Modified Le Fort I interpositional grafting of the severe atrophied maxilla-a retrospective study of 106 patients over 10 years.

OBJECTIVES: The objective of this study was to evaluate a modified Le Fort I interpositional grafting followed by dental implants for the rehabilitation of edentulous atrophied maxillae (Cawood classes IV and V). The surgical modification was a bilateral sinus floor augmentation prior to the osteotomy. This generated a closed recipient bed which allowed the use of particulated bone grafts (xenogenic bone mineral) and a reduced amount of autologous iliac bone grafts. MATERIALS AND METHODS: A total of 106 patients with maxillary interpositional bone grafts were included in this retrospective analysis between 2006 and 2020. The panoramic radiographs and lateral cephalograms were analyzed to assess the gain and stability of the maxillary bone and the peri-implant bone loss. In addition, the observational period of up to 14 years implant survival and success was evaluated. RESULTS: A stable vertical bone height with mean 0.63 ± 1.41 mm resorption over 5 years after implant loading was observed. A mean of 0.20 ± 0.37 mm marginal bone loss was noted after 5 years. The implant survival was 96.4% after 5 years and implant success can be rated 91.7% in a mean follow-up period of 93 months and 168 months maximal observation time. Perioperative complications included sinus membrane perforation (59.43%), wound healing disturbances (25.47%), and transient primary complications (13.78%). All receded apart from two subtotal graft losses (1.8%). CONCLUSIONS: The modified Le Fort I osteotomy with interpositional bone grafts is a predictable procedure in terms of bone and implant stability. Patients with atrophic maxillae who are fit for surgery should be informed about risks and benefits of this treatment alternative.

In vivo biocompatibility evaluation of 3D-printed nickel-titanium fabricated by selective laser melting.

Nickel-titanium (NiTi) belongs to the group of shape-memory alloys (SMAs), which are characterized by flexibility and reversible deformability. Advanced techniques in 3D printing by selective laser-melting (SLM) process allow the manufacturing of complex patient-specific implants from SMAs. Osteosynthesis materials made of NiTi could be used for minimally invasive surgical approaches in oral- and maxillofacial surgery. However, the in vivo biocompatibility has not yet been fully investigated, especially in load-sharing and load-bearing implants. The aim of this study was to evaluate the in vivo biocompatibility of SLM-produced NiTi for intraosseous and subperiosteal applications. Test specimens were implanted into the frontonasal bone of ten miniature pigs. To assess peri-implant bone metabolism, fluorescent dye was administered after 2, 4, 6, 10, 12, and 14 weeks intraperitoneally. Specimens and the surrounding tissues were harvested after 8 and 16 weeks for histological analysis. While the NiTi implants presented a higher bone-to-implant contact ratio (BIC) after 8 than after 16 weeks (43.3 vs. 40.3%), the titanium implants had a significantly higher BIC after 16 weeks (33.6 vs. 67.7%). Histologically, no signs of peri-implant inflammation or foreign-body reaction were detectable. With respect to this preliminary study design, 3D-printed NiTi shows sufficient biocompatibility for intraosseous and subperiosteal implant placement.

BMP-2 Long-Term Stimulation of Human Pre-Osteoblasts Induces Osteogenic Differentiation and Promotes Transdifferentiation and Bone Remodeling Processes.

Bone morphogenic protein (BMP-) 2 plays an important role in the regeneration of bone defects by promoting osteogenic differentiation. However, several animal studies have reported adverse side effects of BMP-2, including osteoclast activation, induction of peroxisome proliferator- activated receptor gamma (PPARG)expression, and inflammation. High BMP-2 concentrations are thought to be responsible for these side effects. For this reason, primary pre-osteoblasts were exposed to lower BMP-2 concentrations (1 and 2 µg/mL). Long-term exposure (up to 28 days) was performed to investigate whether this stimulation protocol may promote osteogenic differentiation without causing the side effects mentioned above. The results showed that BMP-2 treatment for 14 or 28 days resulted in increased osteogenesis, through an increase in runt-related transcription factor 2, osterix, alkaline phosphatase, and integrin-binding sialoprotein expression. However, an increase in tumor necrosis factor alpha and receptor activator of nuclear factor kappa-Β ligand protein levels was observed after BMP-2 exposure, indicating also an increased potential for osteoclast activation by osteoblasts. Additionally, morphological changes like intracellular, filled vacuoles could be detected. Enhanced PPARG and perilipin 1 mRNA transcripts and lipid droplets indicated an induced adipogenic differentiation. Overall, the data demonstrate that long-term BMP-2 exposure promotes not only osteogenic differentiation but also adipogenesis and regulates mediators involved in osteoclast activation in vitro.

