螺旋CT测量腭中缝骨厚度及骨密度的可行性

背景:腭部种植体支抗可以作为一种支抗形式长期承受较大的应力,其置入部位的骨厚度及骨密度是影响种植体成功的重要因素.目前口腔医学临床常用的放射检查手段,如拍摄曲面断层片及头颅侧位片均不能提供腭部骨厚度及骨密度的确切信息.目的:运用螺旋CT对腭中缝骨厚度、骨密度进行测量,期望能为腭部种植体支抗的应用提供参考.设计、时间及地点:测量试验,于2008-07/12在新疆医科大学第一附属医院医学影像中心完成.对象:选取于新疆医科大学第一附属医院医学影像中心行64排螺旋CT扫描患者194例,要求扫描图像中可见硬腭及上颌牙列,年龄18~50岁,按其年龄分为3组,分别为18~30岁组、31-40岁组、41-50岁组.方法:先在三维重建图像上以鼻根为准确定面中线平面为参考平面,在此线上选择1个位于中切牙牙颈部的点,在其矢状位图像上,选取位于口腔内侧骨皮质上距切牙孔后缘6 mm处为标测点,通过此点向硬腭做垂线确定腭骨厚度,测量范围自口腔内腭部骨皮质外侧边缘至鼻腔侧骨皮质外侧边缘.在此位点同时可进行骨密度的测量,取其皮质骨及松质骨密度的平均值.主要观察指标:口腔内侧骨皮质上距切牙孔后缘6 mm处腭中缝的骨厚度及骨密度.结果:男性在腭骨厚度及腭骨密度方面均高于女性(P<0.05),维汉民族间差异均无显著性意义(P>0.05).男性及女性3个年龄段间腭骨厚度及腭骨密度差异均无显著性意义(P>0.05).年龄、腭骨厚度及腭骨密度间无显著相关性.结论:螺旋CT可用于颌骨不同部位厚度及密度的测量分析:在辅助测量到位的情况下,腭中缝区可置入种植体作为正畸支抗.

Feasibility of measuring palate bone thickness and bone mineral density using spiral computed tomography

BACKGROUND: Palatal implant could be an effective type of anchorage that can afford long-term stress, and bone thickness and bone density of the implant placement will affect the success of the implant stability. Presently, actinoscopy commonly used in stomatological clinic cannot provide the precise information of palatal bone thickness and bone mineral density such as toroidal slide plate photograph and skull lateral projection. OBJECTIVE: To measure the thickness and density of median palatine suture, and to provide the consultation for implant anchorage using spiral CT. DESIGN, TIME AND SETTING: A measurement study was performed at the Medical Imaging Center, First Affiliated Hospital of Xinjiang Medical University from July to December in 2008 PARTICIPANTS: The sample consisted of 194 cases undergoing 64 slice CT at the Medical Imaging Center of First Affiliated Hospital of Xinjiang Medical University, including the scope of the hard palate and maxillary dentition. They were aged from 18 to 50, and divided into three groups by age, 18-30-year-old group, 31-40-year-old group, and 41-50-year-old group. METHODS: Measurement of palatal raphe area first three-dimensional reconstruction of images at up to nasion plane centerline, whichever was determined as a reference surface plane, selection one point on incisor cervix in this line, to measurement of the available palatal bone height; sagittal views were selected at 6 mm dorsally from the incisive canal. The available bone height was defined as the distance from the palatal baseline (lower cortical border of the palate) to the nasal cavity (upper cortical border of the nasal cavity). Bone mineral density can also be measured at the same site, take the average of the cortical and cancellous bone. MAIN OUTCOME MEASURES: The palatal bone thickness and bone thickness density were measured at 6 mm dorsally from the incisive canal. RESULTS: Male in the palatal bone thickness and bone mineral density were significantly higher than female (P < 0.05); there were no significant difference between Han and Uygur (P>0.05). In different age's group of men and women, the palatal bone thickness and bone mineral density showed no statistical difference (P > 0.05). Age, palatal bone thickness and palatal bone mineral density had no significant correlation. CONCLUSION: Spiral CT can be used in different parts of mandible thickness and density measurement and analysis. The palate raphe can be implant as orthodontic anchorage if it measured exactly.