Maxillary Reconstruction With a Rib-attached Free Latissimus Dorsi Muscle Flap.

In defect reconstruction after maxillary tumor resection, filling the dead space created by resection and reconstruction of surrounding areas are crucial for good cosmetic outcomes. Although various procedures have been described in the literature, most are complex and require advanced surgical skills. Therefore, in this study, the authors aimed to identify a simple procedure for successful reconstruction with minimal bone fixation. Three patients who underwent total maxillectomy and reconstruction using the rib-attached free latissimus dorsi flap at Keio University Hospital between 2012 and 2014 were included and followed up with for a minimum of 5 years. After total maxillectomy, the authors used a free latissimus dorsi flap with a portion of the rib to fill the dead space and reconstructed the orbit, nasal cavity, and oral cavity.The authors performed a rigid reconstruction of the zygomatic ridge using only 2-point plate fixations of the ribs at the outer orbit and anterior nasal spine. Patients were followed up for ≥5 years, and the flap successfully survived in all cases. There was an issue with rib fixation in 1 case; however, all patients were highly satisfied with the procedure's cosmetic results.

Notch signaling supports the appearance of follicular helper T cells in the Peyer's patches concomitantly with the reduction of regulatory T cells.

The intracellular fragment of Notch1, a mediator of Notch signaling that is frequently detected in thymic immigrants, is critical for specifying T-cell fate in the thymus, where Delta-like 4 (Dll4) functions as a Notch ligand on the epithelium. However, as such Notch signaling has not been detected in mature T cells, how Notch signaling contributes to their response in secondary lymphoid organs has not yet been fully defined. Here, we detected the marked expression of Dll4 on the stromal cells and the active fragment of Notch1 (Notch1 intracellular domain, N1ICD) in CD4+ T cells in the follicles of Peyer's patches (PPs). In addition, N1ICD-bearing T cells were found in the T-cell zone of PPs, especially in the transcription factor Foxp3+ regulatory T (Treg) cells, with slight expression of Dll4 on the stromal cells. These fragments disappeared in Dll4-deficient conditions. It was also found that Notch1- and Notch2-deficient T cells preferentially differentiated into Treg cells in PPs, but not CXCR5+PD-1+ follicular helper T (Tfh) cells. Moreover, these phenotypes were also observed in chimeric mice reconstituted with the control and T-cell-specific Notch1/2-deficient bone marrow or Treg cells. These results demonstrated that Dll4-mediated Notch signaling in PPs is required for the efficient appearance of Tfh cells in a Treg cell-prone environment, which is common among the gut-associated lymphoid tissues, and is critical for the generation of Tfh-mediated germinal center B cells.

Muscle Fiber Composition Changes after Selective Nerve Innervation.

Facial nerve paralysis interferes with mimetic muscle function. To reconstruct natural facial movement, free muscle flaps are transplanted as new muscles. However, it is difficult to maintain resting tonus. A dual innervation technique in which other nerves such as the hypoglossal nerve or contralateral facial nerve are added is often applied. Using 10-week-old rats (n = 10), the masseteric and hypoglossal nerves were cut, and the distal stump of the masseteric nerve and the proximal stump of the hypoglossal nerve were then sutured (suture group). In the other group, the masseteric nerve was cut and cauterized (cut group). Immunohistochemistry and microarray were performed on the extracted masseter muscle. The immunohistochemistry results suggested that the muscles in the suture group obtained oxidative characteristics. The microarray showed the genes involved in mitochondrial function, including Perm1. In summary, our data support the validity of the dualinnervation technique for facial paralysis treatment.

Megakaryocytes and platelets from a novel human adipose tissue-derived mesenchymal stem cell line.