Graphene Oxide Framework Structures and Coatings: Impact on Cell Adhesion and Pre-Vascularization Processes for Bone Grafts.

Graphene oxide (GO) is a promising material for bone tissue engineering, but the validation of its molecular biological effects, especially in the context of clinically applied materials, is still limited. In this study, we compare the effects of graphene oxide framework structures (F-GO) and reduced graphene oxide-based framework structures (F-rGO) as scaffold material with a special focus on vascularization associated processes and mechanisms in the bone. Highly porous networks of zinc oxide tetrapods serving as sacrificial templates were used to create F-GO and F-rGO with porosities >99% consisting of hollow interconnected microtubes. Framework materials were seeded with human mesenchymal stem cells (MSC), and the cell response was evaluated by confocal laser scanning microscopy (CLSM), deoxyribonucleic acid (DNA) quantification, real-time polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), and alkaline phosphatase activity (ALP) to define their impact on cellular adhesion, osteogenic differentiation, and secretion of vascular growth factors. F-GO based scaffolds improved adhesion and growth of MSC as indicated by CLSM and DNA quantification. Further, F-GO showed a better vascular endothelial growth factor (VEGF) binding capacity and improved cell growth as well as the formation of microvascular capillary-like structures in co-cultures with outgrowth endothelial cells (OEC). These results clearly favored non-reduced graphene oxide in the form of F-GO for bone regeneration applications. To study GO in the context of a clinically used implant material, we coated a commercially available xenograft (Bio-Oss® block) with GO and compared the growth of MSC in monoculture and in coculture with OEC to the native scaffold. We observed a significantly improved growth of MSC and formation of prevascular structures on coated Bio-Oss®, again associated with a higher VEGF binding capacity. We conclude that graphene oxide coating of this clinically used, but highly debiologized bone graft improves MSC cell adhesion and vascularization.

Regenerative Potential of Platelet Concentrate Lysate in Mechanically Injured Cartilage and Matrix-Associated Chondrocyte Implantation In Vitro.

Adjuvant therapy in autologous chondrocyte implantation (ACI) can control the post-traumatic environment and guide graft maturation to support cartilage repair. To investigate both aspects, we examined potential chondro-regenerative effects of lysed platelet concentrate (PC) and supplementary interleukin 10 (IL-10) on mechanically injured cartilage and on clinically used ACI scaffolds. ACI remnants and human cartilage explants, which were applied to an uniaxial unconfined compression as injury model, were treated with human IL-10 and/or PC from thrombocyte concentrates. We analyzed nuclear blebbing/TUNEL, sGAG content, immunohistochemistry, and the expression of COL1A1, COL2A1, COL10A1, SOX9, and ACAN. Post-injuriously, PC was associated with less cell death, increased COL2A1 expression, and decreased COL10A1 expression and, interestingly, the combination with Il-10 or Il-10 alone had no additional effects, except on COL10A1, which was most effectively decreased by the combination of PC and Il-10. The expression of COL2A1 or SOX9 was statistically not modulated by these substances. In contrast, in chondrocytes in ACI grafts the combination of PC and IL-10 had the most pronounced effects on all parameters except ACAN. Thus, using adjuvants such as PC and IL-10, preferably in combination, is a promising strategy for enhancing repair and graft maturation of autologous transplanted chondrocytes after cartilage injury.

Sandwich osteotomy in atrophic mandibles: A retrospective study with a 2- to 144-month follow-up.

