Tip Defects Research Articles

Reconstruction of Nasal Alar and Tip Defect.

*Department of Dermatology, The Royal Melbourne Hospital, Parkville, VIC, Australia; †Division of Dermatologic Surgery, Department of Dermatology, Icahn School of Medicine at Mount Sinai, New York, NY; and ‡The Skin Hospital, Darlinghurst, NSW, Australia Address correspondence and reprint requests to: Hnin Pwint Oo, MD, Department of Dermatology, The Royal Melbourne Hospital, Level 8, CMR Building, 300 Grattan Street, Parkville, VIC3050, Australia, or e-mail: [email protected] The authors have indicated no significant interest with commercial supporters. The Skin Hospital, 121 Crown Street, Darlinghurst, New South Wales, Australia 2010.

Aesthetic Outcomes of the Adipofascial Turnover Flap for Nasal Defects

A retrospective review was conducted of patients who underwent either a forehead flap or an AFT flap for nasal reconstruction between January 2016 and January 2021. Aesthetic outcomes were compared via patient surveys and photographic analysis by plastic surgeons. All photographs were standardized and masked to conceal which reconstructive technique was utilized. Wilcoxon rank-sum tests and t-tests were performed to determine significance. Ten forehead flaps and 22 AFT flaps were performed between January 2016 and January 2021. Seven forehead flap patients and 18 AFT flap patients participated in the aesthetic outcome survey. Seven forehead flap postoperative photographs and 20 AFT flap postoperative photographs were available for analysis. Patients who underwent forehead flap reconstruction reported higher satisfaction for color match of the reconstruction to the surrounding nasal skin (P = 0.005). Otherwise, there was no statistical significance between the two patient groups. There was no statistical difference in the photographic analysis of the two groups. The single-stage AFT flap with full thickness skin grafting provides similar aesthetic outcomes compared with the two-stage forehead flap when reconstructing large defects of the nasal tip, which is supported by both patient-reported outcome measures and standardized photographic analysis by a panel of plastic surgeons.

Superior Antihelix Composite Graft for Repair of Nasal Ala and Lateral Nasal Tip Defects: A Retrospective Case Series.

Deep defects on the nasal ala and lateral nasal tip may result in nasal valve insufficiency or alar notching and are often repaired with a 2-stage reconstruction. Previous literature has demonstrated high failure rates of composite grafts. Identify survival rates and cosmetic outcomes of nasal composite grafts harvested from the antihelix. A retrospective review of 52 patients who underwent ala or lateral nasal tip composite graft repair from April 2019 through May 2022, with statistical analysis of cosmetic outcomes graded by 2 surgeons. Defect size ranged from 0.7 cm × 0.8 cm to 1.9 cm × 2.5 cm. 48 grafts survived (92.3% survival rate). Four patients sustained at least partial integument sloughing (epidermal necrosis), but the cartilage survived in all 52 cases. Overall, aesthetic results yielded the following: excellent (19.5%), very good (35.5%), good (11.5%), decent (16.5%), and poor (6%). In 93% of cases, there was no evidence of nasal collapse or retraction. Two patients (3.8%) required surgical revision. Donor site morbidity was low. The antihelical composite skin graft is a 1-step reliable repair option for ala and lateral nasal tip defects with an acceptable cosmetic outcome.

Martens hardness of Constantan thin films on (100) Si wafer: Improvement in contact area function in nanoindentation

This work presents a mechanical study by nanoindentation of Constantan thin films deposited by cathodic sputtering technique with an intermediate thin adhesion layer of titanium on a (100) silicon wafer substrate. A methodology based on a modified contact area function is proposed for a suitable processing of the nanoindentation data in order to extract the Martens hardness both of the substrate, titanium layer and Constantan films. The raw data of the substrate Martens hardness have been studied using the most useful models among them those of Nix & Gao, Li & Bradt and Bull & Page showing a significant indentation size effect. However, when considering the tip defect length in the Martens hardness computation, the corrected values are found constant and no indentation size effect occurs. Within this objective, an accurate determination of the tip defect length is required. Its value has been determined both with a correlation between the contact area function of Oliver & Pharr and the improved model of Chicot et al. and also with the self-calibration method proposed by Chicot et al. The tip defect length is afterwards implemented in the model of Jönsson & Hogmark modified by Rahmoun et al. for the hardness determination of the titanium layer and the Constantan thin films. As a main result, the Martens hardness of the titanium layer and of the substrate are found equal to 8 GPa thus allowing to neglect the influence of the titanium layer in the film hardness determination. As a main result, the hardness of the 4 Constantan films is constant whereas the substrate hardness changes with the film thickness. This unexpected behavior is related to the brittleness of the substrate where cracks are observed at the interface and by the film compacting which is trapped between the rigid indenter and the hard substrate.

