A New Approach to Virtual Occlusion in Orthognathic Surgery Planning Using Mixed Reality-A Technical Note and Review of the Literature.

Orthognathic surgery plays a vital role in correcting various skeletal discrepancies of the maxillofacial region. Achieving optimal occlusion is a fundamental aspect of orthognathic surgery planning, as it directly influences postoperative outcomes and patient satisfaction. Traditional methods for setting final occlusion involve the use of dental casts which are time-consuming, prone to errors and cannot be easily shared among collaborating specialties. In recent years, advancements in digital technology have introduced innovative approaches, such as virtual occlusion, which may offer enhanced accuracy and efficiency in orthognathic surgery planning. Furthermore, the emergence of mixed reality devices and their 3D visualization capabilities have brought about novel benefits in the medical field, particularly in computer-assisted planning. This paper presents for the first time a prototype tool for setting virtual occlusion during orthognathic surgery planning using mixed reality technology. A complete walkthrough of the workflow is presented including an explanation of the implicit advantages of this novel tool. The new approach to defining virtual occlusion is set into context with other published methods of virtual occlusion setting, discussing advantages and limitations as well as concepts of surgical occlusion for orthognathic surgery.

Metallic Artifact Reduction in Midfacial CT Scans Using Patient-Specific Polymer Implants Enhances Image Quality.

Midfacial reconstruction after tumor resection surgery is commonly conducted by using autologous bone grafts or alloplastic implants. Titanium is the most frequently used osteosynthesis material in these cases but causes disturbing metallic artifacts in CT imaging. The purpose of this experimental study was to evaluate whether the use of midfacial polymer implants reduces metallic artifacts in CT imaging to improve image quality. Zygomatic titanium (n = 1) and polymer (n = 12) implants were successively implanted in a human skull specimen. Implants were analyzed for their effect on Hounsfield Unit values (streak artifacts) and virtual growth in CT images (blooming artifacts) as well as image quality. Multi-factorial ANOVA and Bonferroni's post hoc test were used. Titanium (173.7 HU; SD ± 5.1) and hydroxyapatite containing polymers (155.3 HU; SD ± 5.9) were associated with significantly more streak artifacts compared to all other polymer materials. There was no significant difference in blooming artifacts between materials. The metallic artifact reduction algorithm showed no significant difference. Image quality was slightly better for polymer implants compared to titanium. Personalized polymer implants for midfacial reconstruction significantly reduce metallic artifacts in CT imaging which improves image quality. Hence, postoperative radiation therapy planning and radiological tumor aftercare around the implants are facilitated.

Lethal Aeromonas veronii Sepsis in the Course of Medicinal Leech Therapy.

A patient with oral squamous cell carcinoma (OSCC) underwent complex surgical tumor therapy, including the reconstruction of soft tissues using a radial forearm flap. Due to venous congestion that could only partly be resolved by revision surgery, leech therapy was started on the second postoperative day. The patient developed pneumonia and sepsis and died as a result of septic shock, despite having received targeted broad-spectrum antibiotic therapy since day 5. Aeromonas spp. were cultured from both the patient's specimens and unused leeches. Biochemical identification and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) yielded inconsistent identification results. Finally, microbiological identification of Aeromonas spp. was performed via 16S rDNA sequencing and use of the basic local alignment search tool (BLAST), and strains from both the patient and the leeches were identified as Aeromonas veronii. Aeromonas spp. strains derived from the patient and leeches and independent laboratory strains were submitted to randomly amplified polymorphic DNA (RAPD) subtyping. RAPD of A. veronii strains from both sources revealed an identical pattern, strongly suggesting the transmission of A. veronii from the leeches to the patient. Physicians should be aware of the potential for severe lethal infections as a fatal side-effect of leech therapy in critically ill patients, which should be addressed using antibiotic prophylaxis.

Influence of Xenogeneic and Alloplastic Carriers for Bone Augmentation on Human Unrestricted Somatic Stem Cells.

