To correct an asymmetric smile, which is caused by abnormal motion of the zygomaticus
major muscle, the toxin is injected in the lateral margin of the muscle to a depth of -4.6 mm (Fig.
This phenomenon was defined as premier expression, which Zhu and Suzuki (2016) studied in response to auditory surprise stimuli in the corrugator supercilii muscle and zygomaticus
The approach based on EMG data uses physical sensors attached to subjects to measure electrical activity of facial muscles, such as the zygomaticus
, the orbicularis oculi, and the corrugator supercilii muscles (Figure 1), associated with smiling, eyelids control, and frowning, respectively.
For example, when observing a happy face, one tends to activate the zygomaticus
major muscles, which turn the corners of the mouth upwards into a smile, as well as the orbicularis oculi muscles, which are responsible for squinting the eyes.
LLSM: levator labii superioris muscle; ZM: zygomaticus
minor muscle; MF: malar fat; M: medial side.
Sharma, "Reconstruction of extensive maxillary defects using zygomaticus
implants," Journal of Oral and Maxillofacial Surgery, vol.
Strack, Martin, and Stepper try to facilitate or inhibit the contraction of the zygomaticus
(smiling) muscle unobtrusively by asking participants to hold a pen in their mouth while they evaluate cartoons.
Specific variants of nevus of Ota have been described in the literature under the names of nevus fuscoceruleus zygomaticus
, plaque-type variant of blue nevus.
The study in journal Appetite says activating the zygomaticus
'smile muscle' in the cheek can improve your mood and stop you snacking.
Movement Muscles involved Kissing Orbicularis oris Blowing Buccinator, orbicularis oris Lifting Frontalis, corrugator supercilii, and upper eyebrows eyelid orbicularis oculi Smiling Risorius, zygomaticus
minor, caninus, levator labii superioris, and orbicularis oris TABLE 2: Examples of results provided by SONRIE.
Blackbeard, "Surgical modifications to the Branemark zygomaticus
protocol in the treatment of the severely resorbed maxilla: a clinical report," The International Journal of Oral & Maxillofacial Implants, vol.
Injecting BoNT too far above the lateral margin of orbit can cause superior eyelid ptosis, while injection too far below can result in zygomaticus
muscle paralysis and lip asymmetry (lip ptosis).