OBJECTIVES: The aim of the present retrospective study was to assess the long-term clinical outcome of sandwich osteotomy in pre-implant augmentation of atrophic mandible. MATERIALS AND METHODS: Sandwich osteotomies were performed in partially and fully edentulous mandibles of 63 consecutive patients in the present study. The vertical bone gain, graft stability, and marginal bone loss were measured radiographically. Implant survival and success rates were estimated in the follow-up ranged from 2 to 144 months (mean, 58 months). RESULTS: A total of 75 procedures were reviewed. After an average healing time of 148 days, 220 implants were placed in 74 procedures. Perioperative complications included intraoperative fracture (1/75), transient paresthesia (18/75), wound healing disturbance (18/75), and keratinized tissue deficiency (14/75). The average vertical bone gain was 5.4 mm at the time of implant placement. Significant marginal bone loss occurred during the first 6 months, after which the resorption remained stable. The implant survival rate was estimated as 96.7%, and the success rate was 95.3%. Implant survival and success showed no significant correlation with higher age, anticoagulation therapy, cardiovascular disease, or thyroid disorder. Smoking was correlated with significant lower success rate. CONCLUSION: Sandwich osteotomy is a suitable augmentation procedure for atrophic mandible, allowing for implant placement with promising outcome.

Effects of degradable osteosynthesis plates of MgYREZr alloy on cell function of human osteoblasts, fibroblasts and osteosarcoma cells.

The aim was to evaluate the biocompatibility of osteosynthesis plates of the MgYREZr/WE43 alloy by using human cells in vitro. Eluates of degradable magnesium osteosynthesis plates as well as halved plates were used for incubation with human osteoblasts, fibroblasts and osteosarcoma cells. The cell viability was evaluated by using FDA/PI-Staining and LDH analysis. Cell proliferation was assessed by MTT, WST-Test and BrdU-ELISA. Scanning electron microscope was used for investigation of the cell adhesion. The number of devitalized cells in all treatment groups did not significantly deviate from the control group. According to MTT results, the number of metabolically active cells was not significantly affected by the addition of the eluates. The number of metabolically active cells was reduced by 24 to 38% compared to the control on incubation in direct contact with the osteosynthesis plates. The proliferation of the cells was inhibited by the addition of the eluates. While the eluate of the half-hour elution has only a very small effect, the 24 h eluate significantly inhibits proliferation by 23-25% compared to the control. The roughened surface of the magnesium osteosynthesis plate after incubation showed adherent cells. However, some areas of the plates were also free of adherent cells. WE43 based magnesium alloys showed favorable biocompatibility considering the viability of the cells evaluated; however, proliferation rates were reduced in a time dependent manner, especially in fibroblast group. This might be a potential clinical benefit of magnesium osteosynthesis plates and their superiority to titanium, thus the fibroblastic ingrowth might negatively influence the bone-plate contact.

Bone regeneration in critical-size defects of the mandible using biomechanically adapted CAD/CAM hybrid scaffolds: An in vivo study in miniature pigs.

The study aimed to analyze bone regeneration in critical-size defects using hybrid scaffolds biomechanically adapted to the specific defect and adding the growth factor rhBMP-2. For this animal study, ten minipigs underwent bilateral defects in the corpus mandibulae and were subsequently treated with novel cylindrical hybrid scaffolds. These scaffolds were designed digitally to suit the biomechanical requirements of the mandibular defect, utilizing finite element analysis. The scaffolds comprised zirconium dioxide-tricalcium phosphate (ZrO2-TCP) support struts and TCP foam ceramics. One scaffold in each animal was loaded with rhBMP-2 (100 µg/cm³), while the other served as an unloaded negative control. Fluorescent dyes were administered every 2 weeks, and computed tomography (CT) scans were conducted every 4 weeks. Euthanasia was performed after 3 months, and samples were collected for examination using micro-CT and histological evaluation of both hard and soft tissue. Intravital CT examinations revealed minor changes in radiographic density from 4 to 12 weeks postoperatively. In the group treated with rhBMP-2, radiographic density shifted from 2513 ± 128 (mean ± SD) to 2606 ± 115 Hounsfield units (HU), while the group without rhBMP-2 showed a change from 2430 ± 131 to 2601 ± 67 HU. Prior to implantation, the radiological density of samples measured 1508 ± 30 mg HA/cm³, whereas post-mortem densities were 1346 ± 71 mg HA/cm³ in the rhBMP-2 group and 1282 ± 91 mg HA/cm³ in the control group (p = 0.045), as indicated by micro-CT measurements. The histological assessment demonstrated successful ossification in all specimens. The newly formed bone area proportion was significantly greater in the rhBMP-2 group (48 ± 10%) compared with the control group without rhBMP-2 (42 ± 9%, p = 0.03). The mean area proportion of remaining TCP foam was 23 ± 8% with rhBMP-2 and 24 ± 10% without rhBMP-2. Successful bone regeneration was accomplished by implanting hybrid scaffolds into critical-size mandibular defects. Loading these scaffolds with rhBMP-2 led to enhanced bone regeneration and a uniform distribution of new bone formation within the hybrid scaffolds. Further studies are required to determine the adaptability of hybrid scaffolds for larger and potentially segmental defects in the maxillofacial region.

