The Classic Technique.

Step 1: Prepare the recipient site. The purpose of this step is to prepare a firm connective tissue bed to receive the graft. The recipient site can be prepared by incising at the existing mucogingival junction with a #15 blade to the desired depth, blending the incision on both ends with the existing mucogingival line. Periosteum should be left covering the bone.

Another technique consists of outlining the recipient site with two vertical incisions from the incised gingival margin into the alveolar mucosa. Extend the incisions to approximately twice the desired width of the attached gingiva, allowing for 50% contraction of the graft when healing is complete. The amount of contraction depends on the extent to which the recipient site penetrates the muscle attachments. The deeper the recipient site, the greater is the tendency for the muscles to elevate the graft and reduce the final width of the attached gingiva. The periosteum along the apical border of the graft is sometimes penetrated in an effort to prevent postoperative narrowing of the attached gingiva.

The #15 blade is used to incise along the gingival margin to separate a flap consisting of epithelium and underlying connective tissue without disturbing the periosteum. Extend the flap to the depth of the vertical incisions. Suture the flap where the apical portion of the free graft will be located. Three to four independent gut sutures are placed. The needle is first passed as a superficial mattress suture perpendicular to the incision and then on the periosteum parallel to the incision (Figure 63-4).

An aluminum foil template of the recipient site can be made to be used as a pattern for the graft.

Grafts can also be placed directly on bone tissue. For this technique, the flap should be separated by blunt dissection with a periosteal elevator. The advantages of this variant are less postoperative mobility of the graft, less swelling, better hemostasis,³² and 1.5 to 2 times less shrinkage.^52,53 However, there is a healing lag period that is observed for the first 2 weeks.^21,22,36

Step 2: Obtain the graft from the donor site. The classic or conventional free gingival graft technique consists of transferring a piece of keratinized gingiva approximately the size of the recipient site. To avoid the large wound that this procedure sometimes leaves in the donor site, some alternative methods have been proposed. The original technique is described first, followed by several of the most common variants.

For the classic technique, a partial-thickness graft is used. The palate is the usual site from which the donor tissue is removed. The graft should consist of epithelium and a thin layer of underlying connective tissue. Place the template over the donor site, and make a shallow incision around it with a #15 blade. Insert the blade to the desired thickness at one edge of the graft. Elevate the edge and hold it with tissue forceps. Continue to separate the graft with the blade, lifting it gently as separation progresses to provide visibility. Placing sutures at the margins of the graft helps control it during separation and transfer and simplifies placement and suturing to the recipient site.¹⁰

Proper thickness is important for survival of the graft. It should be thin enough to permit diffusion of fluid from the recipient site, which is essential in the immediate posttransplant period. A graft that is too thin may necrose and expose the recipient site.75,82 If the graft is too thick, its peripheral layer is jeopardized because of the excessive tissue that separates it from new circulation and nutrients. Thick grafts may also create a deeper wound at the donor site, with the possibility of injuring major palatal arteries.¹¹² The ideal thickness of a graft is between 1.0 and 1.5 mm.^75,82 After the graft is separated, remove the loose tissue tags from the undersurface. Thin the edge to avoid bulbous marginal and interdental contours. Special precautions must be taken with grafts from the palate.

The submucosa in the posterior region is thick and fatty and should be trimmed so that it will not interfere with vascularization. Grafts tend to reestablish their original epithelial structure, so mucous glands may occur in grafts obtained from the palate.

A thick graft can be thinned by holding it between two wet wooden tongue depressors and slicing it longitudinally with a sharp #15 blade.

Step 3: Transfer and immobilize the graft. Remove the sponge from the recipient site; reapply it with pressure if necessary until bleeding is stopped. Remove the excess clot. A thick clot interferes with vascularization of the graft.⁷⁶

Position the graft and adapt it firmly to the recipient site. A space between the graft and the underlying tissue (dead space) impairs vascularization and jeopardizes the graft. Suture the graft at the lateral borders and to the periosteum to secure it in position. The graft must be immobilized. Any movement interferes with healing. Avoid excessive tension, which can distort the graft from the underlying surface. Every precaution should be taken to avoid trauma to the graft. Tissue forceps should be used delicately and a minimum number of sutures used to avoid unnecessary tissue perforation.

Step 4: Protect the donor site. Cover the donor site with a periodontal pack for 1 week, and repeat if necessary. Retention of the pack on the donor site can be a problem. If facial attached gingiva was used, the pack may be retained by locking it through the interproximal spaces onto the lingual surface. If there are no open interdental spaces, the pack can be covered by a plastic stent wired to the teeth. A modified Hawley retainer is useful to cover the pack on the palate and over edentulous ridges.

