Anatomical Injection Guidelines for Glabellar Frown Lines Based on Ultrasonographic Evaluation

Abstract

When botulinum neurotoxin (BoNT) is injected to treat glabellar frown lines, the corrugator supercilia muscle (CSM) and procerus muscles are the main targets. Although there have been many studies on the treatment of glabellar frown lines, no study has confirmed the dynamic movement under ultrasonography (US). This study examined and evaluated dynamic muscle movements under US, thereby providing more effective BoNT injection guidelines for glabellar frowning. Glabellar frowning was categorized as either Type A or B. Type A is the general frowning pattern in which vertical wrinkles are made by contracting the CSM and procerus muscles (81%, n = 13). On US images, the procerus muscle thickens and the bilateral CSMs contract. Type B is an upward frowning pattern demonstrating upward elevation of vertical wrinkles due to hyperactive contraction of the frontalis muscle during frowning (19%, n = 3). On US images, the hypoechoic frontalis muscle thickens, forming horizontal forehead lines. After BoNT injection into the CSM and frontalis muscle but not the procerus muscle, Type B patterns showed improvements in the vertical crease and horizontal forehead line. Both types showed improvement in glabellar frown lines after conventional injection, but the horizontal forehead line did not improve in Type B. Type B wrinkles improved after additional injections into the frontalis muscle. This study provided novel anatomical findings related to the injection of glabellar frown lines with BoNT. Preliminary analysis and optimized procedures using US will enable more effective and safer injections.

Hefestos five. La identificación de 5 patrones glabelares son clave para un tratamiento de excelente respuesta con toxina botulínica

“…Más allá de estas discrepancias, debidas a que las expresiones faciales obedecen a rasgos culturales que, obviamente, deberán ser tenidos en cuenta en un mundo global. Este autor también propicia el estudio ecográfico del complejo glabelar [14], lo que sin duda puede contribuir a la mayor precisión al colocar las inyecciones, aunque hace la práctica más farragosa y, en ocasiones, se puede perder de vista lo más importante que es ver lo que acontece en la cara en su conjunto.…”

Optimizing Botulinum Toxin A Administration for Forehead Wrinkles: Introducing the Lines and Dots (LADs) Technique and a Predictive Dosage Model

“…Moreover, such an approach might expose the patient to unnecessary pain and to excessive botulinum toxin A (BoNT-A) due to injections into the aponeurotic tissue rather than into the muscle belly [ 20 ]. Therefore, a one-size-fits-all approach falls short in addressing these individual variations [ 21 , 22 , 23 , 24 ].…”

Analysis of facial ultrasonography images based on deep learning

“…Facial esthetic research has been conducted by using deep learning in facial aesthetic prediction 35 – 37 and the facial rejuvenation recommendation system 38 . However, studies on the examination of the facial anatomical structures, which is helpful in diagnosing facial skin disease 39 , preventing iatrogenic side effects, and establishing the safest and most effective treatment plan, are few 1 , 4 , 6 , 8 , 9 , 32 , 40 , 41 . Moreover, several previous deep learning models have not yet established which model is acceptable to classify the facial US images and how many data sets are needed, even though the anatomical information is crucial for some clinical tasks such as deciphering facial structures of US images before a procedure.…”