Search

Due to its capacity to drive osteoclast differentiation, the receptor activator of nuclear factor kappa-β ligand (RANKL) is believed to exert a pathological influence in periodontitis. However, RANKL was initially identified as an activator of dendritic cells (DCs), expressed by T cells, and exhibits diverse effects on the immune system. Hence, it is probable that RANKL, acting as a bridge between the bone and immune systems, plays a more intricate role in periodontitis. Using ligature-induced periodontitis (LIP), rapid alveolar bone loss was detected that was later halted even though the ligature was still present. This late phase of LIP was also linked with immunosuppressive conditions in the gingiva. Further investigation revealed that the ligature prompted an immediate migration of RANK-expressing Langerhans cells (LCs) and EpCAM + DCs, the antigen-presenting cells (APCs) of the gingival epithelium, to the lymph nodes, followed by an expansion of T regulatory (Treg) cells in the gingiva. Subsequently, the ligatured gingiva was repopulated by monocyte-derived RANK-expressing EpCAM + DCs, while gingival epithelial cells upregulated RANKL expression. Blocking RANKL signaling with monoclonal antibodies significantly reduced the frequencies of Treg cells in the gingiva and prevented gingival immunosuppression. In addition, RANKL signaling facilitated the differentiation of LCs from bone marrow precursors. To further investigate the role of RANKL, we used K14-RANKL mice, in which RANKL is overexpressed by gingival epithelial cells. The elevated RANKL expression shifted the steady-state frequencies of LCs and EpCAM + DCs within the epithelium, favoring LCs over EpCAM + DCs. Following ligature placement, heightened levels of Treg cells were observed in the gingiva of K14-RANKL mice, and alveolar bone loss was significantly reduced. These findings suggest that RANKL-RANK interactions between gingival epithelial cells and APCs are crucial for suppressing gingival inflammation, highlighting a protective immunological role for RANKL in periodontitis that was overlooked due to its osteoclastogenic activity., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

To compare the reconstruction of orbital fractures using patient-specific implants (PSI) and conventional pre-formed titanium mesh; to develop a method of three-dimensional (3D) superimposition and analysis of the reconstructed orbits; and to present the pitfalls in 3D planning of orbital PSI and how to avoid them. This was a retrospective study of patients with orbital fractures who were treated in our institution between the years 2022 and 2023 using PSI or conservative prefabricated titanium mesh. Three different methods for virtual reconstruction of orbital fractures were used and are detailed with advantages, disadvantages and indications. Data acquired included age, gender, method of reconstruction, functional outcomes and aesthetic outcomes. 3D analysis for accuracy of reconstruction was performed. A total of 23 patients were included; 12 were treated using PSI and 11 using prefabricated titanium meshes. There were 8 male and 4 female patients in the PSI group comparted to 5 and 6 in the prefabricated group. All three virtual methods for reconstruction were used successfully, each with the proper indications. When comparing PSI reconstruction to conventional mesh, a significant difference in accuracy was observed; PSI cases showed an inaccuracy of 0.58 mm compared to 1.54 mm with the conventional method. Complications are presented, and tips for avoiding them are detailed. Three different methods for virtual reconstruction were used successfully; automated computerized reconstruction is used for small defects, repositioning is the superior method for non-comminuted cases while mirroring is the method of choice in comminuted fractures. 3D analysis can be performed using a novel method detailed in this report. PSI reconstruction showed superior results, indicating it should be the method of choice when possible. Pitfalls are presented and approaches to prevent them are discussed. Orbital reconstruction is a very important entity in maxillofacial surgery with crucial functional and esthetical implications, and one should use virtual planning and PSI implants, as they significantly improve outcomes., Competing Interests: Declaration of competing interest None., (Copyright © 2024 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Background: Comminuted fractures of the jaws are complex injuries requiring special attention. In the past, treatment included closed reduction using maxillomandibular fixation. With advancements in technology and fixation systems, open reduction became a prevalent option. These fractures are difficult to reconstruct during the primary treatment phase, thus resulting in higher complication rates. The introduction of three-dimensional (3D) planning and printing brought about superior outcomes, yet these focus on secondary reconstruction due to the need for outsourcing planning and titanium printing., Methods: In this report, we describe real-time in-house 3D planning and printing using computer-assisted design software and a 3D-fused deposition printer for virtual reduction of the comminuted fractures and printing of the reconstructed mandible., Results: Following virtual 3D reduction, the newly created mandibles were 3D printed. The model was then used to preband a reconstruction plate, which in turn was used as a template during surgery for reducing the segments. The process of virtual reduction and printing should take a couple of hours at most. The results of five cases showed good alignment and proper function., Conclusion: Three-dimensional technology can be applied in the everyday primary care treatment protocol of comminuted fractures as an in-house tool which greatly improves both functional and aesthetic outcomes., Competing Interests: The authors have no financial interest to declare in relation to the content of this article., (Copyright © 2024 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of The American Society of Plastic Surgeons.)

Objectives: To compare long-term results of different treatment modalities in central giant cell granuloma of the maxillofacial-skeleton. Primary resection may result in major defects. Alternative treatments include pharmacological agents. As yet there has been no consensus on the use of the variety of treatment options, and few studies have reported clarifying long-term results., Materials and Methods: This retrospective study on 22 patients with 25 lesions evaluated clinical, radiological and histological features, treatment preformed and lesion recurrence. Success was defined as regression/calcification and failure as recurrence, progression or un-responsiveness., Results: Of the presenting patients, 77% were under age 40. Lesion prevalence was higher in the anterior mandible and left posterior maxilla. Most cases exhibited pain, tooth-mobility or mucosal-expansion. The appearance was predominantly unilocular in the maxilla and multilocular in the mandible, which also exhibited higher prevalence of cortical perforation. Up to 80% of lesions were classified as aggressive. Intralesional steroids/calcitonin were used in 7 cases. Mean follow-up was 39.8 months. Two cases showed recurrence. In 71% of the cases treated pharmacologically, calcification/regression were observed., Conclusions: Our analysis indicates better outcomes using a combined approach, including both pharmacological and surgical treatments in large aggressive lesions. Pharmacological treatment resulted in decreased size or well-defined lesions, thus reducing the need for extensive bone resection. Dual treatment with corticosteroids and calcitonin showed no superior outcomes, but a larger cohort should be assessed., Clinical Relevance: There are several protocols for treatment of central-giant-cell-granuloma lesions, but most are not fully established. It is important to report results that contribute to the establishment of proven protocols. This report attempts to establish the relevance of the combined approach: pharmacological treatment followed by surgical resection., (© 2024. The Author(s).)

