The lower third of Asian faces is wider than that of Caucasians and it is determined by the size and width of the mandibular bone and the thickness of muscles and subcutaneous fat tissues surrounding it. Efforts to create an aesthetically slim and smooth facial contour line in nonobese people have led the authors to focus on two approaches: surgical resection of the masseteric muscle and modeling ostectomy of the square-angled mandibular bone. Because these procedures present some problems, the authors adopted a nonsurgical concept that chemically denervates muscles and reduces the bulk of the muscle. The authors have conducted a total of 1021 clinical cases from March of 2001 through September of 2002, in which patients were treated with botulinum toxin type A (Dysport; Ipsen Ltd, Slough, United Kingdom) for remodeling the lower facial contour line; 383 of those cases were followed up for at least 3 months after the initial injection. A database was made by measuring the change in the thickness of the injected muscle with an ultrasonogram. Eleven patients underwent resection of the mandibular angle before injection. The preinjection ostectomy group was involved in the study as a result of their dissatisfaction with the surgical results; they had a rather thick masseter muscle and not a bone problem. Some had both bone problems and a thick masseter muscle. Three months after the botulinum toxin injection, the thickness of the muscle was reduced by 31 percent on average. The atrophic effect of injection was observed after 2 to 4 weeks for most patients. Seventy percent of the 383 patients tracked were greatly satisfied with the result, with another 23 percent generally satisfied. No long-term side effects were reported. Masseteric hypertrophy is frequent in Asians because of racial characteristics and dietary habits. Botulinum toxin type A has made a new epoch in facial contouring for Asians. Considering that Asians have a prominent malar and a prominent mandible angle, the reduction in the thickness of the masseter can provoke relative prominence of the malar and mandible angle. Therefore, precise indication and anatomy of the facial muscle should be thoroughly understood, which will decrease the incidence of side effects and problems. Botulinum toxin type A (Dysport) injection is simple in technique, has few side effects, and promises a rapid return to daily life. The authors conclude that the injection of botulinum toxin type A can replace surgical masseter resection.

IV.

In cell culture, medium supplemented with fetal bovine serum is commonly used, and it is widely known that fetal bovine serum supplies an adequate environment for culture and differentiation of stem cells. Nevertheless, the use of xenogeneic serum can cause several problems. We compared the effects of four different concentrations of autologous serum (1, 2, 5, and 10%) on expansion and adipogenic differentiation of adipose-derived stem cells using 10% fetal bovine serum as a control. The stem cells were grafted on nude mice and the in vivo differentiation capacity was evaluated. The isolation of adipose-derived stem cells was successful irrespective of the culture medium. The proliferation potential was statistically significant at passage 2, as follows: 10% autologous serum > 10% fetal bovine serum = 5% autologous serum > 2% autologous serum = 1% autologous serum. The differentiation capacity appeared statistically significant at passage 4, as follows: 10% fetal bovine serum > 10% autologous serum = 5% autologous serum > 2% autologous serum = 1% autologous serum. Ten percent autologous serum and 10% fetal bovine serum had greater differentiation capacity than 1 and 2% autologous serum in vivo, and no significant difference was observed between the groups at ≥ 5% concentration at 14 weeks. In conclusion, 10% autologous serum was at least as effective as 10% fetal bovine serum with respect to the number of adipose-derived stem cells at the end of both isolation and expansion, whereas 1 and 2% autologous serum was inferior.

Palatal fistula is a challenging complication following cleft palate repair. We investigated the usefulness of collagen matrix in the prevention of postoperative fistula. We performed a retrospective cohort study of patients with cleft palate who underwent primary palatoplasty (Furlow’s double opposing z-plasty) in Seoul National University Children’s Hospital. Collagen Graft and Collagen Membrane (Genoss, Suwon, Republic of Korea) were selectively used in patients who failed complete two-layer closure. The effect of collagen matrix on fistula formation was evaluated according to palatal ratio (cleft width to total palatal width) and cleft width. A total of 244 patients (male, 92 and female, 152; median age, 18 months) were analyzed. The average cleft width was 7.0 mm, and the average palatal ratio was 0.21. The overall fistula rate was 3.6% (9/244). Palatal ratio (p = 0.014) and cleft width (p = 0.004) were independent factors impacting the incidence of postoperative fistula. Receiver operating characteristic curve analysis showed that the cutoff values in terms of screening for developing postoperative fistula were a palatal ratio of 0.285 and a cleft width of 9.25 mm. Among nonsyndromic patients with values above those cutoffs, the rates of fistula development were 0/5, 1/6 (16.7%), and 4/22 (18.2%) for those who received Collagen Graft, Collagen Membrane, and no collagen, respectively. Collagen matrix may serve as an effective tool for the prevention of palatal fistula when complete two-layer closure fails, especially in wide palatal clefts. The benefit was most evident in Collagen Graft with thick and porous structure.