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High-amplitude freestream turbulence and surface roughness elements can excite a laminar boundary-layer flow sufficiently to cause streamwise-oriented vortices to develop. These vortices resemble elongated streaks having alternate spanwise variations of the streamwise velocity. Downstream, the vortices “wobble” through an inviscid secondary instability mechanism and, ultimately, transition to turbulence. We formulate an optimal control algorithm to suppress the growth rate of the streamwise vortex system. Considering a high-Reynolds-number asymptotic framework, we reduce the full compressible Navier–Stokes equations to the nonlinear compressible boundary-region equations. We then implement the method of Lagrange multipliers via an appropriate transformation of the original constrained optimization problem into an unconstrained form to obtain the disturbance equations in the form of the adjoint compressible boundary-region equations (ACBREs) and corresponding optimality conditions. Numerical solutions of the ACBRE approach for high-supersonic and hypersonic flows reveal a significant reduction in the kinetic energy and wall shear stress for all considered configurations. We present contour plots to demonstrate the qualitative effect of increased control iterations. Our results indicate that the primary vortex instabilities gradually flatten in the spanwise direction thanks to the ACBRE algorithm.

The present report describes a case of Epstein-Barr virus (EBV)-positive mucocutaneous ulcer (EBVMCU) with an ulcerative lesion on the right tongue. A 69-year-old Japanese woman with awareness of pain in the right lingual margin visited our hospital. The patient had rheumatoid arthritis and had been treated with methotrexate (MTX) for 9 years. Vitiligo was found throughout the oral cavity, and ulceration was found on the right tongue. Under a diagnosis of oral candidiasis and suspected right tongue tumor, treatment for candidiasis and biopsy of the right tongue ulcer were performed. Histopathological results were positive for CD20 and CD30 and negative for CD3 and CD5. EBV-encoded small RNA in situ hybridization confirmed positive results in large, atypical cells, suggesting involvement of EBV. EBVMCU was diagnosed based on the history of MTX use associated with rheumatoid arthritis, blood biochemical findings, and histopathological findings. The ulcer on the right tongue margin resolved spontaneously after treatment for oral candidiasis prior to discontinuation of MTX. No recurrence was seen for 18 months.

The transplantation of pre-vascularized bone grafts is a promising strategy to improve the efficacy of engraftment and bone regeneration. We propose a hydrogel microbead-based approach for preparing vascularized and high-density tissue grafts. Mesenchymal stem cell-encapsulated collagen microgels (2 µL), termed bone beads, were prepared through spontaneous constriction, which improved the density of the mesenchymal stem cells and collagen molecules by more than 15-fold from the initial day of culture. Constriction was attributed to cell-attractive forces and involved better osteogenic differentiation of mesenchymal stem cells than that of spheroids. This approach was scalable, and ∼2000 bone beads were prepared semi-automatically using a liquid dispenser and spinner flask. The mechanical stimuli in the spinner flask further improved the osteogenic differentiation of the mesenchymal stem cells in the bone beads compared with that in static culture. Vascular endothelial cells readily attach to and cover the surface of bone beads. The in vitro assembly of the endothelial cell-enveloped bone beads resulted in microchannel formation in the interspaces between the bone beads. Significant effects of endothelialization on in vivo bone regeneration were shown in rats with cranial bone defects. The use of endothelialized bone beads may be a scalable and robust approach for treating large bone defects. STATEMENT OF SIGNIFICANCE: A unique aspect of this study is that the hMSC-encapsulated collagen microgels were prepared through spontaneous constriction, leading to the enrichment of collagen and cell density. This constriction resulted in favorable microenvironments for the osteogenic differentiation of hMSCs, which is superior to conventional spheroid culture. The microgel beads were then enveloped with vascular endothelial cells and assembled to fabricate a tissue graft with vasculature in the interspaces among the beads. The significant effects of endothelialization on in vivo bone regeneration were clearly demonstrated in rats with cranial bone defects. We believe that microgel beads covered with vascular endothelial cells provide a promising approach for engineering better tissue grafts for bone-regenerative medicine.

