Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University, Shanghai, China.
Orthod Craniofac Res. 2019 Nov;22(4):337-344. doi: 10.1111/ocr.12332. Epub 2019 Jul 15.
To identify the mesiodistal angulation and faciolingual inclination of whole tooth and clinical crown in Chinese young adults with normal occlusion, by examining CBCT digitalized images.
Forty-two volunteers, who presented with normal occlusion and without previous orthodontic treatment, were selected for this study.
The subjects were advised to take dental CBCT and the digital images of the dentition were obtained. The widely recognized University of Southern California (USC) root vector analysis was adopted to detect the angulation and inclination of the whole tooth, as well as of the clinical crown.
No statistically significant difference was detected between male and female subjects. The fluctuations of the angulation and the inclination of the whole tooth from anterior to posterior in both arches manifested distinctive trends. The changes in maxillary dentition seem relatively marked, whereas those in mandibular dentition show less obvious, demonstrating moderate fluctuation both in angulation or inclination. The angulation and inclination of clinical crown are obtained and are shown positively correlated with that of each whole tooth.
The normal range of the mesiodistal angulation and faciolingual inclination of whole tooth and clinical crown in Chinese adults with normal occlusion are identified. This study could establish clinical standards for designing 3D dental data-based orthodontic appliances for Chinese, and for providing the guidance for orthodontic treatment.
通过检查锥形束 CT(CBCT)数字化图像,确定中国正常牙合年轻人全牙及临床牙冠的近远中向倾斜角度和颊舌向倾斜角度。
本研究选取 42 名无正畸治疗史的正常牙合志愿者。
嘱受检者拍摄口腔 CBCT,获取牙列的数字化图像。采用公认的南加利福尼亚大学(USC)根向量分析法来检测全牙及临床牙冠的倾斜角度和倾斜度。
男女受检者之间无统计学差异。从前后牙弓来看,全牙倾斜角度和倾斜度的波动均呈现出明显的趋势。上颌牙列的变化似乎更为显著,而下颌牙列的变化则不那么明显,其倾斜角度和倾斜度都呈现出中等波动。获得了临床牙冠的倾斜角度和倾斜度,并显示与每个全牙的倾斜角度和倾斜度呈正相关。
确定了中国正常牙合成年人全牙及临床牙冠的近远中向倾斜角度和颊舌向倾斜角度的正常范围。该研究可为设计基于 3D 牙颌数据的中国正畸矫治器提供临床标准,并为正畸治疗提供指导。