OBJECTIVES It is still not clear why impaction of third molars occurs. Craniofacial morphology and facial parameters have been discussed to be strong predictors for third molar impaction. Thus, this study aimed to investigate the effect of craniofacial morphology on erupted or impacted third molars in a German population sample. MATERIALS AND METHODS Erupted and impacted third molars in 2,484 participants from the Study of Health in Pomerania were assessed by whole-body magnetic resonance imaging. Markers of facial morphology were determined in 619 individuals of those participants in whose 421 participants (16.7%) had at least one impacted third molar. Craniofacial morphology was estimated as linear measurements and was associated in a cross-sectional study design with impacted and erupted third molars by multinomial logistic regression models. Erupted third molars were used as reference outcome category and regression models were adjusted for age and sex. RESULTS Maximum Cranial Width (Eurion-Eurion distance) was significantly associated with impacted third molars (RR: 1.079; 95% confidence interval 1.028-1.132). This association was even more pronounced in the mandible. Individuals with a lower total anterior facial height (Nasion-Menton distance) and a lower facial index also have an increased risk for impacted third molars in the mandible (RR 0.953; 95% confidence interval 0.913-0.996 and RR: 0.943; 95% confidence interval 0.894-0.995). No significant associations of third molar status with facial width (Zygion-Zygion distance), and sagittal cranial dimension (Nasion-Sella distance; Sella-Basion distance) were observed. CONCLUSION Individuals with an increased maximal cranial width have a higher risk for impaction of third molars in the mandible and in the maxilla. Individuals with a lower anterior total anterior facial height and lower facial index also have an increased risk for third molars impaction in the mandible. These findings could help orthodontic dentists, oral surgeons and oral and maxillofacial surgeons in decision-making for third molars removal in their treatment. These findings highlight the necessity of an additional analysis of the maximal cranial width by the Eurion- Eurion distance.

中文翻译：

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颅面形态会影响第三磨牙的撞击吗？来自德国东北部基于人口的研究的结果。

目的尚不清楚为什么发生第三磨牙的撞击。已经讨论了颅面形态和面部参数是第三磨牙撞击的有力预测指标。因此，本研究旨在调查颅面形态对德国人群样本中第三颗磨牙的爆发或影响。材料与方法通过全身磁共振成像评估了来自《波美拉尼亚健康研究》的2484名参与者的第三磨牙的爆发和影响。在619名参与者中确定了面部形态学标记，其中421名参与者（16.7％）的至少一名第三磨牙受到了影响。颅面形态被估计为线性测量值，并通过多项逻辑回归模型在横断面研究设计中与第三磨牙的撞击和爆发相关。爆发的第三磨牙用作参考结果类别，并针对年龄和性别调整了回归模型。结果最大颅骨宽度（Eurion-Eurion距离）与第三磨牙的影响显着相关（RR：1.079； 95％置信区间1.028-1.132）。下颌骨之间的这种联系更加明显。总前脸高度较低（Nasion-Menton距离）且脸部指数较低的个体，下颌第三磨牙受累的风险也增加（RR 0.953； 95％置信区间0.913-0.996和RR：0.943； 95％置信度区间0.894-0.995）。没有观察到第三磨牙状态与面部宽度（Zygion-Zygion距离）和矢状颅骨尺寸（Nasion-Sella距离； Sella-Basion距离）的显着相关性。结论最大颅骨宽度增加的个体在下颌骨和上颌中第三磨牙的撞击风险较高。较低的前部总前脸高度和较低的面部指数的个体也增加了下颌中的第三磨牙撞击的风险。这些发现可以帮助正畸牙医，口腔外科医生以及口腔颌面外科医生决定在治疗中去除第三颗磨牙。这些发现凸显了通过Eurion-Eurion距离对最大颅骨宽度进行额外分析的必要性。这些发现可以帮助正畸牙医，口腔外科医生以及口腔颌面外科医生决定在治疗中去除第三颗磨牙。这些发现凸显了通过Eurion-Eurion距离对最大颅骨宽度进行额外分析的必要性。这些发现可以帮助正畸牙医，口腔外科医生以及口腔颌面外科医生在治疗中去除第三磨牙的决策。这些发现凸显了通过Eurion-Eurion距离对最大颅骨宽度进行额外分析的必要性。