The clinical need for platelet transfusions is increasing; however, donor-dependent platelet transfusions are associated with practical problems, such as the limited supply and the risk of infection. Thus, we developed a manufacturing system for platelets from a donor-independent cell source: a human adipose-derived mesenchymal stromal/stem cell line (ASCL). The ASCL was obtained using an upside-down culture flask method and satisfied the minimal criteria for defining mesenchymal stem cells (MSCs) by The International Society for Cellular Therapy. The ASCL showed its proliferation capacity for ≥2 months without any abnormal karyotypes. The ASCL was cultured in megakaryocyte induction media. ASCL-derived megakaryocytes were obtained, with a peak at day 8 of culture, and ASCL-derived platelets (ASCL-PLTs) were obtained, with a peak at day 12 of culture. We observed that CD42b+ cells expressed an MSC marker (CD90) which is related to cell adhesion. Compared with peripheral platelets, ASCL-PLTs exhibit higher levels of PAC1 binding, P-selectin surface exposure, ristocetin-induced platelet aggregation, and ADP-induced platelet aggregation, as well as similar levels of fibrinogen binding and collagen-induced platelet aggregation. ASCL-PLTs have lower epinephrine-induced platelet aggregation. The pattern of in vivo kinetics after infusion into irradiated immunodeficient NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ mice was similar to that of platelet concentrates. ASCL-PLTs have similar characteristics to those of peripheral platelets and might have an additional function as MSCs. The establishment of the ASCL and its differentiation into ASCL-PLTs do not require gene transfer, and endogenous thrombopoietin is used for differentiation. The present protocol is a simple method that does not require feeder cells, further enhancing the clinical application of our approach.

Delta-like 4-mediated Notch signaling is required for early T-cell development in a three-dimensional thymic structure.

Delta-like 4 (Dll4)-mediated Notch signaling is critical for specifying T-cell fate, but how Dll4-mediated Notch signaling actually contributes to T-cell development in the thymus remains unclear. To explore this mechanism in the thymic three-dimensional structure, we performed fetal thymus organ culture using Dll4-deficient mice. DN1a/b+DN2mt cells, which had not yet committed to either the αß T or γδ T/NK cell lineage, did not differentiate into the αß T-cell lineage in Dll4-deficient thymus despite the lack of cell fate conversion into other lineages. However, DN3 cells efficiently differentiated into a later developmental stage of αß T cells, the double-positive (DP) stage, although the proliferation was significantly impaired during the differentiation process. These findings suggest that the requirement for Notch signaling differs between the earliest and pre-TCR-bearing precursors and that continued Notch signaling is required for proper differentiation with active proliferation of αß T lineage cells. Furthermore, we showed that Notch signaling increased the c-Myc expression in DN3 cells in the thymus and that its overexpression rescued the proliferation and differentiation of DN3 cells in the Dll4-null thymus. Therefore, c-Myc plays a central role in the transition from stage DN3 to DP as a downstream target of Notch signaling.

Disappearance of centroacinar cells in the Notch ligand-deficient pancreas.

Notch signaling has been shown to contribute to murine pancreatic development at various stages. Delta-like 1 (Dll1) or Jagged1 (Jag1) are the Notch ligands that solely function to trigger this signaling during the pancreatic bud stage (~e9.5) or after birth, respectively. However, it has not been elucidated whether these Notch ligands are required at the later stage (e10.5-18.5) when the particular pancreas structures form. Here, we detected the dual expression of Dll1 and Jag1 in the epithelium after e10.5, which was restricted to the ductal cell lineage, including centroacinar cells expressing Sox9, CD133 and Hes1 but not the ductal cell markers Hnf1ß and DBA, at e18.5. To evaluate the significance of the Notch ligands during this period, we established double-floxed mice of Dll1 and Jag1 genes with Ptf1a-Cre knock-in allele and examined the effects on development. The abrogation of both ligands but not a single one led to the loss of centroacinar cells, which was due to the decrease in cell proliferation and the increase in cell death, as well as to the reduction of Sox9. These results suggested that Dll1 and Jag1 function redundantly and are necessary to maintain the centroacinar cells as an environmental niche in the developing pancreas.

Reconstruction of the Urethral Sphincter with Dynamic Graciloplasty in a Male Rabbit Model.