Pronounced mediastinal emphysema after restorative treatment of the lower left molar-a case report and a systematic review of the literature.

This case report presents an iatrogenic induced mediastinal emphysema after restorative treatment of the lower left second molar, aimed to highlight the potential life-threatening consequences, and providing diagnostics and treatment concepts of complicated dental induced emphysema based on literature review. A 74-year-old female patient was admitted to the emergency department due to a fall on her shoulder. Additional finding was a significant swelling of the face and neck. In the computer tomography of the head, neck, and thorax, a humerus fracture and pronounced soft tissue emphysema from the infraorbital region to the mediastinum was detected. The patient reported that she had been treated by her dentist 4 days earlier. The treatment had to be discontinued after beginning of a pronounced swelling. Other reasons for the emphysema could be excluded out on an interdisciplinary teamwork. The patient was monitored as an inpatient for 5 days and received intravenous antibiotic therapy. This case report shows the rare complication of pronounced mediastinal emphysema after root canal treatment. Emphysema should always be a differential diagnosis of soft tissue swelling and, in case of doubt, a general medical presentation should be made.

Evaluation of Lower Leg Arteries and Fibular Perforators before Microsurgical Fibular Transfer Using Noncontrast-Enhanced Quiescent-Interval Slice-Selective (QISS) Magnetic Resonance Angiography.

(1) Background: Preoperative imaging of the lower leg arteries is essential for planning fibular grafting. The aim of this study was to evaluate the feasibility and clinical value of non-contrast-enhanced (CE) Quiescent-Interval Slice-Selective (QISS)-magnetic resonance angiography (MRA) for reliably visualizing the anatomy and patency of the lower leg arteries and for preoperatively determining the presence, number, and location of fibular perforators. (2) Methods: The anatomy and stenoses of the lower leg arteries and the presence, number, and location of fibular perforators were determined in fifty patients with oral and maxillofacial tumors. Postoperative outcomes of patients after fibula grafting were correlated with preoperative imaging, demographic, and clinical parameters. (3) Results: A regular three-vessel supply was present in 87% of the 100 legs. QISS-MRA was able to accurately assign the branching pattern in patients with aberrant anatomy. Fibular perforators were found in 87% of legs. More than 94% of the lower leg arteries had no relevant stenoses. Fibular grafting was performed in 50% of patients with a 92% success rate. (4) Conclusions: QISS-MRA has the potential to be used as a preoperative non-CE MRA technique for the diagnosis and detection of anatomic variants of lower leg arteries and their pathologies, as well as for the assessment of fibular perforators.

In Vitro Comparison of 2 Clinically Applied Biomaterials for Autologous Chondrocyte Implantation: Injectable Hydrogel Versus Collagen Scaffold.

OBJECTIVE: In autologous chondrocyte implantation (ACI), there is no consensus about used bioscaffolds. The aim of this study was to perform an in vitro comparative analysis of 2 clinically applied biomaterials for cartilage lesion treatment. DESIGN: Monolayer expanded human chondrocytes (n = 6) were embedded in a collagen scaffold (CS) and a hyaluronic acid-based hydrogel (HA). Cells were cultured in chondropermissive medium supplemented with and without interleukin-10 (IL-10) and bone morphogenetic protein-2 (BMP-2). Gene expression of chondrogenic markers (COL1A1, COL2A1, COL10A1, ACAN, SOX9) was detected via quantitative real-time-polymerase chain reaction (RT-qPCR). Biosynthesis of matrix compounds, cell viability, morphology as well as migration from surrounding native bovine cartilage into cell-free scaffolds were analyzed histologically. Adhesion of the material to adjacent cartilage was investigated by a custom-made push-out test. RESULTS: The shift of COL1/2 ratio toward COL2A1 was more pronounced in HA, and cells displayed a more spherical morphology compared with CS. BMP-2 and IL-10 significantly increased COL2A1, SOX9, and ACAN expression, which was paralleled by enhanced staining of glycosaminoglycans (GAGs) and type 2 collagen in histological sections of CS and HA. COL10A1 was not significantly expressed in HA and CS. Better interfacial integration and enhanced cell invasion was observed in CS. Push-out tests using CS showed higher bonding strength to native cartilage. CONCLUSION: HA-based hydrogel revealed a more chondrocyte-like phenotype but only allowed limited cell invasion, whereas CS were advantageous in terms of cellular invasion and interfacial adhesion. These differences may be clinically relevant when treating cartilaginous or osteochondral defects.

