Elimination of a “Gummy Smile” With Crown Lengthening and Lip Repositioning

A smile that displays more than 3 mm of gingiva is considered unattractive by many patients.¹ Controlling the gingival contours and the amount of gingival display is important in the development of an esthetic smile. A combination of approaches may be necessary to achieve ideal results.^2-4

Guidelines for tooth proportions have been proposed to aid with smile design.^5,6 Suggestions for teeth arrangements according to age, sex, and personality have also been presented.⁷ In addition, studies have been conducted to determine the perception of laypeople and dental professionals about changes in the size of anterior teeth, their alignment, and their relationship to the surrounding soft tissues.^8,9 This information can be utilized as a starting point for smile design.

Clinical crown lengthening involves the removal of hard and soft periodontal tissues to gain supracrestal tooth length and to re-establish the biologic width.¹⁰ In cases with high crestal bone levels,¹¹ removal of crestal bone is necessary to expose the entire anatomic crown. In addition, reduction of facial bony prominences may be necessary to achieve a more esthetic soft-tissue architecture.¹²

Lip repositioning involves the removal of a band of nonkeratinized mucosa from the maxillary buccal vestibule. The lip mucosa is then sutured to the mucogingival line, resulting in a more shallow vestibule.^13-15 Muscle pulls are limited, which restricts gingival display during smiling.

This article describes a case in which a combination of clinical crown lengthening and lip repositioning is used to correct excessive gingival display when the patient smiles.

A 58-year-old female presented with a chief complaint of a “gummy smile” (Figure 1). Her maxillary teeth were proportionately short in appearance. She had a thick periodontal soft-tissue biotype with prominent bony ridges, which created a bulbous appearance (Figure 2). Her high lip line exposed this architecture when smiling.

To begin the crown-lengthening surgery, profound local anesthesia was obtained using 2% lidocaine with 1:100,000 epinephrine. Initial incisions were made using a #15 Bard-Parker scalpel blade on the facial aspect of teeth Nos. 2 through 15. The incision line followed the contours and position of the cemento-enamel junction (CEJ). The excess gingiva was removed (Figure 3).

Upon reflection of full-thickness mucogingival flaps, thick crestal bone levels close to the CEJ were noted (Figure 4). Crestal bone levels on the facial aspects of the teeth were recontoured to approximately 3 mm from the CEJ. This was accomplished primarily using round carbide burs. Prominent bony ridges on the facial alveolus were festooned and thinned out to create a more natural architecture (Figure 5). To maintain the volume of interdental papillae, the interdental bone and gingiva were minimally treated. The gingival flaps were secured in the proper position using a continuous 4.0 chromic gut suture (Ethicon, www.ecatalog.ethicon.com)(Figure 6).

The patient was prescribed ibuprofen 600 mg for discomfort, amoxicillin 875 mg twice daily for 10 days, and instructed to rinse twice daily with 0.12% chlorhexidine gluconate (Peridex™, 3M, solutions.3m.com) for 1 week. Sutures were removed after 1 week of healing. At 12 weeks post-treatment, the surgical site appeared to have healed well and was free of inflammation (Figure 7). The patient was happy with the improved soft-tissue contours and was ready for the lip-repositioning surgery.

Profound local anesthesia was obtained using 2% lidocaine with 1:100,000 epinephrine. A sterile surgical marker was used to outline the band of mucosa to be excised (Figure 8). This band extended between the maxillary first molars. The width of the band was approximately 8 mm. The epithelial layer of the mucosa was removed using a #15 scalpel blade (Figure 9). The wound margins were sutured together with coated VICRYL™ 4.0 sutures (Ethicon) (Figure 10).

The patient was given the same prescriptions as those used following the clinical crown-lengthening surgery. At the 2-week postoperative appointment, sutures were removed. At the 8-week re-evaluation, the surgical site was found to have healed very well (Figure 11). When the patient was smiling, the new lip position exposed significantly less gingiva and eliminated the gummy appearance. The superior lip also appeared fuller and more attractive (Figure 12).

Excessive gingival display when the patient is smiling can be the result of several conditions.¹⁶ These conditions include gingival hyperplasia, altered passive eruption, vertical maxillary excess, hypermobile upper lip, and short upper lip. Tjan and colleagues found in a study of 450 adults aged 20 to 30 years that 7% of men and 14% of women were found to have a gummy smile.¹⁷

In the case presentation above, the patient was found to have a thick soft-tissue biotype with high crestal bone levels, such as those described in a 1994 article by Kois.¹¹ In order to correct this condition, clinical crown lengthening was performed to expose the entire anatomical crown. The crestal bone levels were recontoured to achieve stable gingival margins and accommodate traditional expectations regarding biologic width.¹⁰

In addition to the clinical crown lengthening, prominent bony areas of the alveolar ridge were reduced to minimize the bulbous appearance of the soft-tissue architecture. This effectively reduced the thick soft-tissue biotype.¹² The results of this treatment improved the clinical tooth proportions and overall appearance of the soft-tissue architecture.

At 12 weeks of healing, the desired tooth proportions and final gingival margins were achieved and considered stable.¹⁰ The patient was ready at this point for lip-repositioning surgery to reduce the gingival display. The amount of epithelium to be excised was determined by doubling the amount of gingival display.¹⁵ In this case, the band was approximately 8 mm wide. Individual sutures were placed to ensure the stability of the wound margins.

Lip repositioning was first reported as a correction of a gummy smile in 1973 by Rubinstein and Kostianovsky.¹⁸ The original technique was modified in 1983 by including muscle resection and nerve repositioning.¹⁹ The goal was to make lip-repositioning results more stable. In 2006 and 2007, the use of an elliptical surgical design was described.^13,14 The surgical design used in the present case was described in 2010 and involved removing an elliptical band of epithelium whose width was twice the gingival display.¹⁵

Lip-repositioning surgery is a safe procedure with low morbidity.²⁰ This surgery was designed to have fewer complications compared to orthognathic surgery.¹⁸ Complications of lip-repositioning surgery include discomfort, ecchymosis, and swelling of the upper lip.^13,20 Rosenblatt and Simon¹³ reported that one patient developed a mucocele that resolved without treatment. High satisfaction with treatment after 2.5 years was reported by Silva and colleagues²⁰; 70% of patients considered the postoperative amount of gingival display to be “about right,”²⁰ and 90% of patients said they would undergo the procedure again.²⁰ Case reports show good short-term results.^13-15,20 Long-term studies are needed, however, to determine the stability of the lip-repositioning techniques.

While this procedure is most commonly referred to as “lip repositioning,” the term “lip stabilization” may be more appropriate. By limiting the mobility of the lip when smiling, the lip position could be considered stabilized in a more esthetically pleasing position. It is the opinion of the author that patients find the term lip stabilization more agreeable than lip repositioning.

A combination of clinical crown lengthening and lip repositioning can be an effective method of reducing gingival display and improving the appearance of the smile.

Douglas H. Mahn, DDS
Private Practice
Manassas, Virginia