Jonasson Grethe
Department of Orthodontics, Faculty of Odontology, The Sahlgrenska Academy at Göteborg University, Sweden.
Swed Dent J Suppl. 2005(177):1-63.
The aim of this series of studies was to investigate the relationship between skeletal bone mineral density (BMD) and mandibular alveolar bone mass (MABM), structure, and thickness, as well as to evaluate the possible effect of local functional factors on MABM and alveolar thickness. A further aim was to elucidate whether longitudinal changes in mandibular radiographic characteristics and the bucco-lingual dimension of the alveolar process were related to alterations of BMD. BMD was measured in 160 dentate women using dual X-ray absorptiometry of the forearm. On periapical radiographs MABM was estimated using densitometry and the grey-level value. The alveolar bone structure was evaluated with a visual index and by examining the bone texture on periapical radiographs. The thickness of the masseter was assessed with ultrasound imaging to estimate the masticatory functional factor, and the bucco-lingual alveolar thickness was measured on casts. MABM and alveolar structure were significantly correlated to BMD. The best correlation was found between BMD and trabecular pattern evaluated with the visual index (r = 0.62, p < 0.001). The alveolar thickness was correlated to BMD, and to masseter thickness. MABM was influenced of age, the alveolar thickness, the number of occluding teeth, and the masseter muscle thickness but these factors had no effect on the trabecular structure. After five years, all measurements except the ultrasound imaging of the masseter muscle were repeated in 136 women. The mean BMD, MABM, and alveolar thickness decreased significantly during this period, whereas no significant change was found in the bone structure. In posterior region, the alterations in alveolar bone thickness, radiographic grey-level value, and bone texture were significantly correlated to the changes in BMD. In the anterior region, the alterations in alveolar thickness were not correlated with the changes in BMD. Furthermore, no correlation was found between alterations in MABM, estimated by densitometry, and changes in BMD. In conclusion, a significant relationship exists between BMD and mandibular alveolar bone mass, structure, and thickness. The local functional factors mainly influence MABM and the alveolar thickness in the molar region, whereas BMD influences the trabecular structure. Dense trabeculation is a strong indicator of high BMD, whereas sparse trabeculation predicts low bone mass. In peri- and postmenopausal women the alveolar shape in the premolar region can be used to predict BMD level. In the lower premolar region, the longitudinal alterations in BMD are related to longitudinal changes in grey-level value, bone texture and alveolar thickness. The decrease in bucco-lingual alveolar thickness may be due to periosteal resorption related to skeletal bone loss.
本系列研究的目的是调查骨骼骨密度（BMD）与下颌牙槽骨质量（MABM）、结构及厚度之间的关系，同时评估局部功能因素对MABM和牙槽骨厚度的可能影响。另一个目的是阐明下颌骨影像学特征和牙槽突颊舌径的纵向变化是否与BMD的改变相关。使用双能X线吸收法对160名有牙女性的前臂进行BMD测量。在根尖片上，使用密度测定法和灰度值估算MABM。通过视觉指数和检查根尖片上的骨纹理来评估牙槽骨结构。用超声成像评估咬肌厚度以估算咀嚼功能因素，并在模型上测量颊舌向牙槽骨厚度。MABM和牙槽骨结构与BMD显著相关。用视觉指数评估的BMD与小梁模式之间的相关性最佳（r = 0.62，p < 0.001）。牙槽骨厚度与BMD及咬肌厚度相关。MABM受年龄、牙槽骨厚度、咬合牙数量和咬肌厚度影响，但这些因素对小梁结构无影响。五年后，对136名女性重复进行除咬肌超声成像外的所有测量。在此期间，平均BMD、MABM和牙槽骨厚度显著下降，而骨结构无显著变化。在后部区域，牙槽骨厚度、影像学灰度值和骨纹理的改变与BMD的变化显著相关。在前部区域，牙槽骨厚度的改变与BMD的变化不相关。此外，通过密度测定法估算的MABM改变与BMD变化之间未发现相关性。总之，BMD与下颌牙槽骨质量、结构及厚度之间存在显著关系。局部功能因素主要影响磨牙区的MABM和牙槽骨厚度，而BMD影响小梁结构。致密的小梁是高BMD的有力指标，而稀疏的小梁预示着低骨量。在围绝经期和绝经后女性中，前磨牙区的牙槽骨形态可用于预测BMD水平。在下颌前磨牙区，BMD的纵向改变与灰度值、骨纹理和牙槽骨厚度的纵向变化相关。颊舌向牙槽骨厚度的减少可能是由于与骨骼骨质流失相关的骨膜吸收。