Variant Techniques.

The free gingival graft technique is a predictable procedure, but the donor site (palate) is left with an open wound that must heal by secondary intention. The following variant techniques attempt to minimize the donor site wound by removing the donor tissue in a different configuration and altering the shape to maximize coverage over the recipient site. These techniques are (1) the accordion technique, (2) the strip technique, and (3) the combination epithelial-connective tissue strip technique. All are modifications of the free gingival grafts.

The accordion technique, described by Rateitschak et al,⁸⁸ attains expansion of the graft by alternate incisions in opposite sides of the graft. This technique increases the donor graft tissue by changing the configuration of the tissue.

The strip technique, developed by Han et al,⁴⁸ consists of obtaining two or three strips of gingival donor tissue about 3 to 5 mm wide and long enough to cover the entire length of the recipient site (Figure 63-5). These strips are placed side by side to form one donor tissue and sutured on the recipient site. The area is then covered with aluminum foil and surgical dressing.

The advantages of this technique are the rapid healing of the donor site. The epithelial migration of the close wound edges (3 to 5 mm) allows rapid epithelialization of the open wound. The donor site usually does not require suturing and heals uneventfully in 1 to 2 weeks.

In some cases, a combination technique can be performed where a deep strip graft is taken from the palate and is split into both an epithelial-connective tissue strip and a pure connective strip. The tissue is obtained as follows: Remove a strip of tissue from the palate about 3 to 4 mm thick, place it between two wet tongue depressors, and split it longitudinally with a sharp #15 blade. Both will be used as free grafts. The superficial portion consists of epithelium and connective tissue, and the deeper portion consists only of connective tissue. These donor tissues are placed on the recipient site as in the strip technique. The minimal donor site wound obtained by two donor tissues from one site is the advantage of this technique.

Alternative Donor Tissue.

Another technique to minimize the use of the palate as a donor site is the use of acellular dermal matrix (ADM) as a substitute for palatal donor tissue. The use of the palate as a donor site for gingival augmentation has numerous disadvantages, for not only are the patients fearful of palatal surgery from where the donor tissue is procured but, there is also a limitation on the amount of tissue that can be removed. Currently, there are numerous clinicians who advocate the use of ADM as a substitute for palatal donor tissue. (See Tissue Engineering for more information regarding ADM.) This product is commercially available under the name AlloDerm and is derived from donated human skin.¹ Commercial preparation of this tissue includes a multistep proprietary process that removes both the epidermis and the cells that can lead to tissue rejection and graft failure without damaging the matrix. The remaining ADM consists of a nondenatured three-dimensional arrangement of intact collagen fibers, ground substance, and vascular channels.²⁹ Randomized, controlled clinical trials have demonstrated outcomes with ADM equivalent to palatal donor tissue in treatment of gingival recession.^{1,29,40,79,81,103} Equivalent root coverage has been shown in four trials.^1,79,81,103 Equivalent increase in marginal tissue thickness has been demonstrated at 6 and 12 months postoperatively, both by clinical assessment and by histometric analysis.^1,29,81 Equivalent attachment to the root surface has been found by histologic evaluation of human block sections at 6 months postoperatively.²⁹

In addition to avoiding palatal donor surgery, ADM offers the advantage of availability of unlimited donor tissue for treatment of multiple teeth in a single surgical appointment.

Surgical Techniques.

Two surgical techniques are suggested for use of ADM in treating gingival recession. Each is a coronally positioned pouch method. The first is the alternate papilla tunnel (APT) method and the second is the papilla retention pouch (PRP) method (Figure 63-6, A–G).

In the APT method, an incision is made in a papilla adjacent to a tooth with recession while the adjacent papilla is tunneled. The next papilla is incised, and the following papilla tunneled. Intrasulcular incisions are made facial to each tooth and interproximally at each tunneled papilla. The papilla in the anatomic midline is always tunneled to reduce tension and retraction of the recipient pouch. At each incised papilla, a V-incision (or inverted V in the mandibular arch) is made to form a new surgical papilla tip approximately 3 mm from the anatomic papilla tip. The portion of the anatomic papilla coronal to the surgical papilla is denuded to expose a vascular recipient bed for the surgical papilla when coronally advanced. The initial dissection is performed with a microperiosteal elevator, extending apically past the mucogingival junction and laterally under the facial aspect of the tunneled papillae. The tunneling process is facilitated by the access provided at the incised papillae. The tunneled papillae are lifted from the interdental crest by blunt reflection with a curette. Following blunt reflection, supraperiosteal sharp dissection is used to deepen and mobilize the recipient pouch.

