The Functional and Aesthetic Indications for Soft- Tissue (Gingival) Grafting

Dentistry Today

0 Shares

The healthy soft tissue surrounding the natural dentition is composed of the gingiva and alveolar mucosa, which are clearly demarcated into clinically identifiable zones. The free gingiva begins at the gingival margin, which is normally located 1 to 3 mm coronal to the cemento-enamel junction and extends to the base of the gingival sulcus. The attached gingiva refers to the tissue that is firmly bound by Sharpey’s fibers to the cementum of the tooth and underlying bone and begins at the base of the gingival sulcus in health—or periodontal pocket in disease—and extends to the mucogingival junction. The apical migration of the gingival margin results in gingival recession, which may lead to root exposure that not only may be aesthetically unacceptable to the patient, but more importantly, is always accompanied by bone loss. This migration can also result in tooth sensitivity, difficulty in plaque removal, root caries, and cervical abrasion and erosion. Gingival recession is a common clinical finding that affects almost 90% of the American population.1

Gingival health can usually be maintained with as little as 1 or 2 mm of attached gingiva.2-4 Occasionally, with good oral hygiene, movable alveolar mucosa can be maintained indefinitely.5-8 However, soft-tissue grafting procedures are often indicated to optimize function and aesthetics. Clinical situations in which grafting is indicated include the following:

(1) Areas of minimal or no attached gingiva where the movable alveolar mucosal margins interfere with plaque control. These areas become chronically inflamed and may be further compromised by a frenum pull or shallow vestibule.9,10
(2) Areas of progressive recession.4,11
(3) Areas in which orthodontic procedures may position the roots of a tooth in a prominent part of the arch, or when a tooth is tipped lingually, resulting in buccal displacement of the roots.12
(4) Areas where there is a need for restorative treatment, and the margins of the restorations will be placed subgingivally and impinge upon the biologic width of connective tissue attachment.13 It is generally accepted that 5 mm of keratinized gingiva are required prior to restorative procedures (2 mm is the average width of the free gingiva plus approximately 3 mm of attached keratinized gingiva). Soft-tissue grafting procedures may also be indicated if the clasps of a removable prosthesis irritate the marginal tissues.14
(5) Areas where recession presents an aesthetic concern to the patient.
(6) Areas where root exposure has resulted in tooth sensitivity.
In younger patients who present with any of the factors mentioned above (especially orthodontics), soft-tissue grafting should be considered to help reduce future complications.

Periodontal plastic surgical techniques designed to increase the zone of attached keratinized gingiva date to 1957 when Friedman defined mucogingival problems and described denudation and pushback procedures for their correction.15 In 1963, Bjorn described the first free gingival graft.16 In that study, free gingival grafts were used to gain keratinized attached gingiva. Bjorn’s technique to extend the vestibular fornix was presented in the United States by King and Pennel at the Philadelphia Academy of Periodontology in 1964.17 
Mucogingival defects can now be corrected by several periodontal plastic surgical techniques, including (1) laterally or coronally advanced pedicle grafts, (2) coronally advanced flaps alone or in conjunction with barrier membranes or enamel matrix proteins, (3) free gingival grafts, and (4) connective tissue autografts and allografts. Each technique has its indications, advantages, and limitations. However, the amount of root coverage that can be achieved through periodontal plastic surgery can be predicted based upon Miller’s classification of marginal tissue recession (Table).18 Upon healing, 100% root coverage is obtained if the marginal tissue is at the CEJ, the sulcus depth is 2 mm or less, and there is no bleeding on probing.

 

GINGIVAL GRAFTING TECHNIQUES

(1) Free Gingival Graft
The free gingival graft is an autograft obtained from a palatal donor site, an edentulous ridge, or tuberosity. After transplantation to the recipient site, the graft benefits from plasmic diffusion from the adjacent tissue. This helps sustain the graft over avascular root surfaces. The graft’s connective tissue will determine the surface appearance of the new gingiva. If it is obtained from the palate, the mature graft may resemble palatal tissue, resulting in aesthetic complications.19,20

The application of a free gingival graft for root coverage was first described by Nabers in 1966, and with few modifications, the principles and techniques described by Sullivan and Atkins in 1968 are still valid.21-23 
The free gingival graft has the advantage of being a predictable procedure when properly performed. However, the free gingival graft may result in an unaesthetic “patch-like” appearance, and is therefore often contraindicated in the aesthetic zone. It is especially indicated for vestibular extension procedures, but the size of the transplanted graft is limited by the availability of donor tissue.

 

Case Report No. 1

Figure 1. Preoperative view of the mandibular anterior sextant in a patient requiring orthodontic treatment. Note recession and lack of attached gingiva associated with tooth No. 24.

