Reconstruction of the mandibular denture bearing area and freeing of the tongue after tumor surgery

Clinical application of tissue-engineered transplants. Part I: mucosa

OBJECTIVES

The study series aims at testing the feasibility of the clinical application of tissue-engineered oral mucosa. The preliminary results were gathered over a period varying from 6 months to 12 years depending on the surgical method.

METHODS

Tissue-engineered oral mucosa was used to cover defects in various surgical procedures like vestibuloplasty (n=42), freeing of the tongue (n=10), prelaminating the radial flap (n=5) and reconstruction of the urethra (n=16). In all interventions small samples of oral mucosa were harvested, cut into small pieces, resuspended in culture medium and seeded into a culture flask. Cultured keratinocytes were transferred onto membranes which then were used to cover mucosal defects in the oral cavity.

RESULTS

To gain a graft of 15 cm(2) size a mucosa biopsy of 4-8 mm(2) and 40 ml autologous patients serum is needed. Tissue-engineered oral mucosa was applied successfully in all four surgical methods. Six months after transplantation a regular epithelial layering with a histological delimitation of the stratum, epithelial crest and a strong basal membrane appeared. According to the reception site the tissue engineered oral mucosa differentiated in several ways.

CONCLUSION

Tissue-engineered oral mucosa fulfils the requirements for clinical routine. With view to healing time and outcome it does not appear to be superior to regular harvested oral mucosa transplants. Because of a smaller harvesting defect and primary wound closure at the actual operation site the patients' convenience is increased. Thus this method reduces morbidity and advances the quality of life.

Use of facial artery musculomucosal flap for closure of soft tissue defects of the mandibular vestibule

We present the use of the inferiorly based facial artery musculomucous (FAMM) flap to repair a defect of the mandibular vestibule, and discuss the advantages and disadvantages of this procedure. The FAMM flap an effectively cover defects of the mandibular vestibule and other regions of the oral cavity, and its softness, toughness, and minimal shrinkage allow for the use of dental prostheses.

Tissue-engineered mucosa graft for reconstruction of the intraoral lining after freeing of the tongue: a clinical and immunohistologic study

PURPOSE

This article describes the use of tissue-engineered mucosal grafts instead of split-thickness skin grafts after freeing of the tongue in patients who had previous resection of an oral squamous cell carcinoma and initial primary wound closure.

PATIENTS AND METHODS

Tissue-engineered mucosal grafts, up to 75 cm2 in size, were cultured from biopsy specimens of the hard palate in 6 patients, starting 3 to 4 weeks before the operation. After freeing of the tongue, the engineered mucosa was implanted on the wound surface by using vaseline gauze as carrier and fixed with an intraoral gauze wound dressing.

RESULTS

A good glossoalveolar sulcus was formed in 5 patients, resulting in good mobility of the tongue and a satisfactory denture-bearing surface. In 1 patient, there was a disturbance of wound healing, leading to severe shrinkage of the glossoalveolar sulcus and very limited improvement in tongue mobility. Preoperative bromodeoxyuridine (BrdU) labeling of the graft and postoperative immunohistochemical staining of biopsy specimens from the grafted areas with anti-BrdU showed that the cultured cells are integrated into the newly formed mucosal epithelium. Postoperative histologic investigations showed a differentiation process in the grafted mucosal epithelium, with a change in the expression of cytokeratins. At 6 months postoperatively, the typical pattern of normal nongrafted mucosa was regained.

CONCLUSIONS

This investigation provides evidence that tissue-engineered mucosal cells can serve as a graft for large intraoral wounds. Complete intraoral lining is quickly reestablished, and normal epithelial differentiation is seen in the graft area within a 6-month postoperative period.