Identification of a key signaling network regulating perennating bud dormancy in Panax ginseng.

Background: The cycle of seasonal dormancy of perennating buds is an essential adaptation of perennial plants to unfavorable winter conditions. Plant hormones are key regulators of this critical biological process, which is intricately connected with diverse internal and external factors. Recently, global warming has increased the frequency of aberrant temperature events that negatively affect the dormancy cycle of perennials. Although many studies have been conducted on the perennating organs of Panax ginseng, the molecular aspects of bud dormancy in this species remain largely unknown. Methods: In this study, the molecular physiological responses of three P. ginseng cultivars with different dormancy break phenotypes in the spring were dissected using comparative genome-wide RNA-seq and network analyses. These analyses identified a key role for abscisic acid (ABA) activity in the regulation of bud dormancy. Gene set enrichment analysis revealed that a transcriptional network comprising stress-related hormone responses made a major contribution to the maintenance of dormancy. Results: Increased expression levels of cold response and photosynthesis-related genes were associated with the transition from dormancy to active growth in perennating buds. Finally, the expression patterns of genes encoding ABA transporters, receptors (PYRs/PYLs), PROTEIN PHOSPHATASE 2Cs (PP2Cs), and DELLAs were highly correlated with different dormancy states in three P. ginseng cultivars. Conclusion: This study provides evidence that ABA and stress signaling outputs are intricately connected with a key signaling network to regulate bud dormancy under seasonal conditions in the perennial plant P. ginseng.

Cytokinin signaling promotes root secondary growth and bud formation in Panax ginseng.

Background: Panax ginseng, one of the valuable perennial medicinal plants, stores numerous pharmacological substrates in its storage roots. Given its perennial growth habit, organ regeneration occurs each year, and cambium stem cell activity is necessary for secondary growth and storage root formation. Cytokinin (CK) is a phytohormone involved in the maintenance of meristematic cells for the development of storage organs; however, its physiological role in storage-root secondary growth remains unknown. Methods: Exogenous CK was repeatedly applied to P. ginseng, and morphological and histological changes were observed. RNA-seq analysis was used to elucidate the transcriptional network of CK that regulates P. ginseng growth and development. The HISTIDINE KINASE 3 (PgHK3) and RESPONSE REGULATOR 2 (PgRR2) genes were cloned in P. ginseng and functionally analyzed in Arabidopsis as a two-component system involved in CK signaling. Results: Phenotypic and histological analyses showed that CK increased cambium activity and dormant axillary bud formation in P. ginseng, thus promoting storage-root secondary growth and bud formation. The evolutionarily conserved two-component signaling pathways in P. ginseng were sufficient to restore CK signaling in the Arabidopsis ahk2/3 double mutant and rescue its growth defects. Finally, RNA-seq analysis of CK-treated P. ginseng roots revealed that plant-type cell wall biogenesis-related genes are tightly connected with mitotic cell division, cytokinesis, and auxin signaling to regulate CK-mediated P. ginseng development. Conclusion: Overall, we identified the CK signaling-related two-component systems and their physiological role in P. ginseng. This scientific information has the potential to significantly improve the field-cultivation and biotechnology-based breeding of ginseng.

The AFB1 auxin receptor controls the cytoplasmic auxin response pathway in Arabidopsis thaliana.

The phytohormone auxin triggers root growth inhibition within seconds via a non-transcriptional pathway. Among members of the TIR1/AFB auxin receptor family, AFB1 has a primary role in this rapid response. However, the unique features that confer this specific function have not been identified. Here we show that the N-terminal region of AFB1, including the F-box domain and residues that contribute to auxin binding, is essential and sufficient for its specific role in the rapid response. Substitution of the N-terminal region of AFB1 with that of TIR1 disrupts its distinct cytoplasm-enriched localization and activity in rapid root growth inhibition by auxin. Importantly, the N-terminal region of AFB1 is indispensable for auxin-triggered calcium influx, which is a prerequisite for rapid root growth inhibition. Furthermore, AFB1 negatively regulates lateral root formation and transcription of auxin-induced genes, suggesting that it plays an inhibitory role in canonical auxin signaling. These results suggest that AFB1 may buffer the transcriptional auxin response, whereas it regulates rapid changes in cell growth that contribute to root gravitropism.