Figure 2. Free gingival graft secured in position.

A 19-year-old female patient presented for a periodontal evaluation prior to orthodontic treatment. Of concern was the lack of attached gingiva in the area of tooth No. 24. The remainder of the sextant had a very thin layer of keratinized attached gingiva that could be susceptible to recession, especially if the roots of the teeth were to be torqued buccally during the orthodontic treatment (Figure 1). After preparing the recipient bed for the free gingival graft, the donor tissue was harvested from the palate (Figure 2). The free gingival graft was secured using interrupted sutures and periosteal sling sutures. The graft must remain immobile and firmly bound to the periosteum (Figure 3). Two years after treatment, the increased zone of keratinized attached gingiva has protected the roots of the mandibular anterior teeth from dehiscences or fenestrations that could result from buccal displacement of the roots during orthodontic movement (Figure 4).

(2) Subepithelial Connective Tissue Graft
The subepithelial connective tissue graft (SCTG) is one of the most versatile and predictable periodontal plastic surgical procedures. It consists of a bilaminar reconstruction of the gingiva using both free and pedicle connective tissue layers to preserve graft viability over denuded root surfaces.24-27 Because of the dual blood supply to the graft (from the underlying connective tissue and the overlying flap), the SCTG results in improved root coverage.28 The results are limited by the amount of avascular root surface and the interdental periodontal attachment levels.18 Based on Miller’s classification, virtually 100% root coverage can be anticipated in class I and class II defects where there is no interproximal loss of bone or gingiva, but is limited in class III and IV defects where there is interdental periodontal attachment loss.18

It has been shown that it is the underlying connective tissue that determines epithelial differentiation.20 Therefore, since only the connective tissue is transplanted in the “interpositional” SCTG, the result is an enhanced color match and more aesthetic results due to the surface characteristics of the overlaying flap. In addition, because the connective tissue is harvested from beneath a partial thickness flap, wound healing in both the donor and recipient sites occurs mostly by primary intention. This helps expedite maturation and also reduces postoperative discomfort.
SCTGs are not indicated in areas where the surface characterization of the gingival tissue needs to be changed (such as with amalgam tattoos). Also, in patients with very thin palatal tissue, alternate donor sites (such as the retromolar pad) or alternative procedures should be considered. As with all periodontal surgical procedures, the SCTG is technique sensitive. To avoid surgical complications, thorough knowledge of the anatomy of the area is imperative.

 

Case Report No. 2

Figure 3. One-week postoperative view of the palatal donor site. Because the surface epithelium was removed with the graft, the site is healing through secondary intention. Figure 4. Two-year postoperative view of graft. Complete root coverage is observed. Note “patch-like” appearance of graft and rugae transplanted with the palatal tissue.
Figure 5. Preoperative view of area of recession associated with teeth Nos. 5 and 6. Figure 6. Partial thickness flap elevation at the recipient site.
Figure 7. Primary intention closure and suturing of palatal flap after removal of connective tissue graft.

A 27-year-old female patient presented with complaints of temperature sensitivity and aesthetic concerns in the areas of gingival recession. Teeth Nos. 5 and 6 had gingival recession and tooth No. 6 had a minimal zone of attached gingiva (Figure 5). The patient did not have any interproximal bone loss, the interdental gingival level was normal, and the recession did not extend beyond the mucogingival junction (Miller class I). Complete root coverage could therefore be anticipated.

The recipient site was prepared with a partial thickness gingival flap elevation (Figure 6), and the donor connective tissue was harvested from under a flap created in the ipsilateral palate. The palatal flap was then re-approximated and sutured for primary intention closure (Figure 7). The interpositional subepithelial connective tissue graft was then placed on the recipient site and covered with the gingival flap (Figure 8). Complete root coverage and enhanced gingival aesthetics were ob­tained after 8 months of maturation (Figure 9).

 

(3) Acellular Dermal Connective Tissue Allografts
The acellular dermal connective tissue (ADCT) allograft permits grafting multiple sites without the need for a donor tissue surgical site. This results in decreased discomfort and morbidity associated with the donor surgical site. Human clinical studies have shown that connective tissue allografts result in root coverage comparable to autogenous tissue grafts.29-32

These soft-tissue allografts are derived from human skin and chemically processed to remove all epidermal and dermal (antigenic) cells while preserving the remaining bioactive dermal matrix. It provides a bioactive matrix consisting of collagen, elastin, blood vessel channels, and bioactive proteins that support natural revascularization, cell repopulation, and tissue remodeling.33 Extensive screening and processing ensures the tissue is safe with respect to an array of pathogens, and there have been no cases of viral transmission in 9 years of use in more than 250,000 grafts.33 
ADCT allografts have been shown to be successful alternatives to the autogenous free gingival graft to increase the gingival width around natural teeth and implants. Case control and clinical studies have supported this technique’s ability to achieve root coverage.29-31,34

The ADCT allograft can be used as a flap extender over bone grafts and extraction sockets, and can also be used for ridge augmentation, to increase the depth of the vestibule, and for soft-tissue augmentation around dental implants.

