Tag Archives: face

Maxillofacial CT Scans In Children

Facial trauma is common, especially in children. And the use of CT scan is even more common, unfortunately for children. What happens when these two events meet?

I’ve noted that many trauma professionals almost reflexively order a face CT when they see any evidence of facial trauma. This ranges from obvious deformity to lacerations to mere contusions. This seems like overkill to me, since most of the face (excluding the mandible) is visualized with the head CT that nearly always accompanies it.

Finally, someone has actually examined the usefulness of the facial CT scan! The trauma group at Albany collaborated with four other Level I trauma centers, performing a retrospective chart and database review of children (defined as less than 18 years old) who underwent both head and maxillofacial CT scans over a five year period. They excluded penetrating injuries and bites. The concordance of facial fractures seen on head CT vs face CT was evaluated.

Here are the factoids:

  • A total of 322 patients with facial fractures was identified, and the most common mechanisms were MVC, pedestrian struck, and bicycle crash
  • Fractures on head CT matched the facial CT in 89% of cases
  • Of the 35 discordant cases, 21 of the head CTs missed nasal fractures, 9 mandibular fractures, 3 orbital fractures, and 2 maxillary fractures
  • Of those 35 cases, only 7 required operative intervention: 6 mandible fractures and 1 maxillary fracture

The authors concluded that the use of head CT alone with a good clinical exam detects nearly all facial fractures requiring repair.

Bottom line: Although this study confirms my own personal bias and experience, it suffers from the usual problems associated with retrospective studies and small numbers. Nonetheless, the results are compelling. This study provides a way to identify nearly all significant fractures while minimizing radiation to the ocular lens, thyroid, and bone marrow.

The key is a good physical exam, as usual. Inspection of the teeth, occlusion testing, and manipulation of the mandible and maxilla should identify nearly all fractures that might require operation.

Once the exam is complete, a standard head CT should be obtained. Identification of displaced fractures on the head CT should prompt a consult to your friendly facial surgeon to see if they really need additional imaging to determine if the fracture requires operation. Frequently, the head CT images are sufficient and nothing further is required.

Here is the algorithm the authors recommend. Although designed for children, it should work for adults just as well.

Reference: Clinical and radiographic predictors of the need for facial CT in pediatric blunt trauma: a multi-institutional study. Trauma Surg Acute Care Open 2022;7:e000899.

When To Obtain A Dedicated Facial CT

Initial CT scan evaluation for blunt trauma patients is fairly standardized. The usual palate consists of scans of the head, cervical spine, chest, abdomen and pelvis. Some choose their “colors” individually, and others just slop everything on the canvas.

However, there are a few other scans that are occasionally helpful and/or necessary. Think soft tissue views, or CT angiogram of the neck, or CT angiogram of potential extremity vascular injuries.

Another study that is occasionally needed but many times unnecessarily ordered is the dedicated CT of the facial bones. This study spans the entire area from mandible to frontal sinus and is performed using finer cuts to display greater detail.

The unfortunate truth is that a large number of dedicated facial CTs either do not show fractures, or show fractures that don’t require operation. The scan does deliver a nice dose of radiation, though. Is there any way to be more selective about ordering it?

About 10 years ago, a plastic surgery group in Madison developed what came to be called the “Wisconsin criteria” for ordering facial imaging.  Here they are:

  • Bony step-off
  • Periorbital ecchymosis
  • GCS < 14
  • Malocclusion
  • Missing teeth

The authors claimed 97% sensitivity and 2.6% missed fracture rate, although external validation suggested those numbers were a bit generous. The Plastic Surgery group from the University of Minnesota and Regions Hospital recently re-studied these criteria with a large number of patients, looking at accuracy as well as cost-savings.

They performed a retrospective review of 1000 patients (based on a power analysis) who had a facial CT and adequate documentation of the Wisconsin criteria in the chart. Here are the factoids in table form:

(click table for larger copy)

  • Periorbital ecchymosis was the most common criterion, which had the highest sensitivity of 70% (terrible)
  • The other criteria fared even worse from a sensitivity standpoint
  • But if you roll them all up together, the presence of any one of the five yielded a 90% sensitivity (true positives) and 52% specificity (true negatives)
  • The negative predictive value was 93% if none of the criteria were present, which means it’s a good tool for ruling out the need for a CT scan
  • The overall missed fracture rate was 2.8%, and only 0.12% for ones that required operation
  • Cost savings by limiting CT to patients who met the criteria was over $300K in 2014

Bottom line: What to do? It’s clear that using the absence of any of the Wisconsin criteria to avoid a facial CT scan is helpful. This makes sense, because 4 of the 5 criteria are findings on facial exam. But it also means that a lot of scans will still get done for low sensitivity criteria. 

How about this? Since nearly all of these patients will have head and cervical CT scans, review the head scan first for facial fractures. Single, non-displaced fractures are nearly always nonoperative in nature. If patterns of fractures are present, or there are significant displacements, a dedicated facial scan will be very helpful in determining operative management.

But remember, the head CT does not include the mandible. A good physical exam and occlusion check is mandatory, and any suspicion of injury should prompt a full scan of the face.

Thanks to Chris Stewart, the lead author on this study for sending it to me for review.

Rreference: Validation of the “Wisconsin criteria” for obtaining dedicated facial imaging and its financial impact at a Level I trauma center. Craniomaxillofacial Trauma & Recon 13(1):4-8, 2020.

Gunshot To The Face!

You’ve just been pre-notified of an incoming trauma activation: gunshot to the face. No other information. How concerned should you be? Here are some things to think about as you wait for the patient to arrive:

  • Is it really a gunshot? Sometimes shotgun injuries are reported as gunshots. Big difference!
  • Will I need to preserve evidence? In general, yes. In most cases other than suicide attempts, there is probably a good chance that criminal activity was involved. Be prepared to preserve all patient belongings in paper bags, and have a chain of custody form available.
  • Am I and my team safe? There is a possibility that someone wants your incoming patient dead. They may want to finish the job, in you emergency department. Make sure the area is secure.

Once the patient arrives, it’s best to think through things via the ATLS framework.

  • Airway. If the injury involves the lower part of the face or neck, make sure the airway is safe and/or secure. Blood may create problems, as can edema from injury to soft tissues, especially in the floor of the mouth.
  • Breathing. Not a problem with these injuries unless significant aspiration has occurred. 
  • Circulation. The face can really bleed, and only a few areas are amenable to the usual surgical control (clamping, tying). Direct pressure must be used for the rest, and this doesn’t always work. Bleeding from sinuses may be controlled with packing or the foley catheter trick (inserted through bullet tract). But if you can’t stop it, then it’s time to expedite to the OR.
  • Disability. You do have to worry about the cervical spine if the path of the bullet is not obvious. If the patient is stable, immobilize the neck and use the CT scanner to see if any fragments involved the spine. If you must run to the OR with an unstable patient, then try to quickly shoot an old-fashioned cross-table lateral. This will give you quick and dirty info on how much you can manipulate the neck.

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