On completion of the recipient site preparation, the length of graft needed is measured and trimmed so that the graft will extend 3 mm past the last tooth with recession at each end of the prepared site. The vertical dimension of the graft should be 6 to 8 mm. The rehydrated and trimmed allograft is then placed into the surgical pouch, with the basement membrane surface facing outward, and secured coronally with 6-0 sling sutures. The graft should be well adapted to the root surface, extending to but not coronal to the CEJ and to the apical margin, but not over the papillary recipient beds. The pouch is then coronally advanced to completely cover the allograft and secured with 6-0 or 7-0 sling sutures.

The APT method combines the advantages of surgical access at the incised papillae with retraction resistance and wound stability at the tunneled papillae.

In the PRP method, all papillae are tunneled. Initially, intrasulcular incisions are made facial and proximal to all teeth to be treated plus an additional tooth at each end. Next, full-thickness elevation of the margin is initiated with a microperiosteal elevator extending apically past the mucogingival junction and laterally under the facial aspect of the papillae. The pouch is extended apically and mobilized by supraperiosteal sharp dissection, and the papillae are lifted from the interdental crest as in the APT method. The allograft is rehydrated, measured, and trimmed. Placement of the allograft within the pouch may be accomplished by drawing it in with a suture or placing it through the sulcus with a curette so that it is aligned within the pouch over the exposed roots.

The unique feature of this method is the suturing of the allograft with a subgingival continuous subgingival double-back sling suture. Starting at the anterior end of the graft, the needle of a 6-0 suture is passed from the lingual side through the mesial embrasure and captured on the facial side. The allograft is engaged at the mesial line angle of the tooth, the needle is passed back through the mesial embrasure to the lingual side, around the lingual aspect toward the distal, through the distal embrasure back to the facial and crosses under the papilla to engage the allograft at the mesial line angle of the next tooth. This process continues until the needle has engaged the graft at the mesial line angle of the most distal tooth. At this point, the needle is passed through the mesial embrasure, around the lingual aspect, back to the facial through the distal embrasure, and the graft is engaged at the distal line angle. The needle is then passed back through the distal embrasure, around the lingual aspect, through the mesial embrasure to the facial, and under the papilla to engage the allograft at the distal line angle of the adjacent tooth. This process continues until passing through the distal embrasure of the initial tooth in which the suture is tied with the knot on the lingual side. The entire suture resides subgingivally and draws the graft and the pouch coronally. The PRP procedure is completed by coronally advancing the pouch over the allograft with a series of interrupted 6-0 or 7-0 sling sutures.

Advantages of the PRP method include enhanced retraction resistance, graft containment, and wound stability.

Postoperative care is similar for both methods and includes the following:

1. Systemic antibiotics for 10 days.

2. Chlorhexidine mouthrinse for 2 to 3 weeks.

3. Pain medication as needed.

4. Inactivity for 24 hours.

5. Ice applied to face for 24 hours.

6. Cold liquids for first three meals.

7. No mastication or toothbrushing at surgical site for 2 to 3 weeks.

8. Remove surface sutures at 2 to 4 weeks.

9. Remove subgingival graft suture at 2 months.

Developed over 15 years ago, ADM is a safe and effective biomaterial for use as a substitute for palatal connective tissue in root coverage grafting. There have been no reports of any disease transmission in medical or dental applications over this time period. ADM has proven equivalence to palatal connective tissue for root coverage procedures in randomized controlled clinical trials. It produces a thicker marginal tissue and a higher percentage of root coverage than a coronally advanced flap alone.¹¹⁶ It provides advantages over palatal connective tissue in that it does not require a second surgical site to obtain donor tissue and provides an unlimited amount of tissue to treat multiple teeth in one appointment. The use of AlloDerm under a coronally advanced flap extends the application of the most esthetic procedure in root coverage. Further discussion regarding ADM and other techniques to avoid palatal donor site morbidity involve the use of biologic mediators, which is presented later in this chapter

Healing of the Graft.

