Localization of the Submandibular Glands Using High-Frequency Ultrasound.

[BACKGROUND] Injecting botulinum toxin (BTX) into the submandibular glands (SMGs) can treat drooling symptoms in neurological diseases and improve the aesthetics of SMG hypertrophy and ptotic SMGs.

[OBJECTIVES] This study aimed to define the size and position of the SMGs by high-frequency ultrasound, and to perform statistical analysis to improve the safety and accuracy of BTX injection therapy.

[METHODS] Neck ultrasonography with high-frequency ultrasound was performed on 214 volunteers. The length, height, and thickness of the SMGs, and the distance between the SMGs and the midline, the anterior border of the sternocleidomastoid, the mandible, and the surface were measured.

[RESULTS] The SMGs were almond-shaped with a mean [standard deviation] length of 33.7 [4.7] mm, a thickness of 13.3 [2.9] mm, and a height of 27.6 [6.0] mm. The length and height were significantly different between underage and youth groups. The size of the SMGs did not show any notable differences with increasing BMI; however, their depth, and the distance from the mandible, midline, and anterior border of the sternocleidomastoid increased. No significant differences were observed between the affected and healthy sides in patients with microtia, hemifacial microsomia, or cleft lip and palate.

[CONCLUSIONS] Ultrasound provides more comprehensive information regarding the size and position of the SMGs, which can serve as a reference in BTX therapy and in the diagnosis of SMG diseases involving size alterations.