Preservation of Natural Gingival Pigmentation When Treating Multiple Gingival Recession Defects

Physiologic pigmentation of the oral mucosa and gingiva is clinically manifested as multifocal or diffuse melanin pigmentation with variable amounts appearing in different ethnic groups.¹ The attached gingiva and interdental papilla have the greatest amount of pigmentation.² The amount of gingival pigmentation correlates with the degree of skin pigmentation and is microscopically similar.^2-4

Melaninis responsible for epithelial pigmentation and is produced by melanocytes.⁵ Melanocytes are dendritic cells of neuroectodermal origin.⁶ Only when melanin granules have been transferred to keratinocytes do areas of pigmentation appear. The close relationship between melanocytes and keratinocytes has been called the epidermal-melanin unit.^7,8

Numerous articles describe the depigmentation of gingiva.^9-12 Depigmentation involves removal of the epithelial layer of the gingiva where pigmented cells reside. The primary reason for gingival depigmentation is to improve esthetics. Less common in the literature are cases in which the goal of treatment is to re-establish lost gingival pigmentation.^13-15

Some patients wish to preserve their natural intraoral pigmentation. For these patients, avoiding alterations in gingival and mucosal color is important. Intraoral scars in a visible area may also have an adverse psychosocial impact on individuals.¹⁶ Clinically, scars vary greatly and can range from fine lines to hypertrophic tissue.¹⁷ Especially for patients concerned with maintaining their natural gingival pigmentation, the use of surgical techniques that minimize the risk of scarring and loss of pigmentation would seem prudent.

Connective tissue grafting has been effective in correcting gingival recession defects.¹⁸ A variety of surgical strategies have been employed to obviate recession and achieve root coverage. Some techniques involve the use of incisions that transect areas of gingival pigmentation producing uneven and unnatural amounts of pigmentation in adjacent tissues.^19,20 Pouch and tunnel techniques can be used to avoid traumatization of areas where gingival pigmentation may be present.^21-25 The use of a modified tunnel technique²³ allows for treatment of multiple adjacent recession defects and placement of a large connective tissue graft while leaving the attached gingiva and interdental papillae relatively undisturbed.²⁵ Use of a coronally positioned flap with an acellular dermal matrix (ADM) has been found to have significantly increased gingival thickness and recession defect coverage compared to using a coronally positioned flap alone.²⁶

The purpose of this article is to describe the preservation of gingival pigmentation when treating adjacent gingival recession defects using a modified tunnel technique and a double layer of an ADM.

A 44-year-old African American male patient reported with a chief concern of progressive gingival recession. In addition to his desire to correct the gingival recession defects, he wanted to maintain his natural gingival pigmentation (Figure 1). Teeth Nos. 28 through 30 displayed Miller Class I gingival recession defects.²⁷ Each had approximately 3 mm of facial gingival recession and noncarious cervical lesions (NCCLs). A 1.5-mm diastema existed between teeth Nos. 27 and 28, but the height of the interdental papillae was similar to that of site Nos. 28 through 31. Gingival pigmentation was present in the zone of keratinized gingiva from the distal of teeth No. 27 through 31. The pigmentation was present in the interdental papillae and in the zone of keratinized gingiva.

Local anesthesia was achieved using 2% lidocaine with 1:100,000 epinephrine. Intrasulcular incisions were carefully made using an Orban knife (Hu-Friedy, hu-friedy.com) in the gingival sulcus along the facial surfaces of teeth No. 27 through No. 31. Using a Bard-Parker #15 blade (Hu-Friedy), a vertical incision was made in the facial mucosa between teeth Nos. 27 and 28 (Figure 2). The coronal aspect of this incision began approximately 3 mm apical to the zone of pigmentation. The incision extended approximately 5 mm apically and was entirely in the elastic mucosal tissues. Using the lateral access provided by the vertical incision, an Orban knife and a periotome were used to create a patent tunnel and confirm that it was present to the distal of tooth No. 31. Careful dissection of a full-thickness flap under the keratinized gingiva and partial-thickness flap under the mucosal tissues permitted passive coronal positioning of the mucogingival tissues of teeth Nos. 28 through 30. After this, prominent root surfaces and root irregularities were reduced with sharp hand scaling and root planing.

Based on periodontal probe measurements, two ADM strips (AlloDerm^®, BioHorizons, biohorizons.com) were trimmed to approximately 5 mm in height and 30 mm in length. Both ADM strips were inserted in a layered fashion into the mucogingival tunnel through the vertical access opening (Figure 3). Both ADMs were positioned with their connective tissue side facing outward in a facial direction.²⁵ Accurate placement was confirmed by palpating the ADMs through the mucogingival tissues.

