The purpose of this study was to determine the late decline in viability of fat cells over time for fat tissue stored at -15 degrees C and -70 degrees C after harvest from abdominal liposuction. A total of 16 females were recruited for this study. The viability of fat cell specimens was measured after freezing for 1, 3, 7, 14, 28, and 56 days. A number of viable mature adipocytes were evaluated by fluorescence microscopy after staining with fluorescein diacetate and propidium iodide. The glycerol-3-phosphate dehydrogenase activity was measured in lipoaspirates before digestion and the XTT reduction assay was performed. In addition, the XTT reduction assay was also performed on isolated lipocytes and preadipocytes.The viability of mature adipocytes was very low for both the -15 degrees C and -70 degrees C samples after 1 day of freezing (13.3% +/- 7.4% and 12.6% +/- 6.3%, respectively). There was no statistically significant difference between the samples stored at the 2 temperatures. The GPDH activity of the lipoaspirates frozen, for 1 day, at -15 degrees C and -70 degrees C was 25.1% +/- 10% and 28.7% +/- 11%, respectively. For the XTT test, the fractional enzyme activity of the lipoaspirates frozen, for 1 day, at -15 degrees C and -70 degrees C was 30.0% +/- 10.9% and 36.1% +/- 12.3%, respectively. In addition, the adipocytes had low activity from day one: 15.4% +/- 7.2% at -15 degrees C and 11.5% +/- 5.6% at -70 degrees C. Furthermore, the preadipocytes had a low activity of 8.0% +/- 6.0% at -15 degrees C and 8.6% +/- 3.8% at -70 degrees C. At 8 weeks, there were few viable mature adipocytes and the activity of the cells was very low by XTT and GPDH testing.The results of this study showed that the viability of adipocytes declined rapidly after frozen storage for 1 day at both -15 degrees C and -70 degrees C, and decreased gradually in storage after 8 weeks; at which time only approximately 5% of the fat cells were alive. These findings suggest that the present fat preservation storage techniques using a -15 degrees C freezer or a -70 degrees C deep freezer are both inadequate to maintain the viability of fat cells.

Objective We investigated the suitability of intraoral-scan models for measuring tooth dimensions and the amount of crowding in patients with severe tooth crowding. Materials and Methods Fifty-eight patients who had undergone intraoral scans for diagnosis were included. Cast models were divided into two groups depending on the amount of crowding, as determined by initial caliper-based measurements (mild crowding [MC] group: <3.0 mm; severe crowding [SC] group: >4.5 mm). Twenty maxillary models and 20 mandibular models were used in this study. For the three types of models (i.e., IS digital model, C cast model, and CS digital model), the reproducibility and the precision of linear measurements were evaluated. Results We found that linear measurements made using digital calipers on a plaster model and on the relevant software were reproducible. There was no significant difference in most linear measurements between digital models and the C model. There were differences in the amount of crowding (p < .05), although these were not clinically significant. There was no relationship between the precision of crowding in the three types of models and the severity of crowding. Conclusions Digital models can be used for measuring crowding in both mild and severe crowding cases. However, crowding measured by digital models tends to be lesser than that measured by cast models, and this should be considered during clinical application.

Different researchers have recommended different lipoaspirate centrifugation speeds and times, probably due to the limits in fat cell viability assays. We assessed fat cell viability using a fluorescein diacetate and propidium iodide (FDA-PI) stain and 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay after harvesting syringe liposuction and spun with different centrifugation speeds to determine the optimal conditions. Lipoaspirates, harvested from 13 donors, were transferred into a centrifuge tube and spun at 1000, 3000, and 4000 rpm for 3 minutes. Mature adipocytes and adipose stem cells were isolated and tested with a direct counting of FDA-PI-stained cells under fluorescence microscope and XTT assay. We incubated adipocytes and adipose stem cells for 1 day and 3 days, and we compared both of them with fresh samples to evaluate the influence of culturing condition on fat cell viability. Centrifugation speeds from 1000 rpm to 4000 rpm for 3 minutes showed no change in the percentage of adipocytes and adipose stem cell viability not only in the fresh samples but also in the cultured samples (1 day and 3 days). Centrifugation speeds under 4000 rpm do not change the percentage of fat cell viability. To differentiate viable cells from dying or dead mature adipocytes and oil accurately, combinations of viability tests are essential.

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After extensive excision of skin cancer on the face, or when skin cancer is located on the 3-dimensional structures of the face, reconstruction with a local flap can be impossible, or clinicians are reluctant to reconstruct defects with a skin graft because of postoperative contraction, hyperpigmentation, or other complication. Instead, an arterialized venous free flap can be used as an alternative method of reconstruction to prevent distortion and recurrence. Eight patients underwent surgery with an arterialized venous-free flap. We evaluated the cosmetic results using ordinary scale methods on the basis of 4 categories (color, contour, texture, and distortion of surrounding structures) and recurrence and metastases of skin cancer physically. The follow-up period ranged between 24 and 48 months, with an average of 33 months. All of the soft-tissue defects made by excising the tumor were reconstructed with good outcomes, except for 1 case. Regarding the cosmetic evaluation, the color was fair, the contour and texture were good, absence of distortion of surrounding structures was excellent, and the overall results in most all cases were good. There were no recurrences or metastases during the follow-up period. The arterialized venous free flap is an alternative plan among several reconstruction methods when skin cancer on the face is extensively excised.