Topics

Topic

design image
Orbital plate

The orbital plate refers to the thin bony component of the frontal, ethmoid, maxillary, or lacrimal bones that forms the roof, medial, or floor of the orbit, contributing to the structural integrity of the orbital cavity. These plates serve as barriers between the orbit and adjacent structures, such as the cranial cavity, paranasal sinuses, and nasal cavity. They are typically flat, smooth, and slightly curved, varying in thickness depending on the bone and anatomical region. The orbital plates provide attachment for periosteum, orbital septa, and extraocular muscles, and their precise orientation defines the shape, volume, and protection of the orbital contents, including the globe, optic nerve, and orbital fat.

Synonyms

  • Orbital bony plate

  • Orbital wall plate

  • Orbital roof/medial/floor plate (depending on location)

Function

  • Forms structural walls of the orbit, separating it from the cranial cavity, sinuses, and nasal cavity

  • Provides attachment sites for orbital soft tissues, including muscles, septa, and fascia

  • Maintains orbital volume and protects the globe and neurovascular structures

  • Serves as a landmark for surgical approaches in ophthalmology and craniofacial procedures

MRI Appearance
T1-weighted images:

  • Orbital plates appear as thin, hypointense (low signal) linear structures surrounding the orbital cavity

  • Surrounded by hyperintense orbital fat, which provides high contrast and clearly delineates the bone margins

  • Pathological changes such as fractures or tumors appear as interruptions in the low-signal cortical line or focal abnormal signal

T2-weighted images:

  • Plates remain hypointense, while surrounding orbital fat and fluid appear hyperintense

  • Useful for identifying edema, orbital hemorrhage, or subtle bony irregularities adjacent to soft tissue pathology

STIR (Short Tau Inversion Recovery):

  • Fat suppression removes high signal from orbital fat, enhancing visualization of soft tissue abnormalities adjacent to the bone

  • Orbital plates remain low signal, while edema, inflammation, or tumor infiltration appears hyperintense

CT Appearance

  • Orbital plates appear as hyperdense, thin, corticated bony structures forming the walls of the orbit

  • Surrounding air-filled sinuses appear hypodense, providing natural contrast

  • Easily evaluated in axial, coronal, and sagittal planes for fractures, congenital anomalies, or bony lesions

  • Critical for assessing orbital trauma, orbital roof or floor fractures, and preoperative planning for craniofacial or orbital surgery

MRI images

Orbital plate mri axial image -img-00000-00000