This study was conducted to determine the most secure implant positioning on the marginally resected mandible to support a fixed complete denture through finite element analysis. Three or 4 implants were placed at near, middle, or far positions from the resected margin in a simulation model with a symmetrical marginal defect in the mandibular symphysis. The height of the residual bone was 5, 10, or 15 mm. The 4 possible implant patterns for 3 or 4 implants were defined as (1) asymmetrically isolated position 1 to position 2, (2) asymmetrically isolated position 1 to position 3, (3) asymmetrically isolated with greater-length position 1 to position 2, and (4) 2 implants symmetrically positioned on each side of the defect. The von Mises stress in the resected and peri-implant bone with respect to the occlusal force was calculated. Initially, because the peri-implant bone stress around the isolated implant at the near position was greater than at the middle and far positions regardless of the residual bone height, the near position was excluded. Second, the von Mises stress in the resected bone region was >10 MPa when the isolated implant was at the far position, and it increased inversely depending on the bone height. However, the stress was

Mucoceles originating in submandibular gland (SMG) which are extravasation type are extremely rare. Because the extraoral approach with potential risks of facial nerve injury and scar formation is commonly performed, we report endoscopically-assisted intraoral removal of submandibular gland mucocele as minimally invasive surgery. A 28-year-old female was referred to our department with an eight-week history of left submandibular painless swelling. Radiological diagnosis was not plunging ranula but SMG mucocele. The patient underwent endoscopically-assisted intraoral removal of SMG under general anesthesia as minimally invasive surgery. A mucosal incision on the left oral floor was made. After soft tissues surrounding the SMG were dissected bluntly, the mucocele and SMG were exposed more prominently by digital pressure applied beneath the lower border of the mandible by an assistant. The SMG was gripped with forceps after aspiration of mucocele, and pulled up through the incision by gland dissection. Because the facial artery penetrated the SMG, the facial artery was ligated and cut. The SMG with mucocele was removed completely in intraoral approach. Although there was no continuity with SMG and sublingual gland (SLG), the SLG was also removed preventively. The pathological diagnosis was SMG mucocele. Although lingual nerve paresthesia occurred postoperatively, the paresthesia was recovered completely 3 weeks after surgery. There was no recurrence 2.5 years after surgery. Because intraoral removal of SMG can be performed without cervical scar and facial nerve injury, this intraoral approach with endoscopic assistance can be an alternative to transcervical approach.

Vascular anomalies in infants and children were separated into hemangiomas and vascular malformations based on their clinical appearance, histopathologic features, and biologic behavior. Whereas vascular malformations are structural abnormalities of capillary, arterial, venous, or lymphatic elements, vascular tumors are characterized by increased endothelial cell turnover. However, misdiagnoses and misperceptions persist around the use of the term "hemangioma". Although venous malformations arising in the submandibular gland are extremely rare, the most have been diagnosed as “hemangioma”. We report a rare submandibular gland venous malformation with multiple phleboliths. A 54-year-old female visited a private dental clinic for the pain of the right mandibular third molar. Panoramic radiograph showed multiple radiopaque lesions below the right mandibular angle. After the diagnosis of submandibular gland stones, she was referred to our department for the treatment. Ultrasonography showed a heterogeneous, hypoechoic lesion with multiple hyperechoic lesions and blood flow in the right submandibular gland. CT showed a well-circumscribed, heterogenous, low-density lesion with multiple calcifications in the right submandibular gland. MRI showed a lesion with signal intensity similar to that of the muscle in the right submandibular gland had multiple low signal intensity lesions on gadolinium-enhanced T1-weighted images. Radiological diagnosis was submandibular gland venous malformation with multiple phleboliths. She underwent intraoral removal of submandibular gland lesion under general anesthesia. Pathological diagnosis was submandibular gland venous malformation with multiple phleboliths.

Purpose: The aim of this study was to evaluate the effect of two types of mandibular autorotation concept (MAC) surgery using maxillary impaction combined with a straight locking miniplate (SLM) te...

Conventional intraoral removal of deeply impacted or ectopic mandibular third molar is challenging for limited surgical access. Because there are potential risks of inferior alveolar nerve (IAN) injury or iatrogenic mandibular fracture, several methods for the removal have been proposed. As minimally invasive and safe surgery, we report image-guided removal of deeply impacted mandibular third molar using navigation system. A 32-year-old male was referred to our department with right mandibular pain and swelling. Panoramic radiograph showed right mandibular third molar was deeply impacted and interrupted the white line of the mandibular canal. Computed tomography (CT) showed deep impacted right mandibular third molar with root projection from the lingual cortical bone, and there was resorption of lingual cortical bone and passing of mandibular nerve between roots. For mandibular navigation surgery, a resin occlusal splint with titanium markers and handle was manufactured to fix reference frame to the mandible. CT was performed preoperatively after the occlusal splint was fixed with patient’s mandibular teeth, and the patient underwent image-guided removal of mandibular third molar with navigation system under general anesthesia. After reference frame was attached to the handle of the occlusal splint fixed with patient’s mandibular teeth, point-based registration was performed. The crown was removed after the sectioning, and the root sectioning with calibrated bur was performed carefully to avoid injury of the IAN under navigational guidance. The roots were completely removed, and the IAN was exposed in the lingual cortical bone defect. Postoperative course was uneventful without paresthesia of the IAN.