DDM1-mediated gene body DNA methylation is associated with inducible activation of defense-related genes in Arabidopsis.

BACKGROUND: Plants memorize previous pathogen attacks and are "primed" to produce a faster and stronger defense response, which is critical for defense against pathogens. In plants, cytosines in transposons and gene bodies are reported to be frequently methylated. Demethylation of transposons can affect disease resistance by regulating the transcription of nearby genes during defense response, but the role of gene body methylation (GBM) in defense responses remains unclear. RESULTS: Here, we find that loss of the chromatin remodeler decrease in DNA methylation 1 (ddm1) synergistically enhances resistance to a biotrophic pathogen under mild chemical priming. DDM1 mediates gene body methylation at a subset of stress-responsive genes with distinct chromatin properties from conventional gene body methylated genes. Decreased gene body methylation in loss of ddm1 mutant is associated with hyperactivation of these gene body methylated genes. Knockout of glyoxysomal protein kinase 1 (gpk1), a hypomethylated gene in ddm1 loss-of-function mutant, impairs priming of defense response to pathogen infection in Arabidopsis. We also find that DDM1-mediated gene body methylation is prone to epigenetic variation among natural Arabidopsis populations, and GPK1 expression is hyperactivated in natural variants with demethylated GPK1. CONCLUSIONS: Based on our collective results, we propose that DDM1-mediated GBM provides a possible regulatory axis for plants to modulate the inducibility of the immune response.

CPR5-mediated nucleo-cytoplasmic localization of IAA12 and IAA19 controls lateral root development during abiotic stress.

Plasticity of the root system architecture (RSA) is essential in enabling plants to cope with various environmental stresses and is mainly controlled by the phytohormone auxin. Lateral root development is a major determinant of RSA. Abiotic stresses reduce auxin signaling output, inhibiting lateral root development; however, how abiotic stress translates into a lower auxin signaling output is not fully understood. Here, we show that the nucleo-cytoplasmic distribution of the negative regulators of auxin signaling AUXIN/INDOLE-3-ACETIC ACID INDUCIBLE 12 (AUX/IAA12 or IAA12) and IAA19 determines lateral root development under various abiotic stress conditions. The cytoplasmic localization of IAA12 and IAA19 in the root elongation zone enforces auxin signaling output, allowing lateral root development. Among components of the nuclear pore complex, we show that CONSTITUTIVE EXPRESSOR OF PATHOGENESIS-RELATED GENES 5 (CPR5) selectively mediates the cytoplasmic translocation of IAA12/19. Under abiotic stress conditions, CPR5 expression is strongly decreased, resulting in the accumulation of nucleus-localized IAA12/19 in the root elongation zone and the suppression of lateral root development, which is reiterated in the cpr5 mutant. This study reveals a regulatory mechanism for auxin signaling whereby the spatial distribution of AUX/IAA regulators is critical for lateral root development, especially in fluctuating environmental conditions.

The AFB1 auxin receptor controls the cytoplasmic auxin response pathway in Arabidopsis thaliana.

The phytohormone auxin triggers root growth inhibition within seconds via a non-transcriptional pathway. Among members of the TIR1/AFBs auxin receptor family, AFB1 has a primary role in this rapid response. However, the unique features that confer this specific function have not been identified. Here we show that the N-terminal region of AFB1, including the F-box domain and residues that contribute to auxin binding, are essential and sufficient for its specific role in the rapid response. Substitution of the N-terminal region of AFB1 with that of TIR1 disrupts its distinct cytoplasm-enriched localization and activity in rapid root growth inhibition. Importantly, the N-terminal region of AFB1 is indispensable for auxin-triggered calcium influx which is a prerequisite for rapid root growth inhibition. Furthermore, AFB1 negatively regulates lateral root formation and transcription of auxin-induced genes, suggesting that it plays an inhibitory role in canonical auxin signaling. These results suggest that AFB1 may buffer the transcriptional auxin response while it regulates rapid changes in cell growth that contribute to root gravitropism.