Alloplastic and xenogeneic bone grafting materials are frequently used for bone augmentation. The effect of these materials on precursor cells for bone augmentation is yet to be determined. The aim of this study was to ascertain, in vitro, how augmentation materials influence the growth rates and viability of human unrestricted somatic stem cells. The biocompatibility of two xenogeneic and one alloplastic bone graft was tested using human unrestricted somatic stem cells (USSCs). Proliferation, growth, survival and attachment of unrestricted somatic stem cells were monitored after 24 h, 48 h and 7 days. Furthermore, cell shape and morphology were evaluated by SEM. Scaffolds were assessed for their physical properties by Micro-CT imaging. USSCs showed distinct proliferation on the different carriers. Greatest proliferation was observed on the xenogeneic carriers along with improved viability of the cells. Pore sizes of the scaffolds varied significantly, with the xenogeneic materials providing greater pore sizes than the synthetic inorganic material. Unrestricted somatic stem cells in combination with a bovine collagenous bone block seem to be very compatible. A scaffold's surface morphology, pore size and bioactive characteristics influence the proliferation, attachment and viability of USSCs.

Mechanical Fatigue Performance of Patient-Specific Polymer Plates in Oncologic Mandible Reconstruction.

Mandible defects are conventionally reconstructed using titanium plates. However, titanium causes metallic artifacts which impair radiological imaging. This study aims at evaluating mechanical fatigue of radiolucent fiber-reinforced polyetheretherketone (f-PEEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), and polyphenylsulfone (PPSU) polymer plates for mandible reconstruction. A total of 30 plates (titanium [n = 6], f-PEEK [n = 6], PEEK [n = 6], PEKK [n = 6], PPSU [n = 6]) were implanted in synthetic mandibulectomized polyurethane mandibles. Servo-pneumatic mechanical testing with cyclic application of 30−300 N at 3 Hz was conducted. Bite forces were 70% on the unresected and 30% on the resected side. Total number of cycles was set to 250,000. Testing was aborted in case of plate or screw failure. Axial load to failure was tested with a speed of 1 mm/s. Kruskal−Wallis and Dunn's post hoc tests were used. Titanium, f-PEEK, and PEEK showed no failure in fatigue testing and PPSU (p < 0.001) failed against titanium, f-PEEK, PEEK, and PEKK. Titanium allowed the highest load to failure compared to f-PEEK (p = 0.049), PEEK (p = 0.008), PEKK (p < 0.001), and PPSU (p = 0.007). f-PEEK, PEEK, and PEKK withstood expected physiological bite force. Although titanium plates provided the highest fatigue strength, f-PEEK and PEEK plates showed no failure over 250,000 chewing cycles indicating sufficient mechanical strength for mandible reconstruction.

Analysis of Spontaneous and Induced Osteogenic Differentiation in 3D-micromasses of Human Multipotent Stem Cells.

BACKGROUND/AIM: Craniofacial reconstruction of extensive bone defects causes high morbidity to patients. Contemporary reconstructive surgery aims at restoring lost bone with either autogenous bone or substitutes. Multipotent unrestricted somatic stem cells (USSC) show a potential for osteoblast differentiation and are increasingly used in tissue engineering. The osteogenic potential of USSC micromasses influenced by dexamethasone, ascorbic acid and ß-glycerophosphate (DAG) seems promising. The present study evaluated the effects of DAG and MAPK, ERK and PI3K/Akt-pathway inhibitors on growth and mineralization of USSC micromasses. MATERIALS AND METHODS: Cells: i) USSC-18 (female, Passage 8), ii) USSC-8 (female Passage 9), and iii) USSC-8/17 (male, Passage 8), all cultured in 350 ml DMEM, with 150 ml fetal bovine serum, 5 ml penicillin/streptomycin and 5 ml L-glutamine. Differentiation was induced using 50 µM dexamethasone in DMEM, 50 mM ascorbic acid in PBS and 1 M ß-glycerolphosphate in PBS. Microtome slices were dyed with OsteoImage™ and analyzed under fluorescence microscopy. RESULTS: Significant increase in size and mineralization of DAG-treated micromasses was found on days 3 (p<0.001), 6 (p<0.001) and 7 (p<0.001). The ERK-pathway inhibitor, FR180204, significantly reduced micromass growth and mineralization in non-DAG treated cells (p<0.001) but showed increased mineralization in DAG-treated cells (p=0.014). The PI3K/Akt-pathway inhibitor, LY294002, did not significantly affect micromass growth but significantly decreased mineralization (p<0.001). The MAP-kinase inhibitor, U0126, significantly reduced micromass growth (p=0.001) and mineralization (p=0.001) of DAG-treated cells. CONCLUSION: DAG is a strong initiator of osteogenic differentiation. The PI3K/Akt-pathway inhibitor and the ERK-pathway inhibitor, FR180204, control osteogenic differentiation of 3D-micromasses. These results may facilitate preconditioning of cell cultures in guided tissue regeneration.

