Guerin’s sign is:

 # Guerin’s sign is: 

A. Ecchymosis at greater palatine foramen 

B. Ecchymosis at mastoid region 

C. Ecchymosis at condylar region 

D. Ecchymosis at infraorbital foramen 

The correct answer is A. Ecchymosis at greater palatine foramen.

Guerin's sign is bruising in the palate in the region of the greater palatine arteries. We present a patient who sustained blunt facial trauma and as a result had a mobile maxilla and a severe malocclusion. An associated laceration in the palate pointed to a split palate confirmed on CT. This is a reminder to clinicians, especially those working in acute medicine to conduct thorough examination of the oral tissues. A laceration in the palate can be easily missed and should be looked for as part of a systematic examination. Intraoperative management may change depending on the fracture pattern and displacement.

Reference: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4184606/