Anterograde signaling controls plastid transcription via sigma factors separately from nuclear photosynthesis genes.

Light initiates chloroplast biogenesis in Arabidopsis by eliminating PHYTOCHROME-INTERACTING transcription FACTORs (PIFs), which in turn de-represses nuclear photosynthesis genes, and synchronously, generates a nucleus-to-plastid (anterograde) signal that activates the plastid-encoded bacterial-type RNA polymerase (PEP) to transcribe plastid photosynthesis genes. However, the identity of the anterograde signal remains frustratingly elusive. The main challenge has been the difficulty to distinguish regulators from the plethora of necessary components for plastid transcription and other essential chloroplast functions, such as photosynthesis. Here, we show that the genome-wide induction of nuclear photosynthesis genes is insufficient to activate the PEP. PEP inhibition is imposed redundantly by multiple PIFs and requires PIF3's activator activity. Among the nuclear-encoded components of the PEP holoenzyme, we identify four light-inducible, PIF-repressed sigma factors as anterograde signals. Together, our results elucidate that light-dependent inhibition of PIFs activates plastid photosynthesis genes via sigma factors as anterograde signals in parallel with the induction of nuclear photosynthesis genes.

Maximizing Thread Usage for Facial Rejuvenation: A Preliminary Patient Study.

BACKGROUND: Surgical facial rejuvenation techniques with thread lifting have gained popularity. To effectively rejuvenate an aging face, it is necessary to perform both soft tissue envelop repositioning and volume restoration procedures. With the trend toward less invasive techniques and long-lasting results with minimal complications, many surgeons have continued changing the techniques. OBJECTIVES: In the present study, we developed the 4 M (Multi-target, Multi-vector, Multi-layer, Multi-material) thread lift technique for long-lasting results. METHODS: A prospective study was conducted on 73 patients who underwent the 4 M thread lifting procedure between January 2016 and February 2018. To evaluate the surgical outcomes objectively, two plastic surgeons compared photographs using a 5-point Global Aesthetic Improvement Scale (GAIS) at 1, 3, 6, 12, 18, and 24 months of follow-up. RESULTS: Based on the GAIS objective assessment, in most patients (85%) experienced better than 3 score ("improved") changes. Approximately 42.5% of the patients experienced better than 4 score ("much improved") changes. The mean GAIS grade improved significantly (p < 0.005) without decline throughout a period of 12 months. No serious adverse complication was observed except one patient, who experienced skin irregularities and dimpling for up to 9 months after the procedure. CONCLUSIONS: This 4 M thread lifting is the multiple layer lifting and rejuvenation using different materials in addition to the multiple targets. Using the concepts of structural rejuvenation, the 4 M thread lifting technique presented modest to significant improvement, maintaining good results at 12 months after procedure. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Comprehensive Comparison Between Shaped Versus Round Implants for Breast Reconstruction: A Systematic Review and Meta-Analysis.

BACKGROUND: Prosthetic breast reconstruction has been gaining popularity and a variety of implant options are currently available. Therefore, it is important to evaluate the safety and efficacy of newly developed shaped implants compared with those of conventional round implants. To date, few studies have investigated the outcomes of breast reconstruction with shaped versus round implants. OBJECTIVES: The present study aimed to comprehensively compare, via meta-analytic methodology, shaped and round breast implant reconstruction in terms of complication profiles and aesthetic satisfaction. METHODS: PubMed/MEDLINE, Ovid, and Cochrane databases were searched to identify relevant studies presenting the complication rates for shaped and round implant groups. The relative risks of the following complications between the groups were calculated: infection, seroma, capsular contracture, rupture, rippling, reconstruction failure, and implant exchange or removal. Outcomes of aesthetic satisfaction included aesthetic results and patient-reported outcomes. RESULTS: Meta-analysis of 8 retrospective cohort studies, representing 2490 cases of implant-based breast reconstruction, was performed. There were no significant differences in the risks of infection, seroma, capsular contracture, and reconstruction failure between the 2 groups. The risks of implant rupture and rippling were significantly reduced with shaped implants. In a subgroup analysis of shaped/textured and round/smooth implants, the risk of infection was significantly enhanced in the former, whereas incidences of other complications, including capsular contracture and reconstruction failure, were similar. Aesthetic satisfaction analysis of the 2 groups demonstrated similar outcome scores with favorable overall results. CONCLUSIONS: Our results suggest that both shaped and round implants might provide favorable breast reconstruction outcomes with similarly low complication rates and aesthetic results.

