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Spontaneous smile assay effective in patients with facial paralysis

Using humorous video clips, researchers created a spontaneous smile assay that elicited smiles in 96.7% of patients with facial paralysis, according to study findings.

The researchers initially administered a series of short video clips to individuals through the use of an online survey service between Jan. 1, 2014, and March, 31, 2014, in which respondents rated the funniness of each clip using a visual analog scale ranging from zero to 100. The top four videos were compiled into a spontaneous smile assay and administered to a control group of 100 healthy individuals and a study group comprising 30 patients with facial paralysis. Two subgroups within the facial paralysis group included patients with flaccid facial paralysis (FFP), or no volitional movement in any division of the facial nerve on the affected side, and the nonflaccid facial paralysis group, or patients with synkinesis, hypertonicity and poor voluntary and/or involuntary motor control after facial nerve insult and recovery.

The researchers analyzed the ability of the assay to elicit at least one spontaneous smile, and smile excursion was calculated and recorded in each group.

In the control group, the assay provoked at least one oral commissure movement in 95% of patients, which reflected a spontaneous smile. Of the 95 patients who smiled during the first video, 91 (95.8%) produced another smile during the second viewing, according to the researchers. Within the control group, mean smile excursion with spontaneous smile was 9.08 mm.

At least one spontaneous smile was produced in 29 patients (96.7%) within the facial paralysis group. In FFP patients, mean oral commissure excursion with spontaneous smile on the healthy side of the face was 6.72 mm, whereas patients with nonflaccid facial paralysis had a mean oral commissure excursion with spontaneous smile of 9.64 mm on the healthy side.

The researchers wrote that an outcome measure that causes a spontaneous smile is important in establishing whether a one-stage free gracilis muscle transfer and nerve transfers have the potential to produce a spontaneous smile.

The assay was successful in provoking a spontaneous smile in nearly all patients, regardless of etiology and duration of paralysis. The researchers concluded that this tool may aid future research in tracking the ability of facial reanimation procedures to restore a spontaneous smile - by Abigail Sutton

Disclosure: The researchers report no relevant financial disclosures.