Which Le Fort classification involves a floating face injury?

The Le Fort classification system is used to categorize fractures of the maxilla and facial skeleton. A "floating face" injury refers to a condition where the midface and upper jaw are disconnected from the cranium and other facial structures due to fractures.

In Le Fort 3 fractures, also known as craniofacial disjunction, there is a complete separation of the midface from the skull base, which results in the facial skeleton being able to move independently of the rest of the skull. This injury typically involves significant trauma that not only affects the maxilla but can also involve the nasal bones, orbit, and zygomatic bones, leading to a "floating" appearance.

Le Fort 1 and Le Fort 2 classifications involve less severe separations; Le Fort 1 involves horizontal fractures above the upper teeth, while Le Fort 2 includes pyramidal fractures that disrupt the nasal bridge and result in less extensive disjunction. Le Fort 4 is less commonly classified and refers to fractures involving additional structures and may not specifically describe the "floating face" notion as clearly as Le Fort 3.

Therefore, the identification of Le Fort 3 as the floating face injury aligns with its definition and clinical implications in trauma scenarios.