Al-Zanoon Noor, Cummine Jacqueline, Jeffery Caroline C, Westover Lindsey, Aalto Daniel
Department of Communication Sciences and Disorders, University of Alberta, Rehabilitation Medicine, Edmonton, AB, Canada.
Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.
Biomech Model Mechanobiol. 2024 Oct;23(5):1649-1660. doi: 10.1007/s10237-024-01860-4. Epub 2024 Jun 13.
Radiation therapy (RT) is an important adjuvant and primary treatment modality for head and neck cancers. A severe side effect of RT is fibrosis or scarring of muscle tissues of the oral cavity including the tongue. Previous studies have demonstrated that increased radiation doses to the oral cavity structures have led to decrements in function, hypothesized to result from changes in muscle tissue properties that affect the tongue's function. To understand the complex relationship between tongue muscle fibrosis and tongue function, the current study used a virtual biomechanical model of the tongue. Fibrosis parameters including density (high, low), area (large, small) and location (946 node centres) were systematically varied in the model to test its impact on a target tongue tip motion (protrusion). The impact of fibrosis lesion parameters on three directional components of the tip (anterior-inferior, lateral-medial, and superior-inferior) were analyzed using multi linear regression models. Increases in density and area of fibrosis significantly predicted tongue protrusion movements compared to baseline. In the anterior-posterior direction, reductions in the tongue protrusion were observed. In the inferior-superior direction, the tongue height remained above baseline for the majority of cases. In the lateral-medial direction, ipsilateral deviations were observed. The location of fibrosis modulated these three main effects by either amplifying the observed effect or minimizing it. The findings support the hypothesis that changes in muscle tissue properties because of fibrosis impact tongue function. Increases in density and area of fibrosis impact key muscles in the target motion. The range of modulating effects of the lesion location (i.e., either amplifying or minimizing certain impact patterns) highlights the intricacy of tongue anatomy/soft tissue biomechanics and may suggest that lesions in any location will compromise the tongue's movement.
放射治疗（RT）是头颈癌重要的辅助和主要治疗方式。放射治疗的一个严重副作用是口腔肌肉组织（包括舌头）的纤维化或瘢痕形成。先前的研究表明，增加口腔结构的辐射剂量会导致功能下降，据推测这是由于影响舌头功能的肌肉组织特性发生变化所致。为了理解舌肌纤维化与舌功能之间的复杂关系，本研究使用了舌头的虚拟生物力学模型。在模型中系统地改变纤维化参数，包括密度（高、低）、面积（大、小）和位置（946个节点中心），以测试其对目标舌尖运动（前伸）的影响。使用多元线性回归模型分析纤维化病变参数对舌尖三个方向分量（前下、内外侧和上下）的影响。与基线相比，纤维化密度和面积的增加显著预测了舌头的前伸运动。在前后方向上，观察到舌头前伸减少。在上下方向上，大多数情况下舌头高度保持在基线以上。在内外侧方向上，观察到同侧偏差。纤维化的位置通过放大或最小化观察到的效应来调节这三种主要效应。这些发现支持了以下假设：纤维化导致的肌肉组织特性变化会影响舌功能。纤维化密度和面积的增加会影响目标运动中的关键肌肉。病变位置的调节效应范围（即放大或最小化某些影响模式）突出了舌解剖结构/软组织生物力学的复杂性，可能表明任何位置的病变都会损害舌头的运动。