To evaluate parental reports of postoperative pain, improvement and satisfaction following frenectomy with scalpel versus carbon dioxide (CO 2 ) laser treatment. Forty-nine patients aged 2-6 years with a short labial or lingual frenulum who required frenectomy were randomly assigned to undergo CO 2 laser or scalpel treatment. They were divided into a labial and a lingual frenulum group based on the severity of attachment. Frenectomy was performed using a scalpel or Pixel CO 2 10,600 nm laser (Alma Lasers Company, Caesarea, Israel). Postoperative follow-up was conducted via a mobile application where pain was evaluated daily using the visual analog scale (VAS) in the first 72 hours, and painkiller use was recorded. Improvement and satisfaction were evaluated at 1-month post-surgery and compared among the groups. Our results showed significant differences between the degree of clinical attachment of the frenulum, one-month postoperative improvement and satisfaction based on VAS scores ( p < 0.001). Although the use of scalpel was associated with lower postoperative pain scores than the CO 2 groups, VAS scores of improvement and satisfaction after 1 month were higher in the CO 2 groups ( p < 0.05). This study showed that although laser was associated with more postoperative pain, it showed greater improvement and higher satisfaction among patients' parents at 1 month post-surgery compared with scalpel., Competing Interests: The authors declare no conflict of interest., (©2023 The Author(s). Published by MRE Press.)

Background: Facial asymmetry includes several etiologies, among them trauma to the condylar area during early childhood and congenital malformations such as hemifacial microsomia. This article describes the management of facial asymmetry in adolescents and young adults using a mandible first approach by distraction osteogenesis, followed by maxillary Le-Fort I as a second stage., Methods: Eighteen patients 14-25 years of age presented with unilateral hypoplasia of the jaws which manifested clinically by deviation of the chin and canting of the occlusal plane. Etiology included hemifacial microsomia and trauma injuries at early childhood.All patients underwent orthodontic treatment and two phases of surgical treatment. Surgical treatment included unilateral mandibular distraction followed by Le-Fort I osteotomy for alignment of the maxilla. Additional bone graft in the affected side and sliding genioplasty were done as required., Results: Marked ramal elongation of 18.94 mm concomitant with mandibular forward traction of 12.5 mm was noted while achieving symmetry. In all cases, the maxilla was centered to the midline in proper occlusion. Post distraction, posteroanterior cephalometric radiographs demonstrated elongation of the affected ramus, improvement in facial symmetry, and correction of the occlusal canting. Relapse was minimal based on long-term follow-ups of 47.4 months., Conclusions: The two-stage surgical approach that includes elongation of the mandible as a first stage followed by adaptation of the maxilla is useful in correcting facial asymmetry. Using this protocol at the correct age (14-18) is very stable, as demonstrated by our results, yet one should always remember the transverse deficiency in the gonial angle requires additional bone grafting or patient specific implants., Competing Interests: The authors have no financial interest to declare in relation to the content of this article., (Copyright © 2023 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of The American Society of Plastic Surgeons.)

We aimed to compare the clinical and histological secondary healing effectiveness of various types of high-level laser versus scalpel excision in mucosa frenectomy., Methods: Forty-five Sprague Dawley rats were used in this study. These rats were divided into two laser intervention groups (CO 2 , n = 15; diode, n = 15) and one control group with scalpel excision (n = 15). The effectiveness of therapy has been assessed based on the comparison of intraoperative, postoperative, and histological parameters on days 7, 21, and 35, and postoperative weight changes as pain indicator., Results: Both laser groups demonstrated significantly ( P < 0.05) less bleeding than did the control group during the intraoperative stage, whereas the CO 2 laser showed more precise cutting compared with the diode laser ( P < 0.05). The highest healing score was reported in the CO 2 and scalpel groups on the first week of healing than in the diode group ( P < 0.05). However, no significant difference was observed between the groups on days 21 and 35. Weight loss was significantly ( P < 0.05) demonstrated in the diode group compared to the scalpel and CO 2 groups till day 7. Both laser groups demonstrated delayed healing process compared with the scalpel. Nevertheless, the CO 2 group followed the scalpel trends after day 7., Conclusion: Scalpel and CO 2 laser yielded a superior clinical outcome compared with the diode excision of oral mucosa, whereby the CO 2 has been proposed as the most effective laser type at the end of the first postoperative month., Competing Interests: The authors have no financial interest to declare in relation to the content of this article. Disclosure statements are at the end of this article, following the correspondence information., (Copyright © 2023 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of The American Society of Plastic Surgeons.)

