Does upper blepharoplasty affect frontalis tonicity?

ABSTRACT

BACKGROUND: Frontalis hypertonicity has long been implicated in patients with significant dermatochalasia or blepharoptosis, as evidenced by eyebrow changes that occur after the resection of redundant skin or after blepharoptosis operation. However, whether upper blepharoplasty affects the forehead muscle has not been reported. Thus, this study investigated electrophysiology of the frontalis muscle and eyebrow morphology in a population of patients undergoing double-eyelid blepharoplasty. METHOD: Patients wishing to undergo upper blepharoplasty were recruited for this prospective study between June 2011 and February 2012. The subjects were excluded for complaints of visual obstruction, trauma history, and for any underlying medical condition that would affect eyebrow height or electromyogram (EMG) findings. Eyebrow morphology was ascertained in a standardized photogrammetric evaluation, and the frontalis muscle activity was recorded with needle EMG. These assessments were carried out at preoperation and at 2 weeks, 3 months, and 6 months. Root-mean-square (RMS) indices of various facial expressions were used to normalize the frontalis activity values across individuals. RESULTS: Thirteen patients with a mean age of 55.5 years were recruited. No statistical significance was observed for eyebrow heights at various assessment points. However, EMG recordings have demonstrated a gradual decrease in the proportional RMS index of the frontalis muscle activity. This difference was statistically significant between preoperation and 6 months postoperation (p < 0.05). CONCLUSION: Upper blepharoplasty was associated with gradual decreases in the frontalis muscle activity. A longer follow-up study is needed to evaluate whether this decreased tonicity results in morphologic changes such as decreased forehead wrinkles and depressed eyebrows. This research indicates that upper blepharoplasty has the potential to interfere with those human-computer interaction designs with facial EMG readings as an input.