The success of the graft depends on survival of the connective tissue. Sloughing of the epithelium occurs in most cases, but the extent to which the connective tissue withstands the transfer to the new location determines the fate of the graft. Fibrous organization of the interface between the graft and the recipient bed occurs within 2 to several days.⁹⁵

The graft is initially maintained by a diffusion of fluid from the host bed, adjacent gingiva, and alveolar mucosa.⁴² The fluid is a transudate from the host vessels and provides nutrition and hydration essential for the initial survival of the transplanted tissues. During the first day, the connective tissue becomes edematous and disorganized and undergoes degeneration and lysis of some of its elements. As healing progresses, the edema is resolved, and degenerated connective tissue is replaced by new granulation tissue.

Revascularization of the graft starts by the second⁶ or third⁴⁴ day. Capillaries from the recipient bed proliferate into the graft to form a network of new capillaries and anastomose with preexisting vessels.⁵⁴

Many of the graft vessels degenerate and are replaced by new ones, and some of these participate in the new circulation. The central section of the surface is the last to vascularize, but this is complete by the tenth day.

The epithelium undergoes degeneration and sloughing, with complete necrosis occurring in some areas.20,80 It is replaced by new epithelium from the borders of the recipient site. A thin layer of new epithelium is present by the fourth day, with rete pegs developing by the seventh day. Heterotopically placed grafts maintain their structure (keratinized epithelium), even after the grafted epithelium has become necrotic and has been replaced by neighboring areas of nonkeratinized epithelium, which suggests that a genetic predetermination of the specific character of the oral mucosa exists that depends on stimuli originating in the connective tissue.⁵⁵ This is the basis for the technique that uses grafts composed only of connective tissue obtained from areas in which it is covered by keratinized epithelium.^17,30,36

As seen microscopically, healing of a graft of intermediate thickness (0.75 mm) is complete by 10.5 weeks; thicker grafts (1.75 mm) may require 16 weeks or longer.⁴³ The gross appearance of the graft reflects the tissue changes within it. At transplantation, the graft vessels are empty and the graft is pale. The pallor changes to an ischemic grayish white during the first 2 days until vascularization begins and a pink color appears. The plasmatic circulation accumulates and causes softening and swelling of the graft, which are reduced when the edema is removed from the recipient site by the new blood vessels. Loss of epithelium leaves the graft smooth and shiny. New epithelium creates a thin, gray, veil-like surface that develops normal features as the epithelium matures.

Functional integration of the graft occurs by the seventeenth day, but the graft is morphologically distinguishable from the surrounding tissue for months. The graft eventually blends with adjacent tissues, but sometimes, although pink, firm, and healthy, it is somewhat bulbous. This usually presents no problem, but if the graft traps plaque or is esthetically unacceptable, thinning of the graft may be necessary. Thinning the surface of the grafted tissue does reduce the bulbous condition because the surface epithelium tends to proliferate again. The graft should be thinned by making the necessary incisions to elevate it from the periosteum, removing tissue from its undersurface, and suturing it back in place.

Accomplishments.

Free gingival grafts effectively widen the attached gingiva. Several biometric studies have analyzed the width of the attached gingiva after the placement of a free gingival graft.19,49,52 After 24 weeks, grafts placed on denuded bone shrink 25%, whereas grafts placed on periosteum shrink 50%.⁶² The greatest amount of shrinkage occurs within the first 6 weeks.

The placement of a gingival graft does not “improve” the status of the gingiva.34,35,108 Therefore the indication for a free gingival graft should be based on the presence of progressive gingival recession and inflammation. When recession continues to progress after a few months with good plaque control, a graft can be placed to prevent further recession and loss of attached gingiva.

Other materials have been used to replace gingival tissue in gingival extension procedures. Attempts with lyophilized dura mater,⁹³ and sclera have not been satisfactory. The use of irradiated free gingival allograft showed satisfactory results,⁹¹ but further research is necessary before it can be considered for clinical use.

Free autogenous gingival grafts have been found to be useful for covering nonpathologic dehiscences and fenestrations. Nonpathologic refers to openings of the bone through the tooth surface not previously exposed to the oral environment and found in the course of flap surgery.³³

The use of free gingival autografts to cover denuded roots is described in the Gingival Augmentation Coronal to Recession section.

Accomplishments.

The apically displaced flap technique increases the width of the keratinized gingiva but cannot predictably deepen the vestibule with attached gingiva. Adequate vestibular depth must be present before the surgery to allow apical positioning of the flap. The edge of the flap may be located in three positions in relation to the bone, as follows:

Placing the flap short of the crest increases the risk of a slight reduction in bone height,²⁸ but the advantage of a well-formed gingival margin compensates for this.