Use of modified lip repositioning technique associated with esthetic crown lengthening for treatment of excessive gingival display: A case report of multiple etiologies.

Excessive gingival display during smile can result in compromised esthetics. This study aims to report a case of excessive gingival display with multiple etiologies treated by means of modified lip repositioning technique associated with esthetic crown lengthening. A 23-year-old female patient, with 5-mm gingival display during smile caused by altered passive eruption and hypermobility of the upper lip, underwent the modified lip repositioning technique associated with gingivectomy followed by flap elevation and ostectomy/osteoplasty. Seven months after the second procedure, the patient had her esthetic complaint solved appearing stable in the observation period. The modified lip repositioning technique is an effective procedure employed to reduce gingival display and when associated with esthetic clinical crown lengthening, can appropriately treat cases of gummy smile.

INTRODUCTION

he smile is a facial expression that originates from many human emotional aspects. For societies that value esthetics, smiling may function as a rule to achieve a good first impression. Many factors are associated with a pleasant smile, for instance, the upper and lower lip line, gingival health, correct anatomy, and teeth proportion.[1] Amount of gingival display is among the aspects that comprises smile esthetics and plays an important role in smile attractiveness.[2]

In this context, excessive gingival display, also known as a gummy smile, affects approximately 10% of the population aged between 20 and 30 years old.[3] It is highly prevalent among women and decreases with age due to loss of muscle tone in both upper and lower lips.[4] It may be caused by hypermobility of upper lip elevator muscles; altered passive eruption (APE); accentuated vertical maxillary growth; maxillary dentoalveolar extrusion; and thin upper lip.[5]

Different treatment methods have been developed to decrease gingival display. Polo,[6] Hwang et al.,[7] Suber et al.,[8] and Dinker et al.[9] prevented the muscles responsible for gingival display from contracting by injecting botulinum toxin. Cairo et al.,[10] Batista et al.,[11] and Ribeiro et al.,[12] increased the crown length and as a consequence, decreased gingival display, by means of esthetic crown lengthening in patients with APE. Rosenblatt and Simon,[1] Gupta et al.,[13] Dayakar et al.,[14] and Gaddale et al.[15] removed a strip from the upper labial mucosa, which diminished upper lip mobility. Ishida et al.,[16] by means of myotomy, sectioned the upper lip elevator muscles and the labial frenulum, causing less lip mobility during smile.

Ribeiro-Júnior et al.[17] recently demonstrated a conservative surgical technique employed to treat excessive gingival display. In their procedure, a modification of the technique proposed by Rosenblatt and Simon,[1] two mucosa strips are removed bilaterally to the midline, preserving the maxillary labial frenulum, and apically suturing the mucosa. In a series of cases, Silva et al.[18] demonstrated a mean gingival display reduction of 4.4 mm employing the aforementioned technique, achieving satisfactory esthetic outcomes for the patients.

Nevertheless, cases of the excessive gingival display with multiple etiologies require more than one technique to achieve desirable outcomes. Few case reports[1719] have used the lip repositioning method associated with gingivectomy for the treatment of excessive gingival display. However, to the best of our knowledge, no study used the modified lip repositioning associated with gingivectomy and ostectomy to treat such cases.

Thus, the present report aims to demonstrate, for the first time, a case of excessive gingival display of multiple etiology, that is, APE and hypermobility of the upper lip, treated by means of modified lip repositioning associated with gingivectomy followed by flap elevation and ostectomy/osteoplasty.

CASE REPORT

A 23-year-old female patient sought dental treatment complaining about short teeth and a significant amount of gingiva that appeared when she smiles. Patient was in good systemic and periodontal health, with normal upper lip length and harmonious facial thirds. After clinical examination, a 5 mm gingival display during smile was detected [Figures 1 and 2]. Gingival contour was irregular, with some teeth presenting disproportionate crown height/width ratio and quadratic shape [Figure 3]. Periodontal probing revealed that cementoenamel junction (CEJ) was localized 2 mm apically from the gingival margin and <1 mm coronally from the alveolar bone crest (ABC), suggesting a case of APE. Additionally, it was observed 10 mm of lip rising during smile, which suggested a case of hypermobility of the upper lip elevator muscle. After all data had been collected, the patient was diagnosed with excessive gingival display caused by APE associated with upper lip elevator muscle hypermobility.