Reduction of CT Artifacts Using Polyetheretherketone (PEEK), Polyetherketoneketone (PEKK), Polyphenylsulfone (PPSU), and Polyethylene (PE) Reconstruction Plates in Oral Oncology.

PURPOSE: Surgical reconstruction after segmental mandibulectomy in patients with oral cancer commonly requires implantation of titanium plates, which cause metallic artifacts in CT examinations detrimental for image quality. Therefore, the aim of the present study was to evaluate CT artifacts and image quality of the polymer plate materials polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyphenylsulfone (PPSU), and polyethylene (PE) in mandible reconstruction. METHODS: Five plates (titanium, PEEK, PEKK, PPSU, and PE) were successively surgically inserted in a human cadaveric specimen using eight (1) titanium and (2) zirconium oxide screws. Streak and blooming artifacts were assessed in 1 mm CT scans with and without metallic artifact reduction algorithms (MAR) in this cross-sectional study. The different plate materials were analyzed for their effect on Hounsfield unit (HU) values resulting in streak artifacts. Blooming artifacts were measured as virtual growth of plates compared to actual size. Subjective image quality was assessed by 3 independent observers. Statistics were conducted by multifactorial ANOVA and Bonferroni's post hoc test. RESULTS: Titanium (182.42 HU; SD ± 3.09) was associated with significantly more streak and blooming artifacts compared to the polymers PEEK (86.41 HU; SD ± 1.72; P < .001), PEKK (85.50 HU; SD ± 2.75; P < .001), PPSU (85.51 HU; SD ± 1.97; P < .001), and PE (85.52 HU; SD ± 3.33; P < .001) implants. No significant differences could be seen between the screw types (titanium vs zirconium oxide) (P = .75) or the activation or inactivation of MAR (P = .85). Image quality was best for PE and worst for titanium implants in combination with zirconium oxide screws. CONCLUSIONS: Polymers plate materials PEEK, PEKK, PPSU, and PE significantly reduce CT artifacts and improve image quality facilitating the radiological interpretation of implant surrounding tissues. This effect is beneficial for radiological tumor follow-up and CT-based planning of adjuvant radiotherapy.

Genetic analysis of single disseminated tumor cells in the lymph nodes and bone marrow of patients with head and neck squamous cell carcinoma.

Considering the limited information on the biology and molecular characteristics of disseminated tumor cells (DTCs) in head and neck squamous cell carcinoma (HNSCC), we examined the genomic alterations in DTCs from HNSCCs and their potential clinical relevance. To analyze both the lymphatic and hematogenous routes of tumor cell dissemination, we investigated samples from lymph nodes (LNs) and bone marrow (BM) of 49 patients using immunofluorescence double staining for epithelial cells expressing cytokeratin 18 (KRT18) and/or epithelial cell adhesion molecules (EpCAM, CD326). The identified marker-positive cells were isolated by micromanipulation followed by single-cell whole-genome amplification and metaphase-based comparative genomic hybridization (mCGH) to determine genome-wide copy number alterations. The findings were correlated with clinical parameters and follow-up data. We detected chromosomal aberrations in KRT18- and EpCAM-positive cells from both compartments; BM-derived cells showed a significantly higher percentage of aberrant genome (PAG) per cell than cells detected in LNs. No significant association was found between DTC data and clinical follow-up. Genomic profiling of BM-DTCs revealed genomic alterations typical for HNSCC, suggesting hematogenous dissemination of subclones around the time of surgery. In contrast, DTC data in LNs revealed that several marker-positive cells were not of malignant origin, indicating the presence of epithelial glandular inclusions in parts of the processed neck LN samples. Therefore, DTC detection of LNs in the neck based only on epithelial markers is not advisable and requires detection of chromosomal instability (CIN), gene mutations, or additional markers, which have yet to be identified. Nevertheless, our investigation paves the way for larger studies to focus on HNSCC BM-DTCs with high-resolution methods to gain deeper insights into the biology of hematogenous metastasis in this cancer.

Accuracy in positioning of dental X-ray images - A comparative study of a portable X-ray device and a wall-mounted device.

