Botulinum Toxin Type A for Treatment of Masseter Hypertrophy: Volumetric Analysis of Masseter Muscle Reduction over Time

BACKGROUND: There has been increasing interest in facial contouring procedures throughout Asian countries. As such, botulinum toxin A injections for masseteric hypertrophy have become a common procedure provided to patients who desire non-surgical correction of a square-angled mandible. We published a retrospective review of our initial results and our technique and treatment protocol in 2005. We also completed a long-term follow-up of the results (average follow-up period of 4.28 years) and the efficacy of repeated injections in 2010. The purpose of the current study is to systematically evaluate the changes to the masseter muscle at weekly intervals to determine the physiologic effects of botulinum toxin A injection. METHODS: Eight patients were prospectively followed on a weekly basis after botulinum toxin A injection for masseteric hypertrophy. Eight patients were followed for 15 weeks and four patients were followed for 25 weeks. Changes in the thickness of the muscle were recorded and analyzed. RESULTS: A reduction in the muscle thickness was found during the clenching phase of the muscle in the first week followed by a reduction in thickness during the resting phase in the second week. The reduction in muscle thickness continued until the eleventh week after which there was a gradual, but incomplete, return of muscle thickness over the study period. CONCLUSIONS: There is a predictable, phasic reduction in muscle thickness after botulinum toxin A injection for masseteric hypertrophy. This reduction first occurs during the clenching phase followed by a concomitant reduction during the resting phase. Maximal size reduction occurs at 11 weeks followed by gradual muscle size recovery.

The Relationship Between Eyebrow Elevation and Height of the Palpebral Fissure: Should Postoperative Brow Descent be Taken into Consideration When Determining the Amount of Blepharoptosis Correction?

BACKGROUND: Combining blepharoptosis correction with double eyelid blepharoplasty is common in East Asian countries where larger eyes are viewed as attractive. This trend has made understanding the relationship between brow position and height of the palpebral fissure all the more important in understanding post-operative results. In this study, authors attempt to quantify this relationship in order to assess whether the expected postoperative brow descent should be taken into consideration when determining the amount of ptosis to correct. METHODS: Photographs of ten healthy female study participants were taken with brow at rest, with light elevation and with forceful elevation. These photographs were then viewed at 2 x magnification on a computer monitor and caliper was used to measure the amount of pull on the eyebrow in relation to the actual increase in vertical fissure of the eye. RESULTS: There was a positive, linear correlation between amount of eyebrow elevation and height of the palpebral fissure, which was statistically significant. Brow elevation increased vertical fissure, and thereby aperture of the eye, by 18%. CONCLUSIONS: Although the eye-opening strength as well as height of the palpebral fissure is improved with ptosis repair, the true effectiveness of ptosis surgery is diminished by the associated descent of the brow from relief of the involuntary frontalis muscle action and this should be taken into account prior to surgical intervention. Regardless, the combination of frontalis muscle relaxation and the increased eye-opening strength from ptosis repair gives the eye and the periorbital region a more natural look.

Mild Ptosis Correction with the Stitch Method During Incisional Double Fold Formation

BACKGROUND: Numerous methods exist for simultaneous correction of mild blepharoptosis during double eyelid surgery. These methods are generally categorized into either incisional (open) or non-incisional (suture) methods. The incisional method is commonly used for the creation of the double eyelid crease in patients with excessive or thick skin. However, concurrent open ptosis correction is often marred by the lengthy period of intraoperative adjustment, causing more swelling, a longer recovery time, and an increased risk of postoperative complications. METHODS: The authors have devised a new, minimally invasive technique to alleviate mild ptosis during incisional double eyelid surgery. The anterior lamella is approached through the incisional technique for the creation of a double eyelid while the posterior lamella, including Muller's and levator muscles, is approached with the suture method for Muller's plication and ptosis correction. RESULTS: The procedure described was utilized in 28 patients from June 2012 to August 2012. Postoperative asymmetry was noted in one patient who had severe preoperative conjunctival scarring. Otherwise, ptosis was corrected as planned in the rest of the cases and all of the patients were satisfied with their postoperative appearance and experienced no complications. CONCLUSIONS: Our hybrid technique combines the benefits of both the incisional and suture methods, allowing for a predictable and easily reproducible correction of blepharoptosis with an aesthetically pleasing double eyelid.