INTRODUCTION: The use of artificial urinary sphincters can improve urinary incontinence after radical prostatectomies; however, complications can arise. We hypothesized that dynamic graciloplasty improves urethral sphincter reconstruction. MATERIALS AND METHODS: Models of urethral sphincter muscle reconstruction were developed in 5 adult rabbits by wrapping the gracilis muscle flap around the urethra. Intra-urethral pressure was measured in each of the models before reconstruction (control), after reconstruction, and after electrical stimulation of the flap in reconstructed models (stimulated models). RESULTS: The mean maximum urethral closure pressure was significantly greater in the reconstruction model (69.7 (66.5-115.8) mm Hg) than in the control model (39.2 (33.7-49.6) mm Hg). The mean integral of the urethral pressure and urethral length was also significantly greater in the reconstruction model than in the control model. Furthermore, sphincter tightening was enhanced by the electrical stimulation of the flap. CONCLUSIONS: Our results support our hypothesis that the functional reconstruction of urethral sphincters using muscle flaps is promising for the treatment of urinary incontinence.

Anti-fibrotic effects of a novel small compound on the regulation of cytokine production in a mouse model of colorectal fibrosis.

Intestinal fibrotic stricture is a major complication of inflammatory bowel disease. Despite its clinical importance, anti-fibrotic therapy has not been implemented. Transforming growth factor-ß (TGF-ß) is considered to be a major factor contributing to tissue fibrosis. We have previously shown that the administration of a small compound, HSc025, which promotes the nuclear translocation of YB-1 as a downstream effector of IFN-γ and antagonizes TGF-ß/Smad signaling, improves fibrosis in several murine tissues. In this study, we evaluated the anti-fibrotic effect of HSc025 on colorectal fibrosis in TNBS-induced murine chronic colitis. Daily oral administration of HSc025 (3, 15 and 75 mg/kg) suppressed collagen production and decreased the severity of colorectal fibrosis in a dose-dependent manner. In addition, the local production of TGF-ß was decreased after HSc025 treatment, whereas that of IL-13 and TNF-α was not affected. HSc025 administration maintained the level of IFN-γ production, even at a late stage when IFN-γ production was lost without the drug treatment. These results demonstrate that HSc025 could be a therapeutic candidate for intestinal fibrosis in inflammatory bowel disease that acts by altering the local production of cytokines, as well as by directly suppressing collagen production.

Anatomic basis of anorectal reconstruction by dynamic graciloplasty with pudendal nerve anastomosis.

BACKGROUND: Dynamic graciloplasty has been proposed for anal reconstruction, but this method has 2 major drawbacks. First, an electrical device is required for control of the gracilis. The anastomosis with the pudendal nerve will provide more physiological control. Second, the limitation in the mobility of the muscle flap results in wrapping the anal canal with the muscle's distal portion, which is tendonlike and inelastic. Enhancing the mobility of the muscle flap will enable wrapping with the proximal, muscle-like, and extensible portion, possibly providing better sphincteric function. However, the basis for such an operative method is lacking. OBJECTIVE: The aim of this study is to provide the basis for the refined method of anal sphincter reconstruction by dynamic graciloplasty with pudendal nerve anastomosis and to verify the feasibility of lengthening the nerve to the gracilis muscle flap by dissecting into the muscle belly, detaching the gracilis muscle from its origin, and enhancing the mobility of the muscle flap. STUDY DESIGN: This is a retrospective, descriptive study. METHODS: The results from the anatomical study on 9 cadavers are reported. RESULTS: Tension-free anastomosis of the pudendal nerve and nerve to the gracilis was successfully performed in all the 9 cases: in 2 cases, by lengthening the nerve. The detachment of the muscle origin improved the mobility of the muscle flap, and the more proximal portion could be used for wrapping the anal canal, as confirmed in 4 cases. LIMITATIONS: The limited number of cases was a shortcoming of this study. CONCLUSIONS: By lengthening the nerve to the muscle, the gracilis can be used for anal sphincter reconstruction with pudendal nerve anastomosis, negating the need for an electrical device. By detaching the origin of the gracilis muscle, its proximal portion can be used to wrap the anal canal, possibly enabling a longer functional canal with stronger constricting force and better vascularity. These modifications to past methods may improve fecal continence after the operation.