INTRODUCTION: The benefits of portable dental X-ray devices remain controversially debated. This study aimed to compare the accuracy in positioning dental X-ray images using handheld (Nomad Pro 2) and wall-mounted (Heliodent Plus) X-ray devices. MATERIALS AND METHODS: Radiographical imaging was exercised on a maxillofacial phantom using the handheld dental X-ray device Nomad Pro 2 (Kavo Kerr, Biberach, Germany) and the wall-mounted dental X-ray device Heliodent Plus (Sirona Dental Systems, Bensheim, Germany). Accuracy of device positioning (i.e., centeredness and perpendicularity) was measured as horizontal and vertical deviation (pixels and millimeters) from a centrally positioned crosshair. The reproducibility of the results was tested for 80 images per device and operator. IBM SPSS (SPSS Inc., Chicago, IL) was used for statistical analyses. RESULTS: Centeredness of produced dental X-rays was significantly better for the wall-mounted device than for the handheld device in both deviation from the x-axis (p = 0.042) and y-axis (p = 0.020). The perpendicularity of the produced dental X-rays was significantly better for the handheld device than for the wall-mounted device for both horizontal (p < 0.001) and vertical (p < 0.001) plains. CONCLUSIONS: Handheld dental X-ray devices appear to provide a high degree of accuracy in image positioning, especially in regard to proper perpendicular image angulation.

The use of solvent-preserved human and bovine cancellous bone blocks for lateral defect augmentation - an experimental controlled study in vivo.

BACKGROUND: The aim of this study was to compare new bone formation, resorbed bone matrix, and fibrous enclosed residual bone substitute material in laterally augmented alveolar bone defects using allogeneic, pre-treated and cleaned human bone blocks (tested in dogs, therefore considered to be xenogeneic), and pre-treated and cleaned bovine cancellous bone blocks, both with and without a collagen membrane in order to evaluate their augmentative potential. METHODS: Thirty-two critical size horizontal defects were prepared in the mandible of 4 adult foxhound dogs (8 per dog, 4 on each side). After 3 months of healing, the defects were laterally augmented in a split-mouth-design with either human (HXB) or bovine solvent-preserved bone blocks (BXB). Afterwards, defects were randomly covered with a bovine collagenous membrane (HXB + M, BXB + M). After a healing interval of 6 months, percentages of new bone formation, resorbed bone matrix, and fibrous enclosed residual bone substitute material were compared. RESULTS: Results showed little new bone formation of up to 3.7 % in human bone blocks (HXB 3.7 % ± 10.2, HXB + M 0.3 %± 0.4, BXB, 0.1 % ± 0.8, BXB + M 2.6 % ± 3.2, p = > 0.05). Percentages of fibrous encapsulation were higher in human bone blocks than in bovine bone blocks (HXB 71.2 % ± 8.6, HXB + M 73.71 % ± 10.6, BXB, 60.5 % ± 27.4, BXB + M 52.5 % ± 28.4, p = > 0.05). Resorption rates differed from 44.8 % in bovine bone blocks covered with a membrane to 17.4 % in human bone blocks (HXB 17.4 % ± 7.4, HXB + M 25.9 % ± 10.7, BXB, 38.4 % ± 27.2, BXB + M 44.8 % ± 29.6, p = > 0.05). The use of additional membranes did not significantly affect results. CONCLUSIONS: Within its limitations, results of this study suggest that solvent-preserved xenogenic human and bovine bone blocks are not suitable for lateral bone augmentation in dogs. Furthermore, defect coverage with a membrane does not positively affect the outcome.

Sialolithiasis: retrospective analysis of the effect of an escalating treatment algorithm on patient-perceived health-related quality of life.

