摘要目的 回顾性分析正常上前牙牙根与牙槽窝位置关系的锥形束CT资料,为前牙区即刻种植适应证的选择提供解剖依据.方法 选取2013年9月至2014年8月于第四军医大学口腔医学院就诊并拍摄锥形束CT的300名正常锥形束CT资料,三维重建后调整至各前牙牙齿正中矢状面,对上颌前牙牙根与牙槽窝的位置关系进行分类,牙根偏唇侧型(B型)、牙根居中型(M型)、牙根偏腭侧型(P型);1型(牙根长轴偏向腭侧)、2型(牙根长轴偏向唇侧但未超过唇侧牙槽骨最凹点A点)、3型(牙根长轴偏向唇侧且超过A点).测量根尖至鼻底骨缘的距离(即根尖区骨高度),锥形束CT资料根据年龄分为3组:19~30岁组、31~50岁组和51~75岁组;比较不同牙位、不同年龄组、不同性别根尖区骨高度的差异.结果 中切牙、侧切牙和尖牙的根尖区骨高度分别为(9.2±3.0)、(10.0±2.9)和(8.1±3.1)mm,中切牙与侧切牙的差异无统计学意义(P>0.05),中切牙、侧切牙与尖牙差异均有统计学意义(P<0.05).对于同一牙位,男性与女性根尖区骨高度差异均无统计学意义(P>0.05).31~50岁组、51~75岁组上前牙各牙位根尖区骨高度均显著大于19~30岁组(P<0.05).上前牙牙根矢状向位置分类B、P、M型占比分别为98.5%(1774/1800)、0.3%(5/1800)、1.2%(21/1800),1、2、3型占比分别为2.6%(46/1800)、58.6%(1055/1800)、38.8%(699/1800).结论 正常上前牙根尖区常有较充足的骨高度,但牙齿正中矢状面上牙根大多偏向牙槽窝唇侧.

abstractsObjective To investigate the sagittal root position and apical bone height of the maxillary anterior teeth in order to provide anatomical information for immediate implant placement in the esthetic region. Methods Cone-beam CT (CBCT) data from 300 randomly selected patients who met the inclusion criteria were included in this study. After three-dimensional reconstruction, the sagittal plane (the sagittal plane through the long axis of the tooth) was determined. The positions and angulations of the tooth roots were classified with reference to the alveolar process. By comparing the buccal and palatal bone thickness at the mid-root level, the toot positions with reference to the mid-alveolar line were defined and classified as follows, type B (closer to the buccal alveolar surface), type M (midway between the buccal and palatal alveolar surface) and type P (closer to the palatal alveolar surface). By comparing the angulations of the alveolar process with the long axis of the roots, the angulations were classified as follows, type 1 (root apex angulated toward the palatal side or parallel to the alveolus), type 2 (root apex angulated toward the buccal side with the long axis passing posterior to point A) and type 3 (root apex angulated toward the buccal side with the long axis passing anterior to point A). The frequency of each category was counted and the apical bone height was measured. The subjects were divided into three age groups, 19-30 years, 31-50 years and 51-75 years. Results The overall mean apical bone height of the healthy maxillary central incisors was (9.2 ± 3.0) mm, the lateral incisors was (10.0 ± 2.9) mm and the canine was (8.1 ± 3.1) mm. There was no significant difference in the height of apical bone between central incisors and lateral incisors (P>0.05). There was no significant difference in the height of apical bone between male and female (P>0.05). The height of apical bone in group 31-50 years and 51-75 years were greater than that in group 19-30 years (P<0.05), respectively. The proportion of the maxillary anterior teeth type B, M, P was 98.5% (1774/1800), 0.3%(5/1800) and 1.2% (21/1800) respectively. The proportion of type 1, 2, 3 was 2.6% (46/1800), 58.6%(1055/1800) and 38.8%(699/1800) respectively. Conclusions There was enough apical bone height in the area of maxillary anterior teeth, but the majority of roots positioned more buccally.