An Exploration of the Anatomy of the Forehead of Asians and Its Relationship With Forehead Lines Based on Ultrasound Imaging

BACKGROUND: A profound understanding of the various frontal tissues' morphology and their relationship with forehead lines can efficiently guide clinical treatment. OBJECTIVES: The authors explored the relationship between frontal anatomy and frontal lines. METHODS: We measured the thickness and shape of tissues in different regions of the forehead of 241 Asians. Then, we analyzed the relationship between the types of frontalis muscle and frontal lines, as well as the relationship between the frontal anatomical structures and the production of frontal lines. RESULTS: We classified the types of frontalis muscle into 3 categories comprising 10 subtypes. The skin (0.78 mm vs 0.90 mm, P < .05), superficial subcutaneous tissue (0.66 mm vs 0.75 mm, P < .05), and frontalis muscle thickness (0.29 mm vs 0.37 mm, P < .05) of people with obvious dynamic forehead lines were significantly thicker than those of people without significant dynamic forehead lines. However, no significant difference in the deep subcutaneous tissue thickness was found between people with and without static forehead lines (1.36 mm vs 1.34 mm, P < .05). CONCLUSIONS: This study shows the relationship between the frontal structure and frontal lines. Therefore, these results can provide references for treating frontal lines, to a certain extent.