Background: The effect of improvement in prenatal identification of cleft lip or palate (CL/P) on termination of pregnancy (TOP) worldwide is scarcely reported. Our aim was to assess changes in the prevalence of cleft palate attributed to the high access and availability of prenatal advanced screening and pregnancy termination in Israel., Methods: A retrospective study was conducted on CL/P patients which were treated in our institute and born between January 2000 and December 2018. Clinical and demographic data were extracted from medical records. Data on TOP were collected based on accessible information from the Ministry of Health. Cleft palate severity was evaluated using the Veau Classification., Results: The study was conducted on 258 patients. Higher incidence of Veau II and III was evident throughout the examined period (2000-2018). However, when evaluating the incidence per year, we found that the incidence of severe cases (Veau III and IV) decreased every year showing a major decline of 60% in the last decade, whereas mild cases (Veau type I and II) demonstrated a marked increase of 90%. Regarding the incidence of abortions in Israel, a decrease of 30% was observed in the last two decades, meanwhile a substantial increase was detected in the rate of abortions related to physical malformations of the fetus. Additionally, the number of late terminations due to physical malformations significantly increased in the last decade., Conclusions: Significant decrease was observed in the incidence of severe cleft palate cases in the last decade. Concurrently, we found a substantial increase in percentage of abortions performed due to physical malformations. We suggest that these changes might be attributed to the accessibility of advanced prenatal screening and pregnancy termination in Israel under the social healthcare system.

Purpose: Identify associations between preoperative radiographic measurements and clinical findings of zygomatic arch fractures and postoperative radiographic measurements. Based on those findings, propose a comprehensive treatment algorithm for the solitary zygomatic arch fracture and combined zygomatic arch-zygomatic complex fracture., Methods: Retrospective cohort study with patients referred to our department for zygomatic arch fractures between 2013 and 2018. Data analyzed included patient demographics, clinical evaluation, and radiographic information. Predictor variables were preoperative morphometric measurements: the initial latero-lateral (LL) defect was determined by the difference between the preoperative LL distances of the fractured and the healthy arches, LL distance was measured from the midsagittal plane in the cranium to the inner cortex of the most displaced arch segment, initial arch coronoid distances were measured from the medial part of the most dislocated arch fragment to the lateral aspect of the coronoid, and the anterior-posterior telescoping was measured as the distance between the 2 points in the arch that lost continuity and overlapped as a result of the fracture. The outcome was defined as the residual defect. It was calculated as the ratio between the postoperative remaining LL distance and the initial LL defect., Results: A total of 179 cases were enrolled, all involving head residual defects. Statistical analysis was performed only on 149 medially displaced fractures. Results show that an initial LL defect larger than 3.5 mm has an 86.3% chance of remaining with a better residual defect (<84.1%), P = .001. Cases with antero-posterior (AP) telescoping > 1.45 mm showed a 72.4% chance of remaining with a poor residual defect >84% (P = .003). Arch-coronoid initial distance showed little effect on the chance of remaining with a large remining defect (P = .417, CI = 95%) CONCLUSION: Based on our results, we found that morphometric measurements can be used to predict the reduction results and can assist the clinician in choosing the optimal reduction method and thus increasing the success rate., (Copyright © 2022 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Extremely atrophic mandibles are difficult to treat. Most patients choose to live with removable dentures. However, what if the atrophy is so extreme that spontaneous fractures occur? The objective of this report is to offer a single-stage augmentation method, which uses patient-specific crib-shaped implants (PSI) combined with autogenous free bone grafts. PSI were planned using three-dimensional (3D) segmentation and 3D virtual-planning software. Implants were designed according to the patient's mandible with a mesh-like structure and included large holes for allowing blood supply recovery. During surgery, the PSI fitted perfectly. In cases exhibiting malposition of the mandibular fragments, repositioning was performed using 3D virtual planning. When repositioning mandibular segments, the PSI served as a guide for the correct positioning. Iliac-crest bone graft was harvested and fixed as an onlay over the residual mandibular basal bone. External approach was used to avoid contamination. Six months following surgery, fixation wires were removed, and dental implants were positioned in the newly formed bone. The PSI allowed for rigid fixation, thus leading to optimal incorporation of the iliac-crest bone graft. No further augmentation was required. Bony continuity for future stability and secession of the spontaneous fractures was achieved. Dental implants were placed effortlessly. Treating extremely atrophic mandibles is an entity of its own and is considered one of the most challenging in craniofacial reconstruction. It mostly requires multiple operations with high rates of failure. We offer a novel method of 3D mandibular reconstruction, both vertically and horizontally, showing promising results and achieving enough bone for further dental rehabilitation., (Copyright © 2022 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of The American Society of Plastic Surgeons.)

Abstract: Titanium plats are the gold-standard for fracture fixation. Titanium is considered biocompatible, corrosion resistant with an elasticity-modulus closest to bone. Nonetheless, titanium plates are not always as inherent as hoped. The authors investigated morbidity associated with titanium plates in mandibular fractures. A retrospective study of mandibular fractures treated between 2000 and 2018 using internal-fixation was conducted. Data included age, gender, complications, and location. Predictor-variable was location. Outcome-variable was plate removal. A total of 571 patients were included, 107 resulted in plate removal (18.7%). Body was the most prevalent location of fracture (29.3%). Symphysis/para-sym-physis showed the highest removal rate (24.1%), followed by body and angle (21.3/19.8%). A total of 23.4% of double-plating cases resulted in plate removal, upper-border in 15% and lower-border in 8.8%, all reconstruction-plates. Exposure was the most frequent complication leading to removal. Although titanium plates are the gold standard, almost every fifth patient returns for plate removal. Age-distribution emphasizing 41 to 50 with decrease towards extremities may imply better healing in the young and soft-tissue elasticity and less complaints in the elderly. Significantly more complications in double-plating compared to lower border suggests proximity to the oral-cavity as a risk-factor for removal. Complication rates and patterns are not negligible and perhaps should encourage clinicians to consider using biodegradable-systems for upper-border plates., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 by Mutaz B. Habal, MD.)

