目的: 利用锥形束体层摄影术(cone-beam computed tomography,CBCT)分析牙周健康的汉族青年上颌前牙唇侧中央嵴顶上牙龈(supraosseous gingiva,SOG)的三维形态及相关解剖结构。方法: 选取25名牙周健康的汉族青年共计150颗上颌前牙纳入研究,受试者男性11名,女性14名,平均年龄(24.5±1.6)岁,佩戴含有显影剂的硅橡胶印模拍摄软组织间接显影CBCT。对影像资料进行三维重建并测量分析唇侧中央嵴顶上牙龈的形态,包括SOG高度、釉牙骨质界(cemento-enamel junction,CEJ)到骨嵴顶的距离、CEJ处牙龈厚度、骨嵴顶下2 mm牙槽骨厚度等。数据用SPSS 22.0软件进行统计分析,比较各牙位参数之间的差异,分析其相互之间的相关关系。结果: 上颌前牙唇侧中央SOG高度测量结果,中切牙为(3.54±0.67) mm、侧切牙为(3.48±0.81) mm、尖牙为(3.49±0.70) mm,各牙位SOG高度差异无统计学意义(P>0.05)。上颌前牙唇侧中央CEJ水平牙龈平均厚度测量结果,中切牙为(1.45±0.23) mm,侧切牙为(1.13±0.24) mm,尖牙为(1.14±0.22) mm,中切牙牙龈最厚,与侧切牙和尖牙相比差异均有统计学意义(P<0.05)。唇侧中央SOG与CEJ处牙龈厚度在所有牙位上均无明显相关性(P>0.05)。结论: 牙周健康的上颌前牙唇侧嵴顶上牙龈中,中切牙牙龈最厚,未发现上颌前牙区唇侧中央SOG高度与厚度存在相关性。

Objective: To measure the three-dimensional morphology of the labial supraosseous gingiva (SOG) and the thickness of related labial bone in maxillary anterior teeth of periodontally healthy Han nationality youth using soft tissue indirect imaging cone-beam computed tomography (CBCT). Methods: Twenty-five periodontally healthy subjects (11 males and 14 females) with 150 maxillary anterior teeth were involved in this study. A special impression with radiopaque material including the maxillary teeth was made, then a CBCT scan with the elastomeric matrix in position was taken for each subject. The imaging data were generated and transferred to a volumetric imaging software in which three-dimensional reconstruction was conducted and the image analyses were carried out. Measurements were made at the site of labial center of the maxillary anterior teeth. The height of the SOG, the distance between cemento-enamel junction (CEJ) and bone crest, the gingival thickness at the CEJ, and the thickness of bone 2 mm below the labial bone crest were measured and the correlation analysis between the parameters was made. All the data analyses were performed using SPSS 22.0. The data were analyzed with ANVOA and Pearson correlation tests with the significance level at α=0.05. Results: The mean SOG values were (3.49±0.70) mm, (3.48±0.81) mm, and (3.54±0.67) mm for central incisors, lateral incisors and canines, respectively. There were no statistically significant differences among the different sites (P>0.05). The mean gingival thickness values were (1.45±0.23) mm, (1.13±0.24) mm, (1.14±0.22) mm for central incisors, lateral incisors and canines, respectively. The gingival thickness of the central incisors was the largest among the maxillary anterior teeth with statistically significant difference (P<0.05). No correlation was found between the SOG and gingival thickness among the maxillary anterior teeth (P>0.05). Conclusion: The gingival thickness of central incisors was the largest and the supraosseous gingival height had no correlation with gingival thickness among the periodontally healthy maxillary anterior teeth.