Imaging for Periorbital Edema and Dental Abscess

Primary Imaging Recommendation

The American College of Radiology recommends obtaining CT orbits with IV contrast immediately as the first-line imaging study for periorbital edema in the setting of dental abscess, to differentiate between preseptal and postseptal cellulitis, detect orbital abscess or subperiosteal abscess, identify underlying sinusitis, and assess complications 1, 2
CT orbits with IV contrast provides critical information for determining the extent of infection and guiding treatment, including detection of orbital abscess or subperiosteal abscess, which would require surgical intervention 1, 4
The American College of Radiology suggests that precontrast imaging is not necessary in this scenario as it does not add significant diagnostic information 1, 3

The American College of Radiology recommends adding CT head with IV contrast if there is suspicion of intracranial complications, including subdural empyema, cavernous sinus thrombosis, or frontal bone osteomyelitis (Pott's puffy tumor) 1, 3, 4

The American College of Radiology suggests that MRI of head and orbits with and without IV contrast serves as complementary imaging when more detailed assessment of intraorbital spread is clinically warranted or when there is clinical or CT-based suspicion for intracranial complications 1, 3, 4

The American College of Radiology recommends obtaining CT orbits with IV contrast if any of the following are present: proptosis, impaired or painful extraocular movements, ophthalmoplegia, decreased visual acuity, gross periorbital edema, age >3 years with significant periorbital swelling, high neutrophil count, or previous antibiotic therapy without improvement 1, 2, 4

The American College of Radiology advises against relying on clinical examination alone to distinguish preseptal from orbital cellulitis, as proptosis and limitation of extraocular movements are not accurate enough to differentiate postseptal inflammation from abscess 1
The American College of Radiology recommends against obtaining plain radiographs, as they are insufficient to detect orbital pathology and have been supplanted by CT 4

Dental abscesses can spread to the orbit through direct extension through bone or fascial barriers, involvement of deep and superficial facial tissues, or extension into preseptal or postseptal orbital spaces 3, 4

The American College of Radiology recommends obtaining imaging emergently in the acute presentation of periorbital edema with suspected dental abscess, and not waiting for elective imaging for chronic disease 4, 5