Pediatric Anatomy of the Sternocleidomastoid Muscle on Magnetic Resonance Imaging Views.

Objective: This study aimed to investigate morphologic features of the sternocleidomastoid muscle (SCM) in children for pediatric head-neck surgeries.

Methods: Magnetic resonance imaging images of 84 (46 males/38 females) pediatric patients aged ages 1 to 18 years (mean age: 9.38 ± 4.46 y) constituted the study universe. The size of SCM (including its height, width, and angulation) was measured, and the origin types of SCM were noted.

Results: All patients had SCM bilaterally. The origin variation of SCM was observed in 22 sides (13.10%). The authors observed type 1 in 146 sides (86.90%), type 2a in 15 sides (8.90%), type 3 in 2 sides (1.20%), type 4 in 1 side (0.60%), and type 5 in 4 sides (2.40%). The absence and presence of SCM variation were not affected by sex (P = 0.370) and side (P = 0.360). All measured parameters were similar in right and left sides, and also in males and females, except from the angle between the junction of the sternal and clavicular heads of SCM. The angle was greater in males than females (P = 0.004). All measured parameters increased with advancing age (between 1 and 18 y; P < 0.05).

Conclusion: The authors' SCM-related data may be useful for clinicians to estimate the size origin variations of SCM in children.