Two 4.0 chromic interrupted sutures were used to approximate the margins of the vertical incision. A continuous 4.0 chromic suture was used to secure the ADMs and overlying mucogingival tissues over the root surfaces. Palpating the ADM strips through the mucogingival tissues with the suture needle enabled verification that the suture had engaged the ADMs. A continuous suture technique was employed that weaved the suture between the teeth. The facial mucogingival tissue was engaged by the suture in a manner that secured it completely over the underlying ADM strips, preventing exposure of the ADM. The site was sutured twice, with the suture beginning distal to tooth No. 31 and extending to the mesial of tooth No. 27. A second continuous suture was placed originating at the mesial of tooth No. 27 extending to the distal of No. 30 (Figure 4). (The author prefers a continuous suture, though multiple mattress sutures would also have been appropriate.)

The patient was prescribed amoxicillin (875 mg) twice a day for 1 week to avoid infection. Ibuprofen (600 mg) was prescribed for discomfort. The patient was instructed to use a 0.12% chlorhexidine rinse for 1 week. In the first week, the patient did not brush the teeth proximate to the surgical site. For the next 5 weeks, the patient was instructed to brush gently. Sutures were removed at the 1-week postoperative appointment. After 6 weeks, the patient was allowed to resume normal brushing.

At approximately 14 weeks postoperative, teeth Nos. 28 through 30 were found to have complete root coverage. Teeth Nos. 28 through 30 had approximately 1 mm to 2 mm of the facial NCCLs exposed. A small amount of scarring was present in the area of the vertical incison. The overall appearance of the mucogival tissues appeared lighter in the areas were the ADMs were positioned. The zone of pigmentation was coronally repositioned along with the gingival margins, but the overall pattern of pigmentation appeared undisturbed. The patient was pleased with the results of his treatment (Figure 5).

It is sensible to preserve existing pigmentation in sites where esthetics matter because repigmentation of such areas may occur slowly and be undesirable for some patients. Dummet and Bolden reported repigmentation in 67% of the areas following intentional depigmentation using a gingivectomy within 33 days.²⁸ Bergamaschi et al concluded that depigmentation using gingival resective procedures offered no permanent results if performed solely for cosmetic reasons.²⁹ Perlmutter and Tal, however, reported depigmentation using a scalpel technique can remain depigmented for more than 7 years.³⁰ A prolonged period to wait for repigmentation could be considered unacceptable for some patients.

The oral mucosa heals rapidly with reduced scarring in comparison with the skin.³¹ Nevertheless, visible scar formation in the oral mucosa can be an undesirable consequence of wound healing.¹⁷ von Arx et al found that submarginal incisions and papilla-saving incisions may produce more scarring than intrasulcular and papilla-based incisons.³² This study also found that, on average, males had less visible scarring than did females. In light of the findings that even small scars in a visible area may have an adverse psychosocial impact on individuals,¹⁶ it would be advisable to use surgical techniques that minimize the effects of scars.

The use of a modified tunnel technique as a means to implant an ADM for the treatment of multiple adjacent recession defects was first described in 2001.²³ Use of this technique to place a double layer of an ADM large enough to treat four adjacent teeth displaying gingival recession was demonstrated in 2016.²⁵ Mahn reported 92.5% root coverage and complete root coverage in 80% of single-site recession defect cases after 4 to 5 years using this technique.³³ In the case presented, a double layer of an ADM was used to treat recession on three adjacent teeth. At 12 weeks postoperative, complete root coverage was essentially achieved. Approximately 1 mm to 2 mm of the NCCLs were still exposed.

As demonstrated in this case, the vertical incision was confined entirely within the non-keratinized and mobile mucosal tissues. The papilla and marginal tissues were intentionally not included. Access for the sharp dissection and ultimately the coronal placement of the mucogingival flap was permitted by the vertical incision. After 12 weeks of healing, virtually no scarring was detected. The patient's natural gingival pigmentation was preserved, root coverage was gained, the risk of further gingival recession was minimized, and improved esthetics resulted.

Natural gingival pigmentation can be preserved when treating gingival recession defects using a modified tunnel technique and a double layer of an ADM.

Douglas H. Mahn, DDS
Private Practice limited to Periodontics and Implantology
Manassas, Virginia