Introduction:

The purpose of this study is to test the efficiency of a new technique for treatment of the gummy smile. The procedure involves the myotomy of the elevator of the upper lip muscle and soft tissue remodeling.

Method:

Ten female patients with excessive gingival exposure were operated between February 2008 and August 2008. Patients with severe vertical maxillary excess or severe altered gingival/ anatomic crown relationship were excluded from the study.

 Patients were filmed using a high definition digital video camera before and 6 months after the surgery.  They were asked to perform their fullest smile and the maximum gingival exposures were measured. Images were analyzed using the ImageJ® software (1).

Technique:

The procedure can be performed under local anesthesia. Two 5mm incisions are made at the inner lateral aspect of the nostrils (figure 1A), and one in the columella. Using a periosteum elevator, the gingival mucosa is freed from the maxilla (Figure 1B). Skin and subcutaneous tissue is blunted dissected from the underlying musculature of the upper lip. A frenuloplasty is performed to lengthen the frenulum of the upper lip (Figure 1C). Both elevator of the upper lip muscles are dissected and divided (Figure 1D).

Results:

The postoperative course was uneventful in all of the patients.  There was a reduction of the gingival exposure in all patients with an esthetic improvement of the smile (figure 2-4). The mean gingival exposure before the surgery was 5.16 ±1.67 mm, and six months after the surgery, 1.89±1.74cm (figure 5). The mean gingival exposure reduction was 3.27± 1.25 mm, ranging from 1.59 to 4.83 mm

Discussion:

                Treatment of excessive gingival display usually involves large procedures like Le Fort impaction or maxillary gingivectomies. Often, the alteration is milder and does not justify such procedures. The authors propose a technique that diminishes the muscular function of the elevator of the upper lip muscle and rearrange the soft tissue in a lower position.

The myotomy results in a similar effect caused by the Botulinum toxin type A injection described to treat this kind of alteration (2). Miskinyar, in 1982 (3), described a technique to correct the gummy smile based on resection of the elevator of the upper lip muscles alone, but did not present long term results. Ellenbogen and Swara (4) experienced recurrence of the gummy smile 6 months after of the myotomy, and suggest that the use of a spacer (cartilage or prosthetic material) would prevent the stumps of the muscle from being reunited.

The authors believe that soft tissue repositioning plays a major role in keeping the lip lower. Subperiostal dissection lowers the superior gingival sulcus, diminishing the total height of the anterior maxillary gingival dimension. Subcutaneous dissection from the lip musculature helps to lower the whole upper lip. The frenuloplasty lengthen the upper lip, helping to cover the exposed gum.

According to Peck et al (5), the ideal gingival exposure during smile is 1-2 mm. In our study, the mean exposure of the gingiva 6 months after the surgery was 1.89 mm, and all patients presented a reduction on the gingival exposure during smile. These results suggest that this technique is efficient in diminishing the amount of exposed gum in the full smile, although sometimes the main cause (vertical maxillary excess, an altered gingival/ anatomic crown relationship)

Figure 1- A- Incision been made at the inner lateral aspect of the nostrils. B- Subperiosteal dissection performed using an elevator. C- Incision of the frenulum of the upper lip. D- Left elevator of the upper lip muscle dissected and ready to be divided.

Figure 2- Left- Preoperative frontal view of a patient performing her fullest smile. Right- Postoperative view 6 months the surgery.

Figure 3- Left- Preoperative frontal view of a patient performing her fullest smile. Right- Postoperative view 6 months after the surgery.

Figure 4- Left- Preoperative frontal view of a patient performing her fullest smile. Right- Postoperative view 6 months after the surgery.

Figure 5- Graphic representing the maximum gingival exposure of the smile of each patient operated in this series. Red bars show the preoperative measurements; and pink ones, the postoperative measurements (in centimeters).

References:

1-Abramoff MD, Magelhaes PJ, Ram SJ. Image Processing with ImageJ.
Biophotonics International ; 11( 7): 36-42, 2004.

2-Polo M. Botulinum toxin type A in the treatment of excessive gingival display. Am J Orthod Dentofacial Orthop. 127(2):214-8, 2005.

3-Miskinyar SA.  A new method for correcting a gummy smile. Plast Reconstr Surg. 72(3):397-400, 1983.

4-Ellenbogen R, Swara N. The improvement of the gummy smile using the implant spacer technique. Ann Plast Surg. 12(1):16-24, 1984.

5-Peck S, Peck L, Kataja M. Some vertical lineaments of lip position. Am J Orthod Dentofacial Orthop. 101(6):519-24, 1992.