Tissue Reaction and Morphologic Change of Gore-Tex Implant in the Rabbit Model

Various materials have been proposed for use in aesthetic and reconstructive augmentation of the face. Three basic types of material are currently available: autografts, homografts, and alloplasts. Alloplastic materials have been used widely for soft tissue augmentation. Many synthetic material have been developed for alloplasty; among these, the porous material, Gore-Tex(r)(ePTFE) allows minimal fibrous tissue ingrowth but the amount is sufficient to confer some stability of the implant in soft tissue over time. The purpose of this study is to evaluate the tissue reaction and size change of Gore-Tex in rabbits. A precise pockets were made in the plane below the panniculus carnosus and periosteum. The 25x5x3mm sized rectangular shape of Gore-Tex(r) was then inserted into the pocket. Tissue specimens including skin and implant were obtained in 1, 3, 6 months after implantation. The specimens were examined grossly and microscopically. Grossly, none of the implants were lost or extruded and there was no evidence of wound infection, hematoma, or seroma formation. Thickness of implants under periosteum decreased more than panniculus carnosus. Results of light microscopy revealed a mild inflammatory cell reaction in the early implant group(1 month) at the tissue-implant interface. Within the substance of the material, tissue ingrowth was not observed in the early implant group(1 month and 3 months), but was observed in the late implant group(6 months). In this study the Gore-Tex appears to be a safe and reliable substance for use in augmentation of bony and soft tissue structure of the face.

Intraoral Compressive Dressing for Prevention of Palatal Fistula after Cleft Palate Repair

The rate of postoperative cleft palate fistula is influenced by palatal repair methods. High incidence of cleft palate fistula is associated with pushback palatoplasty, because wide elevation of mucoperiosteal flaps can cause hematoma and exudate, which make flaps thinner so necrotise. Thus, the authors tried to reduce the wound disruption, hematoma, and dead space while performing pushback palatoplasty in complete cleft palate by applying compressive dressing over mucoperiosteal flaps. As a result, the incidence of cleft palate fistula was statistically reduced after compressive dressing. Three fistulas occurred in 14 patients treated by pushback palatoplasty without compressive dressing, but no fistula occurred in 25 patients treated by pushback palatoplasty with compressive dressing. By applying the compressive dressing after Pushback palatoplasty, it is expected not only reduced short-term complication, but also better results in the long-term follow up of maxillary growth and speech development.

The Frenuloplasty and Speech Therapy Influenced on Phonemes in Tongue-tie

Tongue tie, often referred to as 'Ankyloglossia', is a congenital condition, recognized by an unusually thickened, tightened, or shortened lingual frenulum, which limits movement of the tongue in activities connected with feeding and which has an adverse impact on both dental health and speech. A common definition and objective measurements have been rare because the tongue is a complete soft tissue structure without non- mobile landmarks. From March of 1996 to November of 2001, preoperative and postoperative speech evaluation, post-speech therapy were performed in twelve patients. Each low picture consonants test was observed in tongue-tie patients. Overall picture consonants test was improved after frenuloplasty and postoperative speech therapy. Preoperative value of liquids and fricatives were lower than the other alveolar phonemes(p<0.05) and it was improved after frenuloplasty(p<0.05) and postoperative speech therapy(p<0.05). Frenuloplasty itself can improve the articulation of liquids and fricatives on short follow-up. But Frenuloplasty and postoperative speech therapy can be more improvement of the alveolar phonemes.

Various Vein Conduit Modalities for Nerve Regeneration in Rats

Over the years, many surgeons have used various natural and synthetic materials to bridge the nerve defect. However, none of these materials has surpassed the effectiveness of the nerve autograft. Among natural materials, a vein graft has been used as conduit for nerve regeneration in both research protocols and clinical situations. Unfortunately, the comparison of various research reports is difficult, for each research has employed a different experimental model and method of evaluation for the study of the nerve regeneration. This study introduced various modifications of the vein graft technique, and investigated several vein graft models in an attempt to find the most effective formulation . Four vein graft models were employed: 1) the empty vein graft, 2) the inside-out pattern vein graft, 3) the vein graft filled with skeletal muscle strips, 4) the inside-out pattern vein graft filled with skeletal muscle strips. Regeneration was assessed with gross appearance, histologic examination and electromyography(EMG). In the vein graft filled with muscle strips, there was the increased axonal diameter, myelin sheath thickness, ratio of myelinated axon to unmyelinated axon, and conduction velocities. The result showed that any vein graft filled with muscle strips is superior to the empty vein graft and the inside-out pattern vein graft model which are not filled with muscle strips. It is concluded that the nerve repair using a vein graft filled with skeletal muscle strips can be effectively employed in the clinical field. Further study should be aimed at the regeneration of a longer distance nerve gap and its clinical application.

Reconstruction of Major Articular Osteochondral Defects with OP-1 Treated Allografts and Vascularized Tissue

The treatment of articular cartilage and bone defect has been challenging for many years. Autologous osteochondral grafting represents the most physiologic procedure for reconstructing joint defects but is severely limited by the availability of donor material. Allogenic osteochondral grafting differs from the other grafting method in obtaining almost unlimited amounts of material of exact size and form for complex joint reconstructions. An alternative approach that may improve allograft revascularization and incorporation was to combine an autologous muscle flap with an allograft and vascularized osteochondral allografts that have reported excellent long term results. The vascular characteristics of muscle flaps, with their capacity as a source for mesenchymal stem cells, provide the muscle flap with the ability to initiate bone formation and repair in transplanted allografts in response to osteogenic factors. Forty adult New Zealand White rabbits underwent complete resection of the proximal 2/3 of the humerus. The defects were immediately grafted following substance: (1) lyophilized osteochondral allografts (n=10); (2) lyophilized osteochondral allograft with a muscle flap filling the bone marrow cavity(n=10); (3) OP-1(Osteogenic protein-1) treated lyophilized osteochondral allografts (n=10); (4) OP-1 treated lyophilized osteochondral allograft with OP-1 injected muscle flap filling the bone marrow cavity(n=0). All the examinations were operated under aseptic conditions, and follow-up evaluations were performed in the 4th, 6th, 8th, 10th, 12th, and 24th week. Range of motion showed no difference between the groups, but more limited in OP-1 treated allograft groups. Under the histologic examination, the groups of lyophilized osteochondral allograft with a muscle filling the bone marrow cavity regenerated more articular cartilage than that of OP-1 treated allograft. These results suggest that using OP-1 treated lyophilized osteochondral allograft with OP-1 injected muscle flap filling the bone marrow cavity could get more organized articular cartilage and bone regeneration.

New Zygometer Incorporating Exophthalmometer

The zygoma is essential key element determining midface contour and symmetry. The height and width of the zygoma are changed during midfacial surgery such as reduction of fractured zygoma, esthetic malar reduction and correction of congenital midfacial deformity. The exact preoperative and postoperative evaluation of the zygoma is very important step in midfacial surgery. The estimation of height and width of the zygoma usually depends on gross feature analysis or radiographic measurement. But the results are not accurate and subjective. Several device were used for measuring the height and width of the zygoma, but those are inconvenient and difficult to use. The fracture of the zygoma is frequently combined with blow out fracture resulting enophthalmos. The simultaneous measurement of accurate malar height and degree of enophthlmos is helpful. For this reason, we developed a new zygometer with the function of exophthalmometer. This device is convenient to use and easy for comparative measurement of malar height preoperatively and immediate postoperative period, and the degree of enothphalmos is measured simultaneously with this device. This new zygometer will be applied to many midfacial surgery and craniofacial study.