Posterior lacrimal crest

Posterior lacrimal crest
Left lacrimal bone. Orbital surface. Enlarged. (Posterior lacrimal crest visible but not labeled.)
Details
Part oflacrimal bone
Systemskeletal
Identifiers
Latincrista lacrimalis posterior
TA98A02.1.09.002
TA2745
FMA57609
Anatomical terms of bone

The posterior lacrimal crest is a vertical bony ridge on the orbital surface of the lacrimal bone. It divides the bone into two parts. It gives origin to the lacrimal part of the orbicularis oculi muscle.

Structure

The posterior lacrimal crest is a vertical bony ridge on the orbital (lateral) surface of the lacrimal bone. It divides the lacrimal bone into two parts. It is quite thin and fragile in most people.[1]

The lacrimal groove is in front of this crest. The inner margin of it unites with the frontal process of the maxilla to complete the fossa for the lacrimal sac.[2] The portion of the lacrimal bone behind the posterior lacrimal crest is smooth, and forms part of the medial wall of the orbit. The lacrimal crest ends below in the lacrimal hamulus (a small hook-like projection), which articulates with the lacrimal tubercle of the maxilla.

Relations

The posterior lacrimal crest is just behind the lacrimal sac, and its upper part lodges the lacrimal sac.[3][4] The lower part lodges the nasolacrimal duct. Horner's muscle, part of the orbicularis oris muscle, inserts between 2 mm and 4 mm from the posterior lacrimal crest.[5] Together with the thicker and more prominent anterior lacrimal crest, it forms the fossa for the lacrimal sac.[1]

Variation

In most people, the posterior lacrimal crest is fairly prominent.[6] However, in around 20% of people, it is fairly shallow.[6] In contrast, the anterior lacrimal crest is almost always very prominent.[6]

Function

The posterior lacrimal crest gives origin to the lacrimal part of the orbicularis oculi muscle. It also helps to protect the lacrimal sac.[3]

Clinical significance

The posterior lacrimal crest may be vulnerable to avulsion fractures.[7] It is generally quite thin and fragile.[1] 25% of such avulsion fractures are related to a Le Fort III skull fracture.[7]

Additional images

  • Cranium. Posterior lacrimal crest. Lacrimal bone.
    Cranium. Posterior lacrimal crest. Lacrimal bone.

See also

References

Public domain This article incorporates text in the public domain from page 164 of the 20th edition of Gray's Anatomy (1918)

  1. ^ a b c Tao, Hai; Ma, Zhi-zhong; Wu, Hai-Yang; Wang, Peng; Han, Cui (April 2014). "Anatomic study of the lacrimal fossa and lacrimal pathway for bypass surgery with autogenous tissue grafting". Indian Journal of Ophthalmology. 62 (4): 419–423. doi:10.4103/0301-4738.121137. ISSN 0301-4738. PMC 4064215. PMID 24817745.
  2. ^ Tomazic, Peter Valentin; Dewart, Nora; Witterick, Ian J. (2021-01-01), Sindwani, Raj (ed.), "6 - Rhinologic Evaluation in Orbital and Lacrimal Disease", Endoscopic Surgery of the Orbit, Philadelphia: Elsevier, pp. 36–40, ISBN 978-0-323-61329-3, retrieved 2021-09-23
  3. ^ a b Merbs, Shannath; DeParis, Sarah (2020-01-01), Dorafshar, Amir H.; Rodriguez, Eduardo D.; Manson, Paul N. (eds.), "3.4 - Ocular Considerations: Ectropion, Entropion, Blink, Ptosis, Epiphora", Facial Trauma Surgery, London: Elsevier, pp. 367–378, ISBN 978-0-323-49755-8, retrieved 2021-09-23
  4. ^ Piniara, Anastasia; Georgalas, Christos (2021-01-01), Sindwani, Raj (ed.), "4 - Surgical Anatomy of the Orbit, Including the Intraconal Space", Endoscopic Surgery of the Orbit, Philadelphia: Elsevier, pp. 18–27, ISBN 978-0-323-61329-3, retrieved 2021-09-23
  5. ^ Kakizaki, Hirohiko; Ichinose, Akihiro; Takahashi, Yasuhiro; Kang, Hyera; Ikeda, Hiroshi; Nakano, Takashi; Asamoto, Ken; Iwaki, Masayoshi (February 2012). "Anatomical Relationship of Horner's Muscle Origin and Posterior Lacrimal Crest". Ophthalmic Plastic & Reconstructive Surgery. 28 (1): 66–68. doi:10.1097/IOP.0b013e318239321d. ISSN 0740-9303. PMID 22186989. S2CID 5145634.
  6. ^ a b c Bisaria, K K; Saxena, R C; Bisaria, S D; Lakhtakia, P K; Agarwal, A K; Premsagar, I C (October 1989). "The lacrimal fossa in Indians". Journal of Anatomy. 166: 265–268. ISSN 0021-8782. PMC 1256759. PMID 2621144.
  7. ^ a b Díaz, Oswaldo J. Gómez; Carreño, Andrés Parra; Serna, Daniel Restrepo (October 2019). "Traumatic Telecanthus and Posterior Lacrimal Crest Avulsion in a Six-Year-Old Child". Journal of Craniofacial Surgery. 30 (7): 2224–2226. doi:10.1097/SCS.0000000000005922. ISSN 1049-2275. PMID 31490433. S2CID 201846470.