BACKGROUND: Gland preserving techniques in the treatment of sialolithiasis have continuously replaced radical surgery. The aim of this study was to evaluate a multimodal treatment algorithm in the therapy of sialolithiasis and assess improvement of HRQoL perceived by patients. METHODS: Patients with sialolithiasis were treated by a multimodal treatment algorithm based on multiplicity of stones, stone size, affected gland, and stone position. The therapeutic spectrum ranged from conservative measures, extracorporeal shockwave lithotripsy, interventional sialendoscopy, combined endoscopic-surgical procedures to surgical gland removal as ultima ratio. Outcomes were evaluated by surgeons by means of the electronic patient record and by patients themselves using a standardized questionnaire. RESULTS: 87 patients treated for sialolithiasis were comprised in this study. The submandibular gland (SMG) was affected in 58.6% and the parotid gland (PG) in 41.4% of cases. Mean patient age was 41.67 years for SMG and 48.91 years for PG. In over 80% of cases sialolithiasis was associated with classic meal-related pain and swelling. Type and intensity of symptomatic sialolithiasis were not dependent on patient age or gender, nor could a relation between the affected gland and the occurrence of symptoms be demonstrated. Overall, 86.2% of cases were reported as cured using the multimodal step-by-step treatment algorithm. Resection of the affected gland could be dispensed in 98.9% of cases. According to patients pain could be reduced in 94.3% of cases. CONCLUSIONS: The analyzed treatment algorithm of increasing invasiveness is a favorable and effective tool to successfully treat sialolithiasis in > 86% of cases. For the first time, the present study shows that patient-perceived improvement of HRQoL due to ease of symptoms has an even higher success rate of > 94%.

Navigated Recovery of Fractured Dental Injection Needles: Case Report and Suggestions for Management during Pandemic Crises.

Dislocation of a fractured hypodermic needle is a complication requiring immediate and adequate emergency treatment. In this case report, 3D navigation is evaluated for its use to recover a quickly moving fractured needle. The needle was recovered safely, but it could be demonstrated that navigational planning has to be conducted right before surgery and other navigational tools, such as ultrasound, should be considered as well. Furthermore, an approach is suggested for treatment during pandemic crises such as COVID-19.

Mandible handling in the surgical treatment of oral squamous cell carcinoma: lessons from clinical results after marginal and segmental mandibulectomy.

OBJECTIVE: The aim of this retrospective, single-center study was to analyze long-term results after marginal and segmental mandibulectomies in patients with oral squamous cell carcinoma (OSCC). STUDY DESIGN: The study included 259 patients treated for OSCC with mandibulectomy between 1996 and 2010. Data acquisition consisted of analysis of operation reports, re-evaluation of histologic bone specimens, and collection of clinical follow-up data. RESULTS: Of the included patients, 86.5% had received segmental and 13.5% marginal mandibulectomies. Patients who received segmental mandibulectomy generally displayed a higher TNM (tumor-node-metastasis) stage; 47% of patients who received segmental mandibulectomy and 14% of those receiving marginal mandibulectomy showed bone infiltration (pT4 a). Of all patients with bone infiltration, 49% showed an invasive histologic infiltration pattern, and 35% showed an erosive histologic infiltration pattern. We found healthy residual crestal bone height in 43% of all segmental mandibulectomies. Only 8% of all patients were prosthodontically rehabilitated. With regard to prognostic parameters, there was no significant difference between patients receiving marginal mandibulectomy and those receiving segmental mandibulectomy. CONCLUSIONS: Because healthy residual crestal bone height was found in 43% of all patients who had received segmental mandibulectomies, it is conceivable that a significant number of patients would profit from marginal mandibulectomy, at least in cases of absent or erosive bone infiltration pattern, because the residual crestal bone is functionally stable.

Release kinetics of the model protein FITC-BSA from different polymer-coated bovine bone substitutes.

BACKGROUND: Controlled release of proteins bound to conventional bone substitutes is still insufficient. Therefore, this study evaluates in-vitro release kinetics of the model protein FITC-BSA (fluorescein conjugated bovine serum albumine) from insoluble bovine collagenous bone matrices (ICBM) with different polymer coatings. Analyzes aim at comparing FITC-BSA release from uncoated versus coated ICBM over time to find bone substitute coatings with consistent release profiles. METHODS: Release kinetics of FITC-BSA from uncoated as well as coated ICBM with five different polymers (RESOMER R 203 H, RG 503 H, RG 504 H, RG 505, L 206 S) were measured over a period of 11 days (d). Measurements were conducted after 6 h (h), 12 h, 24 h, 3 d, 5 d, 7 d, 9 d and 11 d with six samples for each coated ICBM. Two groups were formed (1) with and (2) without medium change at times of measurement. For each group ANOVA with post-hoc Bonferroni testing was used. Scanning electron microscopy assessed morphologic differences between ICBM coating. RESULTS: In group 1 approx. 70% of FITC-BSA release from uncoated ICBM occurred after 6 h compared to approx. 50% in group 2. Only polymers with medium inherent viscosity, i.e. RESOMER RG 503 H, constantly showed significantly more FITC-BSA release throughout 11 d than uncoated ICBM (p = 0.007). The same was found for group 2 (p = 0.005). No significant differences between PLA and PLGA polymers were found. Scanning electron microscopy results indicate a weak adhesion of polymer coatings to ICBM explaining its rather weak retentive effect on overall FITC-BSA release. CONCLUSIONS: Medium molecular size polymers reduce the overall released FITC-BSA from ICBM over time. In clinical practice these polymers may prove ideal for bone substitute materials.

