Tongue Volume, Function and Biomechanics

描述：舌头在颅面功能、生物力学和生长中的作用比较大的下颌肌肉更重要，但受到的关注较少。因此，舌头的功能形态和负荷的知识是非常初级的。缩小舌体积是治疗各种颅面畸形和疾病的一种有价值的方法，但这种方法的疗效、功能后果和生长影响尚未得到评估。目前的应用是使用一个完善的猪模型来探索舌头的功能形态，以及它的体积如何影响功能、机械负荷和舌缩小手术后颅面生长的后果。我们建议（目标1）测量舌头在功能过程中的变形，并将这些体积不变的形状变化与舌头肌肉组织和下巴运动的收缩模式联系起来。我们将使用新颖的数字显微超声技术记录舌头的三维功能变形，以及舌/颚肌肉的肌电图和下颌/头部运动跟踪。舌头的神经肌肉和血管组织将用全坐骑组织学来描述。此外，我们提出（目标2）了解舌功能变形如何对口腔硬组织产生负荷，以及舌体积在其中起什么作用。我们将直接测量在自然条件下对下颌骨、上颌前骨和上颌骨的张力和压力，以及对舌下神经和个体舌颌肌肉的电刺激。舌体积将减少手术，以了解舌体积与功能和随之而来的负荷的关系。最后，为了解决舌头体积缩小后的恢复和生长影响的主要问题，我们建议（目标3）评估舌头体积缩小后的功能后果和生长影响。我们将使用慢性肌电图和x线透视来跟踪功能恢复，以及舌头/牙齿铸型的纵向测量，连续头测仪，双能x线吸收仪和组织形态测量来分析生长。全安装和免疫组织化学组织学将用于评估术后舌头的神经肌肉和血管重组以及缝合线和骨骼的成骨细胞复制。该应用程序的独特贡献是表征舌头在功能过程中的内部变形，阐明舌头体积如何影响其生物力学载荷，并将这些载荷与功能恢复和颅面生长参数相关联。这些信息的应用将有助于了解正常舌头的功能形态，并评估舌头体积如何影响功能和颅面生长。

DESCRIPTION: The role of tongue in craniofacial function, biomechanics and growth is more critical than the larger jaw muscles but receives less attention. Thus knowledge of tongue functional morphology and loading is very rudimentary. Reducing tongue volume is a valuable approach to treat various craniofacial deformities and disorders, but the efficacy, functional consequences and growth impact following this approach have not been evaluated. The current application is to use a well-established pig model to explore functional morphology of the tongue and how its volume influences function, mechanical loads and the consequences for craniofacial growth following tongue reduction surgery. We propose (Aim 1) to measure tongue deformation during function and relate these volume-constant shape changes to the patterns of contraction in tongue musculature and to the jaw movements. We will record 3D functional deformation of the tongue using the novel technology of digital microsonography, along with electromyography of tongue/jaw muscles and jaw/head movement tracking. The neuromuscular and vascular organization of the tongue will be depicted using whole-mount histology. Further, we propose (Aim 2) to understand how tongue functional deformation produces loads on hard tissues of the oral cavity and what role tongue volume plays. We will make direct measurements of strains and pressures on mandibular, premaxillary and maxillary bones during natural conditions and electrical stimulations to hypoglossal nerves and individual tongue and jaw muscles. Tongue volume will be reduced surgically to understand the relations of tongue volume with function and ensuing loads. Finally, to address the major concerns of recovery and growth effect following tongue volume reduction, we propose (Aim 3) to evaluate the functional consequences and growth impact following tongue volume reduction. We will use chronic electromyography and x-ray fluoroscopy to track functional recovery, and longitudinal measurements of tongue/dental casts, serial cephalometrics, dual energy x-ray absorptiometry and histomorphometry to analyze growth. Whole-mount and immunohistochemical histology will be used for evaluating neuromuscular and vascular reorganization of the tongue and osteogenic cellular replication of sutures and bones after the surgery. The unique contribution of this application is to characterize tongue internal deformation during function, to elucidate how tongue volume influences its biomechanical loads, and to correlate these loads to the parameters of function recovery and craniofacial growth. Application of this information will allow understanding of normal tongue functional morphology and to evaluate how tongue volume affects function and craniofacial growth.