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Tongue reconstruction remains a major aspect of head and neck reconstructive procedures. Surgeons planning tongue reconstruction should consider several factors to optimize the overall outcomes. Specifically, various technical aspects related to tongue reconstruction have been found to affect the outcomes. Multidisciplinary teams dedicated to oncologic, reconstructive, and rehabilitative approaches play an essential role in the reconstructive process. Moreover, operative planning addressing certain patient-related and defect-related factors is crucial for optimizing functional speech and swallowing, as well as quality of life outcomes. Furthermore, tongue reconstruction is a delicate process, in which overall functional outcomes result from proper flap selection and shaping, recipient vessel preparation and anastomosis, surgical approaches to flap insetting, and postoperative management. The second part of this review summarizes these factors in relation to tongue reconstruction.

This study aimed to propose a novel surgical technique, named multiple tangential shaving of bone contour, for the conservative management of craniofacial fibrous dysplasia. We retrospectively reviewed 17 patients who underwent conservative management of craniofacial fibrous dysplasia using multiple tangential shaving technique between July 2005 and December 2020. Demographics, tumor characteristics, and surgery-related factors were investigated. All patients underwent preoperative (T0) and postoperative computed tomography scans taken at least twice within 1 month for immediate assessment (T1) and at least 12 months postoperatively for long-term assessment (T2). Clinical outcomes, including tumor recurrence, perioperative complications, and physician measure of esthetic outcomes (Whitaker score), were investigated. This technique was applied for contouring of the zygomatic-maxillary and calvarial bone for patients aged between 16 and 60 years (mean age: 26 y). The mean±SD tumor volume reduction was 15.5±8.95 cm 3 , and the postoperative mean±SD tumor growth rate was 5.52±6.26% per year. Satisfactory outcome was obtained in terms of esthetics with a mean±SD Whitaker score of 1.41±0.62. Patients required a mean operation time of 1.67±0.43 hours and a mean number of shaving operations of 1.35±0.61 during the follow-up period. Five of 17 patients required reoperation because of the tumor recurrence (N=4) and to correct new-onset diplopia after surgery (N=1). In conclusion, the multiple tangential shaving technique allows an easy approach for conservative management of craniofacial fibrous dysplasia. An acceptable rate of tumor recurrence and esthetic outcomes can be obtained by selecting the appropriate candidate for a conservative approach.

Fronto-orbital distraction osteogenesis (FODO), used to correct bilateral coronal craniosynostosis (BCS), is grossly classified into 1-piece and 2-piece FODO. One-piece FODO osteomizes the frontal and supraorbital bones as one block by preserving the attachment between the dura mater and bone, whereas the 2-piece FODO detaches bone segments from the underlying dura mater and reshapes them. This study aimed to determine whether separating the bone-dura attachment would affect osteogenesis and the relapse of the deformity and to compare the surgical outcomes between 1-piece and 2-piece FODO.Patients with BCS who underwent either 1-piece or 2-piece FODO between May 2008 and November 2016 were retrospectively reviewed. Patients older than 12 months who were diagnosed with syndromic or nonsyndromic craniosynostosis were included. The CT images were taken at initial presentation (T0), 1-3 years postoperatively (T1), and4 years postoperatively (T2). These images were used to measure the frontal angle, anterior skull base ratio, and bone defect area.This study included 11 patients in the 1-piece group and 9 patients in the 2-piece group. The relapse ratios of the frontal angle were -2.3% ± 0.6% and -4.9% ± 2.1% in the 1-piece and 2-piece groups, respectively, showing that the 2-piece group had a significantly higher relapse ratio ( P = 0.002). At the T2 period, the 1-piece group had a significantly higher anterior skull base ratio (0.80 ± 0.10) than that in the 2-piece group (0.69 ± 0.08, P = 0.046). In addition, the bone defect area was significantly lower in the 1-piece group (T1: 4.90 ± 2.32 cm 2 , T2: 2.55 ± 1.57 cm 2 ) than in the 2-piece group (T1: 10.74 ± 5.89 cm 2 , T2: 5.35 ± 2.74 cm 2 ) both at the T1 ( P = 0.037) and T2 ( P = 0.025) periods.One-piece FODO can result in the preservation of the bone segments' vascularity and the enhancement of osteogenesis in the distraction gap. Moreover, 1-piece FODO is associated with lower rates of relapse of deformity and bone defects compared with 2-piece FODO. Lastly, 1-piece FODO can be performed to maximize the advantages of distraction osteogenesis and improve surgical outcomes, especially among early childhood patients with BCS.