There are concerns regarding the use of ADCT allografts. Most studies indicate that grafting with ADCT results in less keratinized tissue compared to other grafting techniques.26,29,37,38 In addition, studies have found greater probing depth reductions with autogenous grafts as compared to ADCT allografts.29,32

 

Case Report No. 3

Figure 8. Interpositional SCTG placed on recipient site and covered with a gingival flap. Figure 9. Complete root coverage and enhanced gingival aesthetics observed 8 months after grafting.
Figure 10. Preoperative view of patient with advanced recession on the buccal surface of teeth Nos. 8 and 9.

Figure 11. The flap was coronally advanced to cover the connective tissue allograft and sutured in place with interrupted sutures.33

Figure 12. Nine months postoperative healing.

A 26-year-old male patient presented with advanced recession on the buccal aspect of teeth Nos. 8 and 9. The recession extended to or beyond the mucogingival junction, but there was no loss of interdental bone or soft tissue (Miller classification class II)18 (Figure 10). The site was prepared, a gingival flap elevated, and an acellular dermal connective tissue allograft was placed on teeth No. 8 and 9. The graft was sutured in place with resorbable, single, interrupted 5.0 sutures, and the gingival flap was coronally re-positioned to cover the graft (Figure 11). At 9 months, there was complete root coverage and maturation of the graft (Figure 12).

CONCLUSION
Most studies indicate that with adequate plaque control, minimal to no attached gingiva may be maintained in a state of health over long periods of time.2,5,7,8 However, there are clear indications for augmenting the zone of keratinized gingiva. Numerous periodontal plastic surgical pro­cedures have been developed to correct mucogingival de­fects and to increase the zone of keratinized attached gingiva. Three of the commonly used procedures—the free gingival graft, the subepithelial connective tissue graft, and acellular dermal connective tissue allograft procedures—were described. Each procedure has clear advantages and disadvantages that need to be evaluated according to the patient’s needs. In addition, all procedures are limited by the amount of avascular root surface, the height of the interproximal papillae, and the alveolar bone. Moreover, several mucogingival conditions may occur concurrently, necessitating the consideration of combining or sequencing surgical techniques.

Acknowledgments
The author would like to thank Drs. Vincent Iaconno and Barry Wagenberg for their editorial contributions, and Dr. Louis F. Rose for providing Figures 10 to 12.


