Histological assessment and gene expression analysis of intra‐oral soft tissue graft donor sites

Abstract

AimTo determine the structural and gene expression features of different intra‐oral soft tissue donor sites (i.e., anterior palate, posterior palate, maxillary tuberosity and retromolar pad).Materials and MethodsStandardized mucosal tissue punch biopsies were collected from at least one donor site per subject. Histological processing was performed to determine tissue morphometry and quantify collagen composition. Site‐specific gene distribution was mapped using targeted gene expression analysis and validated using real time polymerase chain reaction (qPCR).ResultsA total of 50 samples from 37 subjects were harvested. Epithelial thickness did not differ between sites. However, lamina propria was thicker in the maxillary tuberosity (2.55 ± 0.92 mm) and retromolar pad (1.98 ± 0.71 mm) than in the lateral palate. Type I collagen was the predominant structural protein in the lamina propria (75.06%–80.21%). Genes involving collagen maturation and extracellular matrix regulation were highly expressed in the maxillary tuberosity and retromolar pad, while lipogenesis‐associated genes were markedly expressed in the lateral palate. The retromolar pad showed the most distinct gene expression profile, and the anterior and posterior palate displayed similar transcription profiles.ConclusionsTissue samples harvested from the anterior and posterior palate differed morphologically from those from the maxillary tuberosity and retromolar pad. Each intra‐oral site showed a unique gene expression profile, which might impact their biological behaviour and outcomes of soft tissue augmentation procedures.

Histological assessment of a novel de-epithelialization method for connective tissue grafts harvested from the palate. An experimental study in cadavers

“…Hence, the best donor site from a histological point of view seems to be the tuberosity, because it has a thick lamina propria without the presence of a smaller submucosal layer [ 6 , 21 ]. Nevertheless, surgical access to this area is difficult and the quantity and shape of connective tissue might be inadequate in some circumstances [ 22 ].…”

Treatment of Multiple RT1 Gingival Recessions Using a Coronally Advanced Flap Associated with L-PRF or Subgingival Connective Tissue Graft from Maxillary Tuberosity: A Randomized, Controlled Clinical Trial

“…The greater capability of tCTG to produce a clinically significant gain in GT is explained by its specific histological and molecular features [15,17,35]. A histomorphometric study by Sthur et al [35] showed a 1.5-2 mm thicker lamina propria in tCTG than in conventional…”

“…Both techniques improved the clinical conditions similarly; however, GT showed significantly greater improvement in patients from the CAF + tCTG group. The greater capability of tCTG to produce a clinically significant gain in GT is explained by its specific histological and molecular features [15,17,35]. A histomorphometric study by Sthur et al [35] showed a 1.5-2 mm thicker lamina propria in tCTG than in conventional CTG and a five-fold increase in COL1A1 gene expression in grafts from the maxillary tuberosity, producing denser, thicker tissue.…”

“…The greater capability of tCTG to produce a clinically significant gain in GT is explained by its specific histological and molecular features [15,17,35]. A histomorphometric study by Sthur et al [35] showed a 1.5-2 mm thicker lamina propria in tCTG than in conventional CTG and a five-fold increase in COL1A1 gene expression in grafts from the maxillary tuberosity, producing denser, thicker tissue. The high amount of collagen, the over-expression of lysyl hydroxylase (LH), predominantly LH2b [15,17,35], and greater cross-linking between collagen molecules result in a denser tissue response [15,21,35].…”

Long‐term stability of gingival margin and periodontal soft‐tissue phenotype achieved after mucogingival therapy: A systematic review

“…FGGs are generally thicker (Borghetti & Gardella, 1990; Corn & Marks, 1983; Holbrook & Ochsenbein, 1983; Mormann et al, 1981; Soehren et al, 1973) compared to bilaminar techniques using SCTG (Chambrone & Tatakis, 2015; Zucchelli et al, 2010, 2014). The connective tissue layer in FGG, namely the lamina propria, which is underneath the epithelium, is typically formed by a dense network of collagen fibres (Bertl et al, 2015; García‐Caballero et al, 2023; Harris, 2003) whose biological and structural properties seem to vary depending on the donor site (Stuhr et al, 2023). Additionally, it has been shown that the lamina propria has two distinct layers: (i) the papillary layer; and (ii) the reticular layer that presents a higher collagen density (García‐Caballero et al, 2023).…”