The present study identified a high frequency of DI. Overall, DI occurred in 12.8% of all polytrauma cases. Furthermore, only 11.8% of these were sufficiently described in the original radiology reports.
The prevalence of DI in a clinical trauma setting is still unknown. In fact, clinical dental investigations showed that the prevalence of dental trauma ranged significantly, namely from 6 to 59% . Furthermore, in a meta-analysis, a prevalence of dental trauma was up to 5% of all trauma findings . However, no study analyzed the frequency of dental injuries on whole-body CT in trauma patients.
It is not unusual that whole-body CT can detect numerous findings of the body with a high accuracy, comprising non-trauma-related incidental findings and possible hazardous trauma findings [10,11,12,13,14]. However, some dental findings might not be detectable by multidetector CT due to only subtle fracture lines . This is a reason why cone-beam CT has a slight superior accuracy compared to multidetector CT and may detect more trauma findings .
Another reason for possible misdiagnosis of DI on whole-body CT can be image artifacts, especially scatter artifacts caused by dental amalgam. These artifacts are a common problem and can obscure the anatomy and potential pathological findings of the oral cavity . Therefore, the frequency of dental injuries might be even higher than reported in this study.
Notably, the radiologist is faced to evaluate numerous images in a small timeframe to make correct diagnoses. In the trauma setting, possible life-threatening conditions must be diagnosed immediately before other imaging findings, including dental-related findings, can be addressed. Then, roughly 40% of patients undergoing a whole-body CT, show additionally at least one incidental finding [11, 12, 20].
This might also be a reason that a lot of findings are not sufficiently reported by the radiologist. For chest CTs, it was acknowledged that only 55% of easily detectable cardiac findings were reported within the radiologist report . Similar results were reported for cardiovascular findings on whole-body CT .
In a recent retrospective study, Bulbul et al. reported that dental findings are frequent findings on CT performed to evaluate paranasal sinus . In fact, 51% of patients had a pathological finding, most commonly carious lesions in 27% of cases . In another study examining different head CT scans, it has been shown that dental diseases were significantly underreported with only 11% of sufficient mentions in the radiology report . We identified that dental findings were significantly more reported when DI was associated with a bone fracture. Presumably, the radiologist is more concerned for bone fracture assessment and the fracture leads the radiologist to the dental trauma finding. In short, one key finding of the present study is that dental trauma findings are severely under-reported by radiologists in acute clinical situations.
Unlike dental trauma involving only teeth, which is managed by a dentist in an outpatient clinic, dental trauma associated with polytrauma is managed in a hospital setting . This might also be a reason why the radiologists at a tertiary hospital tends to overlook findings of the teeth. Another reason might be that dental findings tend to be very subtle, easily to be overlooked . Most of the reported findings were severe trauma findings associated with adjacent bone fractures. These findings might be easily detectable and, thus, were reported by the radiologists. Moreover, there might be not enough clinical information regarding trauma mechanism and possible damage of the teeth. Of note, many dental trauma findings can be diagnosed by a clinical examination, except of root fractures, which can only be diagnosed by imaging.
It should be considered that dental trauma may be caused by the initial trauma or may be iatrogenic especially after endotracheal intubation [23, 24]. It was identified that existing dental anomalies increases the risk for dental injury by endotracheal intubation in a 12-fold manner . So far, in a study investigating 3423 emergency endotracheal intubations, only 6 dental injuries (0.2% of all patients) were identified. This finding indicates that the dental injuries detected in the present study were most commonly caused by the trauma itself .
On the other hand, dental injuries might complicate the acute treatment itself, especially the endotracheal intubation . Moreover, they could acutely compromise the airway and may lead to aspiration, albeit no systematical data exists investigating such complications. So, a recent case report highlighted the importance of imaging modalities to correctly identify these aspirated tooth fragments . In our patient sample no aspirated tooth fragments were identified, which nevertheless diminished the importance of these findings.
Interestingly, our results are in agreement with a recent epidemiological study, which identified a comparable prevalence (13%) of dental traumas . However, the present results might be different in comparison to those based on clinical examination in patients with isolated dental injuries [28, 29].
There are several important factors for the etiology of dental injuries. Overjet was significantly associated with dental injuries in every dentition and age groups . Moreover, orthodontic treatment is associated with dental injuries in children . In adults, there is a moderate evidence that alcohol use is associated with DI . Previous occurrence of dental injuries is also a risk factor for another one .
In summary, the correct diagnosis of dental trauma can be important for the patient and for possible treatment planning. Although not every dental trauma is treated, the cost of dental trauma is high and often time consuming .
Our study emphasizes that radiologists need to pay more attention to findings of the teeth in trauma patients due to its high frequency.
There are some limitations of the present study to address. First, it is a retrospective study with possible inherent bias. However, the CTs were evaluated without clinical information and blinded to the radiological and clinical reports to reduce possible bias. Second, the reporting rate is specific for one university hospital. There might be institutions, in which dental trauma findings are reported more frequently. Thirdly, there might be a bias of preexisting dental injuries, which were included in the present analysis as the exact age of dental trauma findings cannot be determined with the CT. Fourthly, the real frequency of dental trauma findings might be even higher due to missed findings on CT.