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The 'lacrimal bone', the smallest and most fragile bone of the face, is situated at the front part of the medial wall of the orbit. It has two surfaces and four borders.

Contents

Surfaces

Lateral or orbital surface

Medial or nasal surface

Borders

Ossification

Articulations

Additional images

See also

External links

Surfaces

Lateral or orbital surface

The lateral or orbital surface is divided by a vertical ridge, the posterior lacrimal crest, into two parts.
In ''front'' of this crest is a longitudinal groove, the lacrimal sulcus (''sulcus lacrimalis''), the inner margin of which unites with the frontal process of the maxilla, and the lacrimal fossa is thus completed. The upper part of this fossa lodges the lacrimal sac, the lower part, the naso-lacrimal duct.
The portion ''behind'' the crest is smooth, and forms part of the medial wall of the orbit.
The crest, with a part of the orbital surface immediately behind it, gives origin to the lacrimal part of the Orbicularis oculi and ends below in a small, hook-like projection, the lacrimal hamulus, which articulates with the lacrimal tubercle of the maxilla, and completes the upper orifice of the lacrimal canal; it sometimes exists as a separate piece, and is then called the lesser lacrimal bone.

Medial or nasal surface

The medial or nasal surface presents a longitudinal furrow, corresponding to the crest on the lateral surface.
The area in front of this furrow forms part of the middle meatus of the nose; that behind it articulates with the ethmoid, and completes some of the anterior ethmoidal cells.

Borders

Of the four borders:

★ the ''anterior'' articulates with the frontal process of the maxilla;

★ the ''posterior'' with the lamina papyracea of the ethmoid;

★ the ''superior'' with the frontal bone.

★ The ''inferior'' is divided by the lower edge of the posterior lacrimal crest into two parts:

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★ the posterior part articulates with the orbital plate of the maxilla;

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★ the anterior is prolonged downward as the descending process, which articulates with the lacrimal process of the inferior nasal concha, and assists in forming the canal for the nasolacrimal duct.

Ossification

The lacrimal is ossified from a single center, which appears about the twelfth week in the membrane covering the cartilaginous nasal capsule.

Articulations

The lacrimal articulates with ''four'' bones: two of the cranium, the frontal and ethmoid, and two of the face, the maxilla and the inferior nasal concha.

Additional images

See also

★ Bone terminology

★ Terms for anatomical location

External links

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★ Diagram at upstate.edu