Comparison of Structural Topography, Elemental Composition and Qualitative Analysis of two Indian mini-implants: A cross-sectional study

Objectives: This research was conducted to evaluate the surface topography, elemental composition and manufacturing defects of two brands of mini-implants commonly used in India. Clinical significance was derived based on the data of this research. Materials and methods: This research was conducted on 15 orthodontic mini-implants each from two brands commonly used in India. Scanning electron microscope imaging of the head, transmucosal neck, body, and tip was done to assess mini-implant topography and manufacturing defects (n=15/group). Analysis of elemental composition was done using an X-ray Powder Diffractor (n=1/group). Results: The results showed significant differences in both groups. Differences in structural topography of the implant body and tip were observed in both brands. Tip defects were detected in one brand. X-ray Powder Diffraction analyses revealed an alpha and alpha-beta titanium grain structure in both the groups. Conclusions: All the mini-implants tested were composed of titanium alloy. Significant differences were found in the surface area of the threaded parts. We conclude that differences in surface topography and presence of manufacturing defects impact the primary stability of the implants thereby influencing the efficacy of orthodontic anchorage.

Automated quality control inspection of geometric tip defects in medical needle manufacturing

The manufacture of In Vitro Fertilization (IVF) needles is subject to the most stringent quality demands. This makes automated inspection challenging due to difficulty in reliably classifying conforming and non-conforming (defective) products due to factors including multidimensional variation of their tip geometry and the lack of an explicit quality standard. In addition, developing an IVF needle image dataset, which broadly contains the visual characteristics of qualified and defective products, is difficult without commissioning large and costly production runs. The most important original contribution of this work is a new solution to investigate and quantify the uncertainty in the quality standard of IVF needles by integrating inter-disciplinary techniques. This work utilizes a low-cost, virtual dataset of synthetic images, generated by the automated photo-realistic rendering of a three-dimensional (3D) parametric model to simulate manufacturing variation. Then, the unknown numerical (critical) quality thresholds are obtained by estimating the relationship between quality response and measurement predictors using an Ordinal Logistic Regression (OLR) algorithm on the synthetic images. The fitted models exhibited increased overall predictive accuracy of up to 11.02% than the machine learning models (available in MATLAB) and could provide objective guidance on classifying specific quality aspects of a product.

Secondary Intention Healing of Nasal Ala and Tip Defects: A Simple and Valuable Treatment Option.

PurposeTo investigate the cosmetic outcomes of secondary intention healing of small (<1.5cm) nasal ala and tip defects.Patients and MethodsFrom August 2017 to October 2020, 42 patients with nasal reconstructions using secondary intention healing were included. Defects after excision ranged from 0.5cm×0.7cm to 1.2cm×1.5cm in size. Foam dressing covering the wounds was changed every 3 to 5 days. Wound esthetic outcomes were graded as excellent, good, acceptable, and poor based on definitions described in the literature.ResultsAll 42 wounds healed in 3 to 4 weeks, with uniform color, no obvious adverse reactions and high patient satisfaction. Esthetic evaluation: 16 excellent cases (38.1%), 19 good cases (45.2%), 7 acceptable cases (16.7%) and 0 poor cases.ConclusionSecondary intention healing of small nasal tip and ala defects in Chinese yielded satisfactory esthetic outcomes and should be an integral part of the surgeon’s reconstructive algorithm.

Vickers hardness of NiW coating as a potential replacement for Cr-VI: A methodology to consider size effect and tip defect in classical microindentation

