Citation, DOI and article data
- origin: fascia overlying the parotid, masseter and/or platysma muscles
- insertion: angle of the mouth
- innervation: facial nerve (VII)
- action: pulls back the angle of the mouth
The risorius muscle arises from the superficial fascia as a bundle of muscle fibers which pass anteriorly to insert into the angle of the mouth. The bundle is widest at its origin, narrowing towards its insertion.
- angle of the mouth 4
- buccal branch of the facial nerve (VII) 1
- pulls back the angle of the mouth 2
The risorius muscle is commonly absent. Occasionally the risorius muscle is duplicated or markedly larger than normal. The fibers 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.
- 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