References

  1. Miller A, Brunelle J, Carlos J, et al. Oral Health of United States Adults: The National Survey of Oral Health in U.S. Employed Adults and Seniors, 1985-1986: National Findings. Bethesda, Md: US Dept of Health and Human Services, Public Health Service; 1987. NIH publication 87-2868.
  2. Lang NP, Loe H. The relationship between the width of keratinized gingiva and gingival health. J Periodontol. 1972;43:623-627.
  3. Hangorsky U, Bissada NF. Clinical assessment of free gingival graft effectiveness on the maintenance of periodontal health. J Periodontol. 1980;51:274-278.
  4. de Trey E, Bernimoulin JP. Influence of free gingival grafts on the health of the marginal gingiva. J Clin Periodontol. 1980;7:381-393.
  5. Wennstrom JL. Lack of association between width of attached gingiva and development of soft tissue recession. A 5-year longitudinal study. J Clin Periodontol. 1987;14:181-184.
  6. Wennstrom J, Lindhe J. Plaque-induced gingival inflammation in the absence of attached gingiva in dogs. J Clin Periodontol. 1983;10:266-276.
  7. Salkin LM, Freedman AL, Stein MD, et al. A longitudinal study of untreated mucogingival defects. J Periodontol. 1987;58:164-166.
  8. Freedman AL, Green K, Salkin LM, et al. An 18-year longitudinal study of untreated mucogingival defects. J Periodontol. 1999;70:1174-1176.
  9. Gottsegen R. Frenum position and vestibule depth in relation to gingival health. J Oral Surg (Chic). 1954;7:1069-1078.
  10. Gorman WJ. Prevalence and etiology of gingival recession. J Periodontol. 1967;38:316-322.
  11. Baker DL, Seymour GJ. The possible pathogenesis of gingival recession. A histological study of induced recession in the rat. J Clin Periodontol. 1976;3:208-219.
  12. Maynard JG Jr, Ochsenbein C. Mucogingival problems, prevalence and therapy in children. J Periodontol. 1975;46:543-552.
  13. Ericsson I, Lindhe J. Recession in sites with inadequate width of the keratinized gingiva. An experimental study in the dog. J Clin Periodontol. 1984;11:95-103.
  14. Maynard JG Jr, Wilson RD. Physiologic dimensions of the periodontium significant to the restorative dentist. J Periodontol. 1979;50:170-174.
  15. Friedman N. Mucogingival surgery. Tex Dent J. 1957;75:358-362.
  16. Bjorn H. Free transplantation of gingival propria. Odontol Revy. 1963;14:523.
  17. King K, Pennel B. Evaluation of attempts to increase the width of attached gingiva. Presented at the Philadelphia Society of Periodontology; 1964.
  18. Miller PD Jr. A classification of marginal tissue recession. Int J Periodontics Restorative Dent. 1985;5(2):8-13.
  19. Karring T, Lang NP, Loe H. Role of connective tissue in determining epithelial specificity. J Dent Res. 1972;51:1303-1304.
  20. Karring T, Lang NP, Loe H. The role of gingival connective tissue in determining epithelial differentiation. J Periodontol Res. 1975;10:1-11.
  21. Nabers JM. Free gingival grafts. Periodontics. 1966;4:243-245.
  22. Sullivan HC, Atkins JH. Free autogenous gingival grafts. I. Principles of successful grafting. Periodontics. 1968;6:121-129.
  23. Sullivan HC, Atkins JH. Free autogenous gingival grafts. III. Utilization of grafts in the treatment of gingival recession. Periodontics. 1968;6:152-160.
  24. Nelson SW. The subpedicle connective tissue graft. A bilaminar reconstructive procedure for the coverage of denuded root surfaces. J Periodontol. 1987;58:95-102.
  25. Langer B, Calagna L. The subepithelial connective tissue graft. J Prosthet Dent. 1980;44:363-367.
  26. Langer B, Calagna LJ. The subepithelial connective tissue graft. A new approach to the enhancement of anterior cosmetics. Int J Periodontics Restorative Dent. 1982:2(2):22-33.
  27. Langer B, Langer L. Subepithelial connective tissue graft technique for root coverage. J Periodontol. 1985;56:715-720.
  28. Harris RJ. Root coverage with connective tissue grafts: an evaluation of short- and long-term results. J Periodontol. 2002;73:1054-1059.
  29. Harris RJ. A comparative study of root coverage obtained with an acellular dermal matrix versus a connective tissue graft: results of 107 recession defects in 50 consecutively treated patients. Int J Periodontics Restorative Dent. 2000;20:51-59.
  30. Aichelmann-Reidy ME, Yukna RA, Evans GH, et al. Clinical evaluation of acellular allograft dermis for the treatment of human gingival recession. J Periodontol. 2001;72:998-1005.
  31. Henderson RD, Greenwell H, Drisko C, et al. Predictable multiple site root coverage using an acellular dermal matrix allograft. J Periodontol. 2001;72:571-582.
  32. Wei PC, Laurell L, Geivelis M, et al. Acellular dermal matrix allografts to achieve increased attached gingiva. Part 1. A clinical study. J Periodontol. 2000;71:1297-1305.
  33. Alloderm acellular tissue. Available at http://www.biohorizons.com/alloderm.htm. Accessed on June 8, 2004.
  34. Harris RJ. Root coverage with a connective tissue with partial thickness double pedicle graft and an acellular dermal matrix graft: a clinical and histological evaluation of a case report. J Periodontol. 1998;69:1305-1311.
  35. Harris RJ. Clinical evaluation of 3 techniques to augment keratinized tissue without root coverage. J Periodontol. 2001;72:932-938.
  36. Paolantonio M, Dolci M, Esposito P, et al. Subpedicle acellular dermal matrix graft and autogenous connective tissue graft in the treatment of gingival recessions: a comparative 1-year clinical study. J Periodontol. 2002;73:1299-1307.
  37. Tal H, Moses O, Zohar R, et al. Root coverage of advanced gingival recession: a comparative study between acellular dermal matrix allograft and subepithelial connective tissue grafts. J Periodontol. 2002;73:1405-1411.

Dr. Minsk received her degree from Temple University School of Dentistry. She completed advanced graduate training in periodontics at the University of Pennsylvania School of Dental Medicine, and then a 1-year fellowship in implant dentistry at the University of Pennsylvania Implant Center. She is a diplomate of the American Board of Periodontology. Dr. Minsk is clinical assistant professor of periodontics at the University of Pennsylvania School of Dental Medicine. She maintains a private practice limited to periodontics and implant dentistry. She can be reached at minsk@speakeasy.net