Hard chromium coatings are widely used due to their excellent mechanical properties. However, they are historically obtained from hexavalent chromium (Cr-VI) solutions, which are classified as Carcinogenic Mutagenic Reprotoxic (CMR) material due to their very high toxicity. NiW coating is studied in this work as a possible replacement for Cr-VI coating. The substrate used is ST37 steel. The conventional commercial Cr-VI coating is considered here as reference material in terms of hardness.Usually in classical microindentation, the tip defect is always neglected and the indentation size effect (ISE) is studied disjointedly. However, these two aspects can interact together into the hardness measurement. Based on Vickers hardness measurements on steel substrate and both on a cross-section and on the top surface of the Cr-VI coating, 50 μm of thickness, we propose a discussion on the indentation size effect and the influence of the indenter tip defect on the hardness measurement. To validate our approach, the tip defect length was previously determined by SEM observation. Its value allows concluding that the apparent indentation size effect on the Cr-VI coating is only due to the tip defect. However, the corrected Vickers hardness for the steel substrate reveals always a residual ISE. This hardness-load dependence of steels is attributed to the strain hardening generated by the surface preparation.Starting from the methodology developed on the quasi-massive materials, we have corrected the raw indentation data obtained for the NiW coatings and we have applied the model of Jönsson and Hogmark to separate the contribution of the substrate on the hardness measurement to determine the hardness of the coating only. A discussion on the value of the constant involved in their model confirms that it should be cautiously considered. As a result, the macrohardness of the Cr-VI coating is determined around 8.0 GPa whereas for the NiW coating it is found to be from 4.5 to 5 GPa depending on the deposition parameters.

Self-calibration in compliance and indenter tip defect for instrumented indentation

Self-calibration in compliance and indenter tip defect for instrumented indentation

Post dermoid excision nasal tip deformity correction using gelatin sponge.

Reconstruction of the nasal tip after the excision of the dermoid cyst is difficult, especially if the size of the dermoid is large. Tip reconstruction using Interdomal sutures of alar cartilages and auricular cartilage graft has been used in such cases. We share a new method to manage the nasal tip defect following excision of nasal dermoid, using an absorbable gelatin sponge. A 13 years old female presented with a swelling tip of the nose for the past 2 years. The CT scan revealed a dermoid cyst at the tip of the nose over the alar cartilage with prominent buckling of the cartilages. The Dermoid cyst was excised through an open rhinoplasty incision. There was a defect of 2.2cm diameter at the tip of the nose with deformed alar cartilages. A piece of absorbable gelatin sponge was folded, cut according to the shape of the cavity, and used to fill the cavity. The skin was draped over the cartilage and gelatin sponge. The post-operative period was uneventful. After 2 years of follow-up, the patient remained asymptomatic and satisfied with a nice contour of the nasal tip.

Evaluation of Modified Dorsonasal Flap for Reconstruction of Dorsonasal Defect in Erbil

Background and objectives: nasal reconstruction is challenging for plastic surgeons mainly because its midfacial location and the relationship between convexities and concavities of nasal subunits that make it difficult to hide any contour deformity; as a result, proper planning of final scar location is crucial for successful aesthetic outcome. The modified dorsal nasal flap is used for resurfacing nasal tip defects with respecting of these nasal subunits. This paper evaluates the outcome of modified dorsonasal flap for reconstruction of the dorsal nasal defects. Method: in our department twenty nasal defects were reconstructed with modified dorsal nasal flap between years (2016-2019); Charts of these patients were analyzed in relation to their age, cause and size of the defect, complications and appearance. Results: half of patients who underwent nasal reconstruction by dorsal nasal flap were males (n=10) and the other half were females (n=10), mean age 39.5 months, median defect diameter was (21mm), follow up period ranged from (7-42 months), all patients were satisfied with results with no significant complications including: hematoma, infection, flap loss or wound dehiscence. Conclusion: Dorsal nasal flap is reproducible one stage flap for reconstruction of nasal defects with minimal complication and good aesthetic outcome.

Nasal tip defects: satisfaction with Rintala flap for reconstruction—a report of 38 cases

Nasal tip defects: satisfaction with Rintala flap for reconstruction—a report of 38 cases

“THUNDER – LIKE” PLASTY FOR TWIN NASAL TIP DEFECTS. TECHNIQUE DESCRIPTION AND INDICATIONS

​INTRODUCTION: Reconstructive approaches to nasal tip defects are always challenging to perform, depending on the age of the patient, shape of the nose, local anatomy and adjacent structures. Many techniques have been described, each one with its advantages and limitations. AIM: Our aim is a new technique description designed for the reconstruction of twin defects of the nasal tip. The decision-making, the step-by-step description, and its application to a male patient are explained in detail. MATERIAL - METHOD: A 61 years old male patient was referred to our department with two benign lesions of the nasal tip. Due to their proximity, a simultaneous excision was planned in a way that allowed both adequate excision and minor defect dimensions. The remaining defect was reconstructed with a combination of 2 rotation flaps and 2 V-Y plasties. RESULTS: Very good skin match (color and texture). Suture lines are barely detectable because they are buried in the anatomical border between the nasal tip and the alar area. No consequences for the alar shape or the columella are mentioned (deviation, stricture, narrowing or flattening respectively). CONCLUSION: This technique has been influenced by the “East – West plasty”. Its innovative elements are: 1. The upper triangle hereafter contains the second lesion. 2. The V-Y plasties we intendedly added on top of each rotation flap limit loss of length resulting in well aligned scars. The technique is advisable for benign lesions, in situ malignancies or for centers performing Mohs micrographic surgery.