Evaluation of the oral health-related quality of life in patients with odontogenic fascial space abscesses and underlying conditions - a prospective questionnaire-based study.

BACKGROUND: Oral Health-Related Quality of Life (OHRQoL) is an important aspect of quality of life. Acute illnesses, as well as chronic diseases, can have a strong, persisting impact on an individual's quality of life. This study evaluates OHRQoL of patients with odontogenic fascial space abscesses, the underlying conditions, and its consequences for clinical routines. METHODS: The research group consisted of patients presenting themselves to the emergency room or elective clinic of the Department for Cranio-Maxillofacial and Plastic Surgery (n = 94). The validated German version of the Oral Health Impact Profile (OHIP-G) and additional questions (including habits and routines in oral hygiene) with an anamnestic recall period of 1 month was used to evaluate OHRQoL shortly after emergency treatment (baseline) and again after 3-6 months' follow-up. Ninety-four patients completed the questionnaire at baseline, 54 completed both questionnaires. Additionally, OHIP-G scores were compared to those of the non-impacted general German population. RESULTS: Results showed a significant difference in OHIP-G scores from baseline to follow-up (p = 0.001). Overall a mean of 55.24 (±37.02) points was scored at baseline and a mean of 37.02 (±35.79) points was scored at follow-up. Patients scored higher than participants of a representative study of the general German population. CONCLUSION: Overall results suggest an increase in OHRQoL 3-6 months after acute treatment. Nevertheless, OHRQoL of patients suffering from odontogenic fascial space abscesses seems to remain generally lower than the OHRQoL of the general German population. TRIAL REGISTRATION: Trial registration: Central Study Register of the University Hospital Duesseldorf, Registration-ID: 2016085405 . Registered 24 August 2016.

Removal of stones from the superficial lobe of the submandibular gland (SMG) via an intraoral endoscopy-assisted sialolithotomy.

OBJECTIVES: Sialolithiasis is the most common cause of chronic sialadenitis of the submandibular gland (SMG). Symptomatic superficial lobe stones are often treated by submandibulectomy. A gland preserving operation allows for transoral stone removal through endoscopically assisted sialolithotomy. Herein, we provide clinical and sonographical follow-up data in patients who underwent sialolithotomy under general anesthesia. MATERIALS AND METHODS: Sixty patients treated at the Department of Oral and Maxillofacial Surgery at Düsseldorf University Hospital for superficial lobe sialolithiasis of SMG were included in this study. All received transoral sialolithotomy under general anesthesia. Follow-up was conducted via standardized patient questionnaires, clinical examination, and B-mode and color Doppler sonography. RESULTS: Mean patient age was 48.9 years. 56.6% of right and 43.4% of left SMG were affected. Mean follow-up was 45 months. Fifty-five of 59 detected stones could be removed. Mean operation time was 71 min. 3.3% of patients reported recurrent episodes of postoperative pain and 10% felt recurrent episodes of gland swelling. Persistent postoperative lingual nerve hypesthesia was described in one patient. No facial nerve damages occurred. Salivary flow rates remained reduced in most of the affected glands upon stone removal. Sonographical follow-up data of the previously affected SMG after intraoral endoscopy-assisted sialolithotomy showed a regular gland size in 70.8% of cases, a parenchyma free of inflammation in 93.8%, and without signs of fibrosis in 72.9% of cases. 68.7% of patients showed a regular structure of Wharton's duct at time of follow-up. In total, 89.6% of patients were diagnosed stone-free within both glands on follow-up. No case required subsequent submandibulectomy. CONCLUSIONS: Sialolithotomy of Wharton's duct for removal of stones from the SMG's superficial lobe is a promising alternative to submandibulectomy. CLINICAL RELEVANCE: Reduction of postoperative morbidity through endoscopically assisted sialolithotomy for removal of superficial lobe stones from SMG. TRIAL REGISTRATION: Ethics Committee of Heinrich-Heine-University Düsseldorf (no. 5586).