Summary Purpose This study sought to determine the effectiveness of subspinal Le Fort I osteotomy (SLFIO) in preventing nasal deformation, by analyzing changes in the nasal profile on three-dimensional computed tomography (3D-CT) images. Patients and methods The participants were 39 Japanese patients with mandibular prognathism (6 men and 33 women) who underwent bilateral sagittal split ramus osteotomy and Le Fort I osteotomy with maxillary advancement: SLFIO was performed in 20 patients and conventional Le Fort I osteotomy (CLFIO) in 19 patients. All patients underwent modified alar base cinch suture, V-Y closure, and reduction of the piriform aperture. CT data acquired before and 1 year after the surgery were evaluated three-dimensionally with software to determine changes in the nasal profile. Results Changes in alar width, alar base width, nasal length, and nasofrontal angle were significantly smaller following SLFIO than following CLFIO, although there were no significant differences in nasal projection, nasal tip angle, or nasolabial angle between two procedures. Conclusion SLFIO for anterior repositioning of the maxilla can prevent undesirable transverse soft tissue changes of the nose.

Actinomycotic osteomyelitis is an aggressive and persistent disease capable of invading and destroying bone, and chronic osteomyelitis with proliferative periostitis represents new bone formation with periosteal reaction. We report a rare case of actinomycotic osteomyelitis with proliferative periostitis arising in the mandibular ramus and spontaneous bone regeneration after coronoidectomy. A 14-year-old girl was referred for swelling in the right parotid-masseteric region and severe trismus. Contrast-enhanced CT revealed that heterogenous enhancement of the right masseter muscle, and a reactive bone formation over the lateral cortex of the right mandibular ramus and osteolysis of the condyle were seen in plain CT. MRI showed that the mandibular ramus was a low-signal intensity and the reactive bone on the ramus was signal intensity similar to muscle on T1-weighted images. The lesion was clinically and radiologically diagnosed as chronic osteomyelitis of the mandibular ramus. However, a biopsy was performed intraorally under general anesthesia to rule out a malignant bone tumor, and pathological examination showed fibrous bone and Actinomyces druses. Finally, the lesion was diagnosed as actinomycotic osteomyelitis with proliferative periostitis. She underwent image-guided intraoral removal of impacted right third molar and reactive proliferative bone on the right mandibular ramus under general anesthesia. To improve trismus, coronoidectomy also was performed. After the discharge, AMPC was administrated intraorally for 7.5 months. Postoperative panoramic radiograph and CT showed the right mandibular angle resorption and coronoid process regeneration. There was no recurrence of mandibular osteomyelitis 7 years after surgery.

The purpose of this study was to reevaluate preoperative computed tomography lymphography (CTL) and enhanced CT images during follow-up to clarify whether SLNs enhanced by CTL were identified accurately before primary surgery with sentinel lymph node biopsy (SLNB) for clinically N0 early oral cancer. Thirty two early oral cancer patients without cervical lymph node metastasis were enrolled in this study. To clarify whether SLNs enhanced by CTL were identified accurately before primary surgery with SLNB, we reevaluated preoperative CTL and enhanced CT images during follow-up in all patients. SLNs were detected by CTL in 31 of 32 patients (96.9%). During follow-up after primary surgery with SLNB, 4 of 27 patients without SLN metastasis had occult neck metastasis. Of the 4 patients, only 1 patient with cancer of floor of the mouth had overlooking of SLN, and the overlooking rate of SLN was 3.1%. The overlooked small SLN (2.9 × 3.3 × 3.1 mm) was located at contralateral level IB. The CT numbers before, 2, 5, 10 min after iopamidol injection, were 33 HU, 37 HU, 62 HU, 52 HU, respectively. The CT numbers of overlooked SLN 5 and 10 min after the injection was higher than CT images scanned before the iopamidol injection. The enhancement of SLNs in CTL images after iopamidol injection should be compared sufficiently with CT images before iopamidol injection to avoid overlooking of SLNs in N0 early oral cancer.

