A Comprehensive Ultrasound Investigation of Lower Facial and Neck Structure

The jawline and neck significantly influence facial aesthetics. Botulinum toxin and filler are highly favored as minimally invasive jawline rejuvenation procedures. However, little evidence exists on the age-related skin and superficial fat tissue transformations in healthy individuals to guide targeted interventions. A quantitative sonographic assessment was conducted on 51 patients. Total soft tissue thickness (the skin and superficial fat compartments) was measured at eight sites along the jawline and four sites at the neck. Among them, 21 patients received botulinum toxin A (BTX-A) injections for jawline lift. Three-dimensional images and questionaries were obtained before and after the treatment. In this ultrasound study, total superficial soft tissue thickness decreased significantly from the prejowl sulcus to the lateral cheek, with the jowl showing the greatest thickness. Vertically, significant differences in thickness were noted between superior and inferior points, especially at the inferior prejowl sulcus for the middle-aged and the jowl for the elderly group when comparing across age groups. Soft tissue thickness at the neck decreased from zones 1 to 3, consistent in all age groups. BMI and age positively correlated with soft tissue thickness at the jawline and neck. Regarding BTX-A injections, participants described a pain-free injection process, of which 85.7 This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .