Enhancing Surgical Approach: Breakthrough Markerless Surface Registration With Augmented Reality for Zygomatic Complex Fracture Surgeries.

BACKGROUND: Innovative technologies with surgical navigation have been used for enhancing surgical accuracies for zygomaticomaxillary complex (ZMC) fractures and offers advantages in precision, accuracy, effectiveness, predictability, and symmetry improvement. Moreover, augmented reality (AR) navigation technology combines virtual reality, 3-dimensional (3D) reconstruction, and real-time interaction, making it ideal for bone tissue operations. Our study explored the usefulness and clinical efficacy of AR technology in intraoperative guidance for reducing ZMC fractures. METHODS: We retrospectively studied 35 patients with zygomatic complex fractures, comparing outcomes of AR-guided and conventional methods. Furthermore, the AR system provided real-time visualization and guidance. The evaluation included reduction accuracy using root mean square (RMS) value and symmetry analysis using a mirror image of 3D models. Results demonstrated the feasibility and effectiveness of the AR-guided method in improving outcomes and patient satisfaction. RESULTS: In 35 patients (25 males, 10 females), AR-guided (n = 19) and conventional (n = 16) approaches were compared. Age, sex, and fracture type exhibited no significant differences between groups. No complications occurred, and postoperative RMS error significantly decreased ( P < 0.001). The AR group had a lower postoperative RMS error ( P = 0.034). CONCLUSIONS: Augmented reality-guided surgery improved accuracy and outcomes in zygomatic complex fractures. Real-time visualization enhanced precision during reduction and fixation. This innovative approach promises enhanced surgical accuracy and patient outcomes in craniofacial surgery.

Pushing boundaries: Anterolateral thigh free flaps for extensive scalp defects beyond previous limits, leveraging imaging modalities with ultrasound and indocyanine green.

BACKGROUND: Scalp defect reconstruction poses considerable challenges, with ongoing debates regarding the most effective strategies. While the latissimus dorsi (LD) flap has traditionally been favored, the anterolateral thigh (ALT) flap has been well described as a versatile alternative for addressing extensive scalp defects. This study underscores the success of scalp reconstruction using ALT flaps, notably pushing the boundaries of previously reported flap sizes. Our approach leverages the use of indocyanine green (ICG) perfusion to guide precise preoperative planning and vascular modification, contributing to improved outcomes in challenging cases. METHODS: We performed 43 ALT flap reconstructions for scalp defects between 2016 and 2023. We collected patients' demographic and clinical data and evaluated flap size and recipient vessels and additional surgical techniques. Detailed preoperative plans with ultrasound and ICG use for intraoperative plans were performed to find perforators location. The cohort was divided into two, with or without complications on flaps, and analyzed depending on its surgical details. RESULTS: This study involved 38 patients with extensive scalp defects (mean age: 69.4 ± 11 years) who underwent ALT perforator flap transfers (mean flap size: 230.88 ± 145.6 cm2). There was only one case of unsuccessful flap transfer, and four cases had a few complications. The characteristics of the complication group included a large flap size (303.1 ± 170.9 vs. 214.9 ± 136.6 cm2, P = .211), few perforator numbers without pedicle manipulation, lack of intraoperative indocyanine green administration (75% vs. 25%, P = .607), and the use of superficial temporal vessels as recipient vessels. CONCLUSIONS: Scalp reconstruction using large ALT free flaps with the aid of imaging modalities facilitates the optimization of surgical techniques, such as pedicle manipulation, perforator numbers, and vein considerations, thereby contributing to successful reconstruction.

Effect of Therapeutic Radiation on Polycaprolactone/Hydroxyapatite Biomaterials in a Calvarial Model.

Bone defects caused by cancer resection often require postoperative radiotherapy. Although various synthetic polymers have been introduced as graft materials, their biological behavior after radiation exposure remains unclear. Here, we investigated how polycaprolactone/hydroxyapatite (PCL/HA) implants respond to therapeutic radiation exposure (in terms of volume and bone regeneration). Four 8 mm diameter calvaria defects were surgically created on the parietal bone of 6 rabbits. PCL/HA implants made of porous, solid, and hybrid polymers were grafted by random placement in each defect. The fourth defect was left untreated. Four weeks after surgery, radiation exposure was conducted weekly for 6 weeks (total: 48 Gy). Micro-computed tomography and histologic analysis were performed at 3 and 6 months, and 6 months postradiation, respectively. The total augmented volumes of all implants showed no significant differences between 3- and 6-months postradiation computed tomography images. In histologic analysis, new bone areas were 0.45±0.11 mm2, 2.02±0.34 mm2, and 3.60±0.77 mm2 in solid, hybrid, and porous polymer grafts, respectively. Bone regeneration was limited to the periphery of the defect in the hybrid and porous polymer grafts, whereas new bone formed inside the porous implant. The total augmented volume of the defect was maintained without significant absorption even after radiation exposure. The PCL/HA implant maintained its structure despite radiation exposure. The porous PCL/HA implant demonstrated excellent bone regeneration, followed by the hybrid and solid implants. The PCL/HA implant is a promising candidate for bone defect reconstruction.

Effects of an Ultra-Polished Scalpel on Incisional Wounds in a Diabetic Model.

Inflammation after surgical incisions is related to the degree of tissue damage. Healing with low inflammation is desirable, especially in patients with compromised healing potential. This experimental study was conducted to assess the degree of inflammatory reaction and scar formation from incisions made by an ultra-polished scalpel (UPS). Two paravertebral incisions were made with a conventional scalpel (CS) and a UPS in 18 individual rats with diabetes. The fibrotic tissue (scar) area and expression levels of collagen, transforming growth factor, and matrix metalloproteinases were quantified on postoperative days 3, 7, and 30. The scar widths and areas were significantly lower in the UPS group than in the CS group. The scar widths were 64.3 ± 14.7 µm and 86.8 ± 12.1 µm in the UPS and CS groups, respectively (P = 0.03). The scar areas were 11,398 ± 1595 µm2 in the UPS group and 17,433 ± 3487 µm2 in the CS group (P = 0.014). The UPS group had less inflammation on day 3, less transforming growth factor synthesis on days 3 and 7, lower levels of matrix metalloproteinases, and less collagen synthesis on day 7 than did the CS group. The UPS achieved less local inflammation by reducing the local tissue damage in diabetic rat models, enabling better healing, and resulting in less scar formation. The UPS warrants further clinical study as it may bring beneficial outcomes for patients with impaired healing capability and patients who seek to reduce scarring.

A Grading System-Guided Approach to the Severely Contracted Nose.

PURPOSE: Capsular contracture is a rare but serious complication of silicone implant-based augmentation rhinoplasty. When severe, the contracture can affect all layers of the nose, causing significant scarring and disfigurement. There is currently no standardized method of evaluating contracted noses and a paucity of literature on the treatment of severe contracture. Therefore, this study aimed to establish a comprehensive grading system and treatment approach for patients with nasal contracture secondary to silicone implant-based rhinoplasty. METHODS: We conducted a retrospective analysis on patients who presented with nasal contracture from 2012 to 2021. All preoperative photographs were evaluated by two plastic surgeons, twice at 1-month intervals. The proposed grading system comprised: normal (grade I), mild contracture with detectable implant (grade II), moderate contracture with skin thinning (grade III), severe contracture with short nose deformity (grade IV), and destructive contracture with scarring of the dorsal skin (grade Va), or columella deficiency (grade Vb). Inter- and intraobserver agreement was assessed using the kappa value to determine the reliability of the system. RESULTS: Based on 87 patients, interobserver agreement was substantial for both evaluation time points (k = 0.701 and 0.723). Intraobserver agreement was excellent for evaluator 1 (k = 0.822) and substantial for evaluator 2 (k = 0.699). CONCLUSIONS: Using this grading system, we propose a graduated treatment algorithm for contracted noses. Most notable is our use of radial forearm free or forehead flaps to reconstruct the columella in grade Vb patients. By combining reconstructive and aesthetic principles, this treatment approach provides an effective and elegant solution for the management of the severely contracted nose. 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 .

Impact of Dynamic Tongue Reconstruction on Sequential Changes of Swallowing Function in Patients Undergoing Total or Near-Total Glossectomy.

PURPOSE: This study aimed to compare the effects of motor-innervated free flap on sequential changes of swallowing function in patients undergoing total or near-total glossectomy with laryngeal preservation. MATERIALS AND METHODS: The medical charts of 21 patients who underwent tongue reconstruction after total or near-total glossectomy between April 2015 and December 2020 were retrospectively reviewed. Patients were divided into groups by reconstruction type: conventional, reconstruction using an anterolateral thigh free flap (n = 11), and dynamic, reconstruction using an anterolateral thigh with innervated vastus lateralis flap (n = 10). Demographics, surgical details, and survival outcomes were investigated. A videofluoroscopic penetration-aspiration scale and functional outcome swallowing scale were analyzed according to postoperative time courses, classified as within 6 months, 6 to 12 months, and after 12 months postoperative. A time-to-event analysis was performed for gastrostomy tube status. RESULTS: The dynamic group showed improved swallowing outcomes at 6 to 12 months postoperative (dynamic vs conventional group, penetration-aspiration scale: 3 ± 1.51 vs 6 ± 1.63, P = 0.024; functional outcome swallowing scale: 1.89 ± 1.36 vs 4 ± 1.41, P = 0.009). In the multivariate analysis, the dynamic group showed a decreased probability of decompensated swallowing function at 6 to 12 months postoperative (odds ratio, 0.062; 95% confidence interval, 0.004-1.084; P = 0.057). A time-to-event analysis revealed no significant difference in gastrostomy tube status between the dynamic and the conventional group. CONCLUSIONS: Considering higher mortality in patients subjected to total or near-total glossectomy, dynamic reconstruction with motor-innervated free flap is worth to perform in terms of enhancing the swallowing function within 1-year postoperative period, thereby improving the quality of life.

A Comparative Study of Titanium Cranioplasty for Extensive Calvarial Bone Defects: Three-Dimensionally Printed Titanium Implants Versus Premolded Titanium Mesh.

OBJECTIVE: This study compared the complications and symmetry outcomes between 3-dimensionally printed titanium implants and premolded titanium mesh in patients with extensive calvarial bone defects. METHODS: This retrospective analysis included patients with calvarial defects >50 cm2 undergoing cranioplasty who received either a 3-dimensionally printed titanium implant manufactured by selective laser melting techniques (N = 12) or a premolded titanium mesh customized onto a 3-dimensionally printed skull template (N = 23). Complications including intracranial infection, hardware extrusion, wound dehiscence, and cerebrospinal fluid leaks were investigated. Predictive factors affecting complications were investigated to identify the odds ratios in univariate and multivariate analyses. The symmetry was assessed by calculating the root mean square deviation, which showed the morphological deviation of the selected area compared with the mirrored image of the contralateral region. RESULTS: The overall complication rate was 26.1% (6/23 patients) in the premolded titanium group and 16.7% (2/12 patients) in the 3-dimensionally printed group. The reoperation rates did not differ significantly between the 2 groups (3-dimensionally printed group, 16.7%, versus premolded group, 21.7%). In multivariate analysis, only the number of previous cranial operation was significantly associated with the complication rate (odds ratio, 2.42; 95% confidence interval, 1.037-5.649; P = 0.041). The mean ± SD of the root mean square deviation was significantly smaller in the 3-dimensionally printed group (2.58 ± 0.93 versus 4.82 ± 1.31 mm, P < 0.001). CONCLUSIONS: The 3-dimensionally printed titanium implant manufactured by the selective laser melting technique showed comparable stability and improved symmetry outcomes compared with the conventional titanium mesh in the reconstruction of extensive calvarial defects.

Dual Application of Patient-Specific Occlusion-Based Positioning Guide and Fibular Cutting Guide for Accurate Reconstruction of Segmental Mandibular Defect.

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.

A Novel Bone Contouring Technique Using Multiple Tangential Shaving for Conservative Management of Craniofacial Fibrous Dysplasia.

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.

Three-Dimensional Analysis of Flap Volume Change in Total Tongue Reconstruction: Focus on Reinnervated Dynamic Tongue Reconstruction.

In general, flap volume decreases over time and further in the case of a denervated muscle flap. In our institution, dynamic reconstruction, including functional muscle flaps, has been used to aid functional recovery in the past 6 years. This study aimed to determine the effect of volume change of the fat and muscular sections of reconstructed tongue flaps after motor nerve reinnervation in dynamic total tongue reconstruction using 3-dimensional measurement and analysis. A retrospective chart review was performed on 21 patients who underwent total tongue reconstruction using an anterolateral thigh free flap from 2015 to 2020. The fat and muscle volumes of the flap were measured using computed tomography data obtained before surgery (T0), 2 weeks after surgery (T1), and 6 months after surgery (T2) using a 3-dimensional rendering software. Among the 21 patients that underwent tongue reconstruction, 10 underwent dynamic reconstruction, whereas 11 underwent conventional reconstruction using a fasciocutaneous flap. T2 volume compared with T1 was 69.08% in the conventional reconstruction group, and the fat and muscle portions in the dynamic reconstruction group were 77.04% and 69.06%, respectively. No significant difference was noted in the volume change between the 2 groups. After dynamic tongue reconstruction, the muscular volume of the flap had similar volume reduction rate as the fat volume. The dynamic reconstruction was effective not only for functional muscle transfer but also for maintaining the volume of the reconstructed muscle flap.

The Feasibility of Computer Simulations and 3-Dimensional-Printed Resection Guides for Skin Cancer Resection.

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.

Are We Correctly Measuring Mandibular Stability After Surgery-First Approach? A Comparative Study Based on Novel 3-Dimensional Measurements.

Using traditional measures to assess mandibular stability after the surgery-first approach (SFA) may produce inaccurate results because unlike the conventional orthodontic-first approach (OFA), the main dental movements occur after surgery in SFA, which produce unavoidable mandibular movements, especially in cases with postsurgical premature dental contact. As these movements are part of the surgical-orthodontic plan, they should not be considered an actual relapse. In this study, to avoid postsurgical dental movement effects, the authors used the relationship between proximal and distal mandibular segments to evaluate stability after SFA. Four easily located points on computerized tomography/cone-beam computerized tomography reconstructed 3-dimensional images were used to calculate 4 measurements between proximal and distal mandibular segments across the osteotomy line in two matched groups of patients (SFA and OFA) at 3 different time points (before, immediately after, and 1 year after the surgery). A high level of skeletal stability was found in the SFA group, with changes 1 year after surgery not exceeding 0.5 mm. The SFA was as skeletally stable as OFA, and the mandibular counterclockwise rotation after surgery was related to the planned dental movements and not the instability of the surgery itself. To avoid the illusion of this preplanned relapse, stability should be measured as a relation between proximal and distal mandibular segments, across the osteotomy and fixation line, and not as a relation between maxillary and mandibular landmarks or between the mandible and facial planes as classically described.

Comparison of the Relapse Ratio and Osteogenesis Between 1-Piece and 2-Piece Fronto-Orbital Distraction Osteogenesis Among Patients With Bilateral Craniosynostosis in Early Childhood.

BACKGROUND: 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. METHODS: 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), and >4 years postoperatively (T2). These images were used to measure the frontal angle, anterior skull base ratio, and bone defect area. RESULTS: 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. CONCLUSIONS: 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.

A 3-Dimensional Analysis of Flap Volume Change in Hemi-Tongue Reconstruction.

BACKGROUND: An adequate volume of the tongue flap is essential to preserve speech and swallowing functions. However, it is generally known that the volume of the free flap tends to decrease over time because of various reasons. Especially in hemi-tongue reconstruction, as half of the normal tongue is retained, some functions are maintained; consequently, there are few studies related to the volume of the flap and function. This study investigated the relationship between flap volume change and function after hemi-tongue reconstruction. METHODS: A retrospective chart review of 26 patients who underwent hemi-tongue reconstruction between 2003 and 2020 was performed. Patient demographic data, postoperative radiotherapy (RT), and data on flap types were collected. The volume of the flap was measured by converting the computed tomography and magnetic resonance images into 3 dimensions using the Mimics software. In addition, speech scores and feeding scores were collected. RESULTS: The first follow-up computed tomography or magnetic resonance imaging (T1) was performed after an average of 2.09 months, and the second follow-up imaging study (T2) was performed at 16.58 months on average. On average, the T2 volume was 64% of the T1 volume (range, 45.75%-90.54%). Factors including speech and swallowing functions were compared by dividing the group into a group with a more than average decrease in volume (group 1) and a group with a less than average decrease in volume (group 2). In group 1, there were significantly more cases of postoperative RT than in group 2 (85.7%, 50.0%, in group 1 and group 2, respectively; P = 0.049). However, there was no difference in the functional aspects between the 2 groups. CONCLUSIONS: The present study revealed that the flap volume decreased more when RT was performed. However, there was no association between the degree of volume loss and speech and swallowing functions. Regardless of the group, the loss of function was not severe, probably because the remaining half of the tongue was functioning.

Clinical Application of Three-Dimensional Printing of Polycaprolactone/Beta-Tricalcium Phosphate Implants for Cranial Reconstruction.

ABSTRACT: 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.

Scalp Reconstruction Strategy Based on the Etiology of the Scalp Defects.

ABSTRACT: 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 (P < 0.05). 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.

Clinical Applications of Augmented Reality Technology in Microsurgical Planning of Head and Neck Reconstruction.

