개구시 최대 수직속도는 $120{\pm}28m/sec.$이며, 폐구시 최대 수직속도는 $109{\pm}21mm/sec.$로서 개구시의 최대 수직속도가 더 빠르게 나타났다. (P<0.05).