MACHINO Atushi Aichi-Gakuin University, School of Dentistry, Research Fellow, 歯学部, 助手
MORI Takashi Aichi-Gakuin University, School of Dentistry, Assistant Professor, 歯学部, 講師 (00159188)
仲 洋一郎 愛知学院大学, 歯学部, 助手 (30241136)
甲藤 克彦 愛知学院大学, 歯学部, 助手 (10201419)
|Budget Amount *help
¥1,800,000 (Direct Cost : ¥1,800,000)
Fiscal Year 1993 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1992 : ¥1,200,000 (Direct Cost : ¥1,200,000)
This study was to investigate the relationship between the onset of temporomandibular joint (TMJ) disorders and functional and para-functional mandibular movements, and their occlusal contacts on the location.
Noraml subjects were selected to examine the time for the onset of TMJ disorders, while maintaining their mandibular in functional and para-functional positions, and at the same time, we measured occlusal contacts on the location and it's area.
1. In lateral excursions, the distance from intercuspal position (IP) to the right canine edge-to-edge position (R2) was 3.9(〕SY.+-.〔)1.4 mm, and IP to the left canine edge-to-edge position (L2) was 3.7(〕SY.+-.〔)1.6 mm. The distance from IP to the right limit lateral excursive position (R4) was 10.1(〕SY.+-.〔)0.7 mm, and IP to the limit lateral left position (L4) as 10.5(〕SY.+-.〔)1.0 mm. In protrusive excursions, IP to the incisal edge-to-edge position (P2) was 3.2(〕SY.+-.〔)1.1 mm, and IP to limit protrusive position (P4) was 7.4(〕SY.+-.〔)0.5 mm.
2. The total number of occlusal contact points were as follows ; IP : 26.6(〕SY.+-.〔)8.9, P1 - P4 : 4.8(〕SY.+-.〔)4.2 - 2.4(〕SY.+-.〔)1.1, R1 - R4 : 8.2(〕SY.+-.〔)3.9 - 2.6(〕SY.+-.〔)2.1, L1 - L4 : 6.6(〕SY.+-.〔)4.6 - 1.0(〕SY.+-.〔)0.1.
3. The total amount of occlusal contact areas were as follows ; IP : 16.2(〕SY.+-.〔)9.0 mm^2, Pl - P4 : 2.4(〕SY.+-.〔)2.4 mm^2 - 1.2(〕SY.+-.〔)0.7 mm^2, R1 - R4 : 6.1 (〕SY.+-.〔)3.1 mm^2 - 1.9(〕SY.+-.〔)1.8 mm^2, L1 - L4 : 4.7(〕SY.+-.〔)3.7 mm^2 - 0.3(〕SY.+-.〔)0.2 mm^2.
No subject had TMJ disorders in the intercuspal position, but some subjects complained of TMJ disorders when the distance of lateral and protrusive movements were increased. Especially, over tooth edge-to-edge in lateral and protrusive mandibular position, more than 80% of the subjects complained of TMJ disorders.
It seems there were some relationships between the onset of TMJ disorders and para-functional mandibular movements and their occlusal contact phase.