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{{Short description|Corner of the eye where the upper and lower eyelids meet}} |
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{{Use dmy dates|date=March 2023}} |
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{{Other uses}} |
{{Other uses}} |
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{{Refimprove|date=August 2009}} |
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{{Infobox anatomy |
{{Infobox anatomy |
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| Name = Canthus |
| Name = Canthus |
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| Latin = |
| Latin = |
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| Image = Gray892.png |
| Image = Gray892.png |
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| Caption = Front of left |
| Caption = Front of left eye with eyelids separated to show medial canthus. |
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| Image2 = |
| Image2 = |
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| Caption2 = |
| Caption2 = |
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| Lymph = |
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''' |
The '''canthus''' ({{plural form}}: '''canthi''', '''palpebral commissures''') is either corner of the [[eye]] where the upper and lower [[eyelid]]s meet.<ref>{{DorlandsDict|two/000016591|canthus}}</ref> More specifically, the inner and outer canthi are, respectively, the medial and lateral ends/angles of the [[palpebral fissure]]. |
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The '''bicanthal plane''' is the [[transversal plane]] linking both canthi and defines the upper boundary of the [[midface]]. |
The '''bicanthal plane''' is the [[transversal plane]] linking both canthi and defines the upper boundary of the [[midface]]. |
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==Etymology== |
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| ⚫ | [[ |
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The word ''{{wikt-lang|la|canthus}}'' is the [[romanization of Greek|Latinized]] form of the [[Ancient Greek]] {{wikt-lang|grc|κανθός}} (''{{grc-transl|κανθός}}''), meaning 'corner of the eye'. |
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==Population distribution== |
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| ⚫ | The [[Human eye|eyes]] of [[East Asian]] and some [[Southeast Asian]] people tend to have the inner canthus veiled by the [[epicanthus]]. In the [[Caucasian race|Caucasian]] or double eyelid, the inner corner tends to be exposed completely.<ref>Bongsik Kwon, Anh H. Nguyen: [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4536067/ Reconsideration of the Epicanthus: Evolution of the Eyelid and the Devolutional Concept of Asian Blepharoplasty] Semin Plast Surg. 2015 Aug; 29(3): 171–183. {{doi|10.1055/s-0035-1556849}}, {{PMC|4536067}}</ref> |
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==Commissures== |
==Commissures== |
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==Surgery== |
==Surgery== |
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[[File:CuttingLateralCanthus.jpg|thumb|Cutting lateral canthus]] |
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Canthoplasty refers to a plastic surgery of the medial and/or lateral canthus. This technique is common in cosmetic procedures, as well as procedures that address eyelid function or malposition.<ref>{{Cite journal|last=Taban|first=Mehryar R.|date=2010|title=Aesthetic Lateral Canthoplasty|url=https://r7z9r7i7.stackpathcdn.com/wp-content/uploads/2014/08/AestheticLateralCanthoplasty.pdf|journal=Ophthalmic Plastic & Reconstructive Surgery|volume=26|issue=3|pages=190–194|doi=10.1097/IOP.0b013e3181baa23f|pmid=20489545 |via=Stackpath}}</ref> |
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A [[canthotomy]] involves cutting the canthus, often performed to release excessive orbital pressure (i.e., from orbital hemorrhage or infection). |
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A [[canthotomy]] involves cutting the canthus, often performed to release excessive orbital pressure (i.e., from orbital hemorrhage or infection).<ref>{{cite book|title=Nurse Anesthesia |first1=John J. |last1=Nagelhout |first2=Karen |last2=Plaus |year=2009 |url=https://books.google.com/books?id=zfknhzaSOSAC |chapter=Chapter 40. Anesthesia For Ophthalmic Procedures |via=[[Google Books]] |access-date=2023-03-24 |page=[https://books.google.com/books?id=zfknhzaSOSAC&pg=PA963 963] |isbn=9780323081016 |publisher=Elsevier Health Sciences |quote=Canthotomy is a procedure performed to increase the orbital space by cutting the lateral canthus. This procedure reduces the orbital pressure that results from a retrobulbar hemorrhage.}}</ref> |
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The two canthi of each eye (medial and lateral, that is, inner and outer) are represented in [[cephalometric analysis]] by the endocanthion and exocanthion landmarks (single points representing the point of each commissural angle). |
The two canthi of each eye (medial and lateral, that is, inner and outer) are represented in [[cephalometric analysis]] by the endocanthion and exocanthion landmarks (single points representing the point of each commissural angle). |
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==Pathology== |
==Pathology== |
