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Global Translational Medicine Connective tissue harvest techniques

A B C

D E F

G H I

Figure 7. DGG harvested from the maxillary right tuberosity area for root coverage at the mandibular left first premolar. (A) Baseline clinical appearance.
Tooth #20 exhibited a buccal gingival recession defect measuring 2.5 mm in depth. (B) Buccal mucoperiosteal flap (split-full-split flap design). (C)
Maxillary right tuberosity area before graft harvest. (D, E) Deep and superficial surfaces of the graft, respectively. The epithelium was removed with a
scalpel. (F) Donor site after harvest. (G) DGG stabilized with interproximal sutures. (H) Wound closure. (I) Post-operative appearance at 3 months.
Abbreviation: DGG: De-epithelialized gingival graft.
palate lamina propria, and the ratio of lamina propria to that collagen in the tuberosity area may be comparatively
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submucosa is higher in tSCTG relative to palatal SCTGs. resistant to MMP-mediated degradation. This mechanism
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In the tuberosity area, fibrous tissue predominates in the may explain the clinical observations that sites treated with
zone between the lamina propria and the periosteum, tSCTGs tend to exhibit collagen accumulation, fibrosis,
with submucosa typically accounting for <5% of tSCTG and compromised esthetics. 19,39,41 Oral epithelial cells at
composition. In contrast, submucosal tissue may tSCTG and palatal SCTG harvest sites also exhibit distinct
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comprise more than a quarter of the structure of palatal cytokeratin expression patterns. Whether the differential
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SCTGs. 40 expression of specific cytokeratin types indicates that
In addition to these structural differences, tSCTG and tSCTGs more strongly induce keratinization remains
palatal SCTGs appear to differ in gene expression patterns unknown. However, several clinical and patient-oriented
and clinical performance. Lysyl hydroxylase (LH) catalyzes advantages have been associated with soft tissue harvests
the hydroxylation of lysine residues in collagen molecules, from the maxillary tuberosity. Limited evidence suggests
a process critical for collagen maturation, fibril formation, that harvesting soft tissue from the tuberosity results in
and cross-linking. 39,41 Overexpression of LH has been faster donor site healing, less discomfort, reduced analgesic
associated with fibrosis and defective fibrillogenesis. 39,41 consumption, and greater tissue thickness gain compared
Dellavia et al. compared the expression levels of collagen to the use of palatal SCTGs. 19,38,40,42
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type I (COL-I), collagen type III, lysyl hydroxylase 2b 4. Discussion
(LH2b), and matrix metalloproteinases-1 and -2 (MMP-1,
MMP-2) in cell cultures derived from tuberosity and palatal The objectives of this article were to review commonly
fibroblasts. The ratio of LH2b to COL-I mRNA (LH2b/ applied SCTG harvesting methods, propose a preferred
COL-I) was 4 times higher in cell cultures derived from technique applicable in most circumstances, and identify
tuberosity compared to palatal fibroblasts. Consistent with specific clinical scenarios in which alternative harvesting
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these results, immunohistochemical analyses conducted techniques may be superior. Popular biomaterials, such as
by another group of investigators found higher levels of acellular dermal matrix and xenogeneic collagen matrix,
LH2 and MMP-2 in tSCTGs compared to palatal SCTGs. along with emerging alternatives like living cellular
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Based on these studies, an emerging hypothesis posits constructs, are available for patients who wish to avoid

Volume 4 Issue 1 (2025) 42 doi: 10.36922/gtm.4860