BACKGROUND: To perform head and neck reconstruction, the exact location of recipient vessels must be evaluated preoperatively. This study aimed to superimpose arterial and venous pathways identified by computed tomography angiography (CTA) on patients using augmented reality (AR) techniques to freely select recipient vessels. METHODS: Patients who underwent reconstructive microsurgery due to defects on the scalp, forehead, and glabella from July 2019 to October 2019 were enrolled. The superficial temporal artery (STA) and superficial temporal vein (STV) were marked using hand-held Doppler. Furthermore, the three-dimensional reconstructed CTA image was superimposed on the patient's face using a smartphone application, Camera-Lucida, and marked. The accuracy of mapping was evaluated intraoperatively. Success rates and the time consumed for mapping were compared. RESULTS: Twelve patients underwent preoperative marking. Success rates of STA mapping using the AR technology and hand-held Doppler were 100% and 83%, respectively (P = 0.48). The mean time consumed for STA marking was 90.2 ±â€Š17.7 seconds and 121.0 ±â€Š117.7 seconds, respectively (P  = 0.75). The success rate of STY marking with the AR technology was superior to that with hand-held Doppler (100% versus 58.3%; P = 0.037). STY marking was faster with the AR technology than with hand-held Doppler (mean time, 91.2 ±â€Š25.7 seconds versus 94.5 ±â€Š101.6 seconds; P = 0.007). CONCLUSIONS: The AR technology could be the paradigm shift in the field of microsurgical reconstruction. it can connect threedimensional CTA data with patient topography, leading to not only more precise operations but also improved outcomes in patients undergoing microsurgical reconstruction.

Surgical Versus Nonsurgical Lower Face Contouring: Layperson Perceptions of Attractiveness and Personality Traits.

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 < 0.001), femininity (P < 0.001), friendliness (P < 0.001), intelligence (P < 0.001), trustworthiness (P < 0.001), financial wealthiness (P < 0.001), dominance (P < 0.01), and self-esteem (P < 0.001). Gonial angles increased and jaw widths decreased following both surgical and nonsurgical intervention, with no statistically significant difference between treatment groups. CONCLUSIONS: From the layperson perspective, surgical compared to nonsurgical jawline contouring offers greater improvements in perceptions of attractiveness and favorable personality traits.

Dynamic Hemitongue Defect Reconstruction With Functional Gracilis Muscle Free Transfer.

BACKGROUND: Because the tongue consists of 26 intrinsic and extrinsic muscles, even hemiglossectomy, which preserves some of the tongue and its muscles, leads to functional morbidity in speech and swallowing. Subsequent reconstruction using a conventional fasciocutaneous flap results in limited functional recovery. This study compared the functional recovery of patients who underwent hemiglossectomy based on the fasciocutaneous free flap with or without dynamic gracilis muscle flap reconstruction. METHODS: Twenty-three patients were included in the study. Reconstruction was achieved using radial forearm and gracilis conjoined flaps (n = 7), gracilis flaps (n = 7), and radial forearm flaps (RFFFs) (n = 9) between 2014 and 2019. Functional outcome data were collected via videofluoroscopic swallowing, speech analysis, and a tongue movement scale. RESULTS: In the conjoined flap group, the lingual range of motion in terms of elevation and defect-side lateralization was superior to that of the RFFF group. Furthermore, the conjoined flap was associated with superior protrusion, elevation, and lateralization (on both sides) than the gracilis-only flap. Patients who underwent conjoined-flap reconstruction had better articulation, intelligence, and dysphagia outcomes than patients who underwent reconstruction with RFFFs or gracilis-only flaps. CONCLUSIONS: Although this was a preliminary study, the findings suggest that using a conjoined free flap with an RFFF and a functional gracilis muscle flap for dynamic hemitongue reconstructions could improve postoperative tongue function.

Counterclockwise Rotational Orthognathic Surgery for the Obstructive Sleep Apnea in Class II Dentofacial Deformity: Polysomnography and 3D Computed Tomographic Analysis.

ABSTRACT: Traditionally, maxillomandibular advancement is an orthognathic surgical procedure that has been used to manage obstructive sleep apnea in patients not able or willing to maintain adherence to continuous positive airway pressure therapy or for patient who are not able to adhere to treatment. However, maxillomandibular advancement often leads to unsatisfactory cosmetic results.This prospective study investigated functional and esthetic outcomes using polysomnography and 3-dimensional computed tomography, after counterclockwise rotational orthognathic surgery. We enrolled 17 patients with obstructive sleep apnea, who underwent orthognathic surgery at single institution between March 2013 and December 2018.After 12 months, the patients' mean self-rated score for facial appearance, using a 10-step visual analog scale, was 7.36. The preoperative apnea-hypopnea index and respiratory disturbance index were 34.70 and 37.45, respectively; postoperative indices were 11.60 and to 12.69, respectively (P = 0.003, 0.003). The mean posterior pharyngeal airway space increased from 5357.88 mm3 preoperatively to 8481.94 mm3 after 6 postoperative months.Counterclockwise rotational orthognathic surgery for the correction of obstructive sleep apnea turned out to be the ideal solution not only in the correction of the sleep apnea, but also in the facial esthetics.