Primary dural closure and anterior cranial base reconstruction using pericranial and nasoseptal multi-layered flaps in endoscopic-assisted skull base surgery.

INTRODUCTION: Dural and anterior cranial base reconstruction is essential in the surgical resection of a craniofacial tumor that extends from the paranasal sinuses to the subdural space. Watertight reconstruction of vascularized tissue is essential to prevent postoperative liquorrhea, especially under conditions that prevent wound healing (e.g., postoperative irradiation therapy). METHOD: We successfully treated two cases of olfactory neuroblastoma by endoscopic-assisted craniotomy with primary dural closure and anterior cranial base reconstruction using a multi-layered flap technique. Dural defects were closed using temporal fascia or fascia lata in a conventional fashion, immediately after detaching the subdural tumor, in order to isolate and prevent contamination of subdural components and cerebrospinal fluid (CSF) from the tumor and nasal sinuses. Tumor removal and anterior cranial base reconstruction were performed without any concern of CSF contamination after dural closure by craniotomy and endoscopic endonasal approach (EEA). Vascularized pericranial flaps (PCF) and nasoseptal flaps (NSF) were used simultaneously as doubled-over layers for reconstruction. RESULTS: The tumor was completely removed macroscopically and the anterior cranial base was reconstructed in both cases. CSF leak and postoperative meningitis were absent. Postoperative and irradiation therapy courses were successful and uneventful. CONCLUSIONS: This multi-layered anterior cranial base reconstruction consisted of three layers: a fascia for dural plasty and double-layered PCF and NSF. This surgical reconstruction technique is suitable to treat craniofacial tumors extending into the subdural space through the anterior cranial base dura mater.

Evaluation of bone volume after secondary bone grafting in unilateral alveolar cleft using computer-aided engineering.

The purpose of this study was to evaluate the initial defect and the outcome of bone grafts for unilateral alveolar cleft. To determine the absorption of the bone graft in patients with unilateral cleft, computer-aided engineering (CAE) with multi-detector row computed tomography (MDCT) was used. MDCT scans of 29 patients were taken immediately preoperatively and at 1 month and 6 months postoperatively. The patients underwent bone grafting between 8 and 14 years of age using iliac crest bone grafts. Three-dimensional models were created in each period, and the defect at the alveolar cleft and volume of the bone graft were determined in each patient using CAE. Cleft volume and success of alveolar bone grafting were significantly correlated (P < .01). Alveolar clefts with cleft palate required more bone volume than those without cleft palate (P < .01), but the resorption rate did not significantly differ between alveolar clefts with and without cleft palate (0.48 ± 0.14 and 0.49 ± 0.18, respectively; P = .93). In conclusion, three-dimensional reconstruction of bone grafts using CAE based on MDCT provides a valuable objective assessment of graft volume.

Stem cell self-renewal factors Bmi1 and HMGA2 in head and neck squamous cell carcinoma: clues for diagnosis.

Head and neck squamous cell carcinoma (HNSCC) includes both morphological and functional cellular heterogeneity, as would be expected if it arose from dysregulated stem or progenitor cells as opposed to the simple clonal expansion of a mutated cell; however, stemness molecule expression levels and distribution in HNSCC remain unclear. To clarify this, stemness molecule expressions were determined in HNSCC, as well as their properties and prognosis. Two proto-oncogenic chromatin regulators, Bmi-1 and high-mobility-group A2 (Hmga2), were identified in 12 pair cases of HNSCC tumor regions by comparison with their non-cancerous background tissues using cDNA microarray. Both Bmi-1 and Hmga2 are known to promote stem cell self-renewal by negatively regulating the expressions of Ink4a and Arf tumor suppressors. Despite similar targets, Bmi-1 protein was expressed in an early cancerous region and HMGA2 protein was expressed in a region showing more progression. Similarly, Bmi1 expression had no significance with regard to overall survival (P=0.67), whereas HMGA2 expression was associated with decreased overall survival (P=0.05). Quantitative real-time reverse transcription polymerase chain reaction analyses also correlated with protein levels. These findings suggest that Bmi-1 is an early detection marker to distinguish cancerous from non-cancerous regions, whereas HMGA2 is presumed to be a tumor prognosis marker. Among our HNSCC analyses, these stemness molecules expressed fewer primitive rare cells in the tumor than all other cells in the tumor. HNSCC cells with high expression of stemness molecules partly behave like stem cells.