Background: The efficacy and safety of equine cartilage as a competent xenograft material for rhinoplasty were evaluated and compared to the outcomes of rhinoplasty using silicone implants.Methods: We performed a multicenter, double-blind, non-inferiority, and randomized confirmatory study. Fifty-six patients were randomized 1:1 to the study group (using MegaCartilage-E) and control group (using silicone implants). The Rhinoplasty Outcome Evaluation (ROE) score, photo documentation, Global Aesthetic Improvement Scale (GAIS), and adverse event data were obtained until 12 months after surgery. The primary efficacy, which is the change in ROE score 6 months after surgery, was assessed in the modified intention-to-treat set. The secondary efficacy was evaluated in the per-protocol set by assessing the change in ROE score 6 and 12 months after surgery and nasofrontal angle, the height of the nasion, and GAIS 1, 6, and 12 months after surgery.Results: The change in ROE score of the study group was non-inferior to that of the control group; it increased by 24.26 ± 17.24 in the study group and 18.27 ± 17.60 in the control group (p = 0.213). In both groups, all secondary outcome measures increased, but there was no statistical difference. In the safety set, treatment-emergent adverse events occurred in 10 patients (35.71%) in the study group and six patients (21.43%) in the control group (p = 0.237). There were 13 adverse device events in the study group and six adverse device events in the control group (p = 0.515).Conclusion: Processed equine cartilage can be used effectively and safely as xenograft material for rhinoplasty.

Reconstructive surgery in the management of head and neck cancer has evolved to include structure-specific approaches in which organ-specific treatment algorithms help optimize outcomes. Tongue cancer management and reconstruction are surgical challenges for which well-executed reconstructive plans should be completed promptly to avoid delaying any subsequently planned oncologic treatment. Crucial considerations in tongue cancer resection are the significant functional morbidity associated with surgical defects, particularly in terms of speech and swallowing, and the consequent negative impact on patients’ quality of life. With the evolution of microsurgical techniques and the development of the perforator flap concept, flap options can be tailored to the characteristics of various tongue defects. This has allowed the implementation of pliable flaps that can help restore tongue mobility and yield subsequent functional outcomes. Using an evolutional framework, we present this series of reviews related to tongue reconstruction. The first part of the review summarizes flap options and flap-related factors, such as volume and tissue characteristics. Related functional aspects are also presented, including tongue mobility, speech, and swallowing, as well as ways to evaluate and optimize these outcomes.

In sensorless drive of induction motors (IMs), the design of a voltage model (VM) for flux estimation is challenging because of its inherent problems with DC saturation and drift. In the implementation of VM, various strategies have been studied in flux estimator design. The closed-loop (CL) style flux estimator is a popular scheme owing to its good performance in a wide speed range. However, CL style suffers from DC drift problems because of an offset at the back electromotive force. Based on the fact that DC drift always persists in CL style flux estimator, this study proposes an offset extractor (OE) using a parallel structure of two CL style flux estimator. Moreover, a crossover strategy is applied to the comparative flux in CL scheme. This strategy guarantees low speed operation including zero speed. When the proposed OE is applied to the flux estimator in a feedforward manner, the proposed flux estimator exhibits good performance in a wide speed range with robustness to the offset. The proposed OE and flux estimator are compared with conventional methods, and are verified in various situations by simulation and experiment in a sensorless driven IM.