We identified Coxfa4l3, previously called C15orf48 or Nmes1, as a novel accessory protein of Complex IV of the mitochondrial electron transport chain (ETC). Amino acid sequence comparison, the intracellular localization and the protein expression data showed that the protein is the third isoform of Coxfa4 and the expression of Coxfa4 and Coxfa4l3 proteins during spermatogenesis showed a mutually exclusive pattern, implying that Coxfa4 replaces Coxfa4l3 in Complex IV after meiosis. These results may provide some insight into the unique mechanism of ATP production in late spermatogenesis.

We examined blood and protein dynamics potentially influenced by implant threads and hydrophilic/hydrophobic states of implant surfaces.A computational fluid dynamics model was created for a screw-shaped implant with a water contact angle of 70° (hydrophobic surface) and 0° (superhydrophilic surface). Movements and density of blood and fibrinogen as a representative wound healing protein were visualized and quantified during constant blood inflow.Blood plasma did not occupy 40-50% of the implant interface or the inside of threads around hydrophobic implants, whereas such blood voids were nearly completely eliminated around superhydrophilic implants. Whole blood field vectors were disorganized and random within hydrophobic threads but formed vortex nodes surrounded by stable blood streams along the superhydrophilic implant surface. The averaged vector within threads was away from the implant surface for the hydrophobic implant and towards the implant surface for the superhydrophilic implant. Rapid and massive whole blood influx into the thread zone was only seen for the superhydrophilic implant, whereas a line of conflicting vectors formed at the entrance of the thread area of the hydrophobic implant to prevent blood influx. The fibrinogen density was up to 20-times greater at the superhydrophilic implant interface than the hydrophobic one. Fibrinogen density was higher at the interface than outside the threads only for the superhydrophilic implant.Implant threads and surface hydrophilicity have profound effects on vector and distribution of blood and proteins. Critically, implant threads formed significant biological voids at the interface that were negated by superhydrophilicity-induced contact hemodynamics.

The frequency of supernumerary teeth is approximately 1%. The most frequent site is the anterior maxillary region, and supernumerary molars are relatively rare. Regarding the buccolingual position, most supernumerary teeth appear on the lingual side. The majority of cases present with only one supernumerary tooth, and those with multiple supernumerary teeth often have a genetic disorder. The present report describes a rare case of five impacted supernumerary teeth on the buccal side of bilateral upper molars in a healthy subject. Considering the appearance site and current theories on supernumerary teeth, the teeth were presumed to be impacted paramolars.

Peri-implantitis is an unsolved but critical problem with dental implants. It is postulated that creating a seal of gingival soft tissue around the implant neck is key to preventing peri-implantitis. The objective of this study was to determine the effect of UV surface treatment of titanium disks on the adhesion strength and retention time of oral connective tissues as well as on the adherence of mucosal fibroblasts. Titanium disks with a smooth machined surface were prepared and treated with UV light for 15 min. Keratinized mucosal tissue sections (3 × 3 mm) from rat palates were incubated for 24 h on the titanium disks. The adhered tissue sections were then mechanically detached by agitating the culture dishes. The tissue sections remained adherent for significantly longer (15.5 h) on the UV-treated disks than on the untreated control disks (7.5 h). A total of 94% of the tissue sections were adherent for 5 h or longer on the UV-treated disks, whereas only 50% of the sections remained on the control disks for 5 h. The adhesion strength of the tissue sections to the titanium disks, as measured by tensile testing, was six times greater after UV treatment. In the culture studies, mucosal fibroblasts extracted from rat palates were attached to titanium disks by incubating for 24, 48, or 96 h. The number of attached cells was consistently 15–30% greater on the UV-treated disks than on the control disks. The cells were then subjected to mechanical or chemical (trypsinization) detachment. After mechanical detachment, the residual cell rates on the UV-treated surfaces after 24 and 48 h of incubation were 35% and 25% higher, respectively, than those on the control surfaces. The remaining rate after chemical detachment was 74% on the control surface and 88% on the UV-treated surface for the cells cultured for 48 h. These trends were also confirmed in mouse embryonic fibroblasts, with an intense expression of vinculin, a focal adhesion protein, on the UV-treated disks even after detachment. The UV-treated titanium was superhydrophilic, whereas the control titanium was hydrophobic. X-ray photoelectron spectroscopy (XPS) chemical analysis revealed that the amount of carbon at the surface was significantly reduced after UV treatment, while the amount of TiOH molecules was increased. These ex vivo and in vitro results indicate that the UV treatment of titanium increases the adhesion and retention of oral mucosa connective tissue as a result of increased resistance of constituent fibroblasts against exogenous detachment, both mechanically and chemically, as well as UV-induced physicochemical changes of the titanium surface.

