Division of Anatomy and Developmental Biology, Department of Oral Biology, Human Identification Research Institute, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul, Republic of Korea.
Department of Anatomy, Chungbuk National University School of Medicine, Cheongju, Republic of Korea.
Ultrasound Med Biol. 2019 Oct;45(10):2641-2648. doi: 10.1016/j.ultrasmedbio.2019.06.414. Epub 2019 Jul 13.
Botulinum toxin type A (BoNT-A) injections in the forehead region should only target the frontalis. This study applied ultrasonography with the aim of providing guidelines for predicting the layered structure and soft-tissue thickness of the forehead. We performed ultrasound scanning at 7 facial landmarks in 40 Korean adults. Allowing for the error range, the minimum depth from the skin to exclude the muscle layer was 2.3 mm, and the maximum depth from the skin to include the muscle layer was 2.8 mm. Of the total 7 points from the skin to muscle surface, significant differences between the males and females were found in 6 points (p < 0.05). Clinicians can use ultrasonography to identify the structural layers of the scalp. Even if ultrasound-guided injections are not performed, it is possible to target only muscle layers in BoNT-A injections by maintaining a needle depth of around 2.5 mm.
肉毒毒素 A 型（BoNT-A）注射于前额区域时，应仅针对额肌。本研究应用超声技术，旨在为预测前额的分层结构和软组织厚度提供指导。我们对 40 名韩国成年人的 7 个面部标志进行了超声扫描。在允许误差范围的情况下，从皮肤到排除肌肉层的最小深度为 2.3 毫米，从皮肤到包含肌肉层的最大深度为 2.8 毫米。在皮肤到肌肉表面的 7 个总点中，男性和女性在 6 个点上存在显著差异（p<0.05）。临床医生可以使用超声来识别头皮的结构层。即使不进行超声引导注射，通过保持约 2.5 毫米的针深，也可以在 BoNT-A 注射中仅针对肌肉层。