Polycaprolactone (PCL) implants are a biodegradable polymeric material with appropriate mechanical strength and durability for use in cranioplasty. They can be manufactured as patient- customized implants using a three-dimensional (3D) printer. Herein, the authors aimed to share our experience in cranioplasty of patients with deformed and asymmetric skulls using PCL/beta- tricalcium phosphate (ß-TCP) implants.Seven patients underwent cranioplasty using patient-specific PCL/ß-TCP implants. Cranial computed tomography images were converted to a 3D model and mirrored to design a patient-specific implant. Based on the 3D simulation, an implant was 3D printed using PCL/ß-TCP. A 6-month follow-up was conducted with periodic visits and computed tomography scans. Symmetry after surgery and complications were evaluated.Postoperatively, the soft tissue volumes increased to 15.8 ± 17.2 cm 3 and 14.9 ± 15.7 cm 3 at 2 weeks and 6 months of follow-up, respectively. The volume change from 2 weeks to 6 months was -4.4 ± 2.5%. Six patients achieved complete symmetry after cranioplasty, whereas 1 patient noticed partial symmetry. The symmetry remained unchanged at 6 months of follow-up. Upon palpation to assess smoothness, 6 patients exhibited a smooth edge interface, whereas 1 patient had a slightly irregular edge.Based on these findings, 3D-printed PCL/ß-TCP implants are an excellent material for cranioplasty, and a favorable cosmetic outcome can be achieved. Specifically, these novel PCL/ß-TCP implants have good biocompatibility and mechanical strength without any postoperative foreign body reaction.

The surgery-first orthognathic approach has been applied at our institution since 2007. However, its indications remain debated. The aim of this study was to investigate the reliability of the surgery-first approach to correct facial asymmetry compared to the traditional orthodontics-first approach using a novel artificial intelligence-based cephalometric analysis.Intervention outcomes of surgery-first (n = 33) and orthodontics-first (n = 26) approaches to correct facial asymmetry were examined. Patients with facial asymmetry who had undergone orthognathic surgery from January of 2006 to January of 2019 were included in the study. In the surgery-first approach, the novel preoperative simulation process on the dental model was performed to determine the final occlusion without presurgical orthodontic treatment. Changes in cephalometric landmarks were compared using the supervised deep learning process developed at our institution.The surgery-first approach without presurgical orthodontic treatment corrected facial asymmetry and yielded results similar to those of the traditional orthognathic approach. The statistical analysis revealed that changes in skeletal cephalometric landmarks were similar in the two groups.The surgery-first orthognathic approach without presurgical orthodontic treatment treated facial asymmetry, possibly suggesting a possible paradigm shift in treatment. In addition, artificial intelligence-based cephalometric analysis was an effective tool.Therapeutic, III.

Scalp defects of various etiologies require distinct reconstruction strategies. Therefore, the authors divided scalp defects into the following categories: scar alopecia, open scalp wound, benign or low-grade malignant tumor, and high-grade malignancy. The authors reviewed the experience with scalp reconstruction of a single center to determine the factors that affect the reconstructive choices.Patients who underwent scalp reconstruction between 2008 and 2020 were retrospectively reviewed. Reconstruction methods were classified according to the etiology of the defect and were compared for each etiology. Accordingly, a reconstruction algorithm for scalp defects was proposed.A total of 180 patients were included in this study, and the reconstruction methods demonstrated significant differences according to etiology (P0.05). For scar alopecia and open scalp wounds, reconstruction methods such as direct repair, local flap transfer, and tissue expander placement were used depending on the defect size. Patients with benign or low-grade malignancies mainly underwent reconstruction with local flaps or skin grafts and tissue expanders for covering the defects. Patients with high-grade malignancies underwent reconstruction with free flaps if they were scheduled for preoperative or postoperative radiation therapy.Various factors, suchas the etiology, size, location, and depthofthe defect, should be considered in scalp reconstruction. The defect etiology is an important factor that determines the reconstructive goal. Our algorithm is based on the etiology of defects and is intended to aid physicians in choosing the appropriate treatment for various scalp defects.

Background: This aim of this study was to develop an objective tool for rating submental fat applied to Koreans. Methods: The study was conducted between April 2019 and October 2019. A total of 92 subjects were enrolled in the study. Clinical photos of the subjects were categorized using validated CR-SMFRS by three plastic surgeons and one dermatologist. The categorized photos were then shown to six different plastic surgeons for evaluation. Results: The Cohen’s kappa value for the six raters were 0.830, 0.742, 0.703, 0.907, 0.862, and 0.793 with statistical significance (p < 0.001). ICC value was between 0.860 and 0.966 (p < 0.001). Since the Cohen’s value and ICC were above 0.6 for all raters, the ratings performed by all six raters were used in the analysis. The ICC values between raters were between 0.899 and 0.902. Conclusions: We came up with a set of reference photos that can be used for submental fat rating scale applicable to Korean subjects. Level of Evidence: II.

