Prevalence of dental anomalies and bone alterations in children’s panoramic radiographies

ABSTRACT Objective To verify the prevalence of dental anomalies in terms of number, position and shape, and the presence of bone alterations, through analysis of panoramic radiographs. Methods This study evaluated dental anomalies and bone alterations in children aged 6 to 12 years-old, detected on panoramic radiographies recorded in the radiographic database of the Federal University of Espírito Santo between 2012 and 2016. Clinical and demographic information were registered. Dental records were retrieved to obtain the medical history involving syndromes or other diseases that may interfere with the anomalies and alterations. Chi-square and exact Fischer’s statistical tests were performed. Results There were alterations in 83 out of 301 panoramic radiographs analyzed. There were 169 anomalies or alterations (mean of 2,04±1,38 anomalies/patient), involving 201 teeth. The most prevalent anomaly was tooth impaction (26.63%), which affected the canines more frequently, followed by hypodontia (24.26%), more often found in the second premolar, and both affected mostly females. Hyperdontia and radiolucent lesions showed the same prevalence (18.93%), the most affected teeth were those of the anterosuperior region and the first mandibular molars, respectively. The least prevalent anomalies were dilaceration (7.69%), taurodontism (2.37%) and radiopaque lesions (1.18%). Bone alterations were significantly more found in mandible and in the posterior region, which confirms the prevalence in the lower molars. Conclusion Although there was no statistically significant difference regarding sex, there was a high prevalence of anomalies and alterations in our study population, which indicates the importance of its diagnosis by means of a panoramic x-ray examination.

# 摘要
## 目的
通过全景X线片（panoramic radiograph）分析，验证牙齿在数目、位置及形态方面的异常发生率，以及骨骼改变的存在情况。
## 方法
本研究对2012年至2016年间存档于圣埃斯皮里图联邦大学影像学数据库的全景X线片进行评估，分析其中6至12岁儿童的牙齿异常与骨骼改变情况。收集受试者的临床及人口统计学信息，调取牙科病历以获取可能影响牙齿异常及骨骼改变的综合征或其他疾病相关病史。采用卡方检验与费希尔精确检验开展统计学分析。
## 结果
本次共分析301张全景X线片，其中83张存在异常改变；共检出169处异常或病变（平均每例患者2.04±1.38处异常），累及201颗牙齿。最常见的异常为阻生齿（tooth impaction），以尖牙受累最为频繁；其次为少牙症（hypodontia，24.26%），多累及第二前磨牙，且上述两种异常均以女性患者居多。多生牙（hyperdontia）与透射性病变（radiolucent lesion）发生率相同（18.93%），前者最常累及上颌前牙区，后者则以下颌第一磨牙最为多见。发生率最低的异常为牙根弯曲（dilaceration，7.69%）、牛牙症（taurodontism，2.37%）与阻射性病变（radiopaque lesion，1.18%）。骨骼改变在下颌骨及后牙区检出率显著更高，这与下颌磨牙受累率较高的结果相符。
## 结论
尽管性别差异无统计学意义，但本研究人群中牙齿异常与骨骼改变的发生率较高，提示通过全景X线检查进行此类异常诊断具有重要意义。