Comparison of static and dynamic symmetry between masseter-innervated and dual-innervated free multivector serratus anterior muscle transfer for complete facial paralysis.

PURPOSE: In this study, facial symmetry was compared between the masseter-innervated and dual-innervated free multivector serratus anterior muscle transfer (FMSAMT) methods. METHODS: Eighteen patients with unilateral complete facial paralysis underwent facial reanimation surgery between April 2006 and July 2019. The masseter-innervated FMSAMT group (Group M, n = 8) underwent end-to-end coaptation with the ipsilateral masseter nerve in one stage. The dual-innervated FMSAMT group (Group D, n = 10) underwent end-to-end coaptation with the masseter nerve and end-to-side coaptation with the contralateral facial nerve via cross-face nerve graft. They were further divided into the one-stage (Group D1, n = 5) and two-stage (Group D2, n = 5) subgroups. The durations of periods until the first visible muscle contraction with clenching, first spontaneous smile, and the completion of resting tone were evaluated. The possibility of a spontaneous smile and symmetry of the midline and horizontal deviation at rest and during voluntary smiling were compared between each group. RESULTS: Groups M and D differed significantly in the possibility of a spontaneous smile and improvement rate of midline deviation and horizontal deviation at rest (p < 0.001, p < 0.001, and p = 0.001, respectively) but not in the improvement rate of midline and horizontal deviation during voluntary smiling. The duration of the period until the completion of resting tone was significantly shorter in Group D1 than in Group D2 (p = 0.048); however, the possibility of a spontaneous smile and the improvement rate of midline and horizontal deviation were not significantly different. CONCLUSIONS: Dual-innervated FMSAMT was effective in guaranteeing a symmetrical resting tone, voluntary smiling, and reproducing a spontaneous smile.

Modified Urethral Graciloplasty Cross-Innervated by the Pudendal Nerve for Postprostatectomy Urinary Incontinence: Cadaveric Simulation Surgery and a Clinical Case Report.

An artificial sphincter implanted in the bulbous urethra to treat severe postprostatectomy urinary incontinence is effective, but embedding-associated complications can occur. We assessed the feasibility, efficacy, and safety of urethral graciloplasty cross-innervated by the pudendal nerve. A simulation surgery on three male fresh cadavers was performed. Both ends of the gracilis muscle were isolated only on its vascular pedicle with proximal end of the obturator nerve severed and transferred to the perineum. We examined whether the gracilis muscle could be wrapped around the bulbous urethra and whether the obturator nerve was long enough to suture with the pudendal nerve. In addition, surgery was performed on a 71-year-old male patient with severe urinary incontinence. The postoperative 12-month outcomes were assessed using a 24-hour pad test and urodynamic study. In all cadaveric simulations, the gracilis muscles could be wrapped around the bulbous urethra in a γ-loop configuration. The length of the obturator nerve was sufficient for neurorrhaphy with the pudendal nerve. In the clinical case, the postoperative course was uneventful. The mean maximum urethral closure pressure and functional profile length increased from 40.7 to 70 cm H 2 O and from 40.1 to 45.3 mm, respectively. Although urinary incontinence was not completely cured, the patient was able to maintain urinary continence at night. Urethral graciloplasty cross-innervated by the pudendal nerve is effective in raising the urethral pressure and reducing urinary incontinence.