BACKGROUND Traditional approaches to lower face contouring involve ostectomy of the mandibular angle or body. More recently, nonsurgical techniques have gained popularity, including neurotoxin injection to the masseter muscle. This study aims to evaluate layperson perceptions of patient attractiveness and personality traits following lower face contouring using either surgical or nonsurgical treatment. METHODS In this survey study distributed via Amazon's Mechanical Turk, respondents viewed a series of 14 patient images obtained in clinic before and after surgical or nonsurgical jawline slimming, or without any facial aesthetic procedure. Respondents rated changes in attractiveness and personality trait scores between the before and after image (score: -50 to 50, with 50 representing the greatest posttreatment increase and 0 representing no change). We used descriptive statistics and multivariable regression to determine differences in respondent ratings between patient images. RESULTS A total of 415 respondents (mean age 38 years, 50.6% female) successfully completed the survey. Compared to patients who underwent nonsurgical treatment, those who received surgery had significantly greater increases in perceived attractiveness (P

Summary The nasal aesthetic subunit principle has been widely accepted as the standard for nasal reconstruction with forehead flaps. However, in our experience, one's impression of a reconstructed face can easily be represented by the nose's entire appearance rather than a single nasal component. Accordingly, we hypothesized that total nasal reconstruction focusing more on the facial aesthetic subunit principle would be superior to focal nasal subunit partial reconstruction. Here, we investigated the indication range of total nasal reconstruction and analyzed its effectiveness. Between July 2006 and December 2017, 32 patients who underwent total or subtotal nasal reconstruction were recruited. The total nasal reconstruction group (n = 20) was treated according to our modified facial aesthetic unit concept, while the subtotal reconstruction group (n = 16) was treated according to the nasal aesthetic subunit principle. Using retrospective reviews, we compared surgical details and aesthetic, and functional outcomes with visual analog scale scores. In aesthetic evaluation, nose contour (p = 0.009), nasal symmetry (p = 0.001), and nostril shape (p = 0.041) were superior in the total nasal reconstruction group. Satisfaction regarding the nose (p = 0.036) was significantly higher than that regarding the forehead and labial folds in the total group. Regarding function, there were no significant intergroup differences in nasal airflow, snoring, or olfaction. We suggest that total nasal reconstruction is not a strategy to avoid because of its aggressive nature. For selected suitable patients, the use of the total nose reconstruction focusing on our one nose concept can be a successful surgical option, and the reconstructed nose can be visualized as a real part of the face.

BACKGROUND In unilateral cleft nasal deformity, the skeletal, and cartilaginous framework of nose is deformed. The anterior nasal spine (ANS) is usually displaced to the non-cleft-side. In cleft orthognathic surgery, ANS relocation can help correct the deviated ANS and nasal septum and might lead to an improved esthetic and functional outcome. METHODS Patients with unilateral cleft lip who underwent two-jaw orthognathic surgery between July 2016 and July 2020 were reviewed retrospectively. During conventional two-jaw orthognathic surgery, the ANS was separated from the maxilla. The separated ANS with the attached septum was fixed on the maxillary midline by wiring. Computed tomography scan was used to measure the septal deviation angle and septal deviation from the midline. RESULTS The septal deviation from the maxillary midline decreased following surgery (preoperative versus postoperative: 4.6 ± 1.0 mm versus 3.2 ± 1.2 mm; P = 0.016). The coronal septal deviation angle was widened after ANS relocation, although the transverse septal deviation angle remained unchanged (coronal septal deviation angle, preoperative versus postoperative: 146.7 ± 12.6 versus 159.8 ± 7.6; P = 0.01; transverse septal deviation angle, preoperative versus postoperative: 156.5 ± 11.7 versus 162.8 ± 7.7; P = 0.128). CONCLUSIONS This study suggests that simultaneous ANS relocation with orthognathic surgery is a viable option for cleft-related deformities, considering the resultant caudal septum straightening and stable structural support observed in the long-term.

