Gingival depigmentation by free gingival autograft: a case series

Study population

Five systemically healthy female patients aged between 18 to 30 years of age from the outpatient Department of Periodontics, Sharad Pawar Dental College, who were concerned with the unaesthetic appearance of their anterior maxillary gingivae due to melanin hyperpigmentation were treated in this study with free gingival autografts from unpigmented palate. The Dummett Oral Pigmentation Index (DOPI) score was 3 (Figure 1) in all the patients, ie heavy clinical pigmentation (0 – Pink tissue, ie no clinical pigmentation; 1 – Mild light brown tissue, ie mild clinical pigmentation; 2 – Medium brown or mixed brown and pink tissue, ie moderate clinical pigmentation and 3 – Deep brown/blue-black tissue, ie heavy clinical pigmentation). Patients with a habit of smoking, routine use of medications and pregnant or lactating women were excluded from the study. The gingival hyperpigmentation was recorded pre-operatively and 1 week to 6 months post-surgery by measuring the area of hyperpigmentation in square millimetres, which was determined by marking the area of pigmentation on a transparent sheet and then transferring this record onto graph paper. The severity of hyperpigmentation was recorded using Dummett's Oral Pigmentation Index (DOPI). After the completion of surgical procedure, the patients were called next day and after seven days, for an assessment of pain according to the criteria as described by Gedalia et al¹⁷ (0 – No pain; 1 – Discomfort but cannot be called pain; 2 – Mild pain; 3 – Moderate pain; 4 – Severe pain) and at 1 week and 6 months post-surgery for an assessment of gingival repigmentation. Written informed consent was taken from each patient before the surgical procedure.

Surgical procedure

Immediately before the surgical treatment, the patients were made to rinse their mouth with 0.2% chlorhexidine gluconate solution (Rexidine^®, Indoco Remedies Ltd) for one minute. The area subjected to surgery was anesthetized by infiltration anaesthesia, using local anaesthetic solution 2% xylocaine with 1:10,000 epinephrine.

Preparation of recipient site

Under all antiseptic conditions, after giving local infiltration anaesthesia of Xylocaine (Xicaine^®, ICPA Health Products Limited), a shallow horizontal incision was placed using Bard Parker Surgical blade number 15 (Glassvan^®, Niraj Industries Pvt Ltd) over the mucogingival junction on the facial aspect maxilla. The incision was extended to the distal line angle of the canine on both left and right side. The recipient bed was prepared by excising the partial thickness flap of the gingiva from the mucogingival junction to the gingival margin (Figure 2) in such a way that the underlying bone surface would remain covered with periosteum and part of the connective tissue (Figure 3).

Obtaining a free gingival graft from the donor site

Under antiseptic conditions, after giving local infiltration anaesthesia (Xicaine^®), a free gingival graft was harvested from the unpigmented palate between the maxillary first molar and maxillary cuspid. A tin foil template was used on the recipient site to ensure adequate graft size. Using a Bard Parker surgical blade number 15 (Glassvan^®), an incision was made in the palate parallel to the maxillary first molar and canine at a distance of approximately 3 mm apical to the gingival margin. A perpendicular incision was then made to establish the width of the graft for covering the entire area of the recipient site (Figure 4). A split thickness section of 1–2 mm graft was excised using Bard Parker Surgical blade number 15 (Figure 5). The graft was then placed in close contact with the recipient site and held in place by absorbable sutures (4/0 Vicryl, Ethicon, Johnson and Johnson Ltd) (Figure 6). Immediately after surgery the sutured graft was covered with tin foil and periodontal dressing was placed on the recipient site and at the donor site. Analgesics Ibuprofen (Brufen 400 mg, Abbott India Ltd) was prescribed twice daily for 5 days and 0.2% Chlorhexidine gluconate mouthwash (Rexidine^®) for 21 days. Patients were instructed to avoid brushing over the surgical area and were recalled next day and after 7 days (1 week) to assess for pain and 1 week, 6 weeks and 6 months post-operatively for evaluation of repigmentation.

Discussion

Pigmentation of the gingivae may force patients to seek cosmetic treatment. Gingival pigmentation is noticed across all age groups and no gender predilection has been noted. There is no significant difference in the oral pigmentation between males and females.¹⁷ Melanin, which is a brown pigment, is the most common natural pigment contributing to endogenous pigmentation of gingiva. It is a non–haemoglobin-derived pigment formed by cells called melonocytes which are dendritic cells of neuroectodermal origin in the basal and spinous layers.¹⁸ This physiologic pigmentation is probably genetically determined, but the degree of pigmentation is also partially related to mechanical, chemical and physical stimulation.¹⁹ Gingival pigmentation is seen in all races, with a different prevalence in each race and population. The highest rate of gingival pigmentation has been observed in the area of incisors and decreases considerably in the posterior regions.²⁰ It is seen more commonly on the labial surface than on the palatal and lingual surfaces.²¹ Depigmentation of the gingiva is a periodontal plastic surgical procedure whereby the gingival hyperpigmentation is eliminated. The only indication for depigmentation is a patient's demand for improved aesthetics. Demand for cosmetic therapy of gingival melanin pigmentation is common and various methods have been used for depigmentation, including the scalpel technique of surface de-epithelization, cryosurgery, electrosurgery, lasers and free gingival autografts, each with its own merits and limitations.²² The selection of a suitable technique depends solely upon the clinical experience of the operator, patient compliance and affordability and, lastly, an individual's preference. Although cryosurgery and laser therapy achieve satisfactory results, they require highly sophisticated equipment that is costly. The initial results of de-pigmentation procedure by various methods like a surgical blade are highly encouraging, however, repigmentation is a common problem. The mechanism of repigmentation is not understood but, according to the migration theory,^23,24 active melanocytes from the adjacent pigmented tissues migrate to the treated areas, causing repigmentation. This phenomenon seems to be more relevant for depigmentation procedures other than free gingival autografts because, when the non-pigmented palatal mucosa is grafted, the migration of the active melanocytes from adjacent pigmented area is stopped by the basal epithelial layers of the graft. According to Lang and Bernimoulin,²⁵ basal epithelial layers of the graft remain intact and represent the focus of re-epithelization.

In the present case series, free gingival autograft was used for the treatment of gingival pigmentation and the results are in accordance with the previous literature by Tamizi and Taheri 1996¹⁶ and Thakre et al¹⁵ No incidence of repigmentation was observed within 6 months (Table 1) and the post-operative pain (Table 2) was also minimal and subsided completely by the seventh day. However, more long-term and comparative studies are required regarding the efficacy of free gingival graft for the purpose of gingival depigmentation.

Conclusion

In this study, surgical depigmentation using free gingival graft was successful and the patients were satisfied with the results. It is therefore safe to conclude that the procedure adopted was aesthetically acceptable to the patients concerned with no apparent repigmentation in this particular case. All of the patients have reported feeling better about their social appearance, especially when smiling.