Nontraumatic Subperiosteal Orbital Hematoma in a Patient With Behcet Disease.

Orbital subperiosteal hematomas are commonly caused by facial trauma. Nontraumatic subperiosteal orbital hematomas (NTSOHs) are rare but may occur in patients with underlying medical diseases. A 71-year-old woman presented to the emergency department with a 5-day history of left periorbital pain and proptosis. She was known to have Behcet disease and presented with no recent trauma. Clinical features and computed tomography findings aided in establishing the diagnosis of an NTSOH. The hematoma was evacuated via sub brow incision. After surgery, the patient's clinical symptoms resolved and did not recur during the 12-month follow-up period. On the basis of the findings of this case, the authors conclude that patients diagnosed with diseases such as bleeding disorders or autoimmune vasculitis should consider visual symptoms as a sign of an NTSOH. Patients who diagnosed with disease experience visual disturbance, periorbital pain, or periorbital swelling should undergo early surgical treatment for spontaneous NTSOH to avoid permanent visual loss.

Nucleo-cytoplasmic Partitioning of ARF Proteins Controls Auxin Responses in Arabidopsis thaliana.

The phytohormone auxin plays crucial roles in nearly every aspect of plant growth and development. The auxin response factor (ARF) transcription factor family regulates auxin-responsive gene expression and exhibits nuclear localization in regions of high auxin responsiveness. Here we show that the ARF7 and ARF19 proteins accumulate in micron-sized assemblies within the cytoplasm of tissues with attenuated auxin responsiveness. We found that the intrinsically disordered middle region and the folded PB1 interaction domain of ARFs drive protein assembly formation. Mutation of a single lysine within the PB1 domain abrogates cytoplasmic assemblies, promotes ARF nuclear localization, and results in an altered transcriptome and morphological defects. Our data suggest a model in which ARF nucleo-cytoplasmic partitioning regulates auxin responsiveness, providing a mechanism for cellular competence for auxin signaling.

BIL1-mediated MP phosphorylation integrates PXY and cytokinin signalling in secondary growth.

Vascular cambium proliferation in plants is crucial for the generation of vascular tissues and for mechanical strength. Phytohormones and mobile peptides are key regulators of vascular cambial activity during secondary growth; however, the signalling cross-talk underlying their coordinated action is largely unknown. Here, we reveal that BIN2-LIKE 1 (BIL1), a glycogen synthase kinase 3, integrates the PHLOEM INTERCALATED WITH XYLEM/tracheary element differentiation inhibitory factor (TDIF) RECEPTOR (PXY/TDR) module into MONOPTEROS/AUXIN RESPONSE FACTOR 5 (MP/ARF5) transcription factor action during secondary growth. BIL1-mediated phosphorylation of MP/ARF5 enhances its negative effect on vascular cambial activity, which upregulates the negative regulators of cytokinin signalling ARABIDOPSIS RESPONSE REGULATOR 7 (ARR7) and ARR15. PXY/TDR inhibits BIL1 activity, which attenuates the effect of MP/ARF5 on ARR7 and ARR15 expression, thus increasing vascular cambial activity. Together, these results suggest that BIL1 is a key mediator that links peptide signalling with auxin-cytokinin signalling for the maintenance of cambial activity.

Refinements in Elevation of the Reconstructed Auricle: The "Zigzag Incision".

