Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Mar 17;45(4):414-421.
doi: 10.1093/asj/sjae246.

Exploratory Analysis of Upper Facial Muscle Interplay During Emotional Expressions: Magnetic Resonance Imaging (MRI) Insights From Young, Caucasian, Toxin-naïve Individuals

Daniel J Rams, Mateusz Koziej, Sachin M Shridharani, Elżbieta Szczepanek, Agnieszka Gleń, Tadeusz J Popiela, Monika Ostrogórska, Galen Perdikis, Mikaela V Cotofana, Sebastian Cotofana, Michael Alfertshofer

Exploratory Analysis of Upper Facial Muscle Interplay During Emotional Expressions: Magnetic Resonance Imaging (MRI) Insights From Young, Caucasian, Toxin-naïve Individuals

Daniel J Rams et al. Aesthet Surg J. .

Abstract

Background: Understanding the interplay of muscle activity in the upper face is crucial because it can significantly impact the effectiveness and safety of aesthetic treatments. Traditional injection algorithms typically focus on the general 2-dimensional and 3-dimensional anatomy of muscles, often neglecting the areas where muscles exert the greatest force during facial expressions.

Objectives: The goal of this study was to analyze the location of greatest morphological change in the upper facial muscles including the procerus muscle (PM), corrugator supercilii muscle (CSM), orbicularis oculi muscle (OOM), and frontalis muscle (FM) during various facial expressions.

Methods: A total of 34 healthy young individuals (17 females, 17 males), with a mean age of 23.6 ± 2.4 years [range 20-30], were examined with magnetic resonance imaging (MRI) to assess the length, thickness, and width of the upper facial muscles (PM, CSM, OOM, and FM) for 5 different facial expressions: repose, anger, joy, surprise, and sadness.

Results: Facial muscle thickness is a key indicator of activity during expressions such as anger, joy, surprise, and sadness. During anger, the PM and CSM decreased in length and width but increased in thickness, whereas the FM passively contracted to stabilize the expression. The OOM showed increased thickness in its medial, inferior, lateral, and superior portions during various expressions, with specific regions activating differently depending on the expression, such as the medial and lateral parts during surprise and the inferior and lateral parts during joy. The medial third of the CSM was the most active region during contraction.

Conclusions: Upper facial muscles-as either agonists or antagonists-act together during facial expressions to stabilize facial expressions, emphasizing the need to assess both groups in neuromodulator treatments. The medial third of the corrugator supercilii shows the most significant MRI changes, making it the primary target for injections.

PubMed Disclaimer