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[[Telecanthus]], or dystopia canthorum, is a lateral displacement of the inner canthi of the eyes, giving an appearance of a widened [[nasal bridge]].<ref>[http://www.utmb.edu/otoref/grnds/genetic-hl-2004-0317/genetic-hl-2004-0317.doc Genetic Hearing Loss] {{Webarchive|url=https://web.archive.org/web/20130217173715/http://www.utmb.edu/otoref/grnds/Genetic-HL-2004-0317/Genetic-HL-2004-0317.doc |date=2013-02-17 }} from UTMB, Dept. of Otolaryngology, March 17, 2004. Resident physician: Jing Shen, faculty physician: Ronald W. Deskin, MD, series editors: Francis B. Quinn, Jr., MD and Matthew W. Ryan, MD.</ref> It is associated with [[Waardenburg syndrome]], which is due to mutation in PAX gene.<ref name="pmid16880590">{{cite journal |vauthors=Tagra S, Talwar AK, Walia RL, Sidhu P |title=Waardenburg syndrome |journal=Indian J Dermatol Venereol Leprol |volume=72 |issue=4 |pages=326 |year=2006 |pmid=16880590 |doi= 10.4103/0378-6323.26718|doi-access=free }}</ref> |
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==See also== |
==See also== |
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{{Portal|Anatomy|Animals|Medicine|Biology|Science}} |
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* [[Anatomy]] |
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* [[Biological morphology]] |
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* [[Commissure]] |
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* [[Fissure (anatomy)]] |
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==References== |
==References== |
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==External links== |
==External links== |
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* [https://web.archive.org/web/20070311130947/http://www.sheinman.com/Aanatomyp1.htm Diagram at sheinman.com] |
* [https://web.archive.org/web/20070311130947/http://www.sheinman.com/Aanatomyp1.htm Diagram at sheinman.com] |
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* [http://www.solobambini.com/measure_canthus.html Diagram at solobambini.com] (measure of [[Pupillary distance]]) |
* [https://web.archive.org/web/20170303122913/http://www.solobambini.com/measure_canthus.html Diagram at solobambini.com] (measure of [[Pupillary distance]]) |
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{{Accessory organs of the eye}} |
{{Accessory organs of the eye}} |
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[[Category:Human eye anatomy]] |
[[Category:Human eye anatomy]] |
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{{eye-stub}} |
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Latest revision as of 05:42, 25 July 2024
| Canthus | |
|---|---|
 Front of left eye with eyelids separated to show medial canthus. | |
| Identifiers | |
| FMA | 59222 |
| Anatomical terminology | |
The canthus (‹The template Plural form is being considered for merging.› pl.: canthi, palpebral commissures) is either corner of the eye where the upper and lower eyelids meet.[1] More specifically, the inner and outer canthi are, respectively, the medial and lateral ends/angles of the palpebral fissure.
The bicanthal plane is the transversal plane linking both canthi and defines the upper boundary of the midface.
Etymology
[edit]The word canthus is the Latinized form of the Ancient Greek κανθός (kanthós), meaning 'corner of the eye'.
Population distribution
[edit]The eyes of East Asian and some Southeast Asian people tend to have the inner canthus veiled by the epicanthus. In the Caucasian or double eyelid, the inner corner tends to be exposed completely.[2]
Commissures
[edit]- The lateral palpebral commissure (commissura palpebrarum lateralis; external canthus) is more acute than the medial, and the eyelids here lie in close contact with the bulb of the eye.
- The medial palpebral commissure (commissura palpebrarum medialis; internal canthus) is prolonged for a short distance toward the nose, and the two eyelids are separated by a triangular space, the lacus lacrimalis.
Surgery
[edit]
Canthoplasty refers to a plastic surgery of the medial and/or lateral canthus. This technique is common in cosmetic procedures, as well as procedures that address eyelid function or malposition.[3]
A canthotomy involves cutting the canthus, often performed to release excessive orbital pressure (i.e., from orbital hemorrhage or infection).[4]
The two canthi of each eye (medial and lateral, that is, inner and outer) are represented in cephalometric analysis by the endocanthion and exocanthion landmarks (single points representing the point of each commissural angle).
Pathology
[edit]Telecanthus, or dystopia canthorum, is a lateral displacement of the inner canthi of the eyes, giving an appearance of a widened nasal bridge.[5] It is associated with Waardenburg syndrome, which is due to mutation in PAX gene.[6]
See also
[edit]
References
[edit]- ^ "canthus" at Dorland's Medical Dictionary
- ^ Bongsik Kwon, Anh H. Nguyen: Reconsideration of the Epicanthus: Evolution of the Eyelid and the Devolutional Concept of Asian Blepharoplasty Semin Plast Surg. 2015 Aug; 29(3): 171–183. doi:10.1055/s-0035-1556849, PMC 4536067
- ^ Taban, Mehryar R. (2010). "Aesthetic Lateral Canthoplasty" (PDF). Ophthalmic Plastic & Reconstructive Surgery. 26 (3): 190–194. doi:10.1097/IOP.0b013e3181baa23f. PMID 20489545 – via Stackpath.
- ^ Nagelhout, John J.; Plaus, Karen (2009). "Chapter 40. Anesthesia For Ophthalmic Procedures". Nurse Anesthesia. Elsevier Health Sciences. p. 963. ISBN 9780323081016. Retrieved 24 March 2023 – via Google Books.
Canthotomy is a procedure performed to increase the orbital space by cutting the lateral canthus. This procedure reduces the orbital pressure that results from a retrobulbar hemorrhage.
- ^ Genetic Hearing Loss Archived 2013-02-17 at the Wayback Machine from UTMB, Dept. of Otolaryngology, March 17, 2004. Resident physician: Jing Shen, faculty physician: Ronald W. Deskin, MD, series editors: Francis B. Quinn, Jr., MD and Matthew W. Ryan, MD.
- ^ Tagra S, Talwar AK, Walia RL, Sidhu P (2006). "Waardenburg syndrome". Indian J Dermatol Venereol Leprol. 72 (4): 326. doi:10.4103/0378-6323.26718. PMID 16880590.