Private Practice, São Paulo, Brazil.
Sially Institute, São Paulo, Brazil.
J Cosmet Dermatol. 2024 Jul;23(7):2373-2379. doi: 10.1111/jocd.16368. Epub 2024 May 16.
Recent research introduced the concept of the "line of convergence" as a guide for injectors to enhance precision and avoid complications when treating the frontalis muscle with toxins. However, currently, no pre-injection ultrasound scanning is employed to increase precision and reduce adverse events when searching for the line of convergence.
To explore the feasibility and practicality of implementing pre-injection ultrasound scanning into aesthetic neuromodulator treatments of the forehead.
The sample of this study consisted of n = 55 volunteers (42 females and 13 males), with a mean age of 42.24 (10.3) years and a mean BMI of 25.07 (4.0) kg/m. High-frequency ultrasound imaging was utilized to measure the thickness, length, and contractility of the frontal soft tissue and to determine the precise location of the line of convergence during maximal frontalis muscle contraction.
The results revealed that the line of convergence was located at 58.43% (8.7) of the total forehead height above the superior border of the eyebrow cilia without a statistically significant difference between sex, age, or BMI. With frontalis muscle contraction, the forehead shortens in males by 25.90% (6.5), whereas in females it shortens only by 21.74% (5.1), with p < 0.001 for sex differences.
This study demonstrated the feasibility and practicality of pre-injection ultrasound scanning for facial aesthetic neuromodulator treatments. Knowing the location of the line of convergence, injectors can determine precisely and on an individual basis where to administer the neuromodulator deep or superficial or when the injection location is at risk to cause eyebrow ptosis.
最近的研究提出了“汇聚线”的概念，作为指导注射者在治疗额肌时提高精度并避免并发症的方法。然而，目前在寻找汇聚线时，没有预先进行超声扫描来提高精度并减少不良事件。
探索在额部美学神经调节剂治疗中引入预先注射超声扫描的可行性和实用性。
本研究的样本包括 n = 55 名志愿者（42 名女性和 13 名男性），平均年龄为 42.24（10.3）岁，平均 BMI 为 25.07（4.0）kg/m。利用高频超声成像测量额部软组织的厚度、长度和收缩性，并确定在额肌最大收缩时汇聚线的确切位置。
结果显示，汇聚线位于眉毛睫毛上缘以上额部总高度的 58.43%（8.7）处，性别、年龄或 BMI 之间无统计学差异。在额肌收缩时，男性的额头缩短 25.90%（6.5），而女性仅缩短 21.74%（5.1），性别差异具有统计学意义（p < 0.001）。
本研究表明，预先注射超声扫描对面部美学神经调节剂治疗具有可行性和实用性。了解汇聚线的位置，注射者可以精确地确定并根据个体情况，确定在何处进行神经调节剂的深层或浅层注射，或者在注射位置有引起眉毛下垂风险时，应在哪里进行注射。