Adherent-invasive E. coli - induced specific IgA limits pathobiont localization to the epithelial niche in the gut.

Background and aim: Adherent-invasive E. coli (AIEC) has been identified as a pathobiont associated with Crohn's disease (CD), that prefers to grow in inflammatory conditions. Although the colonization by AIEC is implicated in the progression of the disease and exacerbates inflammation in murine colitis models, the recognition and response of host immunity to AIEC remains elusive. Methods: Antibiotic treated female C57BL/6 mice were inoculated by commensal E. coli and LF82 AIEC strains. Luminal-IgA fractions were prepared from feces and their binding to AIEC and other strains was assessed to confirm specificity. IgA binding to isogenic mutant strains was performed to identify the functional molecules that are recognized by AIEC specific IgA. The effect of IgA on epithelial invasion of LF82 strain was confirmed using in vitro invasion assay and in vivo colonization of the colonic epithelium. Results: Persistent colonization by AIEC LF82 induced secretion of luminal IgA, while commensal E. coli strain did not. Induced anti-LF82 IgA showed specific binding to other AIEC strains but not to the commensal, non-AIEC E. coli strains. Induced IgA showed decreased binding to LF82 strains with mutated adhesin and outer membrane proteins which are involved in AIEC - epithelial cell interaction. Consistently, LF82-specific IgA limited the adhesion and invasion of LF82 in cultured epithelial cells, which seems to be required for the elimination in the colonic epithelium in mice. Conclusion: These results demonstrate that host immunity selectively recognizes pathobiont E. coli, such as AIEC, and develop specific IgA. The induced IgA specific to pathobiont E. coli, in turn, contributes to preventing the pathobionts from accessing the epithelium.

Intratemporal Facial Nerve Schwannomas: A Review of 45 Cases in A Single Center.

There are no established indications for facial nerve schwannoma treatment, including surgery, radiation and follow-up observation, and it is difficult to determine treatment policy uniformly. The treatment policy was examined from each treatment course. Data of patients with facial nerve schwannomas at our hospital from 1987 to 2018 were retrospectively examined. Their age, sex, clinical symptoms, tumor localization, treatment policies and outcomes were reviewed. In total, 22 patients underwent surgery and 1 patient underwent radiotherapy; 22 patients were followed up without treatment. After total resection, there were no tumor recurrences, and most patients had grade 3 or 4 postoperative facial paralysis. After subtotal resection, tumor regrowth was observed in four patients and reoperation was required in two patients. Facial nerve function was maintained in four patients and was decreased in two patients. During follow-up, six patients showed tumor growth. Only one patient had worsening facial nerve paralysis; four patients underwent facial nerve decompression owing to facial nerve paralysis during follow-up. If the tumor compresses the brain or it is prone to growth, surgery may be indicated, and when the preoperative facial nerve function is grade ≤3, consideration should be given to preserving facial nerve function and subtotal resection should be indicated. If the preoperative facial nerve function is grade ≥3, total resection with nerve grafting is an option to prevent regrowth. If there is no brain compression or tumor growth, the follow-up is a good indication, and decompression should be considered in facial nerve paralysis cases.

Dll1 Can Function as a Ligand of Notch1 and Notch2 in the Thymic Epithelium.

