Abstract：
OBJECTIVE: This retrospective study aimed to comprehensively delineate the epidemiological and 3-dimensional radiographic characteristics of non-third molar (non-M3) impacted teeth in a Chinese dental population.
METHODS: Patients with impacted teeth except for the third molar (ITEM3) were retrospectively screened via cone-beam CT images from 75,021 patients treated at our institution from June 2012 to December 2018. Demographic and clinical data of patients with ITEM3 were retrieved from medical records. CBCT coupled with 3-dimensional reconstruction was employed to characterize the radiographic features of ITEM3. Associations between these epidemiological, clinical, and radiographic features were further statistically analyzed.
RESULTS: Among 1975 eligible patients, 2467 ITEM3s were identified with a prevalence of 2.63% (1975/75,021). Females slightly outnumbered males with a ratio of 1.12:1. The majority of ITEM3 was single (1577, 79.85%) in the maxilla. The maxillary canine teeth were the most frequently impacted (52.45%), followed by maxillary incisors. The mesioangular position was the most common orientation (43.8%), followed by vertical and buccal-lingual orientations. The most frequently associated lesion was external root resorption of the adjacent tooth, which was significantly correlated with the morphology and position of the impacted tooth.
CONCLUSIONS: Most ITEM3 was single, mesioangular, found at maxillary canines, sometimes associated with diverse complications. Our data advance the current understanding of ITEM3 and offer insights into the management of this dental abnormality.
CONCLUSIONS: These findings are useful for clinicians to comprehensively understand the prevalence, radiographic features, and complications of non-M3 impacted teeth.
METHODS: Patients with impacted teeth except for the third molar (ITEM3) were retrospectively screened via cone-beam CT images from 75,021 patients treated at our institution from June 2012 to December 2018. Demographic and clinical data of patients with ITEM3 were retrieved from medical records. CBCT coupled with 3-dimensional reconstruction was employed to characterize the radiographic features of ITEM3. Associations between these epidemiological, clinical, and radiographic features were further statistically analyzed.
RESULTS: Among 1975 eligible patients, 2467 ITEM3s were identified with a prevalence of 2.63% (1975/75,021). Females slightly outnumbered males with a ratio of 1.12:1. The majority of ITEM3 was single (1577, 79.85%) in the maxilla. The maxillary canine teeth were the most frequently impacted (52.45%), followed by maxillary incisors. The mesioangular position was the most common orientation (43.8%), followed by vertical and buccal-lingual orientations. The most frequently associated lesion was external root resorption of the adjacent tooth, which was significantly correlated with the morphology and position of the impacted tooth.
CONCLUSIONS: Most ITEM3 was single, mesioangular, found at maxillary canines, sometimes associated with diverse complications. Our data advance the current understanding of ITEM3 and offer insights into the management of this dental abnormality.
CONCLUSIONS: These findings are useful for clinicians to comprehensively understand the prevalence, radiographic features, and complications of non-M3 impacted teeth.
摘要：
目的：这项回顾性研究旨在全面描述中国牙科人群中非第三磨牙（非M3）阻生牙的流行病学和3维影像学特征。
方法：通过锥形束CT图像对2012年6月至2018年12月在我们机构接受治疗的75,021例患者进行回顾性筛查。从病历中检索ITEM3患者的人口统计学和临床数据。CBCT与三维重建相结合用于表征ITEM3的影像学特征。这些流行病学之间的关联，临床,和影像学特征进行进一步统计分析。
结果：在1975名符合条件的患者中，发现2467个ITEM3，患病率为2.63%（1975/75,021）。女性人数略多于男性，比例为1.12：1。在上颌骨中，大多数ITEM3是单个的（1577，79.85％）。上颌尖牙受累频率最高(52.45%),其次是上颌切牙。近角位置是最常见的方向（43.8％），其次是垂直和颊舌方向。最常见的相关病变是邻近牙齿的外部牙根吸收，与阻生牙齿的形态和位置显著相关。
结论：大多数ITEM3是单一的，msioangular,在上颌犬上发现，有时与各种并发症有关。我们的数据推进了目前对ITEM3的理解，并提供了对这种牙齿异常管理的见解。
结论：这些发现有助于临床医生全面了解患病率，射线照相特征，和非M3阻生牙的并发症。
方法：通过锥形束CT图像对2012年6月至2018年12月在我们机构接受治疗的75,021例患者进行回顾性筛查。从病历中检索ITEM3患者的人口统计学和临床数据。CBCT与三维重建相结合用于表征ITEM3的影像学特征。这些流行病学之间的关联，临床,和影像学特征进行进一步统计分析。
结果：在1975名符合条件的患者中，发现2467个ITEM3，患病率为2.63%（1975/75,021）。女性人数略多于男性，比例为1.12：1。在上颌骨中，大多数ITEM3是单个的（1577，79.85％）。上颌尖牙受累频率最高(52.45%),其次是上颌切牙。近角位置是最常见的方向（43.8％），其次是垂直和颊舌方向。最常见的相关病变是邻近牙齿的外部牙根吸收，与阻生牙齿的形态和位置显著相关。
结论：大多数ITEM3是单一的，msioangular,在上颌犬上发现，有时与各种并发症有关。我们的数据推进了目前对ITEM3的理解，并提供了对这种牙齿异常管理的见解。
结论：这些发现有助于临床医生全面了解患病率，射线照相特征，和非M3阻生牙的并发症。