Titanium implants undergo temperature fluctuations during manufacturing, transport, and storage. However, it is unknown how this affects their bioactivity. Herein, we explored how storage (six months, dark conditions) and temperature fluctuations (5–50 °C) affected the bioactivity of titanium implants. Stored and fresh acid-etched titanium disks were exposed to different temperatures for 30 min under wet or dry conditions, and their hydrophilicity/hydrophobicity and bioactivity (using osteoblasts derived from rat bone marrow) were evaluated. Ultraviolet (UV) treatment was evaluated as a method of restoring the bioactivity. The fresh samples were superhydrophilic after holding at 5 or 25 °C under wet or dry conditions, and hydrophilic after holding at 50 °C. In contrast, all the stored samples were hydrophobic. For both fresh and stored samples, exposure to 5 or 50 °C reduced osteoblast attachment compared to holding at 25 °C under both wet and dry conditions. Regression analysis indicated that holding at 31 °C would maximize cell attachment (p &lt, 0.05). After UV treatment, cell attachment was the same or better than that before temperature fluctuations. Overall, titanium surfaces may have lower bioactivity when the temperature fluctuates by ≥20 °C (particularly toward lower temperatures), independent of the hydrophilicity/hydrophobicity. UV treatment was effective in restoring the temperature-compromised bioactivity.

High-amplitude free-stream turbulence and large surface roughness elements can excite a laminar boundary layer sufficiently enough to cause streamwise oriented vortices to form. The latter is accompanied by streaks of varying amplitudes that ‘wobble’ through inviscid secondary instabilities and, ultimately, transition to turbulence. In this paper, we formu- late a mathematical framework for the optimal control of compressible boundary layers to suppress the growth rate of the streamwise vortex system before breakdown occurs. This has a commensurate impact on the wall shear stress and heat transfer at the wall. Flow instabilities are introduced either through roughness elements equally separated in the spanwise direction or via free-stream disturbances. The compressible Navier-Stokes equations are reduced to the boundary region equations (BRE) in a high Reynolds number asymptotic framework wherein the streamwise wavelengths of the disturbances are assumed to be much larger than the spanwise and wall-normal counterparts. The method of La- grange multipliers is used to derive the adjoint compressible boundary region equations via an appropriate transformation of the original constrained optimization problem into an unconstrained form. In the present formulation, the wall transpiration velocity represents the control variable while the wall shear stress or the vortex energy represents the cost functional. Our study shows that this kind of control approach induces a significant reduc- tion in the kinetic energy and wall shear stress of the boundary layer flow. Contour plots visually demonstrate how the primary instabilities gradually flatten out as more control iterations are applied.

Background: Osteochondromas of the mandibular condyle show facial asymmetry and malocclusion. Because condylar osteochondromas are generally resected in a preauricular approach with risks of facial nerve injury and visible scar, the authors report endoscopically assisted intraoral resection of osteochondroma of the mandibular condyle with a piezoelectric surgical device.Case presentation: A 38-year-old woman presented with malocclusion and facial asymmetry caused by deviation of the chin to the left. Computed tomography showed a hyperdense, well-circumscribed mass arising from the medial aspect of the right mandibular condyle with resorption of the skull base. The patient underwent an endoscopically-assisted intraoral condylectomy with a piezoelectric surgical device. The postoperative course was uneventful without trismus, malocclusion, or facial asymmetry, and there was no recurrence 4 years after surgery.Conclusion:Endoscopically assisted intraoral resection of osteochondroma of the mandibular condyle with a piezoelectric surgical device is a minimally invasive and safe surgery.

Objective Intra-oral minor salivary gland tumors are relatively rare. This study aimed to clarify the frequency and distribution of intra-oral minor salivary gland tumors in Japanese patients. Methods We retrospectively analyzed the histopathological records of 131 patients with minor salivary gland tumors that were surgically treated between 1967 and 2017 at a single institution. Results Of the 131 minor salivary gland tumors, 61 (47%) were benign and 70 (53%) were malignant. The male:female ratio was 1:1.8 for benign cases and 1:1 for malignant cases. Most of the tumors occurred in the palate, followed by the floor of the mouth. The most frequent minor salivary gland tumor was pleomorphic adenoma among benign tumors and adenoid cystic carcinoma among malignant tumors. The rarest minor salivary gland tumors were Warthin tumors and basal cell adenocarcinoma, accounting for only 0.8% of all cases. Conclusions The present study determined the incidence rates of these rare tumors.