Systematic review on diabetes mellitus and dental implants: an update.

PURPOSE: Dental implant surgery was developed to be the most suitable and comfortable instrument for dental and oral rehabilitation in the past decades, but with increasing numbers of inserted implants, complications are becoming more common. Diabetes mellitus as well as prediabetic conditions represent a common and increasing health problem (International Diabetes Federation in IDF Diabetes Atlas, International Diabetes Federation, Brussels, 2019) with extensive harmful effects on the entire organism [(Abiko and Selimovic in Bosnian J Basic Med Sci 10:186-191, 2010), (Khader et al., in J Diabetes Complicat 20:59-68, 2006, https://doi.org/10.1016/j.jdiacomp.2005.05.006 )]. Hence, this study aimed to give an update on current literature on effects of prediabetes and diabetes mellitus on dental implant success. METHODS: A systematic literature research based on the PRISMA statement was conducted to answer the PICO question "Do diabetic patients with dental implants have a higher complication rate in comparison to healthy controls?". We included 40 clinical studies and 16 publications of aggregated literature in this systematic review. RESULTS: We conclude that patients with poorly controlled diabetes mellitus suffer more often from peri-implantitis, especially in the post-implantation time. Moreover, these patients show higher implant loss rates than healthy individuals in long term. Whereas, under controlled conditions success rates are similar. Perioperative anti-infective therapy, such as the supportive administration of antibiotics and chlorhexidine, is the standard nowadays as it seems to improve implant success. Only few studies regarding dental implants in patients with prediabetic conditions are available, indicating a possible negative effect on developing peri-implant diseases but no influence on implant survival. CONCLUSION: Dental implant procedures represent a safe way of oral rehabilitation in patients with prediabetes or diabetes mellitus, as long as appropriate precautions can be adhered to. Accordingly, under controlled conditions there is still no contraindication for dental implant surgery in patients with diabetes mellitus or prediabetic conditions.

Robot-assisted scaffold implantation and two-stage flap raising of the greater omentum for reconstruction of the facial skeleton: Description of a novel technique.

BACKGROUND: Bone regeneration in the greater omentum is a promising strategy in facial skeleton reconstruction. This feasibility-study aims to perform robot-assisted scaffold implantation and second-stage flap raising. METHODS: Firstly, scaffolds were implanted into the greater omentum using the da Vinci Xi surgical system or conventional technique in five miniature pigs, respectively. After 3 months a free flap including the gastrocolic vascular pedicle was harvested and procedures were evaluated. RESULTS: The average operation time was 59.2 min for open surgery and 73.8 min for robot-assisted surgery. The average incision length of open surgery was 11.6 cm. Both techniques led to successful scaffold implantation without any complication. In all cases the scaffolds were integrated as intended and resulted in bone formation. CONCLUSIONS: Current study demonstrated that the implantation of scaffolds into the greater omentum and flap harvesting using da Vinci Xi surgical system is a promising minimally-invasive approach in regenerative surgery.

Injury patterns and outcomes in bicycle-related maxillofacial traumata: A retrospective analysis of 162 cases.

The objective of the current study is to retrospectively evaluate cycling related dental and maxillofacial injuries and to gain insight into the epidemiology and results of these accidents. Data of patients who were admitted due to the maxillofacial injuries between April 2018 and September 2020 were retrospectively evaluated regarding the patients' characteristics, helmet wearing, type of radiological assessment required for diagnosis and therapy, injury patterns, duration of hospitalization and concomitant injuries. Data of 162 patients were included. 86 (53.08%) patients presented with at least one maxillofacial fracture. A total of 186 maxillofacial bones were fractured. Zygomatico-maxillary complex was the most commonly affected region (n:103, 55,36%). Analysis of the dental traumata revealed that crown fracture without pulp exposure was the most commonly observed entity (n:37, 32.46%) and upper central incisors (n:61, 53.50%) were the most commonly affected teeth. The overall ratio of the number of the fracture line/fracture case was 2.80. However, this ratio was statistically higher in e-bike cases (4.25) compared to non-e-bike riders (2.34) (p:0.014). Bicycle related maxillofacial injuries could correlate with specific morbidity rates and result in severe injuries of the maxillofacial region.

