Suber Jessica S, Dinh Trish P, Prince Melanie D, Smith Paul D
Division of Plastic Surgery, Department of Surgery, University of South Florida, Tampa, Florida.
Aesthet Surg J. 2014 Mar;34(3):432-7. doi: 10.1177/1090820X14527603.
Excessive gingival display, or a "gummy smile," is defined as 2 mm or more of gingival exposure upon smiling. Such excessive gingival exposure can be aesthetically unappealing to patients. One factor that contributes to a gummy smile is hyperfunctional lip elevator muscles.
The authors evaluate onabotulinumtoxinA as a safe and minimally invasive treatment for a gummy smile.
In this prospective study, 14 patients (13 women, 1 man) underwent pretreatment photographs and measurements, followed by bilateral injection of onabotulinumtoxinA into their lip elevator muscles. All patients selected for the study had more than 2mm of gingival show and were classified as having a "cuspid smile," where action of all elevator muscles raised the upper lip- like a window shade-to expose the upper teeth and gingival scaffold; these patients were thought to have a better chance for a more superior result. Repeat measurements and photographs were collected at 2 weeks and 3 months. Patient-reported outcomes were collected at 2 weeks, and data were compared to determine the correlative relationship.
An average of 5 units (range, 4-6 U) of onabotulinumtoxinA were injected into 3 sites bilaterally. The average preinjection gingival show over the central incisors and canines were 4.89 mm and 4.25 mm, respectively. Postinjection gingival show decreased to an average of 0.75 mm (85% improvement) and 0.74 mm (83% improvement) over the central incisors and canines, respectively. Average follow-up time was 12.6 days. One patient felt the resulting smile was unattractive and opted not to undergo repeat injections, while all other study participants experienced no negative effects and wished to undergo repeat treatment.
As treatment for a "gummy smile," onabotulinumtoxinA provides an effective, minimally invasive, and safe therapy. This treatment option can lead to significant improvement in smile aesthetics with high patient satisfaction.
牙龈过度外露，即“露龈笑”，被定义为微笑时牙龈暴露2毫米或更多。这种过度的牙龈暴露在美学上可能会让患者不满意。导致露龈笑的一个因素是唇提肌功能亢进。
作者评估A型肉毒毒素作为一种安全且微创的露龈笑治疗方法。
在这项前瞻性研究中，14名患者（13名女性，1名男性）在治疗前拍摄照片并进行测量，随后双侧将A型肉毒毒素注射到他们的唇提肌中。所有入选该研究的患者牙龈外露均超过2毫米，并被归类为“尖牙型微笑”，即所有提肌的动作会像拉起窗帘一样抬起上唇，露出上牙和牙龈支架；这些患者被认为更有可能获得更好的治疗效果。在2周和3个月时收集重复测量数据和照片。在2周时收集患者报告的结果，并比较数据以确定相关关系。
双侧平均在3个部位注射了5单位（范围为4 - 6单位）的A型肉毒毒素。注射前中切牙和尖牙处的平均牙龈外露分别为4.89毫米和4.25毫米。注射后中切牙和尖牙处的牙龈外露分别降至平均0.75毫米（改善85%）和0.74毫米（改善83%）。平均随访时间为12.6天。一名患者认为最终的笑容不美观，选择不再接受重复注射，而所有其他研究参与者均未出现不良反应，并希望接受重复治疗。
作为“露龈笑”的治疗方法，A型肉毒毒素提供了一种有效、微创且安全的治疗手段。这种治疗选择可显著改善笑容美观度，患者满意度高。
3级。