Early diagnosis of oral squamous cell carcinoma (OSCC) remains an unmet clinical need. Therefore, elucidating the initial events of OSCC preceding tumor development could benefit OSCC prognosis. Here, we define the Langerhans cells (LCs) of the tongue and demonstrate that LCs protect the epithelium from carcinogen-induced OSCC by rapidly priming αβT cells capable of eliminating γH2AX + epithelial cells, whereas γδT and natural killer cells are dispensable. The carcinogen, however, dysregulates the epithelial resident mononuclear phagocytes, reducing LC frequencies, while dendritic cells (DCs), macrophages, and plasmacytoid DCs (pDCs) populate the epithelium. Single-cell RNA-sequencing analysis indicates that these newly differentiated cells display an immunosuppressive phenotype accompanied by an expansion of T regulatory (Treg) cells. Accumulation of the Treg cells was regulated, in part, by pDCs and precedes the formation of visible tumors. This suggests LCs play an early protective role during OSCC, yet the capacity of the carcinogen to dysregulate the differentiation of mononuclear phagocytes facilitates oral carcinogenesis., Competing Interests: The authors declare no competing interest., (Copyright © 2022 the Author(s). Published by PNAS.)

Purpose: Zygomatic arch fractures are commonly treated by closed reduction. This kind of treatment is highly influenced by the treating surgeon and type of fracture. Thus, it is important to choose the optimal treatment for different fractures. Current treatment schemes for zygomatic arch fractures reduction are based on subjective assessments. We believe this approach should be refined. Create a new treatment algorithm for the solitary and combined zygomatic arch fractures based on radiological morphometric measurements. This will assist the clinician in tailoring a suitable treatment for each case and avoiding pitfalls, thus achieving best possible results., Methods: A total of 179 radiologic images of patients treated in our department for zygomatic arch fractures were morphometrically measured and analyzed., Results: Three variables showed a capacity to predict a large remaining defect; The presence of a preoperative esthetic defect and a large initial latero-lateral (LL) defect reduced the probability of a large remaining defect (OR = 0.289, P= .019; (OR = 0.78, P= .008; respectively). Patients with initial LL defect < 3.5 mm presented postoperative residual defect 3-times greater than patients with initial LL defect > 3.5 mm A large antero-posterior telescoping increased the probability of a large remaining defect (OR = 1.27 P= .003). Cases that had antero-posterior telescoping > 1.45 mm had a 72.4% probability of remaining with a poor residual defect > 84.1% (P= .003)., Conclusions: Based on our results we believe that the use of morphometric measurements is important when assessing zygomatic arch fractures. We found that there are measurements that can be used to predict esthetic and functional defects, as well as probability of resolving them. Morphometric measurements can be used to predict the reduction difficulty and can assist the clinician in choosing the optimal reduction method and thus increasing the success rate., (Copyright © 2021. Published by Elsevier Inc.)

Purpose: Mucormycosis is an uncommon aggressive, opportunistic infection that can produce widespread orofacial tissue necrosis. This primarily affects immunocompromised individuals. It is the deadliest and most rapidly progressing type of human-affecting fungal infection. The aim of the study is to investigate the diagnostic criteria and treatment approach in 10 cases of mucormycosis in the author's institute from 2008 to 2019. Moreover, a review of the English literature presents all cases of mucormycosis after tooth extraction., Materials and Methods: Ten patients at our institute have been treated. They were evaluated and discussed as per their diagnostic criteria, surgical treatment, and mortality rates., Results: All 10 immunocompromised patients had a primary hematologic malignancy. The criteria for a positive diagnosis were clinical symptoms and a biopsy for microbiological culture and histologic analysis. Each patient was subjected to vigorous surgical resection and underwent antifungal treatment. Seven patients died because of their main disease. Owing to the unregulated spread of mucormycosis, 2 patients died. Four cases were diagnosed after maxillary tooth extraction., Conclusions: The most important factor for patient survival tends to be the management of the underlying disease with early detection and active surgical and antifungal action. Four of 10 cases diagnosed with mucormycosis appeared after tooth extraction, a relatively high number compared with the literature. Therefore, it is the dental profession's obligation to be familiar with the possibility of the potentially severe and possibly fatal complication., (Copyright © 2021 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Coronavirus disease 2019 obliged many countries to apply lockdown policies to contain the spread of infection. The restrictions in Israel included limitations on movement, reduction of working capacity, and closure of the educational system. The present study focused on patients treated at a referral center for burns in northern Israel. Their goal was to investigate temporal variations in burn injuries during this period. Data were retrospectively extracted from the medical records of burn patients treated at our hospital between March 14, 2020 and April 20, 2020 (ie, the period of aggravated lockdown). Data from this period were compared with that from paralleling periods between 2017 and 2019. During the lockdown and paralleling periods, 178 patients were treated for burn injuries, of whom 44% were under 18. Although no restrictions were enforced during the virus outbreak period with regard to seeking medical care, we noticed a decrease in the number of patients admitted to the emergency room for all reasons. Of particular interest was a 66% decrease in the number of adult burn patients (P < .0001). Meanwhile, among the pediatric population, no significant decrease was observed. Nonetheless, subgroups with higher susceptibility to burn injuries included children aged 2 to 5 years (56.3% vs 23.8%, P = .016) and female patients from all pediatric age groups (57.1% vs 25%, P = .027). These findings may be explained by the presumably busier kitchen and dining areas during the lockdown. Overall, the study results can assist with building a stronger understanding of varying burn injuries and with developing educational and preventive strategies., (© The Author(s) 2020. Published by Oxford University Press on behalf of the American Burn Association. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Implant dentistry is considered to be a safe and routine surgical procedure. However, cases of life-threatening hematoma of the floor of the mouth resulting in airway obstruction were previously reported as a complication of implant placement in the anterior mandible. Massive bleeding in this anatomical site may be caused by perforating the lingual cortex and/or damaging the lingual perimandibular vessels. In the long term, dental implants can fail, mainly due to peri-implantitis, and must be removed. Explantation procedure may occasionally become a complex challenge, with a risk for various complications., Case report: This report presents the first case of life-threatening hematoma of the floor of the mouth, as a complication secondary to a failed attempt of dental implant removal at the anterior mandible. The proximity of the implant to the lingual vascular canal might have served as a cause for vascular damage during explantation., Conclusions: Implant removal complications are scarcely described in the literature. Nonetheless, damaging blood vessels during explantation should not be underestimated. Computed tomography (CT) may be of value not only in preoperative implant planning but also before implant removal in jeopardized anatomical zones such as the anterior mandible. Lingual vascular canals should be looked for on computed tomography scans.

