Department of Oral and Maxillofacial Surgery/Oral Pathology, Amsterdam University Medical Centers and Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands.
Department of Oral and Maxillofacial Surgery/Oral Pathology, Amsterdam University Medical Centers and Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands.
Arch Oral Biol. 2022 Jan;133:105302. doi: 10.1016/j.archoralbio.2021.105302. Epub 2021 Nov 3.
The aim of the present study was to assess mineralization and trabecular microarchitecture in atrophic edentulous mandibles and to identify regional differences and relations with the extent of resorption.
Cortical and trabecular bone volumes in anterior, premolar and molar regions of 10 edentulous cadaveric mandibles (5 males and 5 females; mean age ± SD: 85.4 ± 8.3 years) were assessed by microcomputed tomography. Mandibular height and Cawood & Howell classes were recorded. Concerning trabecular volumes, bone mineral density (BMD), bone volume fraction, trabecular tissue volume fraction, connectivity density, trabecular number, trabecular thickness, trabecular separation, degree of anisotropy, and structural model index were measured; concerning cortical volumes porosity, BMD and cortical thickness were measured.
In molar regions, the bone volume fraction and trabecular number were lower, whereas trabecular separation, degree of anisotropy and cortical BMD were higher compared to anterior regions. In premolar regions, mandibular height correlated negatively with trabecular number (Spearman's correlation r = 0.73, p = 0.017) and connectivity density (Spearman's correlation r = 0.82, p = 0.004), and correlated positively with trabecular separation (Spearman's correlation r = - 0.65, p = 0.04). Cortical BMD was higher at bucco-inferior cortex of molar and inferior border of premolar region and lower at anterior cranial buccal and lingual surface.
In the premolar region, increased resorption coincides with local impairment of trabecular bone quality. Cortical bone BMD is higher in areas with highest strains and lower in areas with most mandibular resorption. Trabecular bone volume and quality is superior in the anterior region of the edentulous mandible, which might explain improved primary stability of dental implants in this region.
本研究旨在评估萎缩性无牙下颌骨的矿化和小梁微结构，并确定区域差异及其与吸收程度的关系。
通过微计算机断层扫描评估 10 具无牙尸体下颌骨（5 名男性和 5 名女性；平均年龄 ± 标准差：85.4 ± 8.3 岁）前牙、前磨牙和磨牙区的皮质和小梁骨体积。记录下颌骨高度和 Cawood 和 Howell 分类。关于小梁体积，测量骨矿物质密度（BMD）、骨体积分数、小梁组织体积分数、连通密度、小梁数量、小梁厚度、小梁分离度、各向异性程度和结构模型指数；关于皮质体积，测量孔隙率、BMD 和皮质厚度。
在磨牙区，骨体积分数和小梁数量较低，而小梁分离度、各向异性程度和皮质 BMD 较高。在前磨牙区，下颌骨高度与小梁数量（Spearman 相关系数 r = 0.73，p = 0.017）和连通密度（Spearman 相关系数 r = 0.82，p = 0.004）呈负相关，与小梁分离度（Spearman 相关系数 r = -0.65，p = 0.04）呈正相关。磨牙区颊-下皮质和前磨牙区下缘的皮质 BMD 较高，而前颅颊侧和舌侧的皮质 BMD 较低。
在前磨牙区，吸收增加与局部小梁骨质量受损相吻合。皮质骨 BMD 在应变最高的区域较高，在吸收最多的区域较低。无牙下颌骨前牙区的小梁骨体积和质量较好，这可能解释了该区域牙种植体的初始稳定性较好。