OBJECTIVE: Auricular elevation with superficial temporal fascia and skin graft is widely used in microtia reconstruction using costal cartilage. However, in some patients, there has been occurrence of contraction of skin graft, which led to insufficient projection of the elevated auricle and diminished auriculocephalic angle with unfavorable long-term results. In this article, the authors introduce their multiple triangular flaps with zigzag incision to maintain stable projection and natural retroauricular sulcus appearance in auricular reconstruction patients. METHODS: The authors have designed zigzag incision along the lateral margin of the ear framework to prepare triangular flaps targeting the root of the helix or inferior half of the auricle. Depending on the extent of remnant skin coverage, the number of triangular flaps is varied. The posterior raw surface of the ear framework was covered with triangular flaps and full-thickness skin graft. RESULTS: Zigzag incision was conducted in 22 microtia patients who underwent auricular elevation using superficial temporal fascia and skin graft. Mean follow-up period was 2 years and there were no reports of occurrence of surgery-related complications, specifically skin necrosis, infection, or hematoma. The auricular projections were well maintained and auriculocephalic angle of the constructed auricles was similar to the healthy ears. CONCLUSIONS: The author's method comprises comparatively easy techniques and leads to good projection of the auricular angle. A zigzag incision using the triangular flaps could be an attractive surgical option for preventing shrinkage of grafted site and in achieving sufficient projection in autologous reconstructed auricle.

Integration of multiple signaling pathways shapes the auxin response.

The phytohormone auxin is a pivotal signaling molecule that functions throughout the plant lifecycle. Proper regulation of the auxin response is critical for optimizing plant growth under ever-changing environmental conditions. Recent studies have demonstrated that the signaling components that modulate auxin sensitivity and responses are functionally and mechanically diverse. In addition to auxin itself, various environmental and hormonal signals are integrated to modulate the auxin response through directly controlling auxin signaling components. This review explores the non-canonical mechanisms that modulate auxin signaling components, including transcriptional, translational, and post-translational regulation. All of these contribute to the wide range in sensitivity and complexity in auxin responses to various signaling cues.

Aesthetic Penoscrotal Resurfacing: Creating Propeller Flaps from Gluteal Folds.

BACKGROUND: Reconstruction of extensive penoscrotal defects is a surgical challenge. Resurfacing defects in highly complex three-dimensional structures and restoring their function are an essential part of the reconstruction of penoscrotal regions. OBJECTIVE: We describe a technique using internal pudendal artery perforator (IPAP) pedicled propeller flaps created from the gluteal fold. This could be a reliable surgical option that maintains a natural looking scrotal pouch with minimal donor site morbidity and optimal sexual activity. DESIGN, SETTING, AND PARTICIPANTS: We retrospectively reviewed data for 10 consecutive patients who had undergone penoscrotal reconstruction using IPAP pedicled propeller flaps between January 2011 and March 2015. SURGICAL PROCEDURE: The IPAP was identified using a hand-held Doppler ultrasound device. This was the pivot around which the flap was internally rotated more than 90° in a tension-free manner. The long axis of the flap was centred on the gluteal fold to provide a better-orientated donor site scar. MEASUREMENTS: Complications and patient satisfaction with respect to size, colour match, scar appearance, and sexual activity were evaluated. RESULTS AND LIMITATIONS: Anatomic and aesthetic penoscrotal reconstruction was performed without any major complications in the follow-up period (mean, 19.7 mo). The mean width of the IPAP pedicled propeller flaps was 6.7cm, and the mean length was 11.7cm. Partial distal flap necrosis occurred in only one case, and healed spontaneously. All of the patients were satisfied with the cosmetic and functional results. CONCLUSIONS: On the basis of reliable perforators, donor site morbidity, flap thickness, and a better orientated scar, our technique using IPAP pedicled propeller flaps created from the gluteal fold could be a reasonable surgical option for extensive penoscrotal reconstruction. PATIENT SUMMARY: The creation of pedicled propeller flaps using an internal pudendal artery perforator could be a reliable surgical option for reconstruction of extensive penoscrotal defects. The approach yields functional and aesthetically acceptable surgical results.