Effect of enriched bone-marrow aspirates on the dimensional stability of cortico-cancellous iliac bone grafts in alveolar ridge augmentation.

BACKGROUND: The objective of the current study was to assess the clinical and radiological outcomes following autologous grafting from the iliac crest treated with autologous stem cells in-situ to reduce the postoperative bone graft resorption rate. MATERIALS AND METHODS: The study group consisted of patients who underwent vertical augmentation of the jaws via bone grafts harvested from the iliac crest enriched with bone-marrow aspirate concentrates (stem cell group). The first control group (control) included 40 patients underwent a vertical augmentation with autologous bone grafts from the iliac crest. In the second control group, 40 patients received identical surgical procedure, whereas the autologous bone graft was covered with a thin layer of deproteinized bovine bone matrix and a collagen membrane (DBBM group). Clinical complications, implant survival, radiological assessment of the stability of the vertical height and histological evaluation at the recipient site have been followed up for 24 months postoperatively. RESULTS: No differences in terms of implant survival were observed in the groups. In the stem cell group, the resorption after 4-6 months was 1.2 ± 1.3 mm and significantly lower than the resorption of the control group with 1.9 ± 1.6 mm (P = 0.029) (DBBM group: 1.4 ± 1.2 mm). After 12 months, the resorption of the stem cell group was 2.1 ± 1.6 mm and significantly lower compared to the control group (4.2 ± 3.0 mm, P = 0.001) and DBBM group (resorption 2.7 ± 0.9 mm, P = 0.012). The resorption rate in the second year was lower compared to the first year and was measured as 2.7 ± 1.7 mm in the stem cell group (1-year bone loss in the time period of 12-24 months of 0.6 mm compared to 2.1 mm in the first 12 months). The resorption was significantly lower compared to the control group (4.7 ± 2.9 mm; P = 0.003, DBBM group: 3.1 ± 0.5 mm, P = 0.075). CONCLUSIONS: Autologous bone-marrow aspirate concentrate could enhance the dimensional stability of the bone grafts and improve the clinical standard of complex reconstruction of the alveolar ridge. Even though the intraoperative cell enrichment requires an additional equipment and technical specification, it represents an alternative method for in-situ regeneration by osteogenic induction with a contribution of a manageable cost factor.

Non-Interventional Prospective Observational Study of Platelet Rich Fibrin as a Therapy Adjunctive in Patients with Medication-Related Osteonecrosis of the Jaw.

BACKGROUND: Medication-related osteonecrosis (MRONJ) of the jaw is a severe and feared side effect of antiresorptive therapy in the oncological setting. With growing evidence that impaired angiogenesis may represent a key factor in pathogenesis, the aim of this study was to evaluate an autologous platelet concentrate as a possible additive in surgical therapy to optimize vascularization and, subsequently, resolution rates. MATERIAL AND METHODS: A non-interventional, prospective, multicenter study was conducted, and all patients with stage I-III MRONJ, undergoing antiresorptive therapy for an oncological indication, were included. The necrosis was treated surgically without (study arm A) or with (arm B) the addition of an autologous platelet concentrate (platelet-rich fibrin, PRF). RESULTS: After 5, 14, and 42 days postoperative, wound healing (primary outcome: mucosal integrity) as well as downstaging, pain perception, and oral health-related quality of life (secondary outcome) were assessed via clinical evaluation. Among the 52 patients included, primarily with MRONJ stage I and II, the use of PRF as an additive in surgical therapy did not display a significant advantage for wound healing (p = 0.302), downstaging (p = 0.9), pain reduction (p = 0.169), or quality of life (p = 0.9). SUMMARY: In conclusion, PRF as an adjunct did not significantly optimize wound healing. Further, no significant changes in terms of downstaging, pain sensation, and oral health-related quality of life were found.

Learning Curve and Comparison of Dynamic Implant Placement Accuracy Using a Navigation System in Young Professionals.