The proposition of analytical expression HM–(√P/S) in microindentation pile-up deformation mode

In this article, the characteristic curves of microindentation measured on Cu99 were analyzed on the basis of the analytical expression proposed by Habibi et al. (J. Mater. Res, 2021, 36 (15): 3074-3085). It was found that the ratio of the applied load to the square of the displacement, P/(h+h0)2, does not remain constant during the loading segment of the microindentation test. An empirical expression for the determination of Martens hardness as a function of indentation load, contact stiffness and reduced modulus of elasticity by analyzing indentation load curves has been proposed for pile-up mode strain with the corrections imposed by the tip defect, the compliance of the instrument and the axial axisymmetry coefficient of the Vickers indenter. The results from microindentation tests on this examined ductile material show excellent agreement.

Reconstruction des pertes de substances du nez : algorithme décisionnel à propos de 229 cas

The Face is the most frequent localization for cutaneous carcinoma. The nose accounts for about 30% of these tumors. Nose tissue loss repair has to pursue 3 types of objectives: carcinologic, aesthetic and functional. The aim of this article is to identify a decision tree to guide the choice of surgical reconstruction technique based on localization and size of the defect. We performed a retrospective analysis in Angers' CHU from 2013 to 2019 including 229 patients referred for cutaneous tumors excision in need of reconstruction. We analyzed the type of reconstruction, size of the tissue loss and localization of the defect in terms of nose aesthetic subunits. Among the 229 patients included, the most frequent localization was nose tip (32%). 44% of patients were reconstructed with skin grafts or composite graft, 56% with flaps (48% local flaps and 4% association of both methods). Limited central resections of nose tip were reconstructed with skingraft. The Rybka flap and bilobed flap were the preferred choice for lateral reconstruction of nose tip. Largest tip defects were reconstructed using Rieger flap or forehead flap. The dorsum was often reconstructed with local flap: glabellar on the upper part, Rieger on the lower part. Lateral side was perfectly reconstructed with island flap. Nose wings needed framework: composite graft was the judicious choice in case of limited tissue loss whereas forehead flap with framework or Schmid-Meyer flap were chosen for larger defects. Our past experience in nasal reconstruction has provided us with an original decision tree to guide surgeons in choosing the right reconstruction technique according to the size and localization of the defect.

OP4: Posterior Auricular Perichondrial Cutaneous Graft for Stable Reconstruction of Nasal Defects: Long-Term Outcomes

INTRODUCTION: The posterior auricular perichondrial cutaneous graft (PCCG) was described in 2005 by Kalbermatten et al. as a functional, stable and aesthetic reconstructive option in case of cartilage or fibrofatty tissue defects of the nasal tip or ala. The composite graft is harvested using a posterior auricular donor site which is closed with a postauricular transposition flap, thus avoiding resection from the anterior conchal bowl. The present study aims at reporting long-term outcomes of the procedure. MATERIALS AND METHODS: We conducted a retrospective review of all patients undergoing nasal tip reconstruction with PCCG between 2005 and 2020. Graft survival, donor-site morbidity, nostril stability, reoperation rate and aesthetic outcomes were assessed at long follow-up. RESULTS: We identified 13 patients undergoing PCCG nasal reconstruction to cover defects presenting an average size of 2 cm2 on the ala and 2.5 cm2 on the tip after basal cell carcinoma resection. Twelve patients showed primary complete healing, while reoperation was required in one case due to partial necrosis of the graft. At a mean follow-up of 14.5 months, nostril stability and symmetry were achieved in all patients, while all donor sites healed uneventfully. Aesthetic outcomes were judged as satisfactory by both patients and surgeons. Oncological control was ensured by this reconstruction, allowing detection of relapse in three cases. CONCLUSION: This follow-up study confirmed the findings initially presented with a shorter 6months follow-up. The PCCG demonstrated to be a reliable and effective reconstructive option, able to restore function and aesthetic with minimal morbidity rate. Notably, the procedure allows optimal oncological control.

