What is the lacrimal bone?

What it is

• 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. Surfaces. —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.
• 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.