Skeletal system · Head and neck
Lacrimal bones !
The lacrimal bones are tiny bones in the inner wall of each eye socket; they hold the tear sac and the start of the tear duct.
Official name: Lacrimal bone
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What it is
Tiny bones in the inner wall of the eye socket.
What it does
Hold the tear sac and the start of the tear duct.
Key facts
- Joints with
- Frontal, maxilla, ethmoid, inferior concha
- Landmarks
- Lacrimal fossa (tear sac), posterior lacrimal crest
Relations
- In front
- Frontal process of the maxilla, which carries the anterior lacrimal crest and the medial canthal tendon
- Behind
- Orbital plate (lamina papyracea) of the ethmoid bone
- Above
- Frontal bone
- Medial
- Anterior ethmoid cells and the front of the middle meatus of the nasal cavity
- Below
- Orbital surface of the maxilla, and the lacrimal process of the inferior nasal concha in the wall of the nasolacrimal canal
How to find it
It is not palpable. In surgery it is reached through the medial canthus or endoscopically from the nose, near the front of the middle concha attachment; on CT it is the thin plate behind the lacrimal sac fossa.
On imaging
CT shows the lacrimal fossa and nasolacrimal canal in naso-orbito-ethmoid fractures; dacryocystography or CT dacryocystography outlines the tear drainage when a blockage is suspected.
Clinical notes
- Dacryocystorhinostomy cuts a window through the lacrimal bone and the adjoining frontal process of the maxilla, letting the lacrimal sac drain straight into the nose and bypassing a blocked nasolacrimal duct
- Naso-orbito-ethmoid fractures can crush the lacrimal bone and the tear drainage, causing a watering eye (epiphora)
- Fractures of the thin medial orbital wall can trap the medial rectus, limiting abduction of the eye
Test yourself
Think of the answer, then tap the question to see it.
What does the lacrimal bone form, and what does its groove hold?
The front part of the medial orbital wall; its lacrimal groove, with the frontal process of the maxilla, forms the fossa for the lacrimal sac.
What does dacryocystorhinostomy do through the lacrimal bone?
It opens a window through the lacrimal bone and frontal process of the maxilla so the lacrimal sac drains straight into the nose, bypassing a blocked duct.
What symptom follows a naso-orbito-ethmoid fracture that crushes the lacrimal bone?
A watering eye (epiphora), because the tear drainage is damaged.
Educational information, not medical advice. For any symptom, see a health professional.
Its names
- Official Latin (TA2)
- os lacrimale TA2 744
- Official Spanish (DeCS)
- Huesos lagrimales
- English (TA2)
- Lacrimal bone
Sources: Terminologia Anatomica (TA2); Anatomy, Head and Neck, Orbit Bones; Anatomy, Head and Neck, Skull.
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Representative model, for educational purposes only.
