Evaluation of a porcine matrix with and without platelet-derived growth factor for bone graft coverage in pigs.

PURPOSE: The aim of this investigation was to compare three different techniques for soft tissue closure over intraoral particulated bone grafts in a pig model: primary closure and nonprimary closure utilizing a porcine collagen matrix (Mucograft), with or without the addition of platelet-derived growth factor (PDGF). An additional aim was to determine whether the addition of PDGF to the collagen matrix would prevent the need for primary closure or later soft tissue grafting. MATERIALS AND METHODS: Twenty-four bilateral mandibular alveolar defects were created in 12 minipigs. These defects were reconstructed with a mixture of autogenous bone and bovine bone and secured with a titanium mesh. The animals were randomly assigned to group A (Mucograft+PDGF), group B (Mucograft alone), or group C (primary closure and no Mucograft). In groups A and B the collagen matrix was placed directly over the mesh, and the soft tissue was closed passively. Exposure of the titanium mesh, height of new bone, and the percentage of keratinized mucosa covering the bone graft were analyzed. RESULTS: Average new bone formation in group A was 7.0 mm, whereas groups B and C had less regenerated bone (4.7 mm and 2.5 mm, respectively). Group A had the thickest keratinized mucosa (1.6 mm), versus 0.9 mm for group B and 0.4 mm for group C. Group A had an average of 95% regenerated keratinized tissue, whereas group B had 41% and group B had 22%. CONCLUSION: The addition of PDGF to the collagen matrix appeared to accelerate soft tissue healing and promote bone formation. Mucograft provided an adequate alternative to autogenous soft tissue grafts or primary closure to cover bone grafts intraorally while eliminating adverse effects, namely disruption of the adjacent soft tissue architecture, loss of vestibular height, and the need for further surgery.

Maxillary vestibular incision for surgically assisted rapid palatal expansion: evidence for a conservative approach.

AIM: To evaluate the soft tissue changes in upper lip, vermilion, and alar bases after surgically assisted rapid palatal expansion (SARPE). A new flap design was proposed to obtain more esthetic results. METHODS: Sixteen patients who had undergone SARPE for skeletal deformities were evaluated. None of the patients treated had any previous maxillary or nasal surgery, nor did they have any previous trauma to the midface. The soft tissue was clinically evaluated before and after surgery. Lip length and width were traced and measured on the radiograph, both preoperatively and postoperatively, by the same investigator. Preoperative and 6-month postoperative photographs were added. RESULTS: The data suggested that the greater the stability in the soft tissue, particularly in the vermilion width and alar base, the more conservative the maxillary vestibular incision could be. CONCLUSION: A conservative anterior vestibular incision at 6 months resulted in better esthetics, influencing a smaller loss of vermilion and less widening of alar bases. Otherwise, a traditional incision associated with decreased lip length slightly increased with the modified incision. SARPE can be effectively performed with a more conservative vestibular incision to prevent excessive scarring and shortening of the lip to achieve predictable results.

Use of a porcine collagen matrix as an alternative to autogenous tissue for grafting oral soft tissue defects.

PURPOSE: Soft tissue grafting is often required to correct intraoral mucosal deficiencies. Autogenous grafts have disadvantages including an additional harvest site with its associated pain and morbidity and, sometimes, poor quality and limited amount of the graft. Porcine collagen matrices have the potential to be helpful for grafting of soft tissue defects. PATIENTS AND METHODS: Thirty consecutive patients underwent intraoral grafting to re-create missing soft tissue. Defects ranged in size from 50 to 900 mm(2). Porcine collagen matrices were used to reconstruct missing tissue. Indications included preprosthetic (22), followed by tumor removal (5), trauma (2), and release of cheek ankylosis (1). RESULTS: The primary efficacy parameters evaluated were the degree of lateral and/or alveolar extension and the evaluation of re-epithelialization and shrinkage of the grafted area. Overall, the percentage of shrinkage of the graft was 14% (range, 5%-20%). The amount of soft tissue extension averaged 3.4 mm (range, 2-10 mm). The secondary efficacy parameters included hemostatic effect, pain evaluation, pain and discomfort, and clinical evaluation of the grafted site. All patients reported minimal pain and swelling associated with the grafted area. No infections were noted. CONCLUSION: This porcine collagen matrix provides a biocompatible surgical material as an alternative to an autogenous transplant, thus obviating the need to harvest soft tissue autogenous grafts from other areas of the oral cavity.