Submental Anatomical Variations: The Uniqueness of a Common Variation
Résumé
Introduction: submental region is subject to many variations, predominantly affecting the anterior belly of the digastric muscle. The medical importance of this area led us to compile a database with the reported cases of the anomalous belly of the anterior belly of the digastric muscle as well as report one case. During a dissection for didactic purposes of the submental region of an adult female formalin-fixed cadaver, a supernumerary belly in the digastric muscle and an abnormal muscle fibres arrangement were observed. No variation was detected in the posterior belly of the digastric muscle or in the intermediate tendon. To gather a database academic search tools such as Pubmed, Web of Science, Scopus and Google scholar using the keywords, accessory belly and abnormalities of digastric muscle, variations in the digastric muscle, variations in the submental region, agenesis and atrophy of digastric muscle. A total of 114 cases were identified in the literature, 62 bilateral and 39 unilateral anomalies and 13 unknown data. From the 62 reported bilateral cases the symmetry was registered in 52 cases, 24 cases showed a symmetric pattern while 28 were asymmetric. The digastric muscle anterior belly variation is relatively frequent, however, its presentation and number are variable and in general unique. Moreover, this variation can easily be confused with pathological conditions. This article highlights the importance of reporting submental anatomical variations to strengthen epidemiological data so as to avoid misdiagnosis and point out the use of these structures as references for surgical procedures and imaging methods.