Experience with specially designed pored polyacetal mold dressing method used in McIndoe-style vaginoplasty.

INTRODUCTION: Appropriate postoperative care and prolonged use of the mold are prerequisites for achieving successful results in McIndoe-style vaginoplasty. OBJECTIVE: We introduce a specially designed pored polyacetal mold to maintain the reconstructed vagina, with favorable long-term results allowing drainage of the serous and bloody discharge without removal of the mold, and reduction of infection rate and the chance of skin graft shearing in McIndoe vaginoplasty. METHODS: We retrospectively reviewed data of 10 consecutive patients with Mayer-Rokitansky-Kuster-Hauser syndrome who underwent McIndoe vaginoplasty between March 2010 and January 2014. We used a specially designed pored polyacetal mold (Figure) in all reconstructed vaginal wounds. The anatomical surgical success was evaluated by physical examination and functional success, which was defined as satisfaction with sex evaluated by patient self-assessed questionnaire. RESULTS: The follow-up period ranged from 1 to 3.5 years. The postoperative mean vaginal length was 9.5 cm in nine patients who used the mold regularly. In all cases in which a pored polyacetal mold was used, skin engraftment was successfully maintained without partial skin graft loss or infection. The subjective patient self-assessed satisfaction evaluation reported a high satisfaction rate. DISCUSSION: The multi-holed polyacetal vaginal mold was designed to perform vaginal irrigation without removal of the mold, allowing drainage of the serous and bloody discharge. This makes it possible to reduce infection rate and maintain successful skin engraftment by reducing the chance of skin graft shearing. The characteristics of polyacetal make it useful as a vaginal mold material as it is lightweight to use, easy to manufacture in accordance with the dimensions of the neovaginal space, and cost-effective. Although a constant follow-up evaluation is required, the pored polyacetal mold is an attractive vaginal mold dressing material to maximize the initial graft uptake, and it can be individually tailored in patients undergoing McIndoe-style vaginoplasty. CONCLUSIONS: The specially designed vaginal mold made up of pored polyacetal is a proper vaginal mold, which could maximize the initial graft uptake, decrease the risk of wound infection, and, therefore, decrease contracture of the neovagina in patients undergoing McIndoe vaginoplasty.

Modified Direct-Type Septal Extension Grafts: Their Stability and Usefulness in Asian Rhinoplasty.

BACKGROUND: In Asian rhinoplasty, many autogenous cartilage grafts are required for correction of the nasal tip and columella, but the amount has limitations. A modified direct-type septal extension graft, in continuity with the entire caudal border of the septal cartilage with an edge-to-edge coaptation, can effectively and concomitantly correct the nasal tip and columella deformities using a limited amount of septal cartilage graft. The purpose of this study was to evaluate long-term cosmetic outcomes and stability from the modified direct extension grafts. METHODS: Fifty-seven patients with a follow-up of more than 1 year were enrolled in the study. A total of 11 measurement items were evaluated from basal and right lateral views by photogrammetry using standardized clinical photographic techniques. RESULTS: The overall mean follow-up period was 20.4 months. When comparing the preoperative and postoperative values, the nasal tip projection, nasal bridge length, nasal tip angle, height of nose, and the columellar labial angle increased significantly; additionally, the soft nose width index, width between ac-ac index, nostril axis inclination, columellar length (Rt-Lt), and the alar length (Rt-Lt) decreased significantly. No resorption, buckling, or displacement of the graft was observed during the follow-up period. CONCLUSIONS: The modified direct extension graft demonstrated a marked aesthetic improvement in the nasal tip and columella, and it provided long-term stability. Therefore, the modified direct extension graft is useful for correction of the nasal tip and columella in Asian rhinoplasty.

A Prospective evaluation of outcomes for midface rejuvenation with mesh suspension thread: "REEBORN lift".

