â– DETAILS: The four-sided pyramid-shaped cavity of the orbit has a thin floor, particularly vulnerable to mechanical impacts.
â– BONY COMPOSITION OF THE FLOOR:
Composed mainly of three bones:
1. Orbital surface of the Maxilla (largest component).
2. Zygomatic bone (anterolaterally).
3. Orbital process of the Palatine bone (posteriorly).
Note: The infraorbital nerve and vessels run along the floor inside the infraorbital groove and canal.
â– ANATOMICAL RELATION:
Directly beneath this paper-thin wall lies the massive, hollow cavity of the Maxillary Sinus. High-force impacts on the eyeball increase intraorbital pressure, blowing the floor downward.
â– SURGICAL LANDMARKS & ANATOMICAL BOUNDARIES:
Intraoperative access requires meticulous dissection along defined tissue planes. Avoid excessive traction near neurovascular bundles and look for key bony landmarks or fascial reflections to secure margins.
â– SURGICAL COMPASS & ANATOMICAL CORRELATION:
Dissection lines must respect established fascial boundaries to prevent neurovascular traction injuries and secure excellent diagnostic margins.
[HY-BOARD-1193]
🌟 Dynamic Clinical Key:
An orbital 'blowout' fracture occurs when trauma forces orbital contents into the Maxillary Sinus. This traps the Inferior Rectus Muscle, preventing upward gaze (diplopia on looking up) and causing infraorbital nerve paresthesia (numb cheek/upper teeth). Never divide or ligate any vessel before clearly isolating and confirming its origin and termination. Verify landmarks dynamically with gentle palpation and specialized intraoperative markers.