SARS-CoV-2 has quickly spread all around the globe causing illness and wide damages. Most countries were unprepared for such a rapid spread and crisis. This led to various strategies for effective control of the new pandemic. A key aspect in all countries was to effectively test the population for the virus. Most countries chose a lockdown strategy in which many workplaces and activities are completely closed, leading to substantial economy costs. Here, we present a protocol we recently developed that allows rapid and simple detection of SARS-CoV-2 for the large population, eliminating costs and involvement of professional teams and laboratories. This protocol is based on Reverse Transcribed Loop-Mediated Isothermal Amplification (RT-LAMP). We tested this protocol directly on patient samples, both nasal and throat clinical swabs as well as saliva. Notably, this protocol is simple, cheap and can be easily applied to other pathogens as well., Competing Interests: Competing interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. While performing this research, no company had invested in the research, and no commercialization was intended., (Copyright © 2020 The Authors; exclusive licensee Bio-protocol LLC.)

Unlike epidermal Langerhans cells (LCs) that originate from embryonic precursors and are self-renewed locally, mucosal LCs arise and are replaced by circulating bone marrow (BM) precursors throughout life. While the unique lifecycle of epidermal LCs is associated with an age-dependent decrease in their numbers, whether and how aging has an impact on mucosal LCs remains unclear. Focusing on gingival LCs we found that mucosal LCs are reduced with age but exhibit altered morphology with that observed in aged epidermal LCs. The reduction of gingival but not epidermal LCs in aged mice was microbiota-dependent; nevertheless, the impact of the microbiota on gingival LCs was indirect. We next compared the ability of young and aged BM precursors to differentiate to mucosal LCs. Mixed BM chimeras, as well as differentiation cultures, demonstrated that aged BM has intact if not superior capacity to differentiate into LCs than young BM. This was in line with the higher percentages of mucosal LC precursors, pre-DCs, and monocytes, detected in aged BM. These findings suggest that while aging is associated with reduced LC numbers, the niche rather than the origin controls this process in mucosal barriers.

We are in the midst of the 3D era in most aspects of life, and especially in medicine. The surgical discipline is one of the major players in the medical field using the constantly developing 3D planning and printing capabilities. Computer-assisted design (CAD) and computer assisted manufacturing (CAM) are used to describe the 3D planning and manufacturing of the product. The planning and manufacturing of 3D surgical guides and reconstruction implants is performed almost exclusively by engineers. As technology advances and software interfaces become more user-friendly, it raises a question regarding the possibility of transferring the planning and manufacturing to the clinician. The reasons for such a shift are clear: the surgeon has the idea of what he wants to design, and he also knows what is feasible and could be used in the operating room. It allows him to be prepared for any scenario/unexpected results during the operation and allows the surgeon to be creative and express his new ideas using the CAD software. The purpose of this method is to provide clinicians with the ability to create their own surgical guides and reconstruction implants. In this manuscript, a detailed protocol will provide a simple method for segmentation using segmentation software and implant planning using a 3D design software. Following the segmentation and stl file production using segmentation software, the clinician could create a simple patient specific reconstruction plate or a more complex plate with a cradle for bone graft positioning. Surgical guides can be created for accurate resection, hole preparation for proper reconstruction plate positioning or for bone graft harvesting and re-contouring. A case of lower jaw reconstruction following plate fracture and nonunion healing of a trauma sustained injury is detailed.

Impact Statement: Humanity is currently experiencing a global pandemic with devastating implications on human health and the economy. Most countries are gradually exiting their lockdown state. We are currently lacking rapid and simple viral detections, especially methods that can be performed in the household. Here, we applied RT-LAMP directly on human clinical swabs and self-collected saliva samples. We adjusted the method to allow simple and rapid viral detection, with no RNA purification steps. By testing our method on over 180 human samples, we determined its sensitivity, and by applying it to other viruses, we determined its specificity. We believe this method has a promising potential to be applied world-wide as a simple and cheap surveillance test for SARS-CoV-2.

Technological advancements in surgical planning and patient-specific implants are constantly evolving. One can either adopt the technology to achieve better results, even in the less experienced hand, or continue without it. As technology develops and becomes more user-friendly, we believe it is time to allow the surgeon the option to plan his/her operations and create his/her own patient-specific surgical guides and fixation plates allowing him full control over the process. We present here a protocol for 3D planning of the operation followed by 3D planning and printing of surgical guides and patient-specific fixation implants. During this process we use two commercial computer-assisted design (CAD) software. We also use a fused deposition modeling printer for the surgical guides and a selective laser sintering printer for the titanium patient-specific fixation implants. The process includes computed tomography (CT) imaging acquisition, 3D segmentation of the skull and facial bones from the CT, 3D planning of the operations, 3D planning of patient-specific fixation implant according to the final position of the bones, 3D planning of surgical guides for performing an accurate osteotomy and preparing the bone for the fixation plates, and 3D printing of the surgical guides and the patient-specific fixation plates. The advantages of the method include full control over the surgery, planned osteotomies and fixation plates, significant reduction in price, reduction in operation duration, superior performance and highly accurate results. Limitations include the need to master the CAD programs.