Figure 1

Extraoral initial front view showing 5 mm gingival display at smiling

Figure 2

Extraoral initial lateral view showing 5 mm gingival display at smiling

Figure 3

Intraoral initial view demonstrating irregular gingival contour and teeth with quadratic shape

The treatment plan included modified lip repositioning technique[17] associated with esthetic crown lengthening. The surgeries were carried out in different moments due to the need for stabilizing the lip after the repositioning procedure.

Paracetamol 750 mg was prescribed for lip repositioning surgery as a preanesthetic medication. Extra-oral antisepsis was performed with 2% chlorhexidine solution, whereas intra-oral antisepsis was performed with 0.12% chlorhexidine rinse for 1 min. Local infiltration with 2% lidocaine associated with 1:100.000 epinephrine was used for anesthesia.

Lip repositioning surgery was initiated at the right side of the maxilla, with a partial-thickness horizontal incision, 1 mm coronally to the mucogingival line, from the midline to the first molar. Afterward, two vertical incisions were made at the end of the first incision, extending 10–12 mm apically. At last, a horizontal incision, parallel to the first one and linking the vertical incisions previously performed [Figure 4], was made. The outlined mucosa was removed, exposing the underlying connective tissue [Figure 5]. The procedure was repeated on the left side [Figure 6] and continuous interlocking sutures (polyglactin 910 5/0) were used to stabilize the mucosa to the gingiva [Figure 7].

Figure 4

Horizontal incision from the midline to the first molar

Figure 5

Epithelium removed, exposing the connective tissue

Figure 6

Epithelium removed on both sides of the maxilla

Figure 7

Mucosa stabilization and suture

Analgesic (paracetamol 750 mg qid) and 0.12% chlorhexidine rinse (twice daily for 1-week) were prescribed. Additionally, the patient was advised to apply ice packs, avoid mechanical trauma, consume only soft food, and keep lip movement to a minimum at smiling and talking for 2 weeks.

Patient was enrolled in a professional plaque control program, scheduled weekly for the first 4 weeks.

After 2 months [Figure 8], esthetic crown lengthening surgery was made by means of gingivectomy followed by flap elevation and ostectomy/osteoplasty. It initiated with the demarcation of CEJ position. Subsequently, an inverted bevel incision was made following CEJ anatomy, from tooth #15 to #25 [Figure 9], followed by intra-sulcular incision, removal of outlined marginal gingiva [Figure 10], and mucoperiosteal flap dissection [Figure 11]. Instruments (#2 Fedi and #36/37 Rhodes chisels) were used for ostectomy and osteoplasty aiming to leave a distance of 2 mm between CEJ and ABC [Figure 12]. To finish the procedure, mattress suture (poligalactina 910 5/0) was used for flap stabilization [Figure 13].

Figure 8

Healing 60 days after lip repositioning surgery

Figure 9

Inverted bevel incision following cementoenamel junction anatomy from #15 to #25

Figure 10

Outlined marginal gingival tissue removed

Figure 11

Mucoperiosteal flap dissection

Figure 12

Ostectomy and osteoplasty made with hand instruments leaving a distance of 2 mm between cementoenamel junction and alveolar bone crest

Figure 13

Flap repositioned and stabilized with vertical mattress sutures

Analgesic (paracetamol 750 mg qid) and 0.12% chlorhexidine rinse (twice daily for 1-week) were prescribed. Suture was removed after 1-week.

Patient was enrolled in a professional plaque control program, scheduled weekly for the first 4 weeks, and then monthly until 7 months.

