Sensory Recovery After Skin Graft Using Allogenic Dermis

It is well known that the thicker dermis is grafted, the lesser adhesion and contracture can be resulted. In spite of all advantages, thicker layer of dermis can also cause pain, infection, hypertrophic scar and delayed healing at the donor site. In addition, full thickness skin graft can result in best quality in recipient site, but it is limited in donor site and harvested size. Processed allogenic dermis(Alloderm(R)) has been developed and applied to solve the above-mentioned problems as permanent dermal augmentation for full thickness skin defect. From March 2002 to December 2003, we have applied allogenic dermis (Alloderm(R)) and ultra-thin split thickness skin graft on 30 patients (Group A) who had hypertrophic scar, 3rd degree burn, full thickness skin defect and various cosmetic problems. The control patients (Group B) are treated by conventional autologous thick split thickness skin graft only. We evaluated wound contracture, degree of sensory recovery, color change, functional and histological aspect between Group A and B. In Group A, by providing a dermal augmentation, the grafted dermal matrix permitted a thin autograft from the donor site. The harvested ultra-thin split-thickness skin remained fewer complications on the donor site and had faster healing process. And allogenic dermis exhibited excellent elastisity and good pigmentation with minimal scarring and wound contracture. But in sensory reinnervation study, Group A was not fully recovered compared to the conventional skin graft in Group B. In histological study, small nerve fiber bundles are scattered in the mid-dermis of processed allogenic dermis in Group A, but in Group B nerve fiber bundles extended into the upper dermis. Most nerve fibers were not sufficiently innervated into upper dermis in allogenic dermis because it was assumed that allogenic dermis play an important role as a barrier. In conclusion, if we perform ultra-thin split thickness skin graft using an allogenic dermis, wounds can be covered in a single stage with an adequate layer of dermal augmentation with minimal donor site morbidity, and we can also get good functional recovery, and avoid undesirable complications. However, application of allogenic dermis in the important area of sensation, such as hands and feet, should be conservative at present. Further scientific refinement is necessary for the improvement of sensory recovery in using allogenic dermis and a large scale experimental study should be performed.

Recurrence Rate after Angle Splitting Ostectomy

For the treatment of the square mandibular angle, the angle splitting ostectomy method is known to have many advantages compared to the conventional angle ostectomy procedure. The splitting method is easy to proceed even for the patients with inverted angle. Better results could be achieved in the lateral profile as well as the anterior view. And this method has less complications such as bleeding, asymmetry and subcondylar fracture. However, there seems to be some doubts about the long-term results because of bone remodeling concept; the new bone could easily grow on the remained cancellous bony surface and prominence could recur on the mandibular angle area. The purpose of this study is to identify the amount of the regrowth on the ostectomized surface. We performed angle contouring surgery in fifty-one patients with wide and squared lower faces for 5 years. Of these patients, we selected 22 patients who fulfilled following categories; (1) those who had angle splitting ostectomy surgery in our institute, (2) those who had preoperative and postoperative CT examinations. The patients were classified into 3 groups. In the group 1, the follow-up CT was checked within 1 month after surgery (n=11). Group 2 included those who had CT examination during 4~6 months after surgery (n=8). In the group 3, the CT was checked more than 1 year after surgery (n=3). We identified one point (Point B) to examine the most possible point on angle of mandible (Point A: a point that 3.5 cm distance from sigmoid notch on parallel line to the posterior border of ramus at sigmoid notch , Point B: a point that 1 cm distance from Point A). We analyzed the preoperative, postoperative thickness of point B using 3 dimensional CT for detecting recurrence rate of cortical bone. The measurement was 8.43 mm before operation, and follow up measurements were 4.92 mm in group 1, 4.84 mm in group 2, and 5.27 mm in group 3, respectively. There was no statistical significant evidence of bony regrowth and recurrence from remaining surface among the groups. In the morphological comparisons, the cortical bone started to appear on the remaining angle in group 2 and covered whole the surface of angle in group 3. We concluded that the surgical procedure of angle splitting ostectomy is a long-term effective and stable method.