The Study on a New Method for Detecting Corona Discharge in Gas Insulated Switchgear

Partial discharge (PD) is the main cause of insulation deterioration and failure of gas-insulated switchgear (GIS). Corona discharge (CD) is a typical type of PD in gas-insulated switchgear. Accurate and sensitive measurement of CD in GIS is of great significance for theoretical research in the laboratory and fault prediction of GIS in the actual operation. A novel method for detecting CD in GIS is proposed in this article. A coaxial structure model for simulating GIS is established. The CD detecting sensor based on the proposed method is designed for this model. An artificial tip defect is designed on the internal high voltage conductor of the coaxial model to simulate CD in GIS. A 50 Hz ac power supply, a dc negative power supply, and a dc positive power supply are applied as excitations to generate the CD at the defect, respectively. The discharge pulse signal is detected by the proposed sensor. The results show that the proposed sensor can completely obtain the information of the CD pulse signal. The proposed method has the same anti-electromagnetic interference ability as the ultrahigh-frequency method and has a high sensitivity to CD in GIS.

28284 Subcutaneous hinge flaps: A great choice, especially in the setting of COVID

A 55-year-old woman presented for Mohs surgery with an infiltrative basal cell carcinoma of the nasal dorsum with a preoperative size of 0.9 cm × 0.7 cm. Negative margins were achieved after five stages, and the resultant defect measured 2.6 × 2.4 cm with exposed cartilage and involvement of 4 subunits of the nose (Figure 1). For large nasal tip defects, a paramedian forehead flap (PMFF) is nearly the gold standard. These flaps are chosen due to good color match between the donor forehead skin and the nose, the presence of sebaceous tissue within the flap, and the ability to match the flap depth to the depth of the defect. Our patient was offered a paramedian forehead flap and adamantly declined, citing her inability to care for the flap. Instead, she elected for a two-stage repair of a subcutaneous hinge flap from the upper nasal dorsum to restore the contour and depth of the nasal tip and supratip, to cover the exposed cartilage, and to provide good blood supply for the subsequent full thickness skin graft performed during the second stage of repair. She had excellent take of the FTSG and was pleased with her result. Several months after the surgery, the area was lightly dermabraded and then treated with several pulse dye laser treatments with good cosmesis. This repair option is especially important during COVID times, when a PMFF would minimize the ability to function in society and to safely wear a mask.

Double-semicircular skin graft: A method to minimize wasted donor tissue

Donor site selection is very important when using a full-thickness skin graft (FTSG) in reconstructive surgery of nasal defects.1 The nasal root has been suggested as an excellent donor site for nasal tip defects because of the similarity in its color, texture, thickness, degree of actinic damage, and sebaceous quality.2 An elliptical excision is often used for harvesting an FTSG where tissues on both sides of the donor skin are discarded. However, since a larger donor area is required for large defects, using the conventional elliptical FTSG from the nasal root was challenging to repair a large nasal tip defect after wide excision of an 8 × 7-mm–sized basal cell carcinoma with a 4-mm margin (Fig 1, A).

Complex nasal reconstruction for skin cancer and posttraumatic deformity using a modified frontonasal flap - Case report.

Introduction and importanceReconstruction of the nasal tip is challenging, especially when large defects are associated with compromised nasal soft tissues and framework. The frontonasal flap is an axial-pattern myocutaneous flap from the glabella and nasal dorsum that allows for various modifications in flap design to cover medium sized defects of the nasal tip.Case presentationA 66-year-old male patient presented with a large and ulcerated squamous cell carcinoma of the nasal tip that was associated with substantial posttraumatic damage of the nasal soft tissue envelope and cartilaginous vault of the dorsum. Considering patient comorbidity, risk factors, and specific nasal condition, a single-stage tumor resection and reconstruction using a modified frontonasal flap was intended. While tumor excision resulting in a tip defect of 1.5 × 1.5 cm and flap coverage were initially achieved in a single stage, histologically incomplete tumor resection and individual patient requests mandated further surgery, including re-excision, cartilage grafting, and soft tissue contouring.Clinical discussionThe frontonasal flap allows for single-stage reconstruction of moderate size tip defects. Even in the case of prior soft tissue damage and scarring, the flap may be used safely pending individual adjustments in flap design. However, additional measures may be employed as needed to optimize the functional and aesthetic outcome in cases of complex nasal pathology.ConclusionIn a case with a combined tumor and posttraumatic nasal deformity, an individualized surgical concept incorporating a modified frontonasal flap with adjunct cartilage grafting and soft tissue contouring achieved an excellent functional and cosmetic outcome.