Romeed Shihab A, Malik Raheel, Dunne Stephen M
1 Deptartment Restorative Dentistry, King's College London Dental Institute, London, UK.
J Oral Implantol. 2014 Jun;40(3):231-7. doi: 10.1563/AAID-JOI-D-11-00245.
Maxillectomy and severely resorbed maxilla are challenging to restore with provision of removable prostheses. Dental implants are essential to restore esthetics and function and subsequently quality of life in such group of patients. Zygomatic implants reduce the complications associated with bone grafting procedures and simplify the rehabilitation of atrophic maxilla and maxillectomy. The purpose of this study was to compare, by means of 3-dimensional finite element analysis, the impact of different zygomatic bone support (10, 15, and 20 mm) on the biomechanics of zygomatic implants. Results indicated that maximum stresses within the fixture were increased by 3 times when bone support decreased from 20 to 10 mm and were concentrated at the fixture/bone interface. However, stresses within the abutment screw and the abutment itself were not significantly different regardless of the bone support level. Supporting bone at 10 mm sustained double the stresses of 15 and 20 mm. Fixture's deflection was decreased by 2 to 3 times when bone support level increased to 15 mm and 20 mm, respectively. It was concluded that zygomatic bone support should not be less than 15 mm, and abutment screw is not at risk of fracture regardless of the zygomatic bone support.
上颌骨切除术和严重吸收的上颌骨在通过可摘义齿修复时具有挑战性。牙种植体对于恢复此类患者的美观和功能以及随后的生活质量至关重要。颧骨种植体可减少与骨移植手术相关的并发症，并简化萎缩性上颌骨和上颌骨切除术的修复。本研究的目的是通过三维有限元分析，比较不同颧骨支撑（10、15和20毫米）对颧骨种植体生物力学的影响。结果表明，当骨支撑从20毫米减少到10毫米时，种植体内的最大应力增加了3倍，并集中在种植体/骨界面处。然而，无论骨支撑水平如何，基台螺钉和基台本身内的应力没有显著差异。10毫米的支撑骨承受的应力是15毫米和20毫米支撑骨的两倍。当骨支撑水平分别增加到15毫米和20毫米时，种植体的位移分别减少了2至3倍。得出的结论是，颧骨支撑不应小于15毫米，并且无论颧骨支撑如何，基台螺钉都没有骨折风险。
