For empirical analysis, t test, which assesses mean differences, and 1-way analysis of variance (ANOVA) were conducted to examine mean differences among different groups.4 The target value was obtained by dividing TP by TC. Herein, both lengths were indicated by a program in the same image on the monitor, and the target value was indicated in percentage (%) (TP/TC × 100). For all empirical analyses, P values of < 0.05 were considered to be statistically significant, and the statistics program SPSS WIN 22.0 (SPSS Inc., Chicago, Ill.) was used for statistical analysis. The mean was significantly higher in the experimental group 1 (132.34) than in the control group (125.28); t test showed a statistically significant difference at t = 18.94 (P < 0.001), implying that the mean increased immediately after the surgery. The mean was significantly higher in experimental group 2 (128.70) than in the control group (125.28); t test showed a statistically significant difference at t = 10.598 (P < 0.001). This result indicated that in the long-term observation, the mean for the experimental group 2 increased compared with that for the control group.
The mean was significantly higher in experimental group 1 (132.34) than in experimental group 2 (128.70); t test showed a statistically significant difference at t = 8.41 (P < 0.001). This result indicates that the mean immediately after surgery was higher than that after long-term observation.
Repeated-measure ANOVA was performed to compare the mean among the control group, experimental group 1, and experimental group 2. The results revealed the highest value of 132.34 in experimental group 1, followed by 128.71 in experimental group 2, and 125.28 in control group. The F-value was statistically significant at 112.32 (P < 0.001).
Adverse effects that could theoretically occur because of the surgery included thread extrusion, infection, foreign body reaction, granuloma, hematoma, bruising, and sensory nerve stimulation in the maxilla. Some adverse effects such as thread extrusion and granuloma were observed, but no apparent infections were observed. Among 62 patients examined in this study, one experienced thread extrusion; however, no serious problems occurred while pulling and removing the thread out of the skin. Thread extrusion could be the most frequent complication if the operator is unable to optimally use an injector.
Since 1997, we have been performing minimally invasive fat grafting for nasal tip projection. Given that only fat grafting cannot produce sufficient forward projection of the nasal tip, in 2003, we started to use absorbable barbed PDO suture threads. Biopsy results obtained in the study showed that in case of using only absorbable # 2 PDO, even after an absorption period of 3–4 months, scarred tissues, into which the material was already absorbed, still exhibited a tendency to maintain their prior condition (Fig. 16).
To maintain the initial effect at most, patients were recommended to undergo an additional treatment that could facilitate the wound healing process under their surgery-induced modified conditions. When fat grafting from another region was attempted, we used procedures such as grafting of fat that was concentrated with stromal cells and extra cellular metrix (ECM) by squeezing or using a micro-cutter (Filler-Geller)4 , 5 and cell-assisted lipotransfer, in which stromal vascular fraction was added.6
Among the types of tip projection surgery, the surgery using autologous fat graft is a nonincisional method with minimized tissue damage and thus has the advantage of flexible surgery timing. The greatest advantage perceived by us was that even if foreign substances were exposed, they could be simply treated unlike existing implants. Hence, a certain level of internal pressure, which could be risky for existing solid implants, could be applied, and the immediate effect of skin expansion could be observed during surgery. The immediate stretching and fixation techniques employed by this surgery can cause immediate modification by sufficient force of only a single hand of an operator and can fix the respective location within a short time. It is important to select an insertion tool that can enable operators to sense delicate changes.
Our suggested evaluation method has the advantage of using only photographs. However, proper lateral images for comparison at similar angles often cannot be obtained, making measurement impossible. Small differences may arise due to facial postures, and axial rotations can cause bigger differences than expected. Therefore, it would be better to use devices for conventional cephalometry with fixing tools for positioning the head such as 2 ear rods and a mouth piece or to use modern 3D measurement methods. However, despite this handicap, photometry, as suggested by us, could be used for objective analysis in cosmetic surgeries, including rhinoplasty.
Because this study verified the ratios from the same view and angle, the absence of actual numerical values was deemed not to affect the verification. This measurement method was first attempted, owing to the absence of other methods for the authors’ retrograde research. Therefore, despite the presence of numerous reasons for which we could be convinced of the study results, multiple discussions and comparative analyses are additionally required, and some standards should be prepared for relevant photography techniques. Fortunately, because our surgical results only showed differences that would not hinder statistical analysis, this method is considered feasible. However, more detailed studies are required to apply this method to surgical procedures that require the verification of other important differences.
Thread extrusion and irritation could be the most frequent complication when the operator is less experienced. We have been instructed to excessively use a sponge block or a thick towel before a clinical trial so that threads can be removed with just pulling, even after several weeks.
Barbed threads with split ends are effective implants that endure pressure even during dorsal length extension and alar rim expansion. Adjunctive filler of fat injections may show better results. Artificial fillers could be used for dorsal nasal augmentation but not for tip projection. Filler injection within caudal border of septal cartilage may sometimes show dramatic results, but if the injected volume spreads to adjacent areas due to internal pressure, the initial strut effects could disappear in a week, particularly in Asians with small noses. Therefore, strut structures should not be constructed with filler only. In summary, we believe barbed threads and autologous fat gel graft would give the best results for the trial of anterior projection of a nasal tip and dorsal lengthening. When patients want minimally invasive procedures, artificial filler and threads should be recommended. Artificial filler only for anterior nasal tip projection is not recommended. Threads were occasionally recommended to be implanted, that is, only when there were enough tissues in the nose. Without a solid structure, liquid form materials like fillers or fat grafts make a flat plane or a sphere shape by tissue pressure distribution rather than longitudinal struts, so we could presume these have rare strut effects. However, when solid struts exist, liquid creates a longitudinal form and then creates tissue remodeling along the struts. Especially in the aspect of long-term effects of liquid forms, threads help to have greater projection effects. As a result, we believe liquid and solid form have strong synergies not only for volume effects but for tip projection effects.
In rhinoplasty performed on Asians, the results of long-term observations indicated that the surgical procedure of lifting the nasal tip with barbed threads was effective. Although a maximum of ≥ 10-mm projection could be attempted, its effects are reduced in long-term results, and thus, the nasal tip is located in the mid-point between the presurgical and maximum projection points. Although an analysis was not performed to assess the differences in the patients’ satisfaction between the simultaneous procedures of fat grafting and nasal tip projection and nasal projection only, more cases require fillers or fat grafting to maintain a natural sense of volume. There may be differences in the frequency of adverse effects and the degree of satisfaction depending on the surgeon’s experience and presurgery explanation. Irreversible adverse effects were almost absent. Although there may be some unsatisfactory results because doctors are gradually becoming familiar with the surgical procedure, there is less incidence of retouching because the procedure is minimally invasive.
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3. Yang H, Lee H. Successful use of squeezed-fat grafts to correct a breast affected by Poland syndrome. Aesthetic Plast Surg. 2011;35:418–425.
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5. Shiffman MA, Di Giuseppe A, Bassetto F. Stem Cells in Aesthetic Procedures: Art, Science, and Clinical Techniques. 2014.Berlin, Germany: Springer.
6. Choi JS, Yang HJ, Kim BS, et al. Human extracellular matrix (ECM) powders for injectable cell delivery and adipose tissue engineering. J Control Release. 2009;139:2–7.
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