Mandibular Jaw Movement and Masticatory Muscle Activity during Dynamic Trunk Exercise
The examination of jaw movement during exercise is essential for an improved understanding of jaw function. Currently, there is no unified view of the mechanism by which the mandible is fixed during physical exercise. We hypothesized that during strong skeletal muscle force exertion in dynamic exerc...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-12-01
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| Series: | Dentistry Journal |
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| Online Access: | https://www.mdpi.com/2304-6767/8/4/132 |
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| author | Daisuke Sugihara Misao Kawara Hiroshi Suzuki Takashi Asano Akihiro Yasuda Hiroki Takeuchi Toshiyuki Nakayama Toshikazu Kuroki Osamu Komiyama |
| author_facet | Daisuke Sugihara Misao Kawara Hiroshi Suzuki Takashi Asano Akihiro Yasuda Hiroki Takeuchi Toshiyuki Nakayama Toshikazu Kuroki Osamu Komiyama |
| author_sort | Daisuke Sugihara |
| collection | DOAJ |
| description | The examination of jaw movement during exercise is essential for an improved understanding of jaw function. Currently, there is no unified view of the mechanism by which the mandible is fixed during physical exercise. We hypothesized that during strong skeletal muscle force exertion in dynamic exercises, the mandible is displaced to a position other than the maximal intercuspal position and that mouth-opening and mouth-closing muscles simultaneously contract to fix the displaced mandible. Therefore, we simultaneously recorded mandibular jaw movements and masticatory muscle activities during dynamic trunk muscle force exertion (deadlift exercise) in 24 healthy adult males (age, 27.3 ± 2.58 years). The deadlift was divided into three steps: Ready (reference), Pull, and Down. During Pull, the mandibular incisal point moved significantly posteriorly (−0.24 mm, <i>p</i> = 0.023) and inferiorly (−0.55 mm, <i>p</i> = 0.019) from the maximal intercuspal position. Additionally, temporal, masseter, and digastric muscles were activated simultaneously and significantly during Pull (18.63 ± 17.13%, 21.21 ± 18.73%, 21.82 ± 19.97% of the maximum voluntary contraction, respectively), with maintained activities during Down (<i>p</i> < 0.001). Thus, during dynamic trunk muscle force exertion, the mandibular incisal point moved to a posteroinferior position without tooth-touch (an open-mouth position). Simultaneously, the activities of the mouth-opening digastric muscles and the mouth-closing temporal and masseter muscles led to mandibular fixation, which is a type of mandible fixing called bracing. |
| first_indexed | 2024-03-10T14:22:38Z |
| format | Article |
| id | doaj.art-bb16ba56de8e4b4d87e453e3aa9cd363 |
| institution | Directory Open Access Journal |
| issn | 2304-6767 |
| language | English |
| last_indexed | 2024-03-10T14:22:38Z |
| publishDate | 2020-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Dentistry Journal |
| spelling | doaj.art-bb16ba56de8e4b4d87e453e3aa9cd3632023-11-20T23:17:06ZengMDPI AGDentistry Journal2304-67672020-12-018413210.3390/dj8040132Mandibular Jaw Movement and Masticatory Muscle Activity during Dynamic Trunk ExerciseDaisuke Sugihara0Misao Kawara1Hiroshi Suzuki2Takashi Asano3Akihiro Yasuda4Hiroki Takeuchi5Toshiyuki Nakayama6Toshikazu Kuroki7Osamu Komiyama8Division of Oral Function and Rehabilitation, Department of Oral Health Science, Nihon University School of Dentistry at Matsudo, 870-1 Sakaecho, Nishi-2, Matsudo, Chiba 271-8587, JapanDivision of Oral Function and Rehabilitation, Department of Oral Health Science, Nihon University School of Dentistry at Matsudo, 870-1 Sakaecho, Nishi-2, Matsudo, Chiba 271-8587, JapanDivision of Oral Function and Rehabilitation, Department of Oral Health Science, Nihon University School of Dentistry at Matsudo, 870-1 Sakaecho, Nishi-2, Matsudo, Chiba 271-8587, JapanDivision of Oral Function and Rehabilitation, Department