Risorius muscle
Citation, DOI, disclosures and article data
Citation:
Bell D, Bickle I, Evangelou K, Risorius muscle. Reference article, Radiopaedia.org (Accessed on 20 Mar 2025) https://doi.org/10.53347/rID-92599
rID:
92599
Article created:
Disclosures:
At the time the article was created Daniel J Bell had no recorded disclosures.
View Daniel J Bell's current disclosures
Last revised:
Disclosures:
At the time the article was last revised Daniel J Bell had no recorded disclosures.
View Daniel J Bell's current disclosures
Revisions:
6 times, by
3 contributors -
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Systems:
Sections:
Synonyms:
- Risorius muscles
- Musculus risorius
- Muscle of Albinus
- Santorini's muscle
- Muscle of Santorini
The risorius muscle (TA: musculus risorius) is one of the muscles of the mouth, a subset of the facial muscles. It is often absent and has been described as an accessory muscle.
On this page:
Summary
- origin: fascia overlying the parotid, masseter and/or platysma muscles
- insertion: modiolus at the angle of the mouth
- innervation: facial nerve (VII)
- action: pulls back the angle of the mouth
Gross anatomy
The risorius muscle arises from the superficial fascia as a bundle of muscle fibres which pass anteriorly to insert into the angle of the mouth. The bundle is widest at its origin, narrowing towards its insertion.
Origin
- parotid fascia 4
- fascia overlying the masseter muscle 4
- fascia enveloping the platysma muscle 4
Insertion
- modiolus at the angle of the mouth 4
Arterial supply
Venous drainage
Innervation
- buccal branch of the facial nerve (VII) 1
Action
- pulls back the angle of the mouth 2
Variant anatomy
The risorius muscle is commonly absent. Occasionally the risorius muscle is duplicated or markedly larger than normal. The fibres of risorius may be merged into the platysma muscle 2 or fused with the transversus nuchae muscle 5.
History and etymology
Giovanni Domenico Santorini (1681-1737), described the risorius muscle, hence its historical name, muscle of Santorini 6. The German born, naturalised Dutch, anatomist Bernhard Siegfried Albinus (1697-1770), wrote a detailed treatise on the risorius muscle, such that it was also called the muscle of Albinus in the past 7.
References
- 1. Chummy S. Sinnatamby. Last's Anatomy. (2020) ISBN: 9780702033957
- 2. Gray, H. Anatomy of the Human Body. Philadelphia: Lea & Febiger, 1918; Bartleby.com, 2000. www.bartleby.com/107/
- 3. FIPAT. Terminologia Anatomica. 2nd Ed. FIPAT.library.dal.ca. Federative International Programme for Anatomical Terminology, 2019. https://fipat.library.dal.ca/TA2/
- 4. Bae J, Choi D, Lee J, Seo K, Tansatit T, Kim H. The risorius muscle: anatomic considerations with reference to botulinum neurotoxin injection for masseteric hypertrophy. Dermatol Surg. 2014;40(12):1334-9. doi:10.1097/DSS.0000000000000223
- 5. Jovanovski T, Umek N, Cvetko E. Transversus Nuchae Muscle Fused with Risorius Muscle: A Case Report. Int. J. Morphol. 2020;38(5):1208-1211. doi:10.4067/s0717-95022020000501208
- 6. Kleinerman R, John A, Etienne D et al. Giovanni Domenico Santorini (1681-1737): a prominent physician and meticulous anatomist. Clin Anat. 2014;27(4):545-7. doi:10.1002/ca.22294
- 7. Bernard Siegfried Albinus (1697-1770), German-Dutch anatomist. JAMA. 1966;196(10):910. PMID 5327733
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