upper lip raiser vs. nasolabial furrow deepener
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complications of levator labii superioris & zygomaticus minor muscles
In the land of facial expressions, there are many, many facial actions that are easy to confuse and difficult to tell apart. Among the contenders for most-difficult-to-distinguish-facial-actions are two upper lip elevators known as upper lip raiser and nasolabial furrow deepener. (These terms are defined by the Facial Action Coding System – FACS.)
Though upper lip raiser and nasolabial furrow deepener are each driven by distinct muscles (levator labii superioris and zygomaticus minor, respectively) their associated muscles are situated in very close proximity. When muscles with overlapping primary expressive outcomes (both lift the upper lip and alter the shape of the nasoalabial furrow) are situated so closely together, differentiating their movements is often challenging.
Distinguishing upper lip raiser from nasolabial furrow deepener is further complicated when we consider anatomical variation. Though all facial muscles are prone to diversity in multiple aspects, zygomaticus minor is documented as one of the more variable facial muscles. Zygomaticus minor varies in terms of its:
- shape.
- size.
- relationship with neighboring muscles (including levator labii superioris).
- presence or absence in individuals.
lip elevator pitch
As mentioned, both levator labii superioris (upper lip raiser) and zygomaticus minor (nasolabial furrow deepener) are upper lip elevator muscles. Though there are three upper lip elevators recognized in anatomy (levator labii superioris, levator labii superioris alaeque nasi, and zygomaticus minor), in art and technology, upper lip raiser (via levator labii superioris) is often designated as the go-to action for lifting the top lip. This designation is likely due to a bias created by upper lip raiser‘s name. From the names of the other two lip elevators, nasolabial furrow deepener and nose wrinkler, it is not readily obvious that these actions are just as much of lip elevators as upper lip raiser. As a consequence, name-based assumptions have led to the unfortunate domination and widespread overuse of upper lip raiser as the main upper lip raising action in art and tech. What’s in a name? A lot of assumptions.
For more on upper lip raiser overuse, see Building Smiles – The Right Way.
let's get visual
When observing facial expressions in the wild, nasolabial furrow deepener is not easy to pick out. On top of this, the FACS Manual and most anatomy documents/textbooks have done a poor job of defining and providing visual examples for nasolabial furrow deepener / zygomaticus minor. In aims to help clarify the differences between upper lip raiser and nasolabial furrow deepener, I have provided a set of side-by-side GIFs that highlight their differences in movement and appearance.
The “Unmarked Set” GIF shows upper lip raiser on the left and nasolabial furrow deepener on the right. The top and bottom images feature multiple angles of each action occurring at the same moment in time (i.e. top image for upper lip raiser is occurring at the same time as the bottom image; same with nasolabial furrow deepener). These mutli-angle shots were achieved with a mirror.
Without markers, these two motions can appear dizzyingly similar. Observe the “Pores and Feature Highlights” and “Pores, Feature Highlights, and Arrows” GIFs. From the markings on these GIFs (i.e. pores, lip highlights, and arrows), you can see that though upper lip raiser and nasolabial furrow deepener both pull the top lip upwards, they do so in distinctly different manners. Further specifications are called out in the text below the marked GIFs.
Unmarked Set
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Pores and Feature Highlights
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In the marked GIF above, watch how the:
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NOTE: For facial landmark clarification, refer to the facial landmark image diagram below.

Pores, Feature Highlights, and Arrows
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In the marked GIF above, arrows have been added to bring attention to the:
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Observe how in:
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- TEXT REMOVED FROM PREVIEW.
closing thoughts
As you can see, upper lip raiser and nasolabial furrow deepener share many similarities but when observed closely, are contrasted by some fundamental differences.
When observing the fast-paced faces of the natural world, it can sometimes be impossible to differentiate these movements. However, luckily we have great quality phone cameras and tons and tons of recorded video footage on social media and streaming services to source references from. Now that you know what key differences to look for, you can more easily extrapolate features from video footage and build more informed reference libraries!
If you would like more personalized assessments and help, please reach out to me for consulting (facetheFACS@melindaozel.com).
notes
Primary expressive outcome was first defined in Stylized Facial Expression Design and refers to “the primary feature-based changes integral to communicating the presence of a particular facial action.”
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