Wisconsin Criteria

The Wisconsin Criteria are a bedside screening rule used after maxillofacial trauma to help decide whether a patient may need a dedicated maxillofacial CT scan. The rule was designed to reduce unnecessary imaging while still identifying patients at meaningful risk of facial fracture.

What the criteria include

The rule is based on five clinical findings:

• bony step-off or instability
• periorbital swelling or contusion
• Glasgow Coma Scale (GCS) < 14
• malocclusion
• tooth absence

A patient is considered to meet the Wisconsin Criteria if any one of these findings is present. If none are present, the patient does not meet the rule.

Why the rule was developed

Facial trauma is common, but not every patient with facial injury needs a dedicated facial CT. The Wisconsin group developed this rule to identify a small set of physical exam findings that could be used quickly in trauma evaluation to screen for possible facial fracture and guide imaging decisions.

Diagnostic performance

In the reports summarizing the rule, the Wisconsin Criteria showed high sensitivity for facial fracture detection in the original/internal validation work. One later review article cites the rule as having about 98.2% sensitivity and 87.8% negative predictive value when any one of the five findings was present.

That said, later external validation studies have been mixed. Some outside centers found lower sensitivity and lower negative predictive value than the original work, suggesting the rule may not perform the same way in every trauma population or institution.

How it is used in practice

In practice, the Wisconsin Criteria are best thought of as a screening aid, not a standalone mandate. If a patient with facial trauma has any of the five findings, the rule supports obtaining dedicated maxillofacial CT imaging. If none are present, the likelihood of fracture may be lower, but imaging decisions still depend on the full clinical picture, associated injuries, mechanism of trauma, and local practice patterns.

This matters especially in trauma settings where clinicians are balancing radiation exposure, cost, workflow, and the risk of missing clinically important fractures. Studies discussing the Wisconsin Criteria focus heavily on this tradeoff between reducing unnecessary scans and maintaining adequate fracture detection.

Strengths

A major strength of the Wisconsin Criteria is their simplicity. The findings are straightforward bedside observations that can usually be assessed during the initial trauma evaluation. That makes the rule easy to remember and potentially useful in busy emergency or trauma settings.

Another strength is that the rule aims to capture patients at risk using findings that are clinically intuitive, such as malocclusion, missing teeth, or obvious bony instability.

Limitations

The biggest limitation is generalizability. Later studies have not consistently reproduced the original test characteristics, and some authors have concluded that the rule may be institution-specific rather than universally reliable across all trauma centers.

Another limitation is that the criteria are designed to screen broadly for facial fractures, not to replace careful specialty examination or identify every fracture subtype equally well. More recent studies have proposed other decision aids for midfacial, mandibular, or orbital injuries, partly because no single simple rule appears perfect across all maxillofacial trauma populations.

Bottom line

The Wisconsin Criteria are a five-item clinical screening rule for deciding whether a patient with maxillofacial trauma may need a dedicated facial CT scan. The patient meets criteria if any one of the following is present: bony step-off/instability, periorbital swelling or contusion, GCS under 14, malocclusion, or tooth absence. The rule is easy to use and was originally reported to be highly sensitive, but later validation studies found mixed results, so it should be used alongside clinical judgment rather than as the only basis for imaging decisions.