Orbital Margin Bones and Cranial Structures

A skeletal structure within the skull that protects the eye and its surrounding structures.

The bony orbit is composed of seven bones: the frontal bone, maxilla, zygomatic bone, ethmoid bone, lacrimal bone, sphenoid bone, and palatine bone.

The maxilla is the upper jawbone that forms part of the medial and inferior walls of the orbit. It connects to the lacrimal, ethmoid, and zygomatic bones.

The maxilla forms the inferior margin of the orbit and part of the medial wall. It houses the nasolacrimal duct, which drains tears from the eye to the nasal cavity.

The palatine bone is found at the back portion of the inferior wall of the orbit, contributing to the posterior part of the orbital floor.

The palatine bone primarily supports the orbital floor at the back, providing structural integrity. It also forms part of the hard palate and the nasal cavity.

Located at the medial part of the orbit, forming part of the medial wall between the lacrimal bone and maxilla.

The ethmoid bone forms the anterior portion of the medial orbital wall, houses the ethmoid sinuses, and forms part of the nasal cavity. It also houses the lacrimal fossa, which holds the lacrimal sac, involved in tear drainage.

The lacrimal bone is found at the front part of the medial wall of the orbit, between the maxilla and ethmoid bone.

The lacrimal bone forms the medial orbital margin and contains the lacrimal fossa, which houses the lacrimal sac. The lacrimal sac is part of the system that drains tears from the eye into the nasolacrimal duct.

The frontal bone forms the superior part of the orbit, specifically the roof.

The frontal bone plays a critical role in tear drainage and helps protect the eye by contributing to the medial boundary of the orbit.

The optic nerve (CN II) is responsible for vision. The oculomotor nerve (CN III) controls most of the extraocular muscles for eye movement.

The extrinsic muscles are muscles located outside a structure that move or control it. Extraocular muscles control the movement of the eye.

Adipose tissue, or fat, acts as a cushion and stabilizer for the ocular globe and other orbital structures.

It forms the roof of the nasal cavity and has a perforated structure called the cribriform plate that allows for the passage of olfactory fibers.

It is a small vertical protrusion on top of the cribriform plate, acting as a point of attachment for the falx cerebri.

They are grooves present lateral to the crista galli where the olfactory bulbs lie.

A porous bone that forms the midfacial region of the skull, allowing olfactory fibers to pass through for smelling.

Cavities within the ethmoid bone that contain the ethmoidal sinus, contributing to the nasal cavity.

It's a flattened bony plate that is the largest part of the ethmoid bone and assists in forming the nasal septum, dividing the nasal cavity.

The most complex bone in the human body, wedge-shaped and forming the base of the skull. It serves as a keystone bone and has a body, greater and lesser wings, and pterygoid processes.

The most centrally positioned part of the sphenoid bone, contributing to the nasal cavity, the optic canal, and the sella turcica.

They project upward from the sphenoid body and contain the optic canal for the passage of the optic nerve and ophthalmic artery.

They arise posterolaterally from the sphenoid body, forming the infratemporal and orbital surfaces.

A rounded depression in the body of the sphenoid bone that houses the pituitary gland.

This is a sulcus formed by the optic chiasm where the nerve fibers cross over.

It transmits the maxillary nerve, facilitating sensation to the face.

It allows the passage of the mandibular nerve, accessory meningeal artery, lesser petrosal nerve and emissary vein.

It is traversed by the middle meningeal vessels and the spinous nerve.

A paired bone in the face that forms the prominence of the cheek, connecting with other bones to form the eye socket.

A bone situated in the medial (inner) part of each orbit, near the corner of the eye. It supports the nasolacrimal duct for tear drainage and contributes to the structure of the orbit, protecting and supporting the eye.

An opening in the lesser wing of the sphenoid bone that transmits the optic nerve (CN II) and the ophthalmic artery into the orbit.

A bone forming the bridge of the nose in the upper-middle area of the face. It provides structural support to the nose, protects internal nasal structures, and helps shape the appearance of the face.

An opening between the greater and lesser wings of the sphenoid bone that connects the orbit to the middle cranial fossa.

A bone found inside the nasal cavity, located along its lateral walls, below the middle nasal conchae. It functions to filter, warm, and humidify air, increasing the surface area for airflow.

A fracture of the orbital floor, typically involving the maxillary bone, which can lead to damage to tissues and structures surrounding the eye.

The oculomotor nerve (CN III) controls most eye movements and pupil size.

The trochlear nerve (CN IV) controls the superior oblique muscle of the eye, which helps with downward gaze.

Problems with tear drainage resulting from lacrimal bone fractures or congenital malformations of the lacrimal system.

The abducens nerve (CN VI) controls the lateral rectus muscle of the eye, which helps with outward gaze.

Abnormalities in the zygomatic, lacrimal, or palatine bones that can affect the alignment of the eye and the muscles controlling eye movement, leading to misalignment of the eyes.

Abnormalities in the paired bones of the orbit (zygomatic, maxillary, or nasal bones) which can cause orbital misalignment or displacement.

Branches of the ophthalmic nerve (CN V1) transmit sensation from the forehead, upper eyelid, and parts of the eye.

Sympathetic nerve branches control automatic functions such as pupil dilation.

Abnormalities in the zygomatic, maxillary, nasal, or lacrimal bones that can lead to facial asymmetry or deformities. These abnormalities may be congenital or caused by trauma.

The superior ophthalmic vein carries blood away from the eye and connects to the brain's blood vessels.

Loss of orbital volume caused by orbital floor fractures or other abnormalities, resulting in the eye sinking back into the orbit (Enophthalmos).

Concerns related to the appearance of the face due to deformities in paired bones, such as nasal or zygomatic bones.

Passageways through the bones of the skull that allow different structures of the nervous and circulatory systems to enter and exit the skull.

A canal that drains tears from the lacrimal sac into the nasal cavity, specifically into the inferior meatus.

A single bone forming the smooth curvature of the forehead. It protects the frontal lobe of the brain and the ethmoid bone's horizontal plate.

Bones that exist in symmetrical pairs, one on each side of the body.

The squamous part of the frontal bone forms the forehead, containing the frontal sinuses. This part is one of the largest areas of the frontal bone.

Located centrally within the skull and makes up the center of the face. It provides bone structure for the face.

The orbital part of the frontal bone forms the roof of the orbit and the ethmoidal sinuses, containing the anterior and posterior ethmoidal foramina.

A bone situated at the back of the nasal cavity between the maxilla and sphenoid. It helps form the nasal and oral cavities.

Abnormalities in the palatine or zygomatic bones that can alter the shape and depth of the orbit, making it challenging to secure an ocular prosthesis due to lack of structural support.