T-cell development in the thymus is dependent on Notch signaling induced by the interaction of Notch1, present on immigrant cells, with a Notch ligand, delta-like (Dll) 4, on the thymic epithelial cells. Phylogenetic analysis characterizing the properties of the Dll4 molecule suggests that Dll4 emerged from the common ancestor of lobe- and ray-finned fishes and diverged into bony fishes and terrestrial organisms, including mammals. The thymus evolved in cartilaginous fishes before Dll4, suggesting that T-cell development in cartilaginous fishes is dependent on Dll1 instead of Dll4. In this study, we compared the function of both Dll molecules in the thymic epithelium using Foxn1-cre and Dll4-floxed mice with conditional transgenic alleles in which the Dll1 or Dll4 gene is transcribed after the cre-mediated excision of the stop codon. The expression of Dll1 in the thymic epithelium completely restored the defect in the Dll4-deficient condition, suggesting that Dll1 can trigger Notch signaling that is indispensable for T-cell development in the thymus. Moreover, using bone marrow chimeras with Notch1- or Notch2-deficient hematopoietic cells, we showed that Dll1 is able to activate Notch signaling, which is sufficient to induce T-cell development, with both the receptors, in contrast to Dll4, which works only with Notch1, in the thymic environment. These results strongly support the hypothesis that Dll1 regulates T-cell development via Notch1 and/or Notch2 in the thymus of cartilaginous fishes and that Dll4 has replaced Dll1 in inducing thymic Notch signaling via Notch1 during evolution.

Dual-innervated multivector muscle transfer using two superficial subslips of the serratus anterior muscle for long-standing facial paralysis.

Recent reports have described several cases of double muscle transfers to restore natural, symmetrical smiles in patients with long-standing facial paralysis. However, these complex procedures sometimes result in cheek bulkiness owing to the double muscle transfer. We present the case of a 67-year-old woman with long-standing facial paralysis, who underwent two-stage facial reanimation using two superficial subslips of the serratus anterior muscle innervated by the masseteric and contralateral facial nerves via a sural nerve graft. Each muscle subslip was transferred to the upper lip and oral commissures, which were oriented in different directions. Furthermore, a horizontal fascia lata graft was added at the lower lip to prevent deformities such as lower lip elongation and deviation. Voluntary contraction was noted at roughly 4 months, and a spontaneous smile without biting was noted 8 months postoperatively. At 18 months after surgery, the patient demonstrated a spontaneous symmetrical smile with adequate excursion of the lower lip, upper lip, and oral commissure, without cheek bulkiness. Dual-innervated muscle transfer using two multivector superficial subslips of the serratus anterior muscle may be a good option for long-standing facial paralysis, as it can achieve a symmetrical smile that can be performed voluntarily and spontaneously.

Development of a microsurgery-assisted robot for high-precision thread traction and tension control, and confirmation of its applicability.

BACKGROUND: Microsurgery requires high skills for suturing using fragile threads, often within narrow surgical fields. Precise tension is required for good healing and to avoid the risk of thread breakage. METHODS: To meet the demands, we developed a novel assist robot utilizing high-precision sensorless haptic technology. The robot adopts a cable-driven mechanism to maintain a distance from the surgical area and enhances compatibility with surgical equipment such as microscopes. The robot performance was verified through in vitro and in vivo experiments using a rat model. RESULTS: The realization of precise tension control was confirmed in both experiments. In particular, in the in vivo experiments, the developed robot succeeded to produce a knot with an accurate tension of 0.66% error. CONCLUSIONS: The developed robot can realize to control traction force precisely. This technology might open up the window for a full assist robot for microsurgery with haptic feeling.

Modification of the position of the angulus oris with a rotation flap and a YV flap in lip reconstruction.

Functionally, the lip serves to prevent food and drink from spilling out of the beginning of the gastrointestinal tract, and it is also used for vocalization. In addition, the lip has cosmetic importance as part of the face involved in making expressions, and in many cultures, it is considered to be sexually appealing. The results of lip reconstruction procedures must therefore be both functionally and cosmetically satisfactory. When the orbicularis oris muscle and oral mucosa are excised, functional reconstruction is prioritized. In contrast, if there are no functional problems, cosmetic reconstruction is the main focus. This case involved the reconstruction of a right upper lip defect caused by a dog bite. When the skin defect was covered with a local flap, the right angulus oris shifted medially, so we incorporated a YV flap at the right angulus oris to modify its position and allow for a cosmetically satisfactory result. We believe that this method can be used not only for cases in which asymmetry of the angulus oris is expected to occur at the time of lip reconstruction, but also for cases in which it has already occurred in the initial operation.