关键词: 下颌牙龈癌, micro-CT, 骨密度, 骨小梁厚度, 骨小梁分离度

Abstract: PURPOSE: To evaluate and analyze the imaging features of mandibular invasion, in order to provide imaging evidences for optimizing the operation plan and guiding postoperative treatment for gingival squamous cell carcinoma (GSCC). METHODS: Sixty patients underwent surgery for mandibular GSCC were included. Preoperative panoramic radiograph, ordinary CT and enhanced CT scanning were analyzed. Micro-CT three-dimensional reconstruction was performed on 30 eligible surgical specimens in order to measure bone mineral density, trabecular thickness, trabecular separation and other related parameters. SPSS 22.0 software package was used for data analysis. RESULTS: Conventional imaging examination with panoramic radiograph, CT and enhanced CT scaning were insufficient. Micro-CT three-dimensional reconstruction could accurately distinguish between cancellous bone and bone cortex, assess the scope and degree of mandibular invasion. The corresponding data parameter analysis indicated that bone mineral density (BMD) of the GSCC central and marginal area was significantly reduced comparing with the BMD at the normal mandibular bone area(P<0.05). In addition, the thickness of trabecular bone was also significantly reduced（P<0.05). The BMD of cancellous bone was significantly decreased(P<0.05). The separation degree of trabecular bone in cancer center was obviously increased comparing with the normal mandibular tissue(P<0.05). CONCLUSIONS: Currently, there are still controversies about the surgical plan for mandibular gingival cancer, and further improving the accuracy of CT examination may provide more accurate guidance for making surgical plan for mandibular gingival cancer.

Key words: Mandibular gingival carcinoma, Micro-CT, Bone mineral density, Bone trabecular thickness, Separation of trabecular bone