After 9 months of the lip repositioning surgery and 7 months of the esthetic crown lengthening procedure, a reduction in gingival display during smile and longer teeth were observed as well as esthetic improvements and patient's satisfaction was achieved [Figure 14].

Figure 14

Postoperative view 9 months after lip repositioning and 7 months after esthetic crown lengthening

DISCUSSION

The present study reported a case of excessive gingival display with multiple etiologies causing esthetic concerns for the patient about her smile. The modified lip repositioning technique, proposed by Ribeiro-Junior et al.,[17] was used to treat the hypermobility of the upper lip. It is a more conservative technique that allows the labial frenulum to be preserved, thus, establishing greater tissue stability.[1718] Moreover, gingivectomy followed by flap elevation and ostectomy/osteoplasty was performed to increase crown length.[1112] The association of these two methods allowed satisfactory final outcomes in terms of patient satisfaction and decrease in the gingival display.

The literature reports other treatment methods for excessive gingival display due to hypermobility of the upper lip.

Botulinum toxin has yielded satisfactory results, given that it blocks the muscular activity. However, this technique has a transitory effect (6–7 months) and for this reason, the toxin must be reapplied periodically to maintain the desired outcome.[6789]

In a more invasive way, the myotomy technique[16] also produces the desired results, however, it is a much more aggressive procedure with the irreversible outcome and great potential for morbidity.[1618]

More recently, Storrer et al.[20] proposed a new surgical technique with the combination of gingival recontouring and the traction and containment surgery of the elevator muscle of upper lip and wing of the nose. In a case report, the authors demonstrated good outcomes after 1-year with this technique that is less aggressive than myotomy.

Therefore, the modified lip repositioning technique[17] becomes a feasible alternative for patients who seek less gingival display during smile. The results are predictable, stable in the short term, and achieve patient's satisfaction.[18] Some case reports[13141521222324] and case series[1825] have demonstrated that the original[1] and the modified[17] techniques present consistent outcomes. However, there is no study in the literature showing more than 1-year of follow-up and a long-term stability still needs to be demonstrated.

The lip repositioning technique can also be used to treat patients with excessive gingival display for maxillary complete arch fixed implant-supported prostheses[26] and a reversible trial can be used, previous to the lip repositioning surgery, to preview the final outcome.[1927]

The esthetic crown lengthening is a technique widely used to treat cases of APE,[101112] a condition that affect approximately 12% of the population[28] with a possible genetic correlation.[29] Usually, it contemplates the use of gingivectomy or apically repositioned flap associated or not with ostectomy, depending on the type of APE.[1030]

APE is classified into two types.[30] Type 1 is characterized by short crowns and excessive amount of attached gingiva. Type 2 is associated with a normal gingival dimension. Moreover, APE can be sub-classified into Classes A and B. In Class A, the distance between ABC and CEJ is >1 mm, while in Class B this distance is shorter than 1 mm, not allowing a correct distance for biological width.

In the present case report, the patient presented a case of type 1B APE, that is, a great amount of attached gingiva and a short distance between ABC and CEJ. In this case, treatment plan must include gingivectomy and ostectomy/osteoplasty.[101112] If the ostectomy is suppressed, the return of gingiva to its original position, covering the tooth, can be expected.

Other authors reported the association of lip repositioning with gingivectomy alone for the treatment of excessive gingival display.[1719] However, to the best of our knowledge, the use of the modified lip repositioning technique associated with gingivectomy and ostectomy has not been previously reported for treatment of excessive gingival display.

If the ostectomy is done as an open flap surgery, the lip repositioning has to be done in a different moment, due to the need of an attached gingival tissue to stabilize the lip flap. On the other hand, the ostectomy can be made as a flapless surgery,[12] in this case both techniques can be made at the same surgical procedure.

CONCLUSION

The use of modified lip repositioning technique associated with esthetic crown lengthening is an effective procedure for reducing gingival display caused by hypermobility of upper lip and APE. Understanding the etiology and possibilities of treatment is essential to define treatment protocol, mainly in cases of multiple etiologies.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.