Background: Limited bone quality in the posterior maxilla results in low success rates for dental implants. Various bone augmentation methods have been described, yet most require two-step surgical procedures with relatively high rates of resorption and failure. An alternative for these patients is zygomatic implants. Zygomatic implants utilize the basal craniofacial bone., Materials and Methods: A retrospective study was conducted on 25 patients exhibiting ridges classified as V-VI according to the Cawood and Howell classification. Seventy-six extramaxillary zygomatic implants were placed. Immediate rehabilitation was performed with a mean follow-up of 18.6 months., Results: Three implants failed, and two were replaced successfully. No significant bone loss was observed in the rest of the implants. Soft tissue around the implant heads healed properly. All implants were prosthetically rehabilitated successfully., Conclusions: Zygomatic implants allow for immediate loading of an atrophic maxilla. The emergence of the implant is prosthetically correct compared to the intrasinus approach, leading to better dental hygiene and decreased mechanical resistance. 96.1% of the implants survived, with good anchorage and proper soft tissue healing and rehabilitation. We suggest using extramaxillary zygomatic fixture as the first line of treatment in severe atrophic maxilla., Competing Interests: There are no conflicts of interest., (Copyright: © 2020 Annals of Maxillofacial Surgery.)

Bone morphogenetic proteins (BMPs) are probably the most important growth factors in bone formation and healing. However, the utilization of BMPs in clinical applications is mainly limited due to the protein poor solubility at physiological pH, rapid clearance and relatively short biological half-life. Herein, we develop degradable porous silicon (PSi)-based carriers for sustained delivery of BMP-2. Two different loading approaches are examined, physical adsorption and covalent conjugation, and their effect on the protein loading and release rate is thoroughly studied. The entrapment of the protein within the PSi nanostructures preserved its bioactivity for inducing osteogenic differentiation of rabbit bone marrow mesenchymal stems cells (BM-MSCs). BM-MSCs cultured with the BMP-2 loaded PSi carriers exhibit a relatively high alkaline phosphatase (ALP) activity. We also demonstrate that exposure of MSCs to empty PSi (no protein) carriers generates some extent of differentiation due to the ability of the carrier's degradation products to induce osteoblast differentiation. Finally, we demonstrate the integration of these promising BMP-2 carriers within a 3D-printed patient-specific implant, constructed of poly(caprolactone) (PCL), as a potential bone graft for critical size bone defects.

The research aimed at investigating potential correlations between craniofacial morphological measurements and mandibular pericondylar fractures, based on a retrospective study of 380 mandible fractures treated in our department, during 2010 to 2017. Predictors included morphological measurements and features. Primary outcome was presence of pericondylar fracture; 133 pericondylar fractures were found, including subcondylar, condylar neck, and condylar head fractures. Condylar neck fractures showed negative correlations with condylar neck width (5.7 mm versus 6.7 mm sagittaly, and 6.1 mm versus 6.8 mm coronally, respectively). Gonial angle (117.3 degrees versus 128.7), and mandibular length 106.2 mm versus 110.4 mm, respectively) showed negative correlation with all pericondylar fractures. Ramus height correlated positively with pericondylar fractures (53.6 mm versus 51.2 mm, respectively). Thus, our results showed condylar neck width was a predictor for condylar neck fractures. In addition, individuals suffering from pericondylar fractures had significantly smaller gonial angles, longer ramus height, and shorter mandibular length. These morphologic features are characteristic of individuals with decreased anterior facial height. Our results corroborated a previous study we had conducted, which suggested that increased anterior vertical growth correlates with angle fractures.

Peri-implantitis is a destructive inflammatory process affecting tissues surrounding dental implants and it is considered a new global health concern. Human studies have suggested that the frequencies of Langerhans cells (LCs), the main antigen-presenting cells (APCs) of the oral epithelium, are dysregulated around the implants. Since LCs play a role in regulating oral mucosal homeostasis, we studied the impact of dental titanium implants on LC differentiation using a novel murine model. We demonstrate that whereas the percentage of LC precursors (CD11c + MHCII + ) increased in the peri-implant epithelium, the frequencies of LCs (CD11c + MHCII + EpCAM + langerin + ) were significantly reduced. Instead, a population of partially developed LCs expressing CD11c + MHCII + EpCAM + but not langerin evolved in the peri-implant mucosa, which was also accompanied by a considerable leukocyte infiltrate. In line with the increased levels of LC precursors, expression of CCL2 and CCL20, chemokines mediating their translocation to the epithelium, was elevated in the peri-implant epithelium. However, expression of TGF-β1, the major cytokine driving final differentiation of LCs, was reduced in the epithelium. Further analysis revealed that while the expression of the TGF-β1 canonical receptor activing-like kinase (ALK)5 was upregulated, expression of its non-canonical receptor ALK3 was decreased. Since titanium ions releasing from implants were proposed to alter APC function, we next analyzed the impact of such ions on TGF-β1-induced LC differentiation cultures. Concurring with the in vivo studies, the presence of titanium ions resulted in the generation of partially developed LCs that express CD11c + MHCII + EpCAM + but failed to upregulate langerin expression. Collectively, these findings suggest that titanium dental implants have the capacity to impair the development of oral LCs and might subsequently dysregulate immunity in the peri-implant mucosa.

