Wei Yating, Wang Yan, Zhang Ming, Yan Gang, Wu Shixue, Liu Wenjun, Ji Gang, Li-Tsang Cecilia W P
Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China; Department of Burn Surgery, The Second Affiliated Hospital of Kunming Medical University, Kunming, China.
Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China.
Burns. 2018 Mar;44(2):453-461. doi: 10.1016/j.burns.2017.08.006. Epub 2017 Oct 9.
Deep facial burns leave conspicuous scar to the patients and affect their quality of life. Transparent facemask has been adopted for the prevention and treatment of facial hypertrophic scars for decades. Recently, with the advancement of 3D printing, the transparent facemask could facilitate the fitting of the facial contour. However, the effectiveness of the device and its biomechanical characteristics on pressure management of hypertrophic scar would need more objective evaluation.
A biomechanical model of the transparent 3D-printed facemask was established through finite element analysis. Ten patients with extensive deep facial burns within 6 months were recruited for clinical study using 3D-printed facemask designed according to biomechanical model, and the interface pressure was measured on each patient. The patients in the treatment group (n=5) was provided with the 3D-printed transparent face mask soon after initial scar assessment, while the delayed treatment group (n=5) began the treatment one month after the initial scar assessment. The scar assessment was performed one month post intervention for both groups.
The biomechanical modeling showed that the 3D, computer-generated facemask resulted in unbalanced pressure if design modifications were not incorporated to address these issues. The interface pressure between the facemask and patient's face was optimized through individualized design adjustments and the addition of silicone lining. After optimization of pressure through additional lining, the mean thickness and hardness of the scars of all 10 patients were decreased significantly after 1-month of intervention. In the delayed treatment group, the mean thickness of the scars was increased within the month without intervention, but it was also decreased after intervention.
Facemask design and the silicone lining are important to ensure adequate compression pressure of 3D-printed transparent facemask. The intervention using the 3D-printed facemask appeared to show its efficacy to control the thickness and hardness of the facial hypertrophic scars.
深度面部烧伤会给患者留下明显的疤痕，影响其生活质量。几十年来，透明面罩一直被用于预防和治疗面部增生性疤痕。近年来，随着3D打印技术的进步，透明面罩能够更好地贴合面部轮廓。然而，该装置在增生性疤痕压力管理方面的有效性及其生物力学特性仍需更客观的评估。
通过有限元分析建立了透明3D打印面罩的生物力学模型。招募了10例6个月内有广泛深度面部烧伤的患者，使用根据生物力学模型设计的3D打印面罩进行临床研究，并测量每位患者的界面压力。治疗组（n=5）在初次疤痕评估后立即佩戴3D打印透明面罩，而延迟治疗组（n=5）在初次疤痕评估后1个月开始治疗。两组均在干预1个月后进行疤痕评估。
生物力学建模表明，如果不进行设计修改以解决这些问题，3D计算机生成的面罩会导致压力不均衡。通过个性化设计调整和添加硅胶衬里，优化了面罩与患者面部之间的界面压力。通过添加衬里优化压力后，所有10例患者的疤痕在干预1个月后的平均厚度和硬度均显著降低。在延迟治疗组中，疤痕平均厚度在未干预的1个月内增加，但在干预后也有所降低。
面罩设计和硅胶衬里对于确保3D打印透明面罩有足够的压缩压力很重要。使用3D打印面罩进行干预似乎显示出其在控制面部增生性疤痕厚度和硬度方面的效果。