of Oral Health Science, Nihon University School of Dentistry at Matsudo, 870-1 Sakaecho, Nishi-2, Matsudo, Chiba 271-8587, JapanDivision of Oral Function and Rehabilitation, Department of Oral Health Science, Nihon University School of Dentistry at Matsudo, 870-1 Sakaecho, Nishi-2, Matsudo, Chiba 271-8587, JapanDivision of Oral Function and Rehabilitation, Department of Oral Health Science, Nihon University School of Dentistry at Matsudo, 870-1 Sakaecho, Nishi-2, Matsudo, Chiba 271-8587, JapanDivision of Oral Function and Rehabilitation, Department of Oral Health Science, Nihon University School of Dentistry at Matsudo, 870-1 Sakaecho, Nishi-2, Matsudo, Chiba 271-8587, JapanDivision of Oral Function and Rehabilitation, Department of Oral Health Science, Nihon University School of Dentistry at Matsudo, 870-1 Sakaecho, Nishi-2, Matsudo, Chiba 271-8587, JapanDivision of Oral Function and Rehabilitation, Department of Oral Health Science, Nihon University School of Dentistry at Matsudo, 870-1 Sakaecho, Nishi-2, Matsudo, Chiba 271-8587, JapanThe examination of jaw movement during exercise is essential for an improved understanding of jaw function. Currently, there is no unified view of the mechanism by which the mandible is fixed during physical exercise. We hypothesized that during strong skeletal muscle force exertion in dynamic exercises, the mandible is displaced to a position other than the maximal intercuspal position and that mouth-opening and mouth-closing muscles simultaneously contract to fix the displaced mandible. Therefore, we simultaneously recorded mandibular jaw movements and masticatory muscle activities during dynamic trunk muscle force exertion (deadlift exercise) in 24 healthy adult males (age, 27.3 ± 2.58 years). The deadlift was divided into three steps: Ready (reference), Pull, and Down. During Pull, the mandibular incisal point moved significantly posteriorly (−0.24 mm, <i>p</i> = 0.023) and inferiorly (−0.55 mm, <i>p</i> = 0.019) from the maximal intercuspal position. Additionally, temporal, masseter, and digastric muscles were activated simultaneously and significantly during Pull (18.63 ± 17.13%, 21.21 ± 18.73%, 21.82 ± 19.97% of the maximum voluntary contraction, respectively), with maintained activities during Down (<i>p</i> < 0.001). Thus, during dynamic trunk muscle force exertion, the mandibular incisal point moved to a posteroinferior position without tooth-touch (an open-mouth position). Simultaneously, the activities of the mouth-opening digastric muscles and the mouth-closing temporal and masseter muscles led to mandibular fixation, which is a type of mandible fixing called bracing.https://www.mdpi.com/2304-6767/8/4/132mandibular jaw movementmasticatory muscle activitydynamic trunk exercisemandibular fixationbracing |
| spellingShingle | Daisuke Sugihara Misao Kawara Hiroshi Suzuki Takashi Asano Akihiro Yasuda Hiroki Takeuchi Toshiyuki Nakayama Toshikazu Kuroki Osamu Komiyama Mandibular Jaw Movement and Masticatory Muscle Activity during Dynamic Trunk Exercise Dentistry Journal mandibular jaw movement masticatory muscle activity dynamic trunk exercise mandibular fixation bracing |
| title | Mandibular Jaw Movement and Masticatory Muscle Activity during Dynamic Trunk Exercise |
| title_full | Mandibular Jaw Movement and Masticatory Muscle Activity during Dynamic Trunk Exercise |
| title_fullStr | Mandibular Jaw Movement and Masticatory Muscle Activity during Dynamic Trunk Exercise |
| title_full_unstemmed | Mandibular Jaw Movement and Masticatory Muscle Activity during Dynamic Trunk Exercise |
| title_short | Mandibular Jaw Movement and Masticatory Muscle Activity during Dynamic Trunk Exercise |
| title_sort | mandibular jaw movement and masticatory muscle activity during dynamic trunk exercise |
| topic | mandibular jaw movement masticatory muscle activity dynamic trunk exercise mandibular fixation bracing |
| url | https://www.mdpi.com/2304-6767/8/4/132 |
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