Palatal Wound Healing with Primary Intention in a Rat Model—Histology and Immunohistomorphometry

Abstract

Background and objectives: Subepithelial connective tissue graft (SCTG) from the palate has been considered as the “gold standard” for the treatment of deep gingival recessions. A single-incision technique was reported to allow primary wound healing. A palatal single incision was performed in a rat model. The present study assessed the histology and histomorphometry of palatal wound healing following surgical closure with primary intention. Materials and Methods: Twenty-six 6-month-old male Wistar rats weighing 427–650 g. An incision was made on the maxillary palate. A full thickness flap was raised palatally, and then repositioned and sutured. Two experimental groups: S—Study group, I—Intact control group. Half of the animals were sacrificed 7 days and the remaining 14 days postoperatively. Outcome parameters included—epithelial gap; inflammatory infiltration; vascular fraction, expression of myofibroblasts and stem cell markers within the oral epithelium and stromal cells and physical properties of stromal collagen fibers. Investigations were performed at two time-points (7 and 14 days) during the wound healing process. Results: The epithelial gap closed completely after 14 days. The inflammatory reaction and vascular fraction were relatively low. Surgical trauma downregulated the expression of cytokeratin (CK) 14 and CK 15, which returned to normal after 14 days. Epithelial differentiation was mediated through upregulation of connective tissue sex- determining-region-Y-box2 (SOX2). Epithelial SOX2, CD34, alpha smooth muscle actin (αSMA) and physical properties of stromal collagen fibers were not influenced by the surgical trauma. Conclusions: Surgical trauma followed by palatal wound healing with primary intention in a rat model heals within 14 days. It induces minimal inflammatory infiltration and vascular proliferation. Epithelization is exerted through promotion of epithelial differentiation from stem cells by connective tissue SOX2.

Gene expression profiles of oral soft tissue‐derived fibroblast from healing wounds: correlation with clinical outcome, autophagy activation and fibrotic markers expression

“…We demonstrated concordance between the results of the present work and our previous study, showing that P tissue behaviour is similar to G when myofibroblast differentiation and autophagic activation were evaluated. In a very recent study evaluating palatal wound healing with primary intention in a rat model, the authors demonstrated that αSMA was not influenced by surgical trauma at 7 days (Chaushu et al, 2020). The results of this in vivo study are consistent with our observation of αSMA modulation at 24 hr from the incision, thus contributing to support the hypothesis that main changes in the wound-healing process occur in a very early stage.…”

Orodispersible hyaluronic acid film delivery for oral wound healing in rats

“… 13 A total of 60 male Sprague–Dawley rats (Youngbio, Seongnam, Korea) aged nine weeks and weighing approximately 250–300 g were used. 14 , 15 The rats were randomly divided into the control ( n = 20), HA gel ( n = 20), and HA film ( n = 20) groups. Each group was randomly subdivided into two groups: one was the three-day sacrifice group ( n = 10) and the other, the seven-day sacrifice group ( n = 10).…”

The Viability of Palatal Connective Tissue Graft Using Single Incision Versus De-Epithelialization Harvesting Technique in New Zealand Rabbits.

“…The decrease in number of necrotic cells in the de-epithelialization group may be due to the trauma directed to the graft was much less in comparison to the single incision group. Chaushu et al described the single incision technique as a traumatic procedure 15 .…”