The aim of the current study was to evaluate the learning curve and accuracy of implant placement by young professionals using a dynamic computer-assisted surgical system for dental implant placement. Ten students tried to place eight implants with a dynamic surgical system in predefined positions on two consecutive weekends, resulting in 160 implant placements in total. Postoperatively, the positions of the implants were scanned with an intraoral scanner and compared for deviations at the entry point, the apex, as well as angular deviations to the master model. The mean values of all measurements improved; statistical significance was found for the changes in the angle as well as for the position of the implants to the apex (p < 0.001). Furthermore, the young professionals indicated subjective improvement in handling the dynamic surgery system. Navigated surgical dental implant placement can be learned quickly and can support young professionals in everyday clinical practice, especially in difficult anatomic situations.

Indications for 3-D diagnostics and navigation in dental implantology with the focus on radiation exposure: a systematic review.

BACKGROUND: Dental implants are a common restorative method used to replace missing teeth. Implant placement techniques guided by three-dimensional imaging and navigation are becoming more widely available. OBJECTIVE: The present review focused on the following questions: 1. What are the advantages and disadvantages of 2-D versus 3-D imaging in dental implantology? 2. What are the advantages and disadvantages of freehand implant placement in comparison with navigation-guided implant placement? METHODS: A systematic review was performed, based on the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement. The following libraries were searched for relevant literature: PubMed, Embase, Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften (AWMF) Online, and the Cochrane Library. The risk of bias was assessed using the Scottish Intercollegiate Guidelines Network (SiGN) checklist. A total of 70 studies were included after screening, and the evidence from these was gathered for review. RESULTS: Three-dimensional imaging is advantageous in terms of image quality, and it provides a distortion-free evaluation of the implant site. However, it is also associated with higher costs and increased radiation exposure. Dynamic and static navigation are equal in accuracy and are both more accurate compared with the freehand method. No benefit in terms of implant survival could be demonstrated within the first 5 years for any specific method. DISCUSSION: A panoramic X-ray with a reference body often provides sufficient imaging and is the primary method for two-dimensional imaging. Cone beam computed tomography with low-dose protocol settings should be used if three-dimensional imaging is needed. Navigational support should be considered in the event of especially complex cases. CONCLUSION: The guidance technique used for implant placement should be decided on an individual basis. With the increasing availability of three-dimensional imaging, there should also be an increase in awareness of radiation exposure.

Digitally designed, personalized bone cement spacer for staged TMJ and mandibular reconstruction - Introduction of a new technique.

The aim of this paper is to introduce an innovative workflow for staged reconstruction of the mandible, including the temporomandibular joint (TMJ), using a temporary, patient-specific spacer. In cases of partial mandibular resection including disarticulation, sometimes needed to treat inflammatory bone disease, the spacer is intended to retain symmetry of the hard tissues, to preserve the soft tissues, and to act as a bactericidal agent. When complete healing of the affected surrounding tissues has occurred, final reconstruction using a patient-matched total TMJ endoprosthesis, in combination with an autogenous free bone flap, can be performed as a second-stage procedure. The crucial steps of the workflow are virtual surgical planning, manufacturing of a two-part silicone mold, and chairside manufacturing of the spacer using an established bone cement with gentamycin. The method was first introduced in two patients suffering from therapy-resistant chronic osteomyelitis. The presented protocol of staged surgery allows a much safer and predictable reconstruction compared with immediate reconstruction. The workflow also minimizes the potential risk of endoprosthesis infection - one of the major risks of implant failure.

Preferences and experiences regarding the treatment of obstructive sleep apnea with mandibular advancement splints - a cross-sectional pilot survey.

OBJECTIVE: To obtain a current overview of the use of mandibular advancement splints (MAS) as a therapeutic option for obstructive sleep apnea (OSA) in the dental profession in Northern Germany. METHODS: A questionnaire was mailed to 2431 dental professionals, and 8.3% responded. Descriptive data analysis was performed on each question separately. RESULTS: Most of the surveyed dentists (51.7%) estimated the success rate of MAS therapy to be higher than 75%. Analysis of the relationship between the number of splints prescribed annually and the dental specialization (p = 0.22), work experience (p = 0.14), estimated success rate of MAS therapy (p = 0.96), and discontinuation of MAS therapy (p = 0.57) revealed no significant correlations. CONCLUSION: Mandibular advancement splints seem to be a safe and successful therapy for OSA. There seems to be a lack of information on the patient side and a lack of education on the dentist side.