Pathogenesis of medication-related osteonecrosis of the jaw: a comparative study of in vivo and in vitro trials.

Objective This study was performed to determine whether the results of prevailing in vivo and in vitro studies offer a reliable model for investigation of medication-related osteonecrosis of the jaw (MRONJ). Methods Embase, Medline, and the Cochrane Library were searched for articles published from September 2003 to June 2017 involving experimental approaches to the pathogenesis of MRONJ. In vivo and in vitro trials were analyzed with respect to the scientific question, study design, methodology, and results. Results Of 139 studies, 87, 46, and 6 conducted in vivo, in vitro, and both in vivo and in vitro experiments, respectively. Rats, mice, dogs, minipigs, sheep, and rabbits were the preferred animal models used. Osteoblasts, osteoclasts, fibroblasts, keratinocytes, macrophages, and human umbilical vein endothelial cells were the preferred cell types. Zoledronate, alendronate, ibandronate, and risedronate were the most frequent bisphosphonates used. MRONJ was most reliably induced in minipigs because of the close relationship with human bone physiology. In vitro studies showed that reduced viability, growth, and migration of cells in the bone and soft tissues were causative for MRONJ. Other than exposed jawbone after tooth extraction, no reliable cofactors were found. Conclusion The minipig is the most suitable animal model for MRONJ.

Extensive Craniocervical Abscess after Transoral Ganglionic Local Opioid Analgesia at the Superior Cervical Ganglion for Atypical Trigeminal Neuralgia: Report of a Severely Complicated Case.

Ganglionic local opioid analgesia (GLOA) describes the application of low-dose opioids close to sympathetic as, for example, to the superior cervical ganglion. GLOA can be effective in different pain syndromes affecting the head and face region and has been considered to be a safe technique with few complications reported so far. We present the case of a patient who received a single, transoral GLOA for a refractory trigeminal neuralgia. The patient subsequently developed an extensive epidural abscess at the craniocervical junction, requiring ultimately transoral odontoid resection and dorsal stabilisation. This severe complication challenges the role of transoral infiltration therapies in analgetic medicine.

Extraskeletal chondroma walling the temporomandibular joint: Report of a rare case and review of the literature.

INTRODUCTION: Extraskeletal or soft-tissue chondroma is a rare benign cartilaginous neoplasm which usually affects hands and feet. Scientific literature only reports one previous case of this pathology in the preauricular region. PRESENTATION OF THE CASE: This report describes a rare case of extraskeletal chondroma surrounding the temporomandibular joint of a 55-year-old female patient. DISCUSSION AND CONCLUSION: Diagnosis of extraskeletal chondroma is challenging since tissue swelling, diagnostic imaging and even histopathological features may be misleading for other joint or gland pathologies.

Secondary Bleedings in Oral Surgery Emergency Service: A Cross-Sectional Study.

INTRODUCTION: Bleeding after dental surgery is still a common cause for emergency presentation in patients using anticoagulants. Our aim was to analyze pertinent characteristic features on the one hand and to bare existing problems in handling on the other. MATERIALS AND METHODS: The study included 76 patients. We documented basic data, anticoagulant medication, type of surgery, and tooth socket sutures in respective patients. RESULTS: The vast majority of patients took a coumarin derivative (41) and acetylsalicylic acid (27). Nine (12%) of the patients had to be hospitalized due to ongoing bleeding despite local haemostyptic steps and/or circulatory dysregulation. Most patients could be successfully treated in outpatient settings. No statistically significant correlation between bleeding, level of INR value, number of extracted teeth, and sewed alveoli could be shown. Sixty-five percent of cases with tooth extractions did not have suture of tooth sockets. Eighty-seven percent of the patients denied being informed about possible self-treatment options by their surgeon/dentist, and none of the patients got presurgical-fabricated bandage plate(s). CONCLUSIONS: Patients taking coumarin derivative currently, furthermore, represent the biggest anticoagulant after-bleeding group in dentoalveolar surgery. The major part of after-bleedings (90%) can be handled in an outpatient setting with simplest surgical interventions. Unfortunately, the biggest part of the patient collective got no suture, no prefabricated dental bandage plate(s), and no explanation by their dentist how to handle in case of after-bleeding. Therefore, dental practitioners should furthermore get enlightenment on how to prevent after-bleeding situations.