Diagnostic performance of brain computed tomography to detect facial bone fractures

The Adelaide Facial Bone Rule: A simple prediction model and clinical guideline for the presence of facial fractures using CT brain scans in victims of minor trauma

BACKGROUND

Facial fractures bleed, resulting in high-density fluid in the sinuses (haemosinus) on computed tomography (CT) scans. A CT brain scan includes most maxillary sinuses in the scan field, which should allow detection of haemosinus as an indirect indicator of a facial fracture without the need for an additional CT facial bone scan, yet no robust evidence for this exists in the literature. The aim of this study was to determine whether the presence of haemosinus on a CT brain scan, alone or in combination with other clinical information, can predict the presence of facial fractures.

METHODS

1231 adult patients, who had both brain and facial CT scans performed on the same day, were selected from a seven year period. Patients were eligible if scans were requested for trauma. Brain and facial scans were reviewed separately for the presence of facial fractures, haemosinus, emphysema and intra-cranial haemorrhage. Prediction modelling was used to assess whether findings from brain scans could be used to identify patients requiring further CT scanning.

FINDINGS

The full prediction model included four predictors and showed excellent discrimination (AUROC 0.982; 95 % CI 0.971 - 0.993). A simplified model, more suitable for clinical implementation, used only facial fractures and haemosinus as predictors. This model showed only marginally poorer discrimination (AUROC 0.964; 95 % CI 0.945 - 0.983) and excellent performance on other measures.

CONCLUSION

Based on the excellent performance of the simplified prediction model, we present the Adelaide Facial Bone Rule: The absence of blood in the sinuses or facial fractures on a CT brain scan means a CT facial bone scan does not need to be routinely performed in the setting of clinically-determined minor trauma.

Evaluation of Concomitant Facial Fracture in Traumatic Brain Injury Patients-Simplification and External Validation of a Prediction Model

BACKGROUND

Patients with traumatic brain injuries (TBIs) often experience concurrent facial bone fractures. In 2021, a prediction model with 10 variables was published and precisely predicted concomitant facial fractures in TBI patients. Herein, external validation and simplification of this model was performed.

METHODS

Traumatic brain injury patients treated at a major referral trauma center were retrospectively reviewed for 1 year. The original prediction model (published in 2021), which was developed from a rural level II trauma center, was applied for external validation. A new and simplified model from our level I trauma center was developed and backwardly validated by rural level II trauma center data.

RESULTS

In total, 313 TBI patients were enrolled; 101 (32.3%) had concomitant facial fractures. When the previous prediction model was applied to the validation cohort, it achieved acceptable discrimination, with an area under the receiver operating characteristic curve (AUC) of 0.713 and good precision, with a Brier score of 0.083. A new and simplified model with 6 variables (age, tooth rupture, epistaxis, facial lesion, eye injury, and intracranial hemorrhage) was created with excellent discrimination (AUC = 0.836) and good precision (Brier score of 0.055). The backward validation of this new model also showed excellent discrimination in the cohort used to develop the original model (AUC = 0.875).

CONCLUSION

The original model provides an acceptable and reproducible prediction of concomitant facial fractures among TBI patients. A simplified model with fewer variables and the same accuracy could be applied in the emergency department and at higher- and lower-level trauma centers.

Head Computed Tomography Versus Maxillofacial Computed Tomography: An Evaluation of the Efficacy of Facial Imaging in the Detection of Facial Fractures

BACKGROUND

In an initial trauma evaluation, computed tomography of the head (CTH) is performed to assess for life-threatening intracranial injury. Given the high incidence of concomitant facial injuries, many facial fractures are diagnosed incidentally during this evaluation. Although maxillofacial CT (CTMF) is widely accepted as the most sensitive method for evaluating facial fractures, it is often excluded from the initial survey. Failure to obtain dedicated imaging can lead to increased costs related to a missed or delayed facial fracture diagnosis. Our study investigates the location and type of missed facial fractures on CTH by reviewing imaging data from patients who presented at a level 1 trauma center and underwent both CTH and CTMF.

METHODS

A retrospective review of all facial fractures diagnosed at a single institution from 2002 through 2016 was conducted. Inclusion criteria included adults aged 18 years or older who received CTH and then subsequent CTMF. Patients who had either CTH or CTMF only or combined CTH/CTMF were excluded. The facial fractures were further subdivided by location.

RESULTS

There were 501 patients with 1743 total facial fractures. CTH successfully identified 788 (45.21%) fractures, versus 1743 (100%) for CTMF. The most common fractures, in both cohorts, were nasal bone (15.7%) and orbital floor (12.8%) fractures. Using CTMF to identify missed fractures on CTH, significant differences were noted in the following locations: anterior table frontal sinus, medial/lateral pterygoid, maxillary sinus, lateral orbital wall, zygomatic arch, palate, and all types of mandible fractures excluding the mandibular condyle.

CONCLUSIONS

CTH for initial trauma evaluation often misses facial fractures. CTH alone was only sufficient in detecting posterior frontal sinus, orbital (excluding lateral wall), and mandibular condyle fractures. In patients with suspected facial injury, dedicated imaging should be performed to detect the location and extent of injury because CTH inadequately identifies most facial fractures.

Clinical and radiographic predictors of the need for facial CT in pediatric blunt trauma: a multi-institutional study

Background

Facial injuries are common in children with blunt trauma. Most are soft tissue lacerations and dental injuries readily apparent on clinical examination. Fractures requiring operative intervention are rare. Guidelines for utilization of maxillofacial CT in children are lacking. We hypothesized that head CT is a useful screening tool to identify children requiring dedicated facial CT.

Methods

We conducted a multicenter retrospective review of children aged 18 years and under with blunt facial injury who underwent both CT of the face and head from 2014 through 2018 at five pediatric trauma centers. Penetrating injuries and animal bites were excluded. Imaging and physical examination findings as well as interventions for facial fracture were reviewed. Clinically significant fractures were those requiring an intervention during hospital stay or within 30 days of injury.

Results

322 children with facial fractures were identified. Head CT was able to identify a facial fracture in 89% (287 of 322) of children with facial fractures seen on dedicated facial CT. Minimally displaced nasal fractures, mandibular fractures, and dental injuries were the most common facial fractures not identified on head CT. Only 2% of the cohort (7 of 322) had facial injuries missed on head CT and required an intervention. All seven had mandibular or alveolar plate injuries with findings on physical examination suggestive of injury.

Discussion

In pediatric blunt trauma, head CT is an excellent screening tool for facial fracture. In the absence of clinical evidence of a mandibular or dental injury, a normal head CT will usually exclude a clinically significant facial fracture.

Level of evidence

III.