AXL, a member of the TYRO3, AXL, and MERTK (TAM) receptor tyrosine kinase family, has been shown to play a role in the differentiation and activation of epidermal Langerhans cells (LCs). Here, we demonstrate that growth arrest-specific 6 (GAS6) protein, the predominant ligand of AXL, has no impact on LC differentiation and homeostasis. We thus examined the role of protein S (PROS1), the other TAM ligand acting primarily via TYRO3 and MERTK, in LC function. Genetic ablation of PROS1 in keratinocytes resulted in a typical postnatal differentiation of LCs; however, a significant reduction in LC frequencies was observed in adult mice due to increased apoptosis. This was attributed to altered expression of cytokines involved in LC development and tissue homeostasis within keratinocytes. PROS1 was then excised in LysM + cells to target LCs at early embryonic developmental stages, as well as in adult monocytes that also give rise to LCs. Differentiation and homeostasis of LCs derived from embryonic precursors was not affected following Pros1 ablation. However, differentiation of LCs from bone marrow (BM) precursors in vitro was accelerated, as was their capability to reconstitute epidermal LCs in vivo. These reveal an inhibitory role for PROS1 on BM-derived LCs. Collectively, this study highlights a cell-specific regulation of LC differentiation and homeostasis by TAM signaling., Competing Interests: The authors declare no conflict of interest.

Growth arrest-specific 6 (GAS6) expressed by oral epithelial cells and dendritic cells (DCs) was shown to play a critical role in the maintenance of oral mucosal homeostasis. In this study, we demonstrate that the induction of pathogen-specific oral adaptive immune responses is abrogated in Gas6 mice. Further analysis revealed that GAS6 induces simultaneously both pro- and anti-inflammatory regulatory pathways upon infection. On one hand, GAS6 upregulates expression of adhesion molecules on blood vessels, facilitating extravasation of innate inflammatory cells to the oral mucosa. GAS6 also elevates expression of CCL19 and CCL21 chemokines and enhances migration of oral DCs to the lymph nodes. On the other hand, expression of pro-inflammatory molecules in the oral mucosa are downregulated by GAS6. Moreover, GAS6 inhibits DC maturation and reduces antigen presentation to T cells by DCs. These data suggest that GAS6 facilitates bi-directional trans-endothelial migration of inflammatory cells and DCs, whereas inhibiting mucosal activation and T-cell stimulation. Thus, the orchestrated complex activity of GAS6 enables the development of a rapid and yet restrained mucosal immunity to oral pathogens.-/- mice. Further analysis revealed that GAS6 induces simultaneously both pro- and anti-inflammatory regulatory pathways upon infection. On one hand, GAS6 upregulates expression of adhesion molecules on blood vessels, facilitating extravasation of innate inflammatory cells to the oral mucosa. GAS6 also elevates expression of CCL19 and CCL21 chemokines and enhances migration of oral DCs to the lymph nodes. On the other hand, expression of pro-inflammatory molecules in the oral mucosa are downregulated by GAS6. Moreover, GAS6 inhibits DC maturation and reduces antigen presentation to T cells by DCs. These data suggest that GAS6 facilitates bi-directional trans-endothelial migration of inflammatory cells and DCs, whereas inhibiting mucosal activation and T-cell stimulation. Thus, the orchestrated complex activity of GAS6 enables the development of a rapid and yet restrained mucosal immunity to oral pathogens.

Mucosal Langerhans cells (LCs) originate from pre-dendritic cells and monocytes. However, the mechanisms involved in their in situ development remain unclear. Here, we demonstrate that the differentiation of murine mucosal LCs is a two-step process. In the lamina propria, signaling via BMP7-ALK3 promotes translocation of LC precursors to the epithelium. Within the epithelium, TGF-β1 finalizes LC differentiation, and ALK5 is crucial to this process. Moreover, the local microbiota has a major impact on the development of mucosal LCs, whereas LCs in turn maintain mucosal homeostasis and prevent tissue destruction. These results reveal the differential and sequential role of TGF-β1 and BMP7 in LC differentiation and highlight the intimate interplay of LCs with the microbiota., (© 2018 Capucha et al.)

Revealing the molecular mechanisms underlying neural stem cell self-renewal is a major goal toward understanding adult brain homeostasis. The self-renewing potential of neural stem and progenitor cells (NSPCs) must be tightly regulated to maintain brain homeostasis. We recently reported the expression of Protein S (PROS1) in adult hippocampal NSPCs, and revealed its role in regulation of NSPC quiescence and neuronal differentiation. Here, we investigate the effect of PROS1 on NSPC self-renewal and show that genetic ablation of Pros1 in neural progenitors increased NSPC self-renewal by 50%. Mechanistically, we identified the upregulation of the polycomb complex protein Bmi-1 and repression of its downstream effectors p16 Ink4a and p19 Arf to promote NSPC self-renewal in Pros1 -ablated cells. Rescuing Pros1 expression restores normal levels of Bmi-1 signaling, and reverts the proliferation and enhanced self-renewal phenotypes observed in Pros1 -deleted cells. Our study identifies PROS1 as a novel negative regulator of NSPC self-renewal. We conclude PROS1 is instructive for NSPC differentiation by negatively regulating Bmi-1 signaling in adult and embryonic neural stem cells.

Neurons are continuously produced in brains of adult mammalian organisms throughout life-a process tightly regulated to ensure a balanced homeostasis. In the adult brain, quiescent Neural Stem Cells (NSCs) residing in distinct niches engage in proliferation, to self-renew and to give rise to differentiated neurons and astrocytes. The mechanisms governing the intricate regulation of NSC quiescence and neuronal differentiation are not completely understood. Here, we report the expression of Protein S (PROS1) in adult NSCs, and show that genetic ablation of Pros1 in neural progenitors increased hippocampal NSC proliferation by 47%. We show that PROS1 regulates the balance of NSC quiescence and proliferation, also affecting daughter cell fate. We identified the PROS1-dependent downregulation of Notch1 signaling to correlate with NSC exit from quiescence. Notch1 and Hes5 mRNA levels were rescued by reintroducing Pros1 into NCS or by supplementation with purified PROS1, suggesting the regulation of Notch pathway by PROS1. Although Pros1-ablated NSCs show multilineage differentiation, we observed a 36% decrease in neurogenesis, coupled with a similar increase in astrogenesis, suggesting PROS1 is instructive for neurogenesis, and plays a role in fate determination, also seen in aged mice. Rescue experiments indicate PROS1 is secreted by NSCs and functions by a NSC-endogenous mechanism. Our study identifies a duple role for PROS1 in stem-cell quiescence and as a pro-neurogenic factor, and highlights a unique segregation of increased stem cell proliferation from enhanced neuronal differentiation, providing important insight into the regulation and control of NSC quiescence and differentiation. Stem Cells 2017;35:679-693., (© 2016 AlphaMed Press.)

