Cranioplasty using Polymethylmethacrylate (PMMA) self-curing by the conventional casting process: clinical case report

ABSTRACT Cranioencephalic trauma which results in extensive edema and / or bruising usually requires surgical treatment through a greater withdrawal of the bone portion. Thus, the absence of bone tissue implies the lack of protection of the brain tissue or even compromises the esthetics especially when located in the frontal or frontoparietal region. The purpose of this case report is to describe a treatment option for head trauma, through the prefabricated part by obtaining the skull model. These bone faults can be reconstructed either by the direct method using polymethylmethacrylate directly on the defects or by means of pre-made pieces such as prototyping or from the skull model. Although other techniques have many good points, some show certain drawbacks, from storage conditions below abdominal fat, preheating due to the release of heat during the high polymerization reaction or the high cost when they are prototyped. The technique described in this work reports its simple performance, eliminating the risk of local heating, allows prior sterilization in autoclave, it is biocompatible, allows perfect anatomical recovery, easy placement, low cost, also highlighs the advantage of the bucomaxillofacial surgeon's performance due to the familiarization with the relevant head and neck procedures. Clinical and tomographic examination after 24 months of treatment showed stability of the polymethylmethacrylate plate, adhesions to the bone margins, and absence of tissue alterations.

摘要：颅脑创伤（cranioencephalic trauma）若引发广泛脑水肿和/或脑挫伤，通常需通过大范围骨瓣开颅进行手术治疗。骨组织缺损会导致脑组织失去保护，还会影响美观，尤其是当缺损位于额部或额顶区域时。
本病例报告旨在介绍一种基于颅骨模型预制修复体的颅脑创伤治疗方案。此类颅骨缺损可通过两种方式修复：一是直接在缺损处使用聚甲基丙烯酸甲酯（polymethylmethacrylate）的直接修复法，二是采用预制修复体，如快速原型件或基于颅骨模型制作的修复体。
尽管其他修复技术具备诸多优势，但仍存在部分缺陷：例如储存条件需低于腹部脂肪温度、高温聚合反应过程中释放热量导致需提前预热，或是快速原型制作成本高昂。
本研究所述的修复技术操作简便，可规避局部加热风险，能够提前使用高压蒸汽灭菌器（autoclave）进行灭菌，生物相容性良好，可实现完美的解剖结构复位，植入便捷且成本低廉；此外，由于口腔颌面外科医师熟悉头颈部相关手术操作，该技术还能充分发挥临床应用优势。
治疗后24个月的临床及影像学检查结果显示，聚甲基丙烯酸甲酯修复板状态稳定，与骨缘贴合紧密，未出现组织异常改变。