Anatomical study on anomalies of the digastric muscle of neck region
Samata Roshini Padala, Jayasree Chada
The digastric muscle has the anterior belly and the posterior belly linked by an intermediate tendon attached to the body and greater horn of the hyoid bone and is characterized to have many variations that do not necessarily produce clinical symptoms. The present study was conducted to investigate anatomical variations of the digastric muscles in the samples of adult cadaveric specimens and discuss clinical significance. The study consisted of 16 (n = 16) adult cadaveric head and neck specimens consisting of n = 10 males and n = 6 females between the age ranging from 33 – 76 years old. The results showed that among the 16 cadavers studied, n = 14 specimens had normal anterior and posterior bellied digastric muscles, while in n = 2 (12.5%) cadavers (1 male and 1 female), variations in the accessory bellies of diagastric muscle were observed. In the present study, n = 14 cadavers out of n = 16 samples showed usual anatomy. In one (n=1) female cadaver sample an accessory belly of the anterior digastric was observed on the left side. The origin of the single accessory belly is tendinous arising from digastric fossa of mandible and had a fleshy attachment to the body of the hyoid bone. No anterior belly of the digastric muscle was present on the right side of the cadaver sample. The posterior bellies were observed to be normal on both the sides. In another one (male) cadaver, an accessory anterior belly was found originating from the mandible's digastric fossa, between the right and left anterior bellies of the digastric muscles dividing into right and left accessory bellies close to its attachment to the hyoid bone. The right accessory belly was found inserted to the muscle fibers on the right side of the anterior belly and to the greater horn of the hyoid bone. The left accessory belly was observed united to the intermediate tendon on the left side and inserted to the body of the hyoid bone and the posterior bellies were observed to be normal on both the sides. The possible occurrences of such anomalies should be considered during surgical procedures involving the submental region and floor of the mouth. Therefore, these findings may be of much significance to the anatomists and contributes to the knowledge of the morphological variations in the digastric muscle, thus facilitating diagnostic and surgical procedures on the anterior area of the neck that could help prevent clinical errors and thus avoid unnecessary invasive procedures in the neck.