The oral epithelium contributes to innate immunity and oral mucosal homeostasis, which is critical for preventing local inflammation and the associated adverse systemic conditions. Nevertheless, the mechanisms by which the oral epithelium maintains homeostasis are poorly understood. Here, we studied the role of growth arrest specific 6 (GAS6), a ligand of the TYRO3-AXL-MERTK (TAM) receptor family, in regulating oral mucosal homeostasis. Expression of GAS6 was restricted to the outer layers of the oral epithelium. In contrast to protein S, the other TAM ligand, which was constitutively expressed postnatally, expression of GAS6 initiated only 3-4 wk after birth. Further analysis revealed that GAS6 expression was induced by the oral microbiota in a myeloid differentiation primary response gene 88 (MyD88)-dependent fashion. Mice lacking GAS6 presented higher levels of inflammatory cytokines, elevated frequencies of neutrophils, and up-regulated activity of enzymes, generating reactive nitrogen species. We also found an imbalance in Th17/Treg ratio known to control tissue homeostasis, as Gas6-deficient dendritic cells preferentially secreted IL-6 and induced Th17 cells. As a result of this immunological shift, a significant microbial dysbiosis was observed in Gas6 -/- mice, because anaerobic bacteria largely expanded by using inflammatory byproducts for anaerobic respiration. Using chimeric mice, we found a critical role for GAS6 in epithelial cells in maintaining oral homeostasis, whereas its absence in hematopoietic cells synergized the level of dysbiosis. We thus propose GAS6 as a key immunological regulator of host-commensal interactions in the oral epithelium., Competing Interests: The authors declare no conflict of interest.

Whereas type I interferons (IFNs-I) were proposed to be elevated in human periodontitis, their role in the disease remains elusive. Using a bacterial-induced model of murine periodontitis, we revealed a prolonged elevation in IFN-I expression. This was due to the downregulation of TAM signaling, a major negative regulator of IFN-I. Further examination revealed that the expression of certain TAM components was reduced as a result of prolonged degradation of MYD88 by the infection. As a result of such prolonged IFN-I production, innate immunological functions of the gingiva were disrupted, and CD4 + T cells were constitutively primed by dendritic cells, leading to elevated RANKL expression and, subsequently, alveolar bone loss (ABL). Blocking IFN-I signaling restored proper immunological function and prevented ABL. Importantly, a loss of negative regulation on IFN-I expression by TAM signaling was also evident in periodontitis patients. These findings thus suggest a role for IFN-I in the pathogenesis of periodontitis., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Langerhans cells (LCs) populate the mucosal epithelium, a major entry portal for pathogens, yet their ontogeny remains unclear. We found that, in contrast to skin LCs originating from self-renewing radioresistant embryonic precursors, oral mucosal LCs derive from circulating radiosensitive precursors. Mucosal LCs can be segregated into CD103(+)CD11b(lo) (CD103(+)) and CD11b(+)CD103(-) (CD11b(+)) subsets. We further demonstrated that similar to non-lymphoid dendritic cells (DCs), CD103(+) LCs originate from pre-DCs, whereas CD11b(+) LCs differentiate from both pre-DCs and monocytic precursors. Despite this ontogenetic discrepancy between skin and mucosal LCs, the transcriptomic signature and immunological function of oral LCs highly resemble those of skin LCs but not DCs. These findings, along with the epithelial position, morphology, and expression of the LC-associated phenotype strongly suggest that oral mucosal LCs are genuine LCs. Collectively, in a tissue-dependent manner, murine LCs differentiate from at least three distinct precursors (embryonic, pre-DC, and monocytic) in steady state., (Copyright © 2015 Elsevier Inc. All rights reserved.)

In vivo studies questioned the ability of Langerhans cells (LCs) to mediate CD8(+) T cell priming. To address this issue, we used intradermal immunization with plasmid DNA, a system in which activation of CD8(+) T cells depends on delayed kinetics of Ag presentation. We found that dendritic cells (DCs) located in the skin at the time of immunization have limited ability to activate CD8(+) T cells. This activity was mediated by a second generation of DCs that differentiated in the skin several days after immunization, as well as by lymph node-resident DCs. Intriguingly, CD8(+) T cell responses were not affected following treatment with clodronate liposomes, immunization of CCR2(-/-) mice, or local neutralization of CCL20. This suggests that local, rather than blood-derived, DC precursors mediate CD8(+) T cell priming. Analysis of DC differentiation in the immunized skin revealed a gradual increase in the number of CD11c(+) cells, which reached their maximum 2 wk after immunization. A similar differentiation kinetics was observed for LCs, with the majority of differentiating LCs proliferating in situ from epidermal precursors. By using B6/Langerin-diphtheria toxin receptor chimeric mice and LC ablation, we demonstrated that epidermal LCs were crucial for the elicitation of CD8(+) T cell responses in vivo. Furthermore, LCs isolated from lymph nodes 2 wk after immunization contained the immunization plasmid and directly activated Ag-specific CD8(+) T cells ex vivo. Thus, these results indicate that second-generation Ag-expressing LCs differentiating from epidermal precursors directly prime CD8(+) T cells and are essential for optimal cellular immune responses following immunization with plasmid DNA.