BACKGROUND AND AIM: In the evolution of facial rejuvenative methods, thread lifts have gained popularity among patients who require mild degree of cosmetic improvement. The REEBORN (PrestigeMedicare, South Korea, Gyeonggi-do) is a newly developed type of mesh suspension thread composed of implantable mesh and barbed thread. In this article, we presented our experience with midface rejuvenation using novel modified mesh suspension thread including reliable esthetic results and minimal complications. METHODS: Prospective record analysis was conducted for 20 female patients who underwent REEBORN thread Lifting. To validate acceptable surgical results, three physicians rated the severity of nasolabial folds and marionette lines of patients. The patients were also asked to complete a questionnaire about satisfaction with this procedure and following adverse effects. RESULTS: The mean operation time was 40 min, and surgery-related complications included two minor complications. Significant improvement in wrinkle severity was observed at 6 months after thread lifting (P < 0.0001). Patients showed high satisfaction with surgical results (≥90%) and procedure (≥80%). CONCLUSIONS: Although further follow-up and more studies are required to prove long-term efficacy of emerging technique, our early experience has been positive. We are expected to provide sufficient holding power apart from cogs; in addition, fixation mesh is ensured by the implantable distal mesh that provides long lasting maintenance in thread lifting rejuvenation.

Satisfactory surgical option for cartilage graft absorption in microtia reconstruction.

BACKGROUND: We routinely perform auricular elevation at least 6 months after implantation of framework in microtia reconstruction using costal cartilage. However, in a few cases, cartilage graft absorption has occurred, which has led to contour irregularity with unfavorable long-term results. In the present study, we recount the details of using additional rib cartilage augmentation to achieve an accentuated contour in cartilage graft absorption cases. MATERIAL AND METHODS: The cartilage graft absorption was defined as contour irregularity or cartilage graft deformation as evaluated by the surgeon and patient. Depending on the extent of cartilage graft absorption, another rib cartilage framework was added to the previously implanted framework, targeting the absorption area. We used banked cartilage or harvested new cartilage based on three-dimensional rib computed tomography. RESULTS: Additional recontouring of framework was conducted in eight patients who were examined for cartilage graft absorption from 1.5 to 5 years after implantation of the framework. Four patients received additional rib cartilage augmentation and tissue expander insertion simultaneously prior to auricular elevation. Two patients underwent auricular elevation simultaneously. In another two patients, additional rib cartilage augmentation was performed before auricular elevation. The mean follow-up period was 18 months, and in all cases reconstructive results were acceptable. CONCLUSIONS: Although further follow-up evaluation is required, additional rib cartilage augmentation is an attractive surgical option for cartilage graft absorption cases.

Aesthetic auricular reconstruction with autologous rib cartilage grafts in adult microtia patients.

BACKGROUND: Cartilage calcification is an important factor in aesthetic auricular reconstruction using autologous rib cartilage grafts in adults, a technique that involves difficult manipulation and unexpected absorption. As a result, artificial implants or prosthetics are considered for auricular reconstruction in adult patients despite the limitations of artificial material. In this article, we present our experience with auricular reconstruction using autologous rib cartilage grafts in adult microtia patients with reliable aesthetic results and minimal complications. METHODS: A retrospective chart review was performed for 84 microtia patients ranging in age from 21 to 56 (average: 29.9) years who underwent auricular reconstruction using autologous rib cartilage grafts from March 2001 to March 2013. To validate our acceptable reconstructive results, two independent observers performed postoperative photographic evaluation of two groups (adults and children) using non-inferiority tests in addition to patient questionnaires. RESULTS: The mean operation time for rib cartilage grafts was 3 h and 53 min, and the follow-up time for all patients ranged from 6 months to 8 years. Surgery-related complications occurred in only three cases. On objective photographic evaluation, the adult group was not inferior to the child group in auricular shape, location, or symmetry. The subjective patient satisfaction evaluation reported a high satisfaction rate. CONCLUSIONS: As this study shows, aesthetic auricular reconstruction using rib cartilage grafts in adult microtia patients is possible even in cases with advanced cartilage calcification. Modification of the fabricating framework, well-preserved flap vascularity, and complete understanding of physiological aspects of rib cartilage are essential for aesthetic auricular reconstruction.