Unlike a sensorless vector drive, because a volts per hertz ( $V/f$ ) drive has a simple controller structure, this drive is extensively used for low-cost drive markets that target applications, such as fan, pump, and blower drives, which do not require high performance. For an induction motor’s $V/f$ drive system, a voltage boost enables correct flux excitation. Moreover, to decrease the steady-state speed error, slip compensation is required. Furthermore, an oscillation suppression compensator (OSC) may be added to improve the system’s stability and dynamic performance. In this article, a rotor field-oriented $V/f$ drive implementation is presented. Both voltage boost and slip compensation strategies based on rotor field orientation are introduced, and a novel OSC design and stability analysis are presented with the numerical analysis of the root locus and stability surface. Finally, regarding the various practical situations of the induction motor, the proposed $V/f$ drive system’s effectiveness is confirmed by simulations and experiments.

In this study, the authors introduced a dual application of patient-specific occlusion-based positioning guide and fibular cutting guide to obtain ideal occlusal relationship and mandibular contour in patients undergoing mandibular reconstruction. A retrospective review was performed in 21 patients who underwent mandibular reconstruction with a fibular osteocutaneous free flap. Using computed tomography and intraoral scanning data, fibular cutting guide and occlusion-based positioning guide were simulated in a modeling software and 3-dimensionally printed. Both guides were applied in 9 patients, defined as dual guide group, while the fibular cutting guide was solely used in the remaining patients, defined as single guide group. Functional outcomes including occlusion status, trismus, presence of osseointegrated implant were assessed at 1-year postoperative period. To evaluate the accuracy of the reconstruction, the discrepancy between the planned simulation and actual surgical result was quantified by measuring mandibular deviation angle and volume conformity. Regarding the functional outcomes, all patients in dual guide group showed satisfactory occlusion and intact oral capacity at postoperative 1-year assessment, while 3 patients in single guide group had prolonged malocclusion. The dual guide group showed significantly decreased deviation angle in coronal (right side, 2.93°±1.98° vs. 7.02°±2.81°, P=0.003) and axial plane (right side, 3.20°±2.04° vs. 7.63°±3.40°, P=0.006). The mean volume conformity between the simulation and actual fibular object was significantly higher in the dual guide group (75.27%±6.12% vs. 59.06%±8.57%, P=0.001). In conclusion, the use of occlusion-based positioning guide combined with the fibular cutting guide can enhance the accuracy of mandible reconstruction and functional outcomes.

The surgical resection margin in skin cancer is traditionally determined by the lesion's surface boundary without 3-dimensional information. Computed tomography (CT) can offer additional information, such as tumor invasion and the exact cancer extent. This study aimed to demonstrate the clinical application of and to evaluate the safety and accuracy of resection guides for skin cancer treatment. This prospective randomized comparison of skin cancer resection with (guide group; n=34) or without (control group; n=28) resection guide use was conducted between February 2020 and November 2021. Patients with squamous cell carcinoma or basal cell carcinoma were included. In the guide group, based on CT images, the surgical margin was defined, and a 3-dimensional-printed resection guide was fabricated. The intraoperative frozen biopsy results and distance from tumor boundary to resection margin were measured. The margin involvement rates were 8.8% and 17.9% in the guide and control groups, respectively. The margin involvement rate was nonsignificantly higher in the control group as compared with the guide group ( P =0.393). The margin distances of squamous cell carcinoma were 2.3±0.8 and 3.4±1.6 mm ( P =0.01) and those of basal cell carcinoma were 2.8±1.0 and 4.7±3.2 mm in the guide and control groups, respectively ( P =0.015). Margin distance was significantly lower in the guide group than the control group. The resection guide demonstrated similar safety to traditional surgical excision but enabled the minimal removal of normal tissue by precisely estimating the tumor border on CT scans.

Traditional orthognathic surgery has long been performed after presurgical orthodontic treatment. Despite some concerns, the surgery-first orthognathic approach (SFOA) or surgery-first approach (SFA) without presurgical orthodontic treatment has gradually gained popularity. In recent years, several articles dealing with the concepts of the SFA have been published worldwide. However, the SFA has not yet been standardized, and many surgeons use slightly different protocols and concepts. This review article discusses the beginning and evolution of the SFA and its current concepts, including some opinions based on the authors’ clinical experiences over the last 15 years. According to recent investigations, the SFA could be applied effectively in several situations including class III malocclusion, class II malocclusion, and facial asymmetry. However, debate on the SFA continues and many issues remain to be resolved. This review article addresses the current issues regarding the SFOA, including its advantages and disadvantages, as well as its indications and contraindications. The authors summarize various aspects of the SFA and expect that this review article will help surgeons and orthodontists better understand the current status of the SFA.