Judy Fan-Hsu DDS, FAGD
Apically positioned flap with vestibuloplasty (APF/V) is a successful treatment to increase the width of the keratinized tissue or attached gingiva.
Soft tissue augmentation favors subepithelial connective tissue graft (SCTG) over free gingiva graft (FGG) with limited data.
Good evidence supports showing APF/V as is a successful soft tissue augmentation treatment for increasing to increase the width of keratinized tissue.
In patients requiring soft tissue graft is APF/V, APF/V with autogenous graft or APF/V with allogenous graft more effective in terms of 1) increasing width of keratinized tissue, and 2) gain in soft tissue volume?
The authors conducted a comprehensive Medline search for human studies published from Jan 1, 1966 to August 31, 2008 in English, French, German, and Italian. The search yielded a total of 28 studies that met the inclusion criteria: with 25 studies of on keratinized tissue (10 randomized-controlled clinical trials, four cohort studies, and 11 controlled clinical trials), and three studies of soft tissue volume (two cohort studies, and one case study).
The authors conducted meta-analysis with 14 studies. In four of the studies, an APF/V plus autogenous tissue produced statistically significant greater gain in keratinized tissue than untreated controls (weighted mean difference [WMD] gain in keratinized tissue was 4.49mm, p = 0 ). The allogenic groups (APF/V plus acellular dermal matrix graft or human fibroblast-derived dermal substitute) showed significantly more shrinkage than control groups (APF/V plus FGG) with WMD of 28 percent more shrinkage in allogenic graft, p = 0. Five studies demonstrated that APF/V plus autogenous tissue resulted significantly more attached gingiva than untreated controls (WMD 3.94mm, P = 0). Similarly, but with fewer studies, autogenous tissue FGG or freeze-dried skin significantly improved attached gingival. The authors could not conduct meta-analysis on three studies (two cohort studies, one case report)of soft tissue volume compared due to heterogeneity in both study design and treatment modalities.
APF/V is a successful treatment for increasing the width of keratinized tissue or attached gingiva. The addition of autogenous tissue significantly increases the amount of keratinized tissue or width of attached gingiva. For soft tissue volume augmentation, the limited data favor SCTGs over FGG.
Source of Funding:
The University of Zurich, Clinic for Fixed and Removable Prosthodontics and Dental Material Science funded the original review.
Importance and Context:
Studies have suggested that the width of keratinized tissue is associated with higher survival rates of dental implants, healthier peri-implant mucosa, and improved esthetic outcomes (1,2,3). Studies also have shown that a certain amount of keratinized tissue is necessary to maintain periodontal health (4,5), and 2 mm keratinized gingiva is adequate to maintain gingival health (6). However, two recent reviews have concluded there is insufficient evidence that the width of keratinized tissue influences survival rate and future mucosal recession (7,8).
Strengths and Weaknesses of the Systematic Review:
The authors used accepted methods in their systematic review. The reviewers performed a detailed analysis, but the clarity of their writing did not match the rigor of the systematic review. Many inconsistencies and discrepancies regarding the cited studies not only limited the review, but created confusion for the reader. For example, the authors listed two keratinized tissue studies on the quantitative table but did not list them on the forest plot. Also, three studies that were listed on the table for analysis were missing from the plot. The date of one study changes from table to graph, as well (Kennedy).
Strengths and Weaknesses of the Evidence:
This review identified high-quality clinical trials on the questions of gain of keratinized tissue (part 1). Fourteen studies met rigorous inclusion and exclusion criteria to provide the data suitable for meta-analysis. Data from these studies were presented clearly in forest plots (figures 3 - 5) to demonstrate the statistically significant advantages for these soft tissue augmentation techniques:(APF/V) and APF/V plus autogenous tissue, and APF/V plus allogeneic tissue.
Multiple weakness are present in the evidence. The authors did not clearly identify the 14 studies used for meta-analysis for the reader. For example, labeling them with an asterisk in table 2 would have been extremely helpful.
Limited data are available on the best techniques for augmentation of the soft tissue volume (part 2), and the data are not homogeneous enough to conduct meta-analyses. The authors identify a need for standardized reliable techniques to measure soft tissue volume, and suggest that optical 3-dimensional scanning methods might be applicable.
Likewise, data on esthetics and patient-reported outcome measures (such as pain) are very limited,
Implications for Dental Practice:
Should keratinized tissue need augmentation, the evidence supports the choice of APF/V plus autogenous tissue for accept able results.
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