Posterior lacrimal crest

The lateral or orbital surface of the lacrimal bone 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 nasolacrimal 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; the hamulus sometimes exists as a separate piece, and is then called the lesser lacrimal bone.