Lacrimal bone: anatomy of the medial wall of the orbit
Quick facts
- Size
- One of the smallest and thinnest bones of the face, paired.
- Location
- Medial wall of the orbit, between the frontal process of the maxilla and the lamina papyracea of the ethmoid.
- Notable structure
- Posterior lacrimal crest and lacrimal groove, which houses the lacrimal sac.
- Clinical relationship
- Anchor of the medial canthal tendon and deep reference of the medial tear trough.
The lacrimal bone is a thin, small bone that forms part of the medial wall of the orbit. It is about the size of a fingernail, is paired (one on each side) and lies between the frontal process of the maxilla and a plate of the ethmoid bone. Despite its size, it frequently appears in descriptions of periorbital anatomy.
Where is it and what does it form?
On the medial wall of the orbit, the lacrimal bone forms, together with the frontal process of the maxilla, a depression called the fossa of the lacrimal sac. This is where the lacrimal sac sits, part of the tear drainage system. The bone is divided by a ridge (the posterior lacrimal crest), to which part of the medial canthal tendon attaches.
| Structure | Role |
|---|---|
| Fossa of the lacrimal sac | Houses the lacrimal sac |
| Posterior lacrimal crest | Bony attachment landmark for the tendon and the orbicularis muscle |
| Relation to the maxilla | Forms the lacrimal groove together |
| Relation to the nose | Lies just lateral to the nasal bone |
Why does it matter in facial harmonization?
The lacrimal bone is a deep reference for the tear trough and the nasojugal groove region, that is, the medial under-eye hollow. Understanding its role helps explain why this region is so delicate.
- Thin bone: the plate is thin, and the medial eye region has compact anatomy, with vessels and the canthal tendon nearby.
- Risk vessels: the angular vein and the angular artery pass near the medial canthus and communicate with the ophthalmic territory.
- Aesthetic reference: the transition from the lacrimal bone to the maxilla is part of the depression the patient sees as an under-eye hollow. Thin skin, fat and ligaments complete the picture, and not every hollow has the same cause.
What to assess before planning?
Before talking about volume, it is worth distinguishing the type of under-eye hollow. A hollow from structural shadow has a bony and ligamentous component. A hollow from pigment does not change with filler. A hollow from thin skin and visible vessels is managed differently. Anyone planning the periorbital region needs this reading before any decision.
Also called: unguis, os lacrimale.
Frequently asked questions
Is the lacrimal bone related to under-eye hollows?
Indirectly, yes. It forms part of the floor of the medial eye region, where the tear trough and the transition to the cheek meet. Under-eye hollows also depend on skin, fat and ligaments.