Influence of the craniomandibular system on human posture control during dynamic balance tasks

流行病学研究表明，颌骨和面部功能障碍与肌肉骨骼疾病的合并症很高。在牙科、骨科和物理治疗的临床环境中，颅下颌系统（CMS）通过筋膜肌肉链的病理生理效应被证明能够引起全身疾病。基于这些发现，提出了成本密集和最大侵入性的治疗模式。神经解剖学和神经生理学研究表明，CMS与体位控制系统存在功能联系。咬人活动的影响可以通过比目鱼h反射看到脊柱兴奋性的增加，同时运动控制系统的兴奋性也普遍增加。一些研究表明，在静态条件下，咬咬活动可能对姿势控制具有稳定作用，肌肉共同收缩模式的可变性减少，以及直立位置时躯干和头部的波动减少。此外，有研究表明，牙列不足的患者摔倒的风险可能会增加。然而，到目前为止，还没有对照研究调查咬咬活动在动态平衡任务中的潜在影响。为了解决这一研究缺陷，目前的后续建议旨在加强DFG基金“颅下颌系统对动态平衡任务中人的姿势控制的影响”的两个工作组的跨学科工作。本研究主要关注两个问题：(1)在解决动态稳态平衡任务时，下颌次极大握紧是否对表现有显著的积极影响？(2)下颌次极大握紧训练是否能增强动态稳态平衡任务的训练，并对动态精密任务产生传递效应？在此背景下，利用生物力学多体模型对参与者在解决动态稳态平衡任务和动态精密任务时的运动进行了运动学和肌肉水平的测量，并重构了关节角度。为了回答这两个问题，使用电机控制领域的最新方法（例如，不受控制的流形分析）分析所产生的时间序列。这种跨学科的研究方法结合了牙科和人体运动科学，首次以结构化的方式研究了动态平衡任务，以便更全面地了解CMS控制运动活动对姿势控制过程的影响。研究结果可以帮助批判性地质疑病理生理琐碎模型，并检查有关咬伤活动所描述的影响的应用相关问题，例如康复方面。

Epidemiological studies show a high comorbidity of dysfunctions in the jaw and face area with the musculoskeletal complaints. In the clinical settings of dentistry, orthopedics and physiotherapy the pathophysiological effects of the craniomandibular system (CMS) via the fascial-muscle-chains were shown to be able to cause whole-body disorders. Based on these findings, cost-intensive and maximally invasive therapy models are proposed.Neuroanatomical and neurophysiological studies indicate that there are functional connections of the CMS with the postural control system. The effects of biting activities were visible as an increased spinal excitability via the soleus H-reflex as well as a generally increased excitability of the motor control system. A number of studies showed that the biting activities may have a stabilizing effect on postural control under static conditions, a reduced variability of muscular co-contraction patterns as well as reduced fluctuations of the trunk and head in an upright position were also reported. In addition, there are studies indicating that patients with an insufficient dentition may have an increased risk of falling. However, to date there are no controlled studies investigating the potential effects of biting activities during dynamic balance tasks.Addressing this research deficit, the present follow-up proposal aims to enhance the interdisciplinary work of the two working groups from the DFG fund "Influence of the craniomandibular system the postural control of people in dynamic balance tasks”. This follow-up proposal focuses on two questions: (1) Does submaximal jaw clenching have acute positive effects on performance when solving a dynamic steady-state balance task? (2) Can submaximal jaw clenching training augment the training of a dynamic steady-state balance task and does this lead to transfer effects on a dynamic precision task? Against this background, the movements of the participants when solving a dynamic steady-state balance task and a dynamic precision task were measured on the kinematic and muscular levels and joint angles were reconstructed with a biomechanical multi-body model. To answer these two questions, the resulting time series are analyzed by use of up-to-date methods from the field of motor control (e.g. Uncontrolled-Manifold analysis).With this interdisciplinary research approach at the interface of dentistry and human movement science, dynamic balance tasks were examined for the first time in a structured manner in order to more comprehensively understand the effects of controlled motor activity of the CMS on postural control processes. The findings can help to critically question the pathophysiological trivial models and to examine application-